--- a/jdk/src/share/classes/java/util/HashMap.java Mon Aug 12 12:22:10 2013 +0200
+++ b/jdk/src/share/classes/java/util/HashMap.java Wed Sep 04 09:34:25 2013 +0200
@@ -25,13 +25,14 @@
package java.util;
-import java.io.*;
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
-import java.util.concurrent.ThreadLocalRandom;
import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
import java.util.function.Consumer;
-import java.util.function.BiFunction;
import java.util.function.Function;
/**
@@ -63,20 +64,25 @@
* structures are rebuilt) so that the hash table has approximately twice the
* number of buckets.
*
- * <p>As a general rule, the default load factor (.75) offers a good tradeoff
- * between time and space costs. Higher values decrease the space overhead
- * but increase the lookup cost (reflected in most of the operations of the
- * <tt>HashMap</tt> class, including <tt>get</tt> and <tt>put</tt>). The
- * expected number of entries in the map and its load factor should be taken
- * into account when setting its initial capacity, so as to minimize the
- * number of rehash operations. If the initial capacity is greater
- * than the maximum number of entries divided by the load factor, no
- * rehash operations will ever occur.
+ * <p>As a general rule, the default load factor (.75) offers a good
+ * tradeoff between time and space costs. Higher values decrease the
+ * space overhead but increase the lookup cost (reflected in most of
+ * the operations of the <tt>HashMap</tt> class, including
+ * <tt>get</tt> and <tt>put</tt>). The expected number of entries in
+ * the map and its load factor should be taken into account when
+ * setting its initial capacity, so as to minimize the number of
+ * rehash operations. If the initial capacity is greater than the
+ * maximum number of entries divided by the load factor, no rehash
+ * operations will ever occur.
*
- * <p>If many mappings are to be stored in a <tt>HashMap</tt> instance,
- * creating it with a sufficiently large capacity will allow the mappings to
- * be stored more efficiently than letting it perform automatic rehashing as
- * needed to grow the table.
+ * <p>If many mappings are to be stored in a <tt>HashMap</tt>
+ * instance, creating it with a sufficiently large capacity will allow
+ * the mappings to be stored more efficiently than letting it perform
+ * automatic rehashing as needed to grow the table. Note that using
+ * many keys with the same {@code hashCode()} is a sure way to slow
+ * down performance of any hash table. To ameliorate impact, when keys
+ * are {@link Comparable}, this class may use comparison order among
+ * keys to help break ties.
*
* <p><strong>Note that this implementation is not synchronized.</strong>
* If multiple threads access a hash map concurrently, and at least one of
@@ -128,11 +134,100 @@
* @see Hashtable
* @since 1.2
*/
+public class HashMap<K,V> extends AbstractMap<K,V>
+ implements Map<K,V>, Cloneable, Serializable {
-public class HashMap<K,V>
- extends AbstractMap<K,V>
- implements Map<K,V>, Cloneable, Serializable
-{
+ private static final long serialVersionUID = 362498820763181265L;
+
+ /*
+ * Implementation notes.
+ *
+ * This map usually acts as a binned (bucketed) hash table, but
+ * when bins get too large, they are transformed into bins of
+ * TreeNodes, each structured similarly to those in
+ * java.util.TreeMap. Most methods try to use normal bins, but
+ * relay to TreeNode methods when applicable (simply by checking
+ * instanceof a node). Bins of TreeNodes may be traversed and
+ * used like any others, but additionally support faster lookup
+ * when overpopulated. However, since the vast majority of bins in
+ * normal use are not overpopulated, checking for existence of
+ * tree bins may be delayed in the course of table methods.
+ *
+ * Tree bins (i.e., bins whose elements are all TreeNodes) are
+ * ordered primarily by hashCode, but in the case of ties, if two
+ * elements are of the same "class C implements Comparable<C>",
+ * type then their compareTo method is used for ordering. (We
+ * conservatively check generic types via reflection to validate
+ * this -- see method comparableClassFor). The added complexity
+ * of tree bins is worthwhile in providing worst-case O(log n)
+ * operations when keys either have distinct hashes or are
+ * orderable, Thus, performance degrades gracefully under
+ * accidental or malicious usages in which hashCode() methods
+ * return values that are poorly distributed, as well as those in
+ * which many keys share a hashCode, so long as they are also
+ * Comparable. (If neither of these apply, we may waste about a
+ * factor of two in time and space compared to taking no
+ * precautions. But the only known cases stem from poor user
+ * programming practices that are already so slow that this makes
+ * little difference.)
+ *
+ * Because TreeNodes are about twice the size of regular nodes, we
+ * use them only when bins contain enough nodes to warrant use
+ * (see TREEIFY_THRESHOLD). And when they become too small (due to
+ * removal or resizing) they are converted back to plain bins. In
+ * usages with well-distributed user hashCodes, tree bins are
+ * rarely used. Ideally, under random hashCodes, the frequency of
+ * nodes in bins follows a Poisson distribution
+ * (http://en.wikipedia.org/wiki/Poisson_distribution) with a
+ * parameter of about 0.5 on average for the default resizing
+ * threshold of 0.75, although with a large variance because of
+ * resizing granularity. Ignoring variance, the expected
+ * occurrences of list size k are (exp(-0.5) * pow(0.5, k) /
+ * factorial(k)). The first values are:
+ *
+ * 0: 0.60653066
+ * 1: 0.30326533
+ * 2: 0.07581633
+ * 3: 0.01263606
+ * 4: 0.00157952
+ * 5: 0.00015795
+ * 6: 0.00001316
+ * 7: 0.00000094
+ * 8: 0.00000006
+ * more: less than 1 in ten million
+ *
+ * The root of a tree bin is normally its first node. However,
+ * sometimes (currently only upon Iterator.remove), the root might
+ * be elsewhere, but can be recovered following parent links
+ * (method TreeNode.root()).
+ *
+ * All applicable internal methods accept a hash code as an
+ * argument (as normally supplied from a public method), allowing
+ * them to call each other without recomputing user hashCodes.
+ * Most internal methods also accept a "tab" argument, that is
+ * normally the current table, but may be a new or old one when
+ * resizing or converting.
+ *
+ * When bin lists are treeified, split, or untreeified, we keep
+ * them in the same relative access/traversal order (i.e., field
+ * Node.next) to better preserve locality, and to slightly
+ * simplify handling of splits and traversals that invoke
+ * iterator.remove. When using comparators on insertion, to keep a
+ * total ordering (or as close as is required here) across
+ * rebalancings, we compare classes and identityHashCodes as
+ * tie-breakers.
+ *
+ * The use and transitions among plain vs tree modes is
+ * complicated by the existence of subclass LinkedHashMap. See
+ * below for hook methods defined to be invoked upon insertion,
+ * removal and access that allow LinkedHashMap internals to
+ * otherwise remain independent of these mechanics. (This also
+ * requires that a map instance be passed to some utility methods
+ * that may create new nodes.)
+ *
+ * The concurrent-programming-like SSA-based coding style helps
+ * avoid aliasing errors amid all of the twisty pointer operations.
+ */
/**
* The default initial capacity - MUST be a power of two.
@@ -152,14 +247,158 @@
static final float DEFAULT_LOAD_FACTOR = 0.75f;
/**
- * An empty table instance to share when the table is not inflated.
+ * The bin count threshold for using a tree rather than list for a
+ * bin. Bins are converted to trees when adding an element to a
+ * bin with at least this many nodes. The value must be greater
+ * than 2 and should be at least 8 to mesh with assumptions in
+ * tree removal about conversion back to plain bins upon
+ * shrinkage.
+ */
+ static final int TREEIFY_THRESHOLD = 8;
+
+ /**
+ * The bin count threshold for untreeifying a (split) bin during a
+ * resize operation. Should be less than TREEIFY_THRESHOLD, and at
+ * most 6 to mesh with shrinkage detection under removal.
+ */
+ static final int UNTREEIFY_THRESHOLD = 6;
+
+ /**
+ * The smallest table capacity for which bins may be treeified.
+ * (Otherwise the table is resized if too many nodes in a bin.)
+ * Should be at least 4 * TREEIFY_THRESHOLD to avoid conflicts
+ * between resizing and treeification thresholds.
+ */
+ static final int MIN_TREEIFY_CAPACITY = 64;
+
+ /**
+ * Basic hash bin node, used for most entries. (See below for
+ * TreeNode subclass, and in LinkedHashMap for its Entry subclass.)
*/
- static final Object[] EMPTY_TABLE = {};
+ static class Node<K,V> implements Map.Entry<K,V> {
+ final int hash;
+ final K key;
+ V value;
+ Node<K,V> next;
+
+ Node(int hash, K key, V value, Node<K,V> next) {
+ this.hash = hash;
+ this.key = key;
+ this.value = value;
+ this.next = next;
+ }
+
+ public final K getKey() { return key; }
+ public final V getValue() { return value; }
+ public final String toString() { return key + "=" + value; }
+
+ public final int hashCode() {
+ return Objects.hashCode(key) ^ Objects.hashCode(value);
+ }
+
+ public final V setValue(V newValue) {
+ V oldValue = value;
+ value = newValue;
+ return oldValue;
+ }
+
+ public final boolean equals(Object o) {
+ if (o == this)
+ return true;
+ if (o instanceof Map.Entry) {
+ Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+ if (Objects.equals(key, e.getKey()) &&
+ Objects.equals(value, e.getValue()))
+ return true;
+ }
+ return false;
+ }
+ }
+
+ /* ---------------- Static utilities -------------- */
/**
- * The table, resized as necessary. Length MUST Always be a power of two.
+ * Computes key.hashCode() and spreads (XORs) higher bits of hash
+ * to lower. Because the table uses power-of-two masking, sets of
+ * hashes that vary only in bits above the current mask will
+ * always collide. (Among known examples are sets of Float keys
+ * holding consecutive whole numbers in small tables.) So we
+ * apply a transform that spreads the impact of higher bits
+ * downward. There is a tradeoff between speed, utility, and
+ * quality of bit-spreading. Because many common sets of hashes
+ * are already reasonably distributed (so don't benefit from
+ * spreading), and because we use trees to handle large sets of
+ * collisions in bins, we just XOR some shifted bits in the
+ * cheapest possible way to reduce systematic lossage, as well as
+ * to incorporate impact of the highest bits that would otherwise
+ * never be used in index calculations because of table bounds.
+ */
+ static final int hash(Object key) {
+ int h;
+ return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);
+ }
+
+ /**
+ * Returns x's Class if it is of the form "class C implements
+ * Comparable<C>", else null.
*/
- transient Object[] table = EMPTY_TABLE;
+ static Class<?> comparableClassFor(Object x) {
+ if (x instanceof Comparable) {
+ Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
+ if ((c = x.getClass()) == String.class) // bypass checks
+ return c;
+ if ((ts = c.getGenericInterfaces()) != null) {
+ for (int i = 0; i < ts.length; ++i) {
+ if (((t = ts[i]) instanceof ParameterizedType) &&
+ ((p = (ParameterizedType)t).getRawType() ==
+ Comparable.class) &&
+ (as = p.getActualTypeArguments()) != null &&
+ as.length == 1 && as[0] == c) // type arg is c
+ return c;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns k.compareTo(x) if x matches kc (k's screened comparable
+ * class), else 0.
+ */
+ @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
+ static int compareComparables(Class<?> kc, Object k, Object x) {
+ return (x == null || x.getClass() != kc ? 0 :
+ ((Comparable)k).compareTo(x));
+ }
+
+ /**
+ * Returns a power of two size for the given target capacity.
+ */
+ static final int tableSizeFor(int cap) {
+ int n = cap - 1;
+ n |= n >>> 1;
+ n |= n >>> 2;
+ n |= n >>> 4;
+ n |= n >>> 8;
+ n |= n >>> 16;
+ return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
+ }
+
+ /* ---------------- Fields -------------- */
+
+ /**
+ * The table, initialized on first use, and resized as
+ * necessary. When allocated, length is always a power of two.
+ * (We also tolerate length zero in some operations to allow
+ * bootstrapping mechanics that are currently not needed.)
+ */
+ transient Node<K,V>[] table;
+
+ /**
+ * Holds cached entrySet(). Note that AbstractMap fields are used
+ * for keySet() and values().
+ */
+ transient Set<Map.Entry<K,V>> entrySet;
/**
* The number of key-value mappings contained in this map.
@@ -167,21 +406,6 @@
transient int size;
/**
- * The next size value at which to resize (capacity * load factor).
- * @serial
- */
- // If table == EMPTY_TABLE then this is the initial capacity at which the
- // table will be created when inflated.
- int threshold;
-
- /**
- * The load factor for the hash table.
- *
- * @serial
- */
- final float loadFactor;
-
- /**
* The number of times this HashMap has been structurally modified
* Structural modifications are those that change the number of mappings in
* the HashMap or otherwise modify its internal structure (e.g.,
@@ -191,627 +415,24 @@
transient int modCount;
/**
- * Holds values which can't be initialized until after VM is booted.
+ * The next size value at which to resize (capacity * load factor).
+ *
+ * @serial
*/
- private static class Holder {
- static final sun.misc.Unsafe UNSAFE;
-
- /**
- * Offset of "final" hashSeed field we must set in
- * readObject() method.
- */
- static final long HASHSEED_OFFSET;
-
- static final boolean USE_HASHSEED;
-
- static {
- String hashSeedProp = java.security.AccessController.doPrivileged(
- new sun.security.action.GetPropertyAction(
- "jdk.map.useRandomSeed"));
- boolean localBool = (null != hashSeedProp)
- ? Boolean.parseBoolean(hashSeedProp) : false;
- USE_HASHSEED = localBool;
-
- if (USE_HASHSEED) {
- try {
- UNSAFE = sun.misc.Unsafe.getUnsafe();
- HASHSEED_OFFSET = UNSAFE.objectFieldOffset(
- HashMap.class.getDeclaredField("hashSeed"));
- } catch (NoSuchFieldException | SecurityException e) {
- throw new InternalError("Failed to record hashSeed offset", e);
- }
- } else {
- UNSAFE = null;
- HASHSEED_OFFSET = 0;
- }
- }
- }
-
- /*
- * A randomizing value associated with this instance that is applied to
- * hash code of keys to make hash collisions harder to find.
- *
- * Non-final so it can be set lazily, but be sure not to set more than once.
- */
- transient final int hashSeed;
-
- /*
- * TreeBin/TreeNode code from CHM doesn't handle the null key. Store the
- * null key entry here.
- */
- transient Entry<K,V> nullKeyEntry = null;
-
- /*
- * In order to improve performance under high hash-collision conditions,
- * HashMap will switch to storing a bin's entries in a balanced tree
- * (TreeBin) instead of a linked-list once the number of entries in the bin
- * passes a certain threshold (TreeBin.TREE_THRESHOLD), if at least one of
- * the keys in the bin implements Comparable. This technique is borrowed
- * from ConcurrentHashMap.
- */
-
- /*
- * Code based on CHMv8
- *
- * Node type for TreeBin
- */
- final static class TreeNode<K,V> {
- TreeNode parent; // red-black tree links
- TreeNode left;
- TreeNode right;
- TreeNode prev; // needed to unlink next upon deletion
- boolean red;
- final HashMap.Entry<K,V> entry;
-
- TreeNode(HashMap.Entry<K,V> entry, Object next, TreeNode parent) {
- this.entry = entry;
- this.entry.next = next;
- this.parent = parent;
- }
- }
+ // (The javadoc description is true upon serialization.
+ // Additionally, if the table array has not been allocated, this
+ // field holds the initial array capacity, or zero signifying
+ // DEFAULT_INITIAL_CAPACITY.)
+ int threshold;
/**
- * Returns a Class for the given object of the form "class C
- * implements Comparable<C>", if one exists, else null. See the TreeBin
- * docs, below, for explanation.
- */
- static Class<?> comparableClassFor(Object x) {
- Class<?> c, s, cmpc; Type[] ts, as; Type t; ParameterizedType p;
- if ((c = x.getClass()) == String.class) // bypass checks
- return c;
- if ((cmpc = Comparable.class).isAssignableFrom(c)) {
- while (cmpc.isAssignableFrom(s = c.getSuperclass()))
- c = s; // find topmost comparable class
- if ((ts = c.getGenericInterfaces()) != null) {
- for (int i = 0; i < ts.length; ++i) {
- if (((t = ts[i]) instanceof ParameterizedType) &&
- ((p = (ParameterizedType)t).getRawType() == cmpc) &&
- (as = p.getActualTypeArguments()) != null &&
- as.length == 1 && as[0] == c) // type arg is c
- return c;
- }
- }
- }
- return null;
- }
-
- /*
- * Code based on CHMv8
+ * The load factor for the hash table.
*
- * A specialized form of red-black tree for use in bins
- * whose size exceeds a threshold.
- *
- * TreeBins use a special form of comparison for search and
- * related operations (which is the main reason we cannot use
- * existing collections such as TreeMaps). TreeBins contain
- * Comparable elements, but may contain others, as well as
- * elements that are Comparable but not necessarily Comparable<T>
- * for the same T, so we cannot invoke compareTo among them. To
- * handle this, the tree is ordered primarily by hash value, then
- * by Comparable.compareTo order if applicable. On lookup at a
- * node, if elements are not comparable or compare as 0 then both
- * left and right children may need to be searched in the case of
- * tied hash values. (This corresponds to the full list search
- * that would be necessary if all elements were non-Comparable and
- * had tied hashes.) The red-black balancing code is updated from
- * pre-jdk-collections
- * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java)
- * based in turn on Cormen, Leiserson, and Rivest "Introduction to
- * Algorithms" (CLR).
+ * @serial
*/
- final class TreeBin {
- /*
- * The bin count threshold for using a tree rather than list for a bin. The
- * value reflects the approximate break-even point for using tree-based
- * operations.
- */
- static final int TREE_THRESHOLD = 16;
-
- TreeNode<K,V> root; // root of tree
- TreeNode<K,V> first; // head of next-pointer list
-
- /*
- * Split a TreeBin into lo and hi parts and install in given table.
- *
- * Existing Entrys are re-used, which maintains the before/after links for
- * LinkedHashMap.Entry.
- *
- * No check for Comparable, though this is the same as CHM.
- */
- final void splitTreeBin(Object[] newTable, int i, TreeBin loTree, TreeBin hiTree) {
- TreeBin oldTree = this;
- int bit = newTable.length >>> 1;
- int loCount = 0, hiCount = 0;
- TreeNode<K,V> e = oldTree.first;
- TreeNode<K,V> next;
-
- // This method is called when the table has just increased capacity,
- // so indexFor() is now taking one additional bit of hash into
- // account ("bit"). Entries in this TreeBin now belong in one of
- // two bins, "i" or "i+bit", depending on if the new top bit of the
- // hash is set. The trees for the two bins are loTree and hiTree.
- // If either tree ends up containing fewer than TREE_THRESHOLD
- // entries, it is converted back to a linked list.
- while (e != null) {
- // Save entry.next - it will get overwritten in putTreeNode()
- next = (TreeNode<K,V>)e.entry.next;
-
- int h = e.entry.hash;
- K k = (K) e.entry.key;
- V v = e.entry.value;
- if ((h & bit) == 0) {
- ++loCount;
- // Re-using e.entry
- loTree.putTreeNode(h, k, v, e.entry);
- } else {
- ++hiCount;
- hiTree.putTreeNode(h, k, v, e.entry);
- }
- // Iterate using the saved 'next'
- e = next;
- }
- if (loCount < TREE_THRESHOLD) { // too small, convert back to list
- HashMap.Entry loEntry = null;
- TreeNode<K,V> p = loTree.first;
- while (p != null) {
- @SuppressWarnings("unchecked")
- TreeNode<K,V> savedNext = (TreeNode<K,V>) p.entry.next;
- p.entry.next = loEntry;
- loEntry = p.entry;
- p = savedNext;
- }
- // assert newTable[i] == null;
- newTable[i] = loEntry;
- } else {
- // assert newTable[i] == null;
- newTable[i] = loTree;
- }
- if (hiCount < TREE_THRESHOLD) { // too small, convert back to list
- HashMap.Entry hiEntry = null;
- TreeNode<K,V> p = hiTree.first;
- while (p != null) {
- @SuppressWarnings("unchecked")
- TreeNode<K,V> savedNext = (TreeNode<K,V>) p.entry.next;
- p.entry.next = hiEntry;
- hiEntry = p.entry;
- p = savedNext;
- }
- // assert newTable[i + bit] == null;
- newTable[i + bit] = hiEntry;
- } else {
- // assert newTable[i + bit] == null;
- newTable[i + bit] = hiTree;
- }
- }
-
- /*
- * Popuplate the TreeBin with entries from the linked list e
- *
- * Assumes 'this' is a new/empty TreeBin
- *
- * Note: no check for Comparable
- * Note: I believe this changes iteration order
- */
- @SuppressWarnings("unchecked")
- void populate(HashMap.Entry e) {
- // assert root == null;
- // assert first == null;
- HashMap.Entry next;
- while (e != null) {
- // Save entry.next - it will get overwritten in putTreeNode()
- next = (HashMap.Entry)e.next;
- // Re-using Entry e will maintain before/after in LinkedHM
- putTreeNode(e.hash, (K)e.key, (V)e.value, e);
- // Iterate using the saved 'next'
- e = next;
- }
- }
-
- /**
- * Copied from CHMv8
- * From CLR
- */
- private void rotateLeft(TreeNode p) {
- if (p != null) {
- TreeNode r = p.right, pp, rl;
- if ((rl = p.right = r.left) != null) {
- rl.parent = p;
- }
- if ((pp = r.parent = p.parent) == null) {
- root = r;
- } else if (pp.left == p) {
- pp.left = r;
- } else {
- pp.right = r;
- }
- r.left = p;
- p.parent = r;
- }
- }
-
- /**
- * Copied from CHMv8
- * From CLR
- */
- private void rotateRight(TreeNode p) {
- if (p != null) {
- TreeNode l = p.left, pp, lr;
- if ((lr = p.left = l.right) != null) {
- lr.parent = p;
- }
- if ((pp = l.parent = p.parent) == null) {
- root = l;
- } else if (pp.right == p) {
- pp.right = l;
- } else {
- pp.left = l;
- }
- l.right = p;
- p.parent = l;
- }
- }
-
- /**
- * Returns the TreeNode (or null if not found) for the given
- * key. A front-end for recursive version.
- */
- final TreeNode getTreeNode(int h, K k) {
- return getTreeNode(h, k, root, comparableClassFor(k));
- }
-
- /**
- * Returns the TreeNode (or null if not found) for the given key
- * starting at given root.
- */
- @SuppressWarnings("unchecked")
- final TreeNode getTreeNode (int h, K k, TreeNode p, Class<?> cc) {
- // assert k != null;
- while (p != null) {
- int dir, ph; Object pk;
- if ((ph = p.entry.hash) != h)
- dir = (h < ph) ? -1 : 1;
- else if ((pk = p.entry.key) == k || k.equals(pk))
- return p;
- else if (cc == null || comparableClassFor(pk) != cc ||
- (dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
- // assert pk != null;
- TreeNode r, pl, pr; // check both sides
- if ((pr = p.right) != null &&
- (r = getTreeNode(h, k, pr, cc)) != null)
- return r;
- else if ((pl = p.left) != null)
- dir = -1;
- else // nothing there
- break;
- }
- p = (dir > 0) ? p.right : p.left;
- }
- return null;
- }
+ final float loadFactor;
- /*
- * Finds or adds a node.
- *
- * 'entry' should be used to recycle an existing Entry (e.g. in the case
- * of converting a linked-list bin to a TreeBin).
- * If entry is null, a new Entry will be created for the new TreeNode
- *
- * @return the TreeNode containing the mapping, or null if a new
- * TreeNode was added
- */
- @SuppressWarnings("unchecked")
- TreeNode putTreeNode(int h, K k, V v, HashMap.Entry<K,V> entry) {
- // assert k != null;
- //if (entry != null) {
- // assert h == entry.hash;
- // assert k == entry.key;
- // assert v == entry.value;
- // }
- Class<?> cc = comparableClassFor(k);
- TreeNode pp = root, p = null;
- int dir = 0;
- while (pp != null) { // find existing node or leaf to insert at
- int ph; Object pk;
- p = pp;
- if ((ph = p.entry.hash) != h)
- dir = (h < ph) ? -1 : 1;
- else if ((pk = p.entry.key) == k || k.equals(pk))
- return p;
- else if (cc == null || comparableClassFor(pk) != cc ||
- (dir = ((Comparable<Object>)k).compareTo(pk)) == 0) {
- TreeNode r, pr;
- if ((pr = p.right) != null &&
- (r = getTreeNode(h, k, pr, cc)) != null)
- return r;
- else // continue left
- dir = -1;
- }
- pp = (dir > 0) ? p.right : p.left;
- }
-
- // Didn't find the mapping in the tree, so add it
- TreeNode f = first;
- TreeNode x;
- if (entry != null) {
- x = new TreeNode(entry, f, p);
- } else {
- x = new TreeNode(newEntry(h, k, v, null), f, p);
- }
- first = x;
-
- if (p == null) {
- root = x;
- } else { // attach and rebalance; adapted from CLR
- TreeNode xp, xpp;
- if (f != null) {
- f.prev = x;
- }
- if (dir <= 0) {
- p.left = x;
- } else {
- p.right = x;
- }
- x.red = true;
- while (x != null && (xp = x.parent) != null && xp.red
- && (xpp = xp.parent) != null) {
- TreeNode xppl = xpp.left;
- if (xp == xppl) {
- TreeNode y = xpp.right;
- if (y != null && y.red) {
- y.red = false;
- xp.red = false;
- xpp.red = true;
- x = xpp;
- } else {
- if (x == xp.right) {
- rotateLeft(x = xp);
- xpp = (xp = x.parent) == null ? null : xp.parent;
- }
- if (xp != null) {
- xp.red = false;
- if (xpp != null) {
- xpp.red = true;
- rotateRight(xpp);
- }
- }
- }
- } else {
- TreeNode y = xppl;
- if (y != null && y.red) {
- y.red = false;
- xp.red = false;
- xpp.red = true;
- x = xpp;
- } else {
- if (x == xp.left) {
- rotateRight(x = xp);
- xpp = (xp = x.parent) == null ? null : xp.parent;
- }
- if (xp != null) {
- xp.red = false;
- if (xpp != null) {
- xpp.red = true;
- rotateLeft(xpp);
- }
- }
- }
- }
- }
- TreeNode r = root;
- if (r != null && r.red) {
- r.red = false;
- }
- }
- return null;
- }
-
- /*
- * From CHMv8
- *
- * Removes the given node, that must be present before this
- * call. This is messier than typical red-black deletion code
- * because we cannot swap the contents of an interior node
- * with a leaf successor that is pinned by "next" pointers
- * that are accessible independently of lock. So instead we
- * swap the tree linkages.
- */
- final void deleteTreeNode(TreeNode p) {
- TreeNode next = (TreeNode) p.entry.next; // unlink traversal pointers
- TreeNode pred = p.prev;
- if (pred == null) {
- first = next;
- } else {
- pred.entry.next = next;
- }
- if (next != null) {
- next.prev = pred;
- }
- TreeNode replacement;
- TreeNode pl = p.left;
- TreeNode pr = p.right;
- if (pl != null && pr != null) {
- TreeNode s = pr, sl;
- while ((sl = s.left) != null) // find successor
- {
- s = sl;
- }
- boolean c = s.red;
- s.red = p.red;
- p.red = c; // swap colors
- TreeNode sr = s.right;
- TreeNode pp = p.parent;
- if (s == pr) { // p was s's direct parent
- p.parent = s;
- s.right = p;
- } else {
- TreeNode sp = s.parent;
- if ((p.parent = sp) != null) {
- if (s == sp.left) {
- sp.left = p;
- } else {
- sp.right = p;
- }
- }
- if ((s.right = pr) != null) {
- pr.parent = s;
- }
- }
- p.left = null;
- if ((p.right = sr) != null) {
- sr.parent = p;
- }
- if ((s.left = pl) != null) {
- pl.parent = s;
- }
- if ((s.parent = pp) == null) {
- root = s;
- } else if (p == pp.left) {
- pp.left = s;
- } else {
- pp.right = s;
- }
- replacement = sr;
- } else {
- replacement = (pl != null) ? pl : pr;
- }
- TreeNode pp = p.parent;
- if (replacement == null) {
- if (pp == null) {
- root = null;
- return;
- }
- replacement = p;
- } else {
- replacement.parent = pp;
- if (pp == null) {
- root = replacement;
- } else if (p == pp.left) {
- pp.left = replacement;
- } else {
- pp.right = replacement;
- }
- p.left = p.right = p.parent = null;
- }
- if (!p.red) { // rebalance, from CLR
- TreeNode x = replacement;
- while (x != null) {
- TreeNode xp, xpl;
- if (x.red || (xp = x.parent) == null) {
- x.red = false;
- break;
- }
- if (x == (xpl = xp.left)) {
- TreeNode sib = xp.right;
- if (sib != null && sib.red) {
- sib.red = false;
- xp.red = true;
- rotateLeft(xp);
- sib = (xp = x.parent) == null ? null : xp.right;
- }
- if (sib == null) {
- x = xp;
- } else {
- TreeNode sl = sib.left, sr = sib.right;
- if ((sr == null || !sr.red)
- && (sl == null || !sl.red)) {
- sib.red = true;
- x = xp;
- } else {
- if (sr == null || !sr.red) {
- if (sl != null) {
- sl.red = false;
- }
- sib.red = true;
- rotateRight(sib);
- sib = (xp = x.parent) == null ?
- null : xp.right;
- }
- if (sib != null) {
- sib.red = (xp == null) ? false : xp.red;
- if ((sr = sib.right) != null) {
- sr.red = false;
- }
- }
- if (xp != null) {
- xp.red = false;
- rotateLeft(xp);
- }
- x = root;
- }
- }
- } else { // symmetric
- TreeNode sib = xpl;
- if (sib != null && sib.red) {
- sib.red = false;
- xp.red = true;
- rotateRight(xp);
- sib = (xp = x.parent) == null ? null : xp.left;
- }
- if (sib == null) {
- x = xp;
- } else {
- TreeNode sl = sib.left, sr = sib.right;
- if ((sl == null || !sl.red)
- && (sr == null || !sr.red)) {
- sib.red = true;
- x = xp;
- } else {
- if (sl == null || !sl.red) {
- if (sr != null) {
- sr.red = false;
- }
- sib.red = true;
- rotateLeft(sib);
- sib = (xp = x.parent) == null ?
- null : xp.left;
- }
- if (sib != null) {
- sib.red = (xp == null) ? false : xp.red;
- if ((sl = sib.left) != null) {
- sl.red = false;
- }
- }
- if (xp != null) {
- xp.red = false;
- rotateRight(xp);
- }
- x = root;
- }
- }
- }
- }
- }
- if (p == replacement && (pp = p.parent) != null) {
- if (p == pp.left) // detach pointers
- {
- pp.left = null;
- } else if (p == pp.right) {
- pp.right = null;
- }
- p.parent = null;
- }
- }
- }
+ /* ---------------- Public operations -------------- */
/**
* Constructs an empty <tt>HashMap</tt> with the specified initial
@@ -832,9 +453,7 @@
throw new IllegalArgumentException("Illegal load factor: " +
loadFactor);
this.loadFactor = loadFactor;
- threshold = initialCapacity;
- hashSeed = initHashSeed();
- init();
+ this.threshold = tableSizeFor(initialCapacity);
}
/**
@@ -853,7 +472,7 @@
* (16) and the default load factor (0.75).
*/
public HashMap() {
- this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR);
+ this.loadFactor = DEFAULT_LOAD_FACTOR; // all other fields defaulted
}
/**
@@ -866,79 +485,35 @@
* @throws NullPointerException if the specified map is null
*/
public HashMap(Map<? extends K, ? extends V> m) {
- this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
- DEFAULT_INITIAL_CAPACITY), DEFAULT_LOAD_FACTOR);
- inflateTable(threshold);
-
- putAllForCreate(m);
- // assert size == m.size();
- }
-
- private static int roundUpToPowerOf2(int number) {
- // assert number >= 0 : "number must be non-negative";
- return number >= MAXIMUM_CAPACITY
- ? MAXIMUM_CAPACITY
- : (number > 1) ? Integer.highestOneBit((number - 1) << 1) : 1;
+ this.loadFactor = DEFAULT_LOAD_FACTOR;
+ putMapEntries(m, false);
}
/**
- * Inflates the table.
- */
- private void inflateTable(int toSize) {
- // Find a power of 2 >= toSize
- int capacity = roundUpToPowerOf2(toSize);
-
- threshold = (int) Math.min(capacity * loadFactor, MAXIMUM_CAPACITY + 1);
- table = new Object[capacity];
- }
-
- // internal utilities
-
- /**
- * Initialization hook for subclasses. This method is called
- * in all constructors and pseudo-constructors (clone, readObject)
- * after HashMap has been initialized but before any entries have
- * been inserted. (In the absence of this method, readObject would
- * require explicit knowledge of subclasses.)
- */
- void init() {
- }
-
- /**
- * Return an initial value for the hashSeed, or 0 if the random seed is not
- * enabled.
+ * Implements Map.putAll and Map constructor
+ *
+ * @param m the map
+ * @param evict false when initially constructing this map, else
+ * true (relayed to method afterNodeInsertion).
*/
- final int initHashSeed() {
- if (sun.misc.VM.isBooted() && Holder.USE_HASHSEED) {
- int seed = ThreadLocalRandom.current().nextInt();
- return (seed != 0) ? seed : 1;
+ final void putMapEntries(Map<? extends K, ? extends V> m, boolean evict) {
+ int s = m.size();
+ if (s > 0) {
+ if (table == null) { // pre-size
+ float ft = ((float)s / loadFactor) + 1.0F;
+ int t = ((ft < (float)MAXIMUM_CAPACITY) ?
+ (int)ft : MAXIMUM_CAPACITY);
+ if (t > threshold)
+ threshold = tableSizeFor(t);
+ }
+ else if (s > threshold)
+ resize();
+ for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) {
+ K key = e.getKey();
+ V value = e.getValue();
+ putVal(hash(key), key, value, false, evict);
+ }
}
- return 0;
- }
-
- /**
- * Retrieve object hash code and applies a supplemental hash function to the
- * result hash, which defends against poor quality hash functions. This is
- * critical because HashMap uses power-of-two length hash tables, that
- * otherwise encounter collisions for hashCodes that do not differ
- * in lower bits.
- */
- final int hash(Object k) {
- int h = hashSeed ^ k.hashCode();
-
- // This function ensures that hashCodes that differ only by
- // constant multiples at each bit position have a bounded
- // number of collisions (approximately 8 at default load factor).
- h ^= (h >>> 20) ^ (h >>> 12);
- return h ^ (h >>> 7) ^ (h >>> 4);
- }
-
- /**
- * Returns index for hash code h.
- */
- static int indexFor(int h, int length) {
- // assert Integer.bitCount(length) == 1 : "length must be a non-zero power of 2";
- return h & (length-1);
}
/**
@@ -976,18 +551,36 @@
*
* @see #put(Object, Object)
*/
- @SuppressWarnings("unchecked")
public V get(Object key) {
- Entry<K,V> entry = getEntry(key);
-
- return null == entry ? null : entry.getValue();
+ Node<K,V> e;
+ return (e = getNode(hash(key), key)) == null ? null : e.value;
}
- @Override
- public V getOrDefault(Object key, V defaultValue) {
- Entry<K,V> entry = getEntry(key);
-
- return (entry == null) ? defaultValue : entry.getValue();
+ /**
+ * Implements Map.get and related methods
+ *
+ * @param hash hash for key
+ * @param key the key
+ * @return the node, or null if none
+ */
+ final Node<K,V> getNode(int hash, Object key) {
+ Node<K,V>[] tab; Node<K,V> first, e; int n; K k;
+ if ((tab = table) != null && (n = tab.length) > 0 &&
+ (first = tab[(n - 1) & hash]) != null) {
+ if (first.hash == hash && // always check first node
+ ((k = first.key) == key || (key != null && key.equals(k))))
+ return first;
+ if ((e = first.next) != null) {
+ if (first instanceof TreeNode)
+ return ((TreeNode<K,V>)first).getTreeNode(hash, key);
+ do {
+ if (e.hash == hash &&
+ ((k = e.key) == key || (key != null && key.equals(k))))
+ return e;
+ } while ((e = e.next) != null);
+ }
+ }
+ return null;
}
/**
@@ -999,49 +592,10 @@
* key.
*/
public boolean containsKey(Object key) {
- return getEntry(key) != null;
+ return getNode(hash(key), key) != null;
}
/**
- * Returns the entry associated with the specified key in the
- * HashMap. Returns null if the HashMap contains no mapping
- * for the key.
- */
- @SuppressWarnings("unchecked")
- final Entry<K,V> getEntry(Object key) {
- if (size == 0) {
- return null;
- }
- if (key == null) {
- return nullKeyEntry;
- }
- int hash = hash(key);
- int bin = indexFor(hash, table.length);
-
- if (table[bin] instanceof Entry) {
- Entry<K,V> e = (Entry<K,V>) table[bin];
- for (; e != null; e = (Entry<K,V>)e.next) {
- Object k;
- if (e.hash == hash &&
- ((k = e.key) == key || key.equals(k))) {
- return e;
- }
- }
- } else if (table[bin] != null) {
- TreeBin e = (TreeBin)table[bin];
- TreeNode p = e.getTreeNode(hash, (K)key);
- if (p != null) {
- // assert p.entry.hash == hash && p.entry.key.equals(key);
- return (Entry<K,V>)p.entry;
- } else {
- return null;
- }
- }
- return null;
- }
-
-
- /**
* Associates the specified value with the specified key in this map.
* If the map previously contained a mapping for the key, the old
* value is replaced.
@@ -1053,202 +607,169 @@
* (A <tt>null</tt> return can also indicate that the map
* previously associated <tt>null</tt> with <tt>key</tt>.)
*/
- @SuppressWarnings("unchecked")
public V put(K key, V value) {
- if (table == EMPTY_TABLE) {
- inflateTable(threshold);
- }
- if (key == null)
- return putForNullKey(value);
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
+ return putVal(hash(key), key, value, false, true);
+ }
- if (table[i] instanceof Entry) {
- // Bin contains ordinary Entries. Search for key in the linked list
- // of entries, counting the number of entries. Only check for
- // TreeBin conversion if the list size is >= TREE_THRESHOLD.
- // (The conversion still may not happen if the table gets resized.)
- int listSize = 0;
- Entry<K,V> e = (Entry<K,V>) table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- Object k;
- if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {
- V oldValue = e.value;
+ /**
+ * Implements Map.put and related methods
+ *
+ * @param hash hash for key
+ * @param key the key
+ * @param value the value to put
+ * @param onlyIfAbsent if true, don't change existing value
+ * @param evict if false, the table is in creation mode.
+ * @return previous value, or null if none
+ */
+ final V putVal(int hash, K key, V value, boolean onlyIfAbsent,
+ boolean evict) {
+ Node<K,V>[] tab; Node<K,V> p; int n, i;
+ if (size > threshold || (tab = table) == null ||
+ (n = tab.length) == 0)
+ n = (tab = resize()).length;
+ if ((p = tab[i = (n - 1) & hash]) == null)
+ tab[i] = newNode(hash, key, value, null);
+ else {
+ Node<K,V> e; K k;
+ if (p.hash == hash &&
+ ((k = p.key) == key || (key != null && key.equals(k))))
+ e = p;
+ else if (p instanceof TreeNode)
+ e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);
+ else {
+ for (int binCount = 0; ; ++binCount) {
+ if ((e = p.next) == null) {
+ p.next = newNode(hash, key, value, null);
+ if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st
+ treeifyBin(tab, hash);
+ break;
+ }
+ if (e.hash == hash &&
+ ((k = e.key) == key || (key != null && key.equals(k))))
+ break;
+ p = e;
+ }
+ }
+ if (e != null) { // existing mapping for key
+ V oldValue = e.value;
+ if (!onlyIfAbsent || oldValue == null)
e.value = value;
- e.recordAccess(this);
- return oldValue;
- }
- listSize++;
- }
- // Didn't find, so fall through and call addEntry() to add the
- // Entry and check for TreeBin conversion.
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin e = (TreeBin)table[i];
- TreeNode p = e.putTreeNode(hash, key, value, null);
- if (p == null) { // putTreeNode() added a new node
- modCount++;
- size++;
- if (size >= threshold) {
- resize(2 * table.length);
- }
- return null;
- } else { // putTreeNode() found an existing node
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- V oldVal = pEntry.value;
- pEntry.value = value;
- pEntry.recordAccess(this);
- return oldVal;
+ afterNodeAccess(e);
+ return oldValue;
}
}
- modCount++;
- addEntry(hash, key, value, i, checkIfNeedTree);
+ ++modCount;
+ ++size;
+ afterNodeInsertion(evict);
return null;
}
/**
- * Offloaded version of put for null keys
+ * Initializes or doubles table size. If null, allocates in
+ * accord with initial capacity target held in field threshold.
+ * Otherwise, because we are using power-of-two expansion, the
+ * elements from each bin must either stay at same index, or move
+ * with a power of two offset in the new table.
+ *
+ * @return the table
*/
- private V putForNullKey(V value) {
- if (nullKeyEntry != null) {
- V oldValue = nullKeyEntry.value;
- nullKeyEntry.value = value;
- nullKeyEntry.recordAccess(this);
- return oldValue;
+ final Node<K,V>[] resize() {
+ Node<K,V>[] oldTab = table;
+ int oldCap = (oldTab == null) ? 0 : oldTab.length;
+ int oldThr = threshold;
+ int newCap, newThr = 0;
+ if (oldCap > 0) {
+ if (oldCap >= MAXIMUM_CAPACITY) {
+ threshold = Integer.MAX_VALUE;
+ return oldTab;
+ }
+ else if ((newCap = oldCap << 1) < MAXIMUM_CAPACITY &&
+ oldCap >= DEFAULT_INITIAL_CAPACITY)
+ newThr = oldThr << 1; // double threshold
}
- modCount++;
- size++; // newEntry() skips size++
- nullKeyEntry = newEntry(0, null, value, null);
- return null;
- }
-
- private void putForCreateNullKey(V value) {
- // Look for preexisting entry for key. This will never happen for
- // clone or deserialize. It will only happen for construction if the
- // input Map is a sorted map whose ordering is inconsistent w/ equals.
- if (nullKeyEntry != null) {
- nullKeyEntry.value = value;
- } else {
- nullKeyEntry = newEntry(0, null, value, null);
- size++;
+ else if (oldThr > 0) // initial capacity was placed in threshold
+ newCap = oldThr;
+ else { // zero initial threshold signifies using defaults
+ newCap = DEFAULT_INITIAL_CAPACITY;
+ newThr = (int)(DEFAULT_LOAD_FACTOR * DEFAULT_INITIAL_CAPACITY);
}
- }
-
-
- /**
- * This method is used instead of put by constructors and
- * pseudoconstructors (clone, readObject). It does not resize the table,
- * check for comodification, etc, though it will convert bins to TreeBins
- * as needed. It calls createEntry rather than addEntry.
- */
- @SuppressWarnings("unchecked")
- private void putForCreate(K key, V value) {
- if (null == key) {
- putForCreateNullKey(value);
- return;
+ if (newThr == 0) {
+ float ft = (float)newCap * loadFactor;
+ newThr = (newCap < MAXIMUM_CAPACITY && ft < (float)MAXIMUM_CAPACITY ?
+ (int)ft : Integer.MAX_VALUE);
}
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
-
- /**
- * Look for preexisting entry for key. This will never happen for
- * clone or deserialize. It will only happen for construction if the
- * input Map is a sorted map whose ordering is inconsistent w/ equals.
- */
- if (table[i] instanceof Entry) {
- int listSize = 0;
- Entry<K,V> e = (Entry<K,V>) table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- Object k;
- if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {
- e.value = value;
- return;
+ threshold = newThr;
+ @SuppressWarnings({"rawtypes","unchecked"})
+ Node<K,V>[] newTab = (Node<K,V>[])new Node[newCap];
+ table = newTab;
+ if (oldTab != null) {
+ for (int j = 0; j < oldCap; ++j) {
+ Node<K,V> e;
+ if ((e = oldTab[j]) != null) {
+ oldTab[j] = null;
+ if (e.next == null)
+ newTab[e.hash & (newCap - 1)] = e;
+ else if (e instanceof TreeNode)
+ ((TreeNode<K,V>)e).split(this, newTab, j, oldCap);
+ else { // preserve order
+ Node<K,V> loHead = null, loTail = null;
+ Node<K,V> hiHead = null, hiTail = null;
+ Node<K,V> next;
+ do {
+ next = e.next;
+ if ((e.hash & oldCap) == 0) {
+ if (loTail == null)
+ loHead = e;
+ else
+ loTail.next = e;
+ loTail = e;
+ }
+ else {
+ if (hiTail == null)
+ hiHead = e;
+ else
+ hiTail.next = e;
+ hiTail = e;
+ }
+ } while ((e = next) != null);
+ if (loTail != null) {
+ loTail.next = null;
+ newTab[j] = loHead;
+ }
+ if (hiTail != null) {
+ hiTail.next = null;
+ newTab[j + oldCap] = hiHead;
+ }
+ }
}
- listSize++;
}
- // Didn't find, fall through to createEntry().
- // Check for conversion to TreeBin done via createEntry().
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin e = (TreeBin)table[i];
- TreeNode p = e.putTreeNode(hash, key, value, null);
- if (p != null) {
- p.entry.setValue(value); // Found an existing node, set value
- } else {
- size++; // Added a new TreeNode, so update size
- }
- // don't need modCount++/check for resize - just return
- return;
}
-
- createEntry(hash, key, value, i, checkIfNeedTree);
- }
-
- private void putAllForCreate(Map<? extends K, ? extends V> m) {
- for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
- putForCreate(e.getKey(), e.getValue());
+ return newTab;
}
/**
- * Rehashes the contents of this map into a new array with a
- * larger capacity. This method is called automatically when the
- * number of keys in this map reaches its threshold.
- *
- * If current capacity is MAXIMUM_CAPACITY, this method does not
- * resize the map, but sets threshold to Integer.MAX_VALUE.
- * This has the effect of preventing future calls.
- *
- * @param newCapacity the new capacity, MUST be a power of two;
- * must be greater than current capacity unless current
- * capacity is MAXIMUM_CAPACITY (in which case value
- * is irrelevant).
+ * Replaces all linked nodes in bin at index for given hash unless
+ * table is too small, in which case resizes instead.
*/
- void resize(int newCapacity) {
- Object[] oldTable = table;
- int oldCapacity = oldTable.length;
- if (oldCapacity == MAXIMUM_CAPACITY) {
- threshold = Integer.MAX_VALUE;
- return;
+ final void treeifyBin(Node<K,V>[] tab, int hash) {
+ int n, index; Node<K,V> e;
+ if (tab == null || (n = tab.length) < MIN_TREEIFY_CAPACITY)
+ resize();
+ else if ((e = tab[index = (n - 1) & hash]) != null) {
+ TreeNode<K,V> hd = null, tl = null;
+ do {
+ TreeNode<K,V> p = replacementTreeNode(e, null);
+ if (tl == null)
+ hd = p;
+ else {
+ p.prev = tl;
+ tl.next = p;
+ }
+ tl = p;
+ } while ((e = e.next) != null);
+ if ((tab[index] = hd) != null)
+ hd.treeify(tab);
}
-
- Object[] newTable = new Object[newCapacity];
- transfer(newTable);
- table = newTable;
- threshold = (int)Math.min(newCapacity * loadFactor, MAXIMUM_CAPACITY + 1);
- }
-
- /**
- * Transfers all entries from current table to newTable.
- *
- * Assumes newTable is larger than table
- */
- @SuppressWarnings("unchecked")
- void transfer(Object[] newTable) {
- Object[] src = table;
- // assert newTable.length > src.length : "newTable.length(" +
- // newTable.length + ") expected to be > src.length("+src.length+")";
- int newCapacity = newTable.length;
- for (int j = 0; j < src.length; j++) {
- if (src[j] instanceof Entry) {
- // Assume: since wasn't TreeBin before, won't need TreeBin now
- Entry<K,V> e = (Entry<K,V>) src[j];
- while (null != e) {
- Entry<K,V> next = (Entry<K,V>)e.next;
- int i = indexFor(e.hash, newCapacity);
- e.next = (Entry<K,V>) newTable[i];
- newTable[i] = e;
- e = next;
- }
- } else if (src[j] != null) {
- TreeBin e = (TreeBin) src[j];
- TreeBin loTree = new TreeBin();
- TreeBin hiTree = new TreeBin();
- e.splitTreeBin(newTable, j, loTree, hiTree);
- }
- }
- Arrays.fill(table, null);
}
/**
@@ -1260,30 +781,8 @@
* @throws NullPointerException if the specified map is null
*/
public void putAll(Map<? extends K, ? extends V> m) {
- int numKeysToBeAdded = m.size();
- if (numKeysToBeAdded == 0)
- return;
-
- if (table == EMPTY_TABLE) {
- inflateTable((int) Math.max(numKeysToBeAdded * loadFactor, threshold));
- }
-
- /*
- * Expand the map if the map if the number of mappings to be added
- * is greater than or equal to threshold. This is conservative; the
- * obvious condition is (m.size() + size) >= threshold, but this
- * condition could result in a map with twice the appropriate capacity,
- * if the keys to be added overlap with the keys already in this map.
- * By using the conservative calculation, we subject ourself
- * to at most one extra resize.
- */
- if (numKeysToBeAdded > threshold && table.length < MAXIMUM_CAPACITY) {
- resize(table.length * 2);
- }
-
- for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
- put(e.getKey(), e.getValue());
- }
+ putMapEntries(m, true);
+ }
/**
* Removes the mapping for the specified key from this map if present.
@@ -1295,834 +794,74 @@
* previously associated <tt>null</tt> with <tt>key</tt>.)
*/
public V remove(Object key) {
- Entry<K,V> e = removeEntryForKey(key);
- return (e == null ? null : e.value);
- }
-
- // optimized implementations of default methods in Map
-
- @Override
- public void forEach(BiConsumer<? super K, ? super V> action) {
- Objects.requireNonNull(action);
- final int expectedModCount = modCount;
- if (nullKeyEntry != null) {
- forEachNullKey(expectedModCount, action);
- }
- Object[] tab = this.table;
- for (int index = 0; index < tab.length; index++) {
- Object item = tab[index];
- if (item == null) {
- continue;
- }
- if (item instanceof HashMap.TreeBin) {
- eachTreeNode(expectedModCount, ((TreeBin)item).first, action);
- continue;
- }
- @SuppressWarnings("unchecked")
- Entry<K, V> entry = (Entry<K, V>)item;
- while (entry != null) {
- action.accept(entry.key, entry.value);
- entry = (Entry<K, V>)entry.next;
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
- }
-
- private void eachTreeNode(int expectedModCount, TreeNode<K, V> node, BiConsumer<? super K, ? super V> action) {
- while (node != null) {
- @SuppressWarnings("unchecked")
- Entry<K, V> entry = (Entry<K, V>)node.entry;
- action.accept(entry.key, entry.value);
- node = (TreeNode<K, V>)entry.next;
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
-
- private void forEachNullKey(int expectedModCount, BiConsumer<? super K, ? super V> action) {
- action.accept(null, nullKeyEntry.value);
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
-
- @Override
- public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
- Objects.requireNonNull(function);
- final int expectedModCount = modCount;
- if (nullKeyEntry != null) {
- replaceforNullKey(expectedModCount, function);
- }
- Object[] tab = this.table;
- for (int index = 0; index < tab.length; index++) {
- Object item = tab[index];
- if (item == null) {
- continue;
- }
- if (item instanceof HashMap.TreeBin) {
- replaceEachTreeNode(expectedModCount, ((TreeBin)item).first, function);
- continue;
- }
- @SuppressWarnings("unchecked")
- Entry<K, V> entry = (Entry<K, V>)item;
- while (entry != null) {
- entry.value = function.apply(entry.key, entry.value);
- entry = (Entry<K, V>)entry.next;
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
- }
-
- private void replaceEachTreeNode(int expectedModCount, TreeNode<K, V> node, BiFunction<? super K, ? super V, ? extends V> function) {
- while (node != null) {
- @SuppressWarnings("unchecked")
- Entry<K, V> entry = (Entry<K, V>)node.entry;
- entry.value = function.apply(entry.key, entry.value);
- node = (TreeNode<K, V>)entry.next;
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
-
- private void replaceforNullKey(int expectedModCount, BiFunction<? super K, ? super V, ? extends V> function) {
- nullKeyEntry.value = function.apply(null, nullKeyEntry.value);
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
+ Node<K,V> e;
+ return (e = removeNode(hash(key), key, null, false, true)) == null ?
+ null : e.value;
}
- @Override
- public V putIfAbsent(K key, V value) {
- if (table == EMPTY_TABLE) {
- inflateTable(threshold);
- }
- if (key == null) {
- if (nullKeyEntry == null || nullKeyEntry.value == null) {
- putForNullKey(value);
- return null;
- } else {
- return nullKeyEntry.value;
- }
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
-
- if (table[i] instanceof Entry) {
- int listSize = 0;
- Entry<K,V> e = (Entry<K,V>) table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- if (e.hash == hash && Objects.equals(e.key, key)) {
- if (e.value != null) {
- return e.value;
- }
- e.value = value;
- e.recordAccess(this);
- return null;
- }
- listSize++;
- }
- // Didn't find, so fall through and call addEntry() to add the
- // Entry and check for TreeBin conversion.
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin e = (TreeBin)table[i];
- TreeNode p = e.putTreeNode(hash, key, value, null);
- if (p == null) { // not found, putTreeNode() added a new node
- modCount++;
- size++;
- if (size >= threshold) {
- resize(2 * table.length);
- }
- return null;
- } else { // putTreeNode() found an existing node
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- V oldVal = pEntry.value;
- if (oldVal == null) { // only replace if maps to null
- pEntry.value = value;
- pEntry.recordAccess(this);
- }
- return oldVal;
- }
- }
- modCount++;
- addEntry(hash, key, value, i, checkIfNeedTree);
- return null;
- }
-
- @Override
- public boolean remove(Object key, Object value) {
- if (size == 0) {
- return false;
- }
- if (key == null) {
- if (nullKeyEntry != null &&
- Objects.equals(nullKeyEntry.value, value)) {
- removeNullKey();
- return true;
- }
- return false;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
-
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>) table[i];
- Entry<K,V> e = prev;
- while (e != null) {
- @SuppressWarnings("unchecked")
- Entry<K,V> next = (Entry<K,V>) e.next;
- if (e.hash == hash && Objects.equals(e.key, key)) {
- if (!Objects.equals(e.value, value)) {
- return false;
- }
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- return true;
- }
- prev = e;
- e = next;
- }
- } else if (table[i] != null) {
- TreeBin tb = ((TreeBin) table[i]);
- TreeNode p = tb.getTreeNode(hash, (K)key);
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- if (Objects.equals(pEntry.value, value)) {
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- return true;
+ /**
+ * Implements Map.remove and related methods
+ *
+ * @param hash hash for key
+ * @param key the key
+ * @param value the value to match if matchValue, else ignored
+ * @param matchValue if true only remove if value is equal
+ * @param movable if false do not move other nodes while removing
+ * @return the node, or null if none
+ */
+ final Node<K,V> removeNode(int hash, Object key, Object value,
+ boolean matchValue, boolean movable) {
+ Node<K,V>[] tab; Node<K,V> p; int n, index;
+ if ((tab = table) != null && (n = tab.length) > 0 &&
+ (p = tab[index = (n - 1) & hash]) != null) {
+ Node<K,V> node = null, e; K k; V v;
+ if (p.hash == hash &&
+ ((k = p.key) == key || (key != null && key.equals(k))))
+ node = p;
+ else if ((e = p.next) != null) {
+ if (p instanceof TreeNode)
+ node = ((TreeNode<K,V>)p).getTreeNode(hash, key);
+ else {
+ do {
+ if (e.hash == hash &&
+ ((k = e.key) == key ||
+ (key != null && key.equals(k)))) {
+ node = e;
+ break;
+ }
+ p = e;
+ } while ((e = e.next) != null);
}
}
- }
- return false;
- }
-
- @Override
- public boolean replace(K key, V oldValue, V newValue) {
- if (size == 0) {
- return false;
- }
- if (key == null) {
- if (nullKeyEntry != null &&
- Objects.equals(nullKeyEntry.value, oldValue)) {
- putForNullKey(newValue);
- return true;
- }
- return false;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
-
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> e = (Entry<K,V>) table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- if (e.hash == hash && Objects.equals(e.key, key) && Objects.equals(e.value, oldValue)) {
- e.value = newValue;
- e.recordAccess(this);
- return true;
- }
- }
- return false;
- } else if (table[i] != null) {
- TreeBin tb = ((TreeBin) table[i]);
- TreeNode p = tb.getTreeNode(hash, key);
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- if (Objects.equals(pEntry.value, oldValue)) {
- pEntry.value = newValue;
- pEntry.recordAccess(this);
- return true;
- }
- }
- }
- return false;
- }
-
- @Override
- public V replace(K key, V value) {
- if (size == 0) {
- return null;
- }
- if (key == null) {
- if (nullKeyEntry != null) {
- return putForNullKey(value);
- }
- return null;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> e = (Entry<K,V>)table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- if (e.hash == hash && Objects.equals(e.key, key)) {
- V oldValue = e.value;
- e.value = value;
- e.recordAccess(this);
- return oldValue;
- }
- }
-
- return null;
- } else if (table[i] != null) {
- TreeBin tb = ((TreeBin) table[i]);
- TreeNode p = tb.getTreeNode(hash, key);
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- V oldValue = pEntry.value;
- pEntry.value = value;
- pEntry.recordAccess(this);
- return oldValue;
+ if (node != null && (!matchValue || (v = node.value) == value ||
+ (value != null && value.equals(v)))) {
+ if (node instanceof TreeNode)
+ ((TreeNode<K,V>)node).removeTreeNode(this, tab, movable);
+ else if (node == p)
+ tab[index] = node.next;
+ else
+ p.next = node.next;
+ ++modCount;
+ --size;
+ afterNodeRemoval(node);
+ return node;
}
}
return null;
}
- @Override
- public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
- if (table == EMPTY_TABLE) {
- inflateTable(threshold);
- }
- if (key == null) {
- if (nullKeyEntry == null || nullKeyEntry.value == null) {
- V newValue = mappingFunction.apply(key);
- if (newValue != null) {
- putForNullKey(newValue);
- }
- return newValue;
- }
- return nullKeyEntry.value;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
-
- if (table[i] instanceof Entry) {
- int listSize = 0;
- @SuppressWarnings("unchecked")
- Entry<K,V> e = (Entry<K,V>)table[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- if (e.hash == hash && Objects.equals(e.key, key)) {
- V oldValue = e.value;
- if (oldValue == null) {
- V newValue = mappingFunction.apply(key);
- if (newValue != null) {
- e.value = newValue;
- e.recordAccess(this);
- }
- return newValue;
- }
- return oldValue;
- }
- listSize++;
- }
- // Didn't find, fall through to call the mapping function
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin e = (TreeBin)table[i];
- V value = mappingFunction.apply(key);
- if (value == null) { // Return the existing value, if any
- TreeNode p = e.getTreeNode(hash, key);
- if (p != null) {
- return (V) p.entry.value;
- }
- return null;
- } else { // Put the new value into the Tree, if absent
- TreeNode p = e.putTreeNode(hash, key, value, null);
- if (p == null) { // not found, new node was added
- modCount++;
- size++;
- if (size >= threshold) {
- resize(2 * table.length);
- }
- return value;
- } else { // putTreeNode() found an existing node
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- V oldVal = pEntry.value;
- if (oldVal == null) { // only replace if maps to null
- pEntry.value = value;
- pEntry.recordAccess(this);
- return value;
- }
- return oldVal;
- }
- }
- }
- V newValue = mappingFunction.apply(key);
- if (newValue != null) { // add Entry and check for TreeBin conversion
- modCount++;
- addEntry(hash, key, newValue, i, checkIfNeedTree);
- }
-
- return newValue;
- }
-
- @Override
- public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
- if (size == 0) {
- return null;
- }
- if (key == null) {
- V oldValue;
- if (nullKeyEntry != null && (oldValue = nullKeyEntry.value) != null) {
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue != null ) {
- putForNullKey(newValue);
- return newValue;
- } else {
- removeNullKey();
- }
- }
- return null;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>)table[i];
- Entry<K,V> e = prev;
- while (e != null) {
- Entry<K,V> next = (Entry<K,V>)e.next;
- if (e.hash == hash && Objects.equals(e.key, key)) {
- V oldValue = e.value;
- if (oldValue == null)
- break;
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue == null) {
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- } else {
- e.value = newValue;
- e.recordAccess(this);
- }
- return newValue;
- }
- prev = e;
- e = next;
- }
- } else if (table[i] != null) {
- TreeBin tb = (TreeBin)table[i];
- TreeNode p = tb.getTreeNode(hash, key);
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- V oldValue = pEntry.value;
- if (oldValue != null) {
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue == null) { // remove mapping
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- } else {
- pEntry.value = newValue;
- pEntry.recordAccess(this);
- }
- return newValue;
- }
- }
- }
- return null;
- }
-
- @Override
- public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
- if (table == EMPTY_TABLE) {
- inflateTable(threshold);
- }
- if (key == null) {
- V oldValue = nullKeyEntry == null ? null : nullKeyEntry.value;
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue != oldValue || (oldValue == null && nullKeyEntry != null)) {
- if (newValue == null) {
- removeNullKey();
- } else {
- putForNullKey(newValue);
- }
- }
- return newValue;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
-
- if (table[i] instanceof Entry) {
- int listSize = 0;
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>)table[i];
- Entry<K,V> e = prev;
-
- while (e != null) {
- Entry<K,V> next = (Entry<K,V>)e.next;
- if (e.hash == hash && Objects.equals(e.key, key)) {
- V oldValue = e.value;
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue != oldValue || oldValue == null) {
- if (newValue == null) {
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- } else {
- e.value = newValue;
- e.recordAccess(this);
- }
- }
- return newValue;
- }
- prev = e;
- e = next;
- listSize++;
- }
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin tb = (TreeBin)table[i];
- TreeNode p = tb.getTreeNode(hash, key);
- V oldValue = p == null ? null : (V)p.entry.value;
- V newValue = remappingFunction.apply(key, oldValue);
- if (newValue != oldValue || (oldValue == null && p != null)) {
- if (newValue == null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- } else {
- if (p != null) { // just update the value
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- pEntry.value = newValue;
- pEntry.recordAccess(this);
- } else { // need to put new node
- p = tb.putTreeNode(hash, key, newValue, null);
- // assert p == null; // should have added a new node
- modCount++;
- size++;
- if (size >= threshold) {
- resize(2 * table.length);
- }
- }
- }
- }
- return newValue;
- }
-
- V newValue = remappingFunction.apply(key, null);
- if (newValue != null) {
- modCount++;
- addEntry(hash, key, newValue, i, checkIfNeedTree);
- }
-
- return newValue;
- }
-
- @Override
- public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
- if (table == EMPTY_TABLE) {
- inflateTable(threshold);
- }
- if (key == null) {
- V oldValue = nullKeyEntry == null ? null : nullKeyEntry.value;
- V newValue = oldValue == null ? value : remappingFunction.apply(oldValue, value);
- if (newValue != null) {
- putForNullKey(newValue);
- } else if (nullKeyEntry != null) {
- removeNullKey();
- }
- return newValue;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
- boolean checkIfNeedTree = false; // Might we convert bin to a TreeBin?
-
- if (table[i] instanceof Entry) {
- int listSize = 0;
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>)table[i];
- Entry<K,V> e = prev;
-
- while (e != null) {
- Entry<K,V> next = (Entry<K,V>)e.next;
- if (e.hash == hash && Objects.equals(e.key, key)) {
- V oldValue = e.value;
- V newValue = (oldValue == null) ? value :
- remappingFunction.apply(oldValue, value);
- if (newValue == null) {
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- } else {
- e.value = newValue;
- e.recordAccess(this);
- }
- return newValue;
- }
- prev = e;
- e = next;
- listSize++;
- }
- // Didn't find, so fall through and (maybe) call addEntry() to add
- // the Entry and check for TreeBin conversion.
- checkIfNeedTree = listSize >= TreeBin.TREE_THRESHOLD;
- } else if (table[i] != null) {
- TreeBin tb = (TreeBin)table[i];
- TreeNode p = tb.getTreeNode(hash, key);
- V oldValue = p == null ? null : (V)p.entry.value;
- V newValue = (oldValue == null) ? value :
- remappingFunction.apply(oldValue, value);
- if (newValue == null) {
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
-
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- }
- return null;
- } else if (newValue != oldValue) {
- if (p != null) { // just update the value
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- pEntry.value = newValue;
- pEntry.recordAccess(this);
- } else { // need to put new node
- p = tb.putTreeNode(hash, key, newValue, null);
- // assert p == null; // should have added a new node
- modCount++;
- size++;
- if (size >= threshold) {
- resize(2 * table.length);
- }
- }
- }
- return newValue;
- }
- if (value != null) {
- modCount++;
- addEntry(hash, key, value, i, checkIfNeedTree);
- }
- return value;
- }
-
- // end of optimized implementations of default methods in Map
-
- /**
- * Removes and returns the entry associated with the specified key
- * in the HashMap. Returns null if the HashMap contains no mapping
- * for this key.
- *
- * We don't bother converting TreeBins back to Entry lists if the bin falls
- * back below TREE_THRESHOLD, but we do clear bins when removing the last
- * TreeNode in a TreeBin.
- */
- final Entry<K,V> removeEntryForKey(Object key) {
- if (size == 0) {
- return null;
- }
- if (key == null) {
- if (nullKeyEntry != null) {
- return removeNullKey();
- }
- return null;
- }
- int hash = hash(key);
- int i = indexFor(hash, table.length);
-
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>)table[i];
- Entry<K,V> e = prev;
-
- while (e != null) {
- @SuppressWarnings("unchecked")
- Entry<K,V> next = (Entry<K,V>) e.next;
- if (e.hash == hash && Objects.equals(e.key, key)) {
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- return e;
- }
- prev = e;
- e = next;
- }
- } else if (table[i] != null) {
- TreeBin tb = ((TreeBin) table[i]);
- TreeNode p = tb.getTreeNode(hash, (K)key);
- if (p != null) {
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- return pEntry;
- }
- }
- return null;
- }
-
- /**
- * Special version of remove for EntrySet using {@code Map.Entry.equals()}
- * for matching.
- */
- final Entry<K,V> removeMapping(Object o) {
- if (size == 0 || !(o instanceof Map.Entry))
- return null;
-
- Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
- Object key = entry.getKey();
-
- if (key == null) {
- if (entry.equals(nullKeyEntry)) {
- return removeNullKey();
- }
- return null;
- }
-
- int hash = hash(key);
- int i = indexFor(hash, table.length);
-
- if (table[i] instanceof Entry) {
- @SuppressWarnings("unchecked")
- Entry<K,V> prev = (Entry<K,V>)table[i];
- Entry<K,V> e = prev;
-
- while (e != null) {
- @SuppressWarnings("unchecked")
- Entry<K,V> next = (Entry<K,V>)e.next;
- if (e.hash == hash && e.equals(entry)) {
- modCount++;
- size--;
- if (prev == e)
- table[i] = next;
- else
- prev.next = next;
- e.recordRemoval(this);
- return e;
- }
- prev = e;
- e = next;
- }
- } else if (table[i] != null) {
- TreeBin tb = ((TreeBin) table[i]);
- TreeNode p = tb.getTreeNode(hash, (K)key);
- if (p != null && p.entry.equals(entry)) {
- @SuppressWarnings("unchecked")
- Entry<K,V> pEntry = (Entry<K,V>)p.entry;
- // assert pEntry.key.equals(key);
- modCount++;
- size--;
- tb.deleteTreeNode(p);
- pEntry.recordRemoval(this);
- if (tb.root == null || tb.first == null) {
- // assert tb.root == null && tb.first == null :
- // "TreeBin.first and root should both be null";
- // TreeBin is now empty, we should blank this bin
- table[i] = null;
- }
- return pEntry;
- }
- }
- return null;
- }
-
- /*
- * Remove the mapping for the null key, and update internal accounting
- * (size, modcount, recordRemoval, etc).
- *
- * Assumes nullKeyEntry is non-null.
- */
- private Entry<K,V> removeNullKey() {
- // assert nullKeyEntry != null;
- Entry<K,V> retVal = nullKeyEntry;
- modCount++;
- size--;
- retVal.recordRemoval(this);
- nullKeyEntry = null;
- return retVal;
- }
-
/**
* Removes all of the mappings from this map.
* The map will be empty after this call returns.
*/
public void clear() {
+ Node<K,V>[] tab;
modCount++;
- if (nullKeyEntry != null) {
- nullKeyEntry = null;
+ if ((tab = table) != null && size > 0) {
+ size = 0;
+ for (int i = 0; i < tab.length; ++i)
+ tab[i] = null;
}
- Arrays.fill(table, null);
- size = 0;
}
/**
@@ -2134,352 +873,20 @@
* specified value
*/
public boolean containsValue(Object value) {
- if (value == null) {
- return containsNullValue();
- }
- Object[] tab = table;
- for (int i = 0; i < tab.length; i++) {
- if (tab[i] instanceof Entry) {
- Entry<?,?> e = (Entry<?,?>)tab[i];
- for (; e != null; e = (Entry<?,?>)e.next) {
- if (value.equals(e.value)) {
- return true;
- }
- }
- } else if (tab[i] != null) {
- TreeBin e = (TreeBin)tab[i];
- TreeNode p = e.first;
- for (; p != null; p = (TreeNode) p.entry.next) {
- if (value == p.entry.value || value.equals(p.entry.value)) {
+ Node<K,V>[] tab; V v;
+ if ((tab = table) != null && size > 0) {
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next) {
+ if ((v = e.value) == value ||
+ (value != null && value.equals(v)))
return true;
- }
- }
- }
- }
- // Didn't find value in table - could be in nullKeyEntry
- return (nullKeyEntry != null && (value == nullKeyEntry.value ||
- value.equals(nullKeyEntry.value)));
- }
-
- /**
- * Special-case code for containsValue with null argument
- */
- private boolean containsNullValue() {
- Object[] tab = table;
- for (int i = 0; i < tab.length; i++) {
- if (tab[i] instanceof Entry) {
- Entry<K,V> e = (Entry<K,V>)tab[i];
- for (; e != null; e = (Entry<K,V>)e.next) {
- if (e.value == null) {
- return true;
- }
- }
- } else if (tab[i] != null) {
- TreeBin e = (TreeBin)tab[i];
- TreeNode p = e.first;
- for (; p != null; p = (TreeNode) p.entry.next) {
- if (p.entry.value == null) {
- return true;
- }
}
}
}
- // Didn't find value in table - could be in nullKeyEntry
- return (nullKeyEntry != null && nullKeyEntry.value == null);
- }
-
- /**
- * Returns a shallow copy of this <tt>HashMap</tt> instance: the keys and
- * values themselves are not cloned.
- *
- * @return a shallow copy of this map
- */
- @SuppressWarnings("unchecked")
- public Object clone() {
- HashMap<K,V> result = null;
- try {
- result = (HashMap<K,V>)super.clone();
- } catch (CloneNotSupportedException e) {
- // assert false;
- }
- if (result.table != EMPTY_TABLE) {
- result.inflateTable(Math.min(
- (int) Math.min(
- size * Math.min(1 / loadFactor, 4.0f),
- // we have limits...
- HashMap.MAXIMUM_CAPACITY),
- table.length));
- }
- result.entrySet = null;
- result.modCount = 0;
- result.size = 0;
- result.nullKeyEntry = null;
- result.init();
- result.putAllForCreate(this);
-
- return result;
- }
-
- static class Entry<K,V> implements Map.Entry<K,V> {
- final K key;
- V value;
- Object next; // an Entry, or a TreeNode
- final int hash;
-
- /**
- * Creates new entry.
- */
- Entry(int h, K k, V v, Object n) {
- value = v;
- next = n;
- key = k;
- hash = h;
- }
-
- public final K getKey() {
- return key;
- }
-
- public final V getValue() {
- return value;
- }
-
- public final V setValue(V newValue) {
- V oldValue = value;
- value = newValue;
- return oldValue;
- }
-
- public final boolean equals(Object o) {
- if (!(o instanceof Map.Entry))
- return false;
- Map.Entry<?,?> e = (Map.Entry<?,?>)o;
- Object k1 = getKey();
- Object k2 = e.getKey();
- if (k1 == k2 || (k1 != null && k1.equals(k2))) {
- Object v1 = getValue();
- Object v2 = e.getValue();
- if (v1 == v2 || (v1 != null && v1.equals(v2)))
- return true;
- }
- return false;
- }
-
- public final int hashCode() {
- return Objects.hashCode(getKey()) ^ Objects.hashCode(getValue());
- }
-
- public final String toString() {
- return getKey() + "=" + getValue();
- }
-
- /**
- * This method is invoked whenever the value in an entry is
- * overwritten for a key that's already in the HashMap.
- */
- void recordAccess(HashMap<K,V> m) {
- }
-
- /**
- * This method is invoked whenever the entry is
- * removed from the table.
- */
- void recordRemoval(HashMap<K,V> m) {
- }
- }
-
- void addEntry(int hash, K key, V value, int bucketIndex) {
- addEntry(hash, key, value, bucketIndex, true);
- }
-
- /**
- * Adds a new entry with the specified key, value and hash code to
- * the specified bucket. It is the responsibility of this
- * method to resize the table if appropriate. The new entry is then
- * created by calling createEntry().
- *
- * Subclass overrides this to alter the behavior of put method.
- *
- * If checkIfNeedTree is false, it is known that this bucket will not need
- * to be converted to a TreeBin, so don't bothering checking.
- *
- * Assumes key is not null.
- */
- void addEntry(int hash, K key, V value, int bucketIndex, boolean checkIfNeedTree) {
- // assert key != null;
- if ((size >= threshold) && (null != table[bucketIndex])) {
- resize(2 * table.length);
- hash = hash(key);
- bucketIndex = indexFor(hash, table.length);
- }
- createEntry(hash, key, value, bucketIndex, checkIfNeedTree);
+ return false;
}
/**
- * Called by addEntry(), and also used when creating entries
- * as part of Map construction or "pseudo-construction" (cloning,
- * deserialization). This version does not check for resizing of the table.
- *
- * This method is responsible for converting a bucket to a TreeBin once
- * TREE_THRESHOLD is reached. However if checkIfNeedTree is false, it is known
- * that this bucket will not need to be converted to a TreeBin, so don't
- * bother checking. The new entry is constructed by calling newEntry().
- *
- * Assumes key is not null.
- *
- * Note: buckets already converted to a TreeBin don't call this method, but
- * instead call TreeBin.putTreeNode() to create new entries.
- */
- void createEntry(int hash, K key, V value, int bucketIndex, boolean checkIfNeedTree) {
- // assert key != null;
- @SuppressWarnings("unchecked")
- Entry<K,V> e = (Entry<K,V>)table[bucketIndex];
- table[bucketIndex] = newEntry(hash, key, value, e);
- size++;
-
- if (checkIfNeedTree) {
- int listSize = 0;
- for (e = (Entry<K,V>) table[bucketIndex]; e != null; e = (Entry<K,V>)e.next) {
- listSize++;
- if (listSize >= TreeBin.TREE_THRESHOLD) { // Convert to TreeBin
- if (comparableClassFor(key) != null) {
- TreeBin t = new TreeBin();
- t.populate((Entry)table[bucketIndex]);
- table[bucketIndex] = t;
- }
- break;
- }
- }
- }
- }
-
- /*
- * Factory method to create a new Entry object.
- */
- Entry<K,V> newEntry(int hash, K key, V value, Object next) {
- return new HashMap.Entry<>(hash, key, value, next);
- }
-
-
- private abstract class HashIterator<E> implements Iterator<E> {
- Object next; // next entry to return, an Entry or a TreeNode
- int expectedModCount; // For fast-fail
- int index; // current slot
- Object current; // current entry, an Entry or a TreeNode
-
- HashIterator() {
- expectedModCount = modCount;
- if (size > 0) { // advance to first entry
- if (nullKeyEntry != null) {
- // assert nullKeyEntry.next == null;
- // This works with nextEntry(): nullKeyEntry isa Entry, and
- // e.next will be null, so we'll hit the findNextBin() call.
- next = nullKeyEntry;
- } else {
- findNextBin();
- }
- }
- }
-
- public final boolean hasNext() {
- return next != null;
- }
-
- @SuppressWarnings("unchecked")
- final Entry<K,V> nextEntry() {
- if (modCount != expectedModCount) {
- throw new ConcurrentModificationException();
- }
- Object e = next;
- Entry<K,V> retVal;
-
- if (e == null)
- throw new NoSuchElementException();
-
- if (e instanceof TreeNode) { // TreeBin
- retVal = (Entry<K,V>)((TreeNode)e).entry;
- next = retVal.next;
- } else {
- retVal = (Entry<K,V>)e;
- next = ((Entry<K,V>)e).next;
- }
-
- if (next == null) { // Move to next bin
- findNextBin();
- }
- current = e;
- return retVal;
- }
-
- public void remove() {
- if (current == null)
- throw new IllegalStateException();
- if (modCount != expectedModCount)
- throw new ConcurrentModificationException();
- K k;
-
- if (current instanceof Entry) {
- k = ((Entry<K,V>)current).key;
- } else {
- k = ((Entry<K,V>)((TreeNode)current).entry).key;
-
- }
- current = null;
- HashMap.this.removeEntryForKey(k);
- expectedModCount = modCount;
- }
-
- /*
- * Set 'next' to the first entry of the next non-empty bin in the table
- */
- private void findNextBin() {
- // assert next == null;
- Object[] t = table;
-
- while (index < t.length && (next = t[index++]) == null)
- ;
- if (next instanceof HashMap.TreeBin) { // Point to the first TreeNode
- next = ((TreeBin) next).first;
- // assert next != null; // There should be no empty TreeBins
- }
- }
- }
-
- private final class ValueIterator extends HashIterator<V> {
- public V next() {
- return nextEntry().value;
- }
- }
-
- private final class KeyIterator extends HashIterator<K> {
- public K next() {
- return nextEntry().getKey();
- }
- }
-
- private final class EntryIterator extends HashIterator<Map.Entry<K,V>> {
- public Map.Entry<K,V> next() {
- return nextEntry();
- }
- }
-
- // Subclass overrides these to alter behavior of views' iterator() method
- Iterator<K> newKeyIterator() {
- return new KeyIterator();
- }
- Iterator<V> newValueIterator() {
- return new ValueIterator();
- }
- Iterator<Map.Entry<K,V>> newEntryIterator() {
- return new EntryIterator();
- }
-
-
- // Views
-
- private transient Set<Map.Entry<K,V>> entrySet = null;
-
- /**
* Returns a {@link Set} view of the keys contained in this map.
* The set is backed by the map, so changes to the map are
* reflected in the set, and vice-versa. If the map is modified
@@ -2491,35 +898,38 @@
* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
* operations. It does not support the <tt>add</tt> or <tt>addAll</tt>
* operations.
+ *
+ * @return a set view of the keys contained in this map
*/
public Set<K> keySet() {
- Set<K> ks = keySet;
- return (ks != null ? ks : (keySet = new KeySet()));
+ Set<K> ks;
+ return (ks = keySet) == null ? (keySet = new KeySet()) : ks;
}
- private final class KeySet extends AbstractSet<K> {
- public Iterator<K> iterator() {
- return newKeyIterator();
+ final class KeySet extends AbstractSet<K> {
+ public final int size() { return size; }
+ public final void clear() { HashMap.this.clear(); }
+ public final Iterator<K> iterator() { return new KeyIterator(); }
+ public final boolean contains(Object o) { return containsKey(o); }
+ public final boolean remove(Object key) {
+ return removeNode(hash(key), key, null, false, true) != null;
}
- public int size() {
- return size;
- }
- public boolean contains(Object o) {
- return containsKey(o);
+ public final Spliterator<K> spliterator() {
+ return new KeySpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
}
- public boolean remove(Object o) {
- return HashMap.this.removeEntryForKey(o) != null;
- }
- public void clear() {
- HashMap.this.clear();
- }
-
- public Spliterator<K> spliterator() {
- if (HashMap.this.getClass() == HashMap.class)
- return new KeySpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
- else
- return Spliterators.spliterator
- (this, Spliterator.SIZED | Spliterator.DISTINCT);
+ public final void forEach(Consumer<? super K> action) {
+ Node<K,V>[] tab;
+ if (action == null)
+ throw new NullPointerException();
+ if (size > 0 && (tab = table) != null) {
+ int mc = modCount;
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next)
+ action.accept(e.key);
+ }
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
}
}
@@ -2535,32 +945,35 @@
* <tt>Collection.remove</tt>, <tt>removeAll</tt>,
* <tt>retainAll</tt> and <tt>clear</tt> operations. It does not
* support the <tt>add</tt> or <tt>addAll</tt> operations.
+ *
+ * @return a view of the values contained in this map
*/
public Collection<V> values() {
- Collection<V> vs = values;
- return (vs != null ? vs : (values = new Values()));
+ Collection<V> vs;
+ return (vs = values) == null ? (values = new Values()) : vs;
}
- private final class Values extends AbstractCollection<V> {
- public Iterator<V> iterator() {
- return newValueIterator();
- }
- public int size() {
- return size;
- }
- public boolean contains(Object o) {
- return containsValue(o);
+ final class Values extends AbstractCollection<V> {
+ public final int size() { return size; }
+ public final void clear() { HashMap.this.clear(); }
+ public final Iterator<V> iterator() { return new ValueIterator(); }
+ public final boolean contains(Object o) { return containsValue(o); }
+ public final Spliterator<V> spliterator() {
+ return new ValueSpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
}
- public void clear() {
- HashMap.this.clear();
- }
-
- public Spliterator<V> spliterator() {
- if (HashMap.this.getClass() == HashMap.class)
- return new ValueSpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
- else
- return Spliterators.spliterator
- (this, Spliterator.SIZED);
+ public final void forEach(Consumer<? super V> action) {
+ Node<K,V>[] tab;
+ if (action == null)
+ throw new NullPointerException();
+ if (size > 0 && (tab = table) != null) {
+ int mc = modCount;
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next)
+ action.accept(e.value);
+ }
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
}
}
@@ -2581,42 +994,324 @@
* @return a set view of the mappings contained in this map
*/
public Set<Map.Entry<K,V>> entrySet() {
- return entrySet0();
+ Set<Map.Entry<K,V>> es;
+ return (es = entrySet) == null ? (entrySet = new EntrySet()) : es;
}
- private Set<Map.Entry<K,V>> entrySet0() {
- Set<Map.Entry<K,V>> es = entrySet;
- return es != null ? es : (entrySet = new EntrySet());
- }
-
- private final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
- public Iterator<Map.Entry<K,V>> iterator() {
- return newEntryIterator();
+ final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
+ public final int size() { return size; }
+ public final void clear() { HashMap.this.clear(); }
+ public final Iterator<Map.Entry<K,V>> iterator() {
+ return new EntryIterator();
}
- public boolean contains(Object o) {
+ public final boolean contains(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry<?,?> e = (Map.Entry<?,?>) o;
- Entry<K,V> candidate = getEntry(e.getKey());
+ Object key = e.getKey();
+ Node<K,V> candidate = getNode(hash(key), key);
return candidate != null && candidate.equals(e);
}
- public boolean remove(Object o) {
- return removeMapping(o) != null;
+ public final boolean remove(Object o) {
+ if (o instanceof Map.Entry) {
+ Map.Entry<?,?> e = (Map.Entry<?,?>) o;
+ Object key = e.getKey();
+ Object value = e.getValue();
+ return removeNode(hash(key), key, value, true, true) != null;
+ }
+ return false;
+ }
+ public final Spliterator<Map.Entry<K,V>> spliterator() {
+ return new EntrySpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
+ }
+ public final void forEach(Consumer<? super Map.Entry<K,V>> action) {
+ Node<K,V>[] tab;
+ if (action == null)
+ throw new NullPointerException();
+ if (size > 0 && (tab = table) != null) {
+ int mc = modCount;
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next)
+ action.accept(e);
+ }
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+ }
+
+ // Overrides of JDK8 Map extension methods
+
+ public V getOrDefault(Object key, V defaultValue) {
+ Node<K,V> e;
+ return (e = getNode(hash(key), key)) == null ? defaultValue : e.value;
+ }
+
+ public V putIfAbsent(K key, V value) {
+ return putVal(hash(key), key, value, true, true);
+ }
+
+ public boolean remove(Object key, Object value) {
+ return removeNode(hash(key), key, value, true, true) != null;
+ }
+
+ public boolean replace(K key, V oldValue, V newValue) {
+ Node<K,V> e; V v;
+ if ((e = getNode(hash(key), key)) != null &&
+ ((v = e.value) == oldValue || (v != null && v.equals(oldValue)))) {
+ e.value = newValue;
+ afterNodeAccess(e);
+ return true;
+ }
+ return false;
+ }
+
+ public V replace(K key, V value) {
+ Node<K,V> e;
+ if ((e = getNode(hash(key), key)) != null) {
+ V oldValue = e.value;
+ e.value = value;
+ afterNodeAccess(e);
+ return oldValue;
}
- public int size() {
- return size;
+ return null;
+ }
+
+ public V computeIfAbsent(K key,
+ Function<? super K, ? extends V> mappingFunction) {
+ if (mappingFunction == null)
+ throw new NullPointerException();
+ int hash = hash(key);
+ Node<K,V>[] tab; Node<K,V> first; int n, i;
+ int binCount = 0;
+ TreeNode<K,V> t = null;
+ Node<K,V> old = null;
+ if (size > threshold || (tab = table) == null ||
+ (n = tab.length) == 0)
+ n = (tab = resize()).length;
+ if ((first = tab[i = (n - 1) & hash]) != null) {
+ if (first instanceof TreeNode)
+ old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
+ else {
+ Node<K,V> e = first; K k;
+ do {
+ if (e.hash == hash &&
+ ((k = e.key) == key || (key != null && key.equals(k)))) {
+ old = e;
+ break;
+ }
+ ++binCount;
+ } while ((e = e.next) != null);
+ }
+ V oldValue;
+ if (old != null && (oldValue = old.value) != null) {
+ afterNodeAccess(old);
+ return oldValue;
+ }
}
- public void clear() {
- HashMap.this.clear();
+ V v = mappingFunction.apply(key);
+ if (old != null) {
+ old.value = v;
+ afterNodeAccess(old);
+ return v;
+ }
+ else if (v == null)
+ return null;
+ else if (t != null)
+ t.putTreeVal(this, tab, hash, key, v);
+ else {
+ tab[i] = newNode(hash, key, v, first);
+ if (binCount >= TREEIFY_THRESHOLD - 1)
+ treeifyBin(tab, hash);
+ }
+ ++modCount;
+ ++size;
+ afterNodeInsertion(true);
+ return v;
+ }
+
+ public V computeIfPresent(K key,
+ BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+ Node<K,V> e; V oldValue;
+ int hash = hash(key);
+ if ((e = getNode(hash, key)) != null &&
+ (oldValue = e.value) != null) {
+ V v = remappingFunction.apply(key, oldValue);
+ if (v != null) {
+ e.value = v;
+ afterNodeAccess(e);
+ return v;
+ }
+ else
+ removeNode(hash, key, null, false, true);
}
+ return null;
+ }
- public Spliterator<Map.Entry<K,V>> spliterator() {
- if (HashMap.this.getClass() == HashMap.class)
- return new EntrySpliterator<K,V>(HashMap.this, 0, -1, 0, 0);
+ public V compute(K key,
+ BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
+ if (remappingFunction == null)
+ throw new NullPointerException();
+ int hash = hash(key);
+ Node<K,V>[] tab; Node<K,V> first; int n, i;
+ int binCount = 0;
+ TreeNode<K,V> t = null;
+ Node<K,V> old = null;
+ if (size > threshold || (tab = table) == null ||
+ (n = tab.length) == 0)
+ n = (tab = resize()).length;
+ if ((first = tab[i = (n - 1) & hash]) != null) {
+ if (first instanceof TreeNode)
+ old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
+ else {
+ Node<K,V> e = first; K k;
+ do {
+ if (e.hash == hash &&
+ ((k = e.key) == key || (key != null && key.equals(k)))) {
+ old = e;
+ break;
+ }
+ ++binCount;
+ } while ((e = e.next) != null);
+ }
+ }
+ V oldValue = (old == null) ? null : old.value;
+ V v = remappingFunction.apply(key, oldValue);
+ if (old != null) {
+ if (v != null) {
+ old.value = v;
+ afterNodeAccess(old);
+ }
else
- return Spliterators.spliterator
- (this, Spliterator.SIZED | Spliterator.DISTINCT);
+ removeNode(hash, key, null, false, true);
+ }
+ else if (v != null) {
+ if (t != null)
+ t.putTreeVal(this, tab, hash, key, v);
+ else {
+ tab[i] = newNode(hash, key, v, first);
+ if (binCount >= TREEIFY_THRESHOLD - 1)
+ treeifyBin(tab, hash);
+ }
+ ++modCount;
+ ++size;
+ afterNodeInsertion(true);
+ }
+ return v;
+ }
+
+ public V merge(K key, V value,
+ BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
+ if (remappingFunction == null)
+ throw new NullPointerException();
+ int hash = hash(key);
+ Node<K,V>[] tab; Node<K,V> first; int n, i;
+ int binCount = 0;
+ TreeNode<K,V> t = null;
+ Node<K,V> old = null;
+ if (size > threshold || (tab = table) == null ||
+ (n = tab.length) == 0)
+ n = (tab = resize()).length;
+ if ((first = tab[i = (n - 1) & hash]) != null) {
+ if (first instanceof TreeNode)
+ old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
+ else {
+ Node<K,V> e = first; K k;
+ do {
+ if (e.hash == hash &&
+ ((k = e.key) == key || (key != null && key.equals(k)))) {
+ old = e;
+ break;
+ }
+ ++binCount;
+ } while ((e = e.next) != null);
+ }
+ }
+ if (old != null) {
+ V v = remappingFunction.apply(old.value, value);
+ if (v != null) {
+ old.value = v;
+ afterNodeAccess(old);
+ }
+ else
+ removeNode(hash, key, null, false, true);
+ return v;
}
+ if (value != null) {
+ if (t != null)
+ t.putTreeVal(this, tab, hash, key, value);
+ else {
+ tab[i] = newNode(hash, key, value, first);
+ if (binCount >= TREEIFY_THRESHOLD - 1)
+ treeifyBin(tab, hash);
+ }
+ ++modCount;
+ ++size;
+ afterNodeInsertion(true);
+ }
+ return value;
+ }
+
+ public void forEach(BiConsumer<? super K, ? super V> action) {
+ Node<K,V>[] tab;
+ if (action == null)
+ throw new NullPointerException();
+ if (size > 0 && (tab = table) != null) {
+ int mc = modCount;
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next)
+ action.accept(e.key, e.value);
+ }
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
+ Node<K,V>[] tab;
+ if (function == null)
+ throw new NullPointerException();
+ if (size > 0 && (tab = table) != null) {
+ int mc = modCount;
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next) {
+ e.value = function.apply(e.key, e.value);
+ }
+ }
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ // Cloning and serialization
+
+ /**
+ * Returns a shallow copy of this <tt>HashMap</tt> instance: the keys and
+ * values themselves are not cloned.
+ *
+ * @return a shallow copy of this map
+ */
+ @SuppressWarnings("unchecked")
+ public Object clone() {
+ HashMap<K,V> result;
+ try {
+ result = (HashMap<K,V>)super.clone();
+ } catch (CloneNotSupportedException e) {
+ // this shouldn't happen, since we are Cloneable
+ throw new InternalError(e);
+ }
+ result.reinitialize();
+ result.putMapEntries(this, false);
+ return result;
+ }
+
+ // These methods are also used when serializing HashSets
+ final float loadFactor() { return loadFactor; }
+ final int capacity() {
+ return (table != null) ? table.length :
+ (threshold > 0) ? threshold :
+ DEFAULT_INITIAL_CAPACITY;
}
/**
@@ -2631,118 +1326,143 @@
* emitted in no particular order.
*/
private void writeObject(java.io.ObjectOutputStream s)
- throws IOException
- {
+ throws IOException {
+ int buckets = capacity();
// Write out the threshold, loadfactor, and any hidden stuff
s.defaultWriteObject();
-
- // Write out number of buckets
- if (table==EMPTY_TABLE) {
- s.writeInt(roundUpToPowerOf2(threshold));
- } else {
- s.writeInt(table.length);
- }
-
- // Write out size (number of Mappings)
+ s.writeInt(buckets);
s.writeInt(size);
-
- // Write out keys and values (alternating)
- if (size > 0) {
- for(Map.Entry<K,V> e : entrySet0()) {
- s.writeObject(e.getKey());
- s.writeObject(e.getValue());
- }
- }
+ internalWriteEntries(s);
}
- private static final long serialVersionUID = 362498820763181265L;
-
/**
* Reconstitute the {@code HashMap} instance from a stream (i.e.,
* deserialize it).
*/
private void readObject(java.io.ObjectInputStream s)
- throws IOException, ClassNotFoundException
- {
+ throws IOException, ClassNotFoundException {
// Read in the threshold (ignored), loadfactor, and any hidden stuff
s.defaultReadObject();
- if (loadFactor <= 0 || Float.isNaN(loadFactor)) {
+ reinitialize();
+ if (loadFactor <= 0 || Float.isNaN(loadFactor))
throw new InvalidObjectException("Illegal load factor: " +
- loadFactor);
- }
-
- // set other fields that need values
- if (Holder.USE_HASHSEED) {
- int seed = ThreadLocalRandom.current().nextInt();
- Holder.UNSAFE.putIntVolatile(this, Holder.HASHSEED_OFFSET,
- (seed != 0) ? seed : 1);
- }
- table = EMPTY_TABLE;
-
- // Read in number of buckets
- s.readInt(); // ignored.
-
- // Read number of mappings
- int mappings = s.readInt();
+ loadFactor);
+ s.readInt(); // Read and ignore number of buckets
+ int mappings = s.readInt(); // Read number of mappings (size)
if (mappings < 0)
throw new InvalidObjectException("Illegal mappings count: " +
- mappings);
-
- // capacity chosen by number of mappings and desired load (if >= 0.25)
- int capacity = (int) Math.min(
- mappings * Math.min(1 / loadFactor, 4.0f),
- // we have limits...
- HashMap.MAXIMUM_CAPACITY);
+ mappings);
+ else if (mappings > 0) { // (if zero, use defaults)
+ // Size the table using given load factor only if within
+ // range of 0.25...4.0
+ float lf = Math.min(Math.max(0.25f, loadFactor), 4.0f);
+ float fc = (float)mappings / lf + 1.0f;
+ int cap = ((fc < DEFAULT_INITIAL_CAPACITY) ?
+ DEFAULT_INITIAL_CAPACITY :
+ (fc >= MAXIMUM_CAPACITY) ?
+ MAXIMUM_CAPACITY :
+ tableSizeFor((int)fc));
+ float ft = (float)cap * lf;
+ threshold = ((cap < MAXIMUM_CAPACITY && ft < MAXIMUM_CAPACITY) ?
+ (int)ft : Integer.MAX_VALUE);
+ @SuppressWarnings({"rawtypes","unchecked"})
+ Node<K,V>[] tab = (Node<K,V>[])new Node[cap];
+ table = tab;
- // allocate the bucket array;
- if (mappings > 0) {
- inflateTable(capacity);
- } else {
- threshold = capacity;
- }
-
- init(); // Give subclass a chance to do its thing.
-
- // Read the keys and values, and put the mappings in the HashMap
- for (int i=0; i<mappings; i++) {
- @SuppressWarnings("unchecked")
- K key = (K) s.readObject();
- @SuppressWarnings("unchecked")
- V value = (V) s.readObject();
- putForCreate(key, value);
+ // Read the keys and values, and put the mappings in the HashMap
+ for (int i = 0; i < mappings; i++) {
+ @SuppressWarnings("unchecked")
+ K key = (K) s.readObject();
+ @SuppressWarnings("unchecked")
+ V value = (V) s.readObject();
+ putVal(hash(key), key, value, false, false);
+ }
}
}
- // These methods are used when serializing HashSets
- int capacity() { return table.length; }
- float loadFactor() { return loadFactor; }
+ /* ------------------------------------------------------------ */
+ // iterators
+
+ abstract class HashIterator {
+ Node<K,V> next; // next entry to return
+ Node<K,V> current; // current entry
+ int expectedModCount; // for fast-fail
+ int index; // current slot
+
+ HashIterator() {
+ expectedModCount = modCount;
+ Node<K,V>[] t = table;
+ current = next = null;
+ index = 0;
+ if (t != null && size > 0) { // advance to first entry
+ do {} while (index < t.length && (next = t[index++]) == null);
+ }
+ }
+
+ public final boolean hasNext() {
+ return next != null;
+ }
- /**
- * Standin until HM overhaul; based loosely on Weak and Identity HM.
- */
+ final Node<K,V> nextNode() {
+ Node<K,V>[] t;
+ Node<K,V> e = next;
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ if (e == null)
+ throw new NoSuchElementException();
+ if ((next = (current = e).next) == null && (t = table) != null) {
+ do {} while (index < t.length && (next = t[index++]) == null);
+ }
+ return e;
+ }
+
+ public final void remove() {
+ Node<K,V> p = current;
+ if (p == null)
+ throw new IllegalStateException();
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ current = null;
+ K key = p.key;
+ removeNode(hash(key), key, null, false, false);
+ expectedModCount = modCount;
+ }
+ }
+
+ final class KeyIterator extends HashIterator
+ implements Iterator<K> {
+ public final K next() { return nextNode().key; }
+ }
+
+ final class ValueIterator extends HashIterator
+ implements Iterator<V> {
+ public final V next() { return nextNode().value; }
+ }
+
+ final class EntryIterator extends HashIterator
+ implements Iterator<Map.Entry<K,V>> {
+ public final Map.Entry<K,V> next() { return nextNode(); }
+ }
+
+ /* ------------------------------------------------------------ */
+ // spliterators
+
static class HashMapSpliterator<K,V> {
final HashMap<K,V> map;
- Object current; // current node, can be Entry or TreeNode
+ Node<K,V> current; // current node
int index; // current index, modified on advance/split
int fence; // one past last index
int est; // size estimate
int expectedModCount; // for comodification checks
- boolean acceptedNull; // Have we accepted the null key?
- // Without this, we can't distinguish
- // between being at the very beginning (and
- // needing to accept null), or being at the
- // end of the list in bin 0. In both cases,
- // current == null && index == 0.
HashMapSpliterator(HashMap<K,V> m, int origin,
- int fence, int est,
- int expectedModCount) {
+ int fence, int est,
+ int expectedModCount) {
this.map = m;
this.index = origin;
this.fence = fence;
this.est = est;
this.expectedModCount = expectedModCount;
- this.acceptedNull = false;
}
final int getFence() { // initialize fence and size on first use
@@ -2751,7 +1471,8 @@
HashMap<K,V> m = map;
est = m.size;
expectedModCount = m.modCount;
- hi = fence = m.table.length;
+ Node<K,V>[] tab = m.table;
+ hi = fence = (tab == null) ? 0 : tab.length;
}
return hi;
}
@@ -2772,56 +1493,33 @@
public KeySpliterator<K,V> trySplit() {
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
- if (lo >= mid || current != null) {
- return null;
- } else {
- KeySpliterator<K,V> retVal = new KeySpliterator<K,V>(map, lo,
- index = mid, est >>>= 1, expectedModCount);
- // Only 'this' Spliterator chould check for null.
- retVal.acceptedNull = true;
- return retVal;
- }
+ return (lo >= mid || current != null) ? null :
+ new KeySpliterator<K,V>(map, lo, index = mid, est >>>= 1,
+ expectedModCount);
}
- @SuppressWarnings("unchecked")
public void forEachRemaining(Consumer<? super K> action) {
int i, hi, mc;
if (action == null)
throw new NullPointerException();
HashMap<K,V> m = map;
- Object[] tab = m.table;
+ Node<K,V>[] tab = m.table;
if ((hi = fence) < 0) {
mc = expectedModCount = m.modCount;
- hi = fence = tab.length;
+ hi = fence = (tab == null) ? 0 : tab.length;
}
else
mc = expectedModCount;
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (m.nullKeyEntry != null) {
- action.accept(m.nullKeyEntry.key);
- }
- }
- if (tab.length >= hi && (i = index) >= 0 &&
- (i < (index = hi) || current != null)) {
- Object p = current;
+ if (tab != null && tab.length >= hi &&
+ (i = index) >= 0 && (i < (index = hi) || current != null)) {
+ Node<K,V> p = current;
current = null;
do {
- if (p == null) {
+ if (p == null)
p = tab[i++];
- if (p instanceof HashMap.TreeBin) {
- p = ((HashMap.TreeBin)p).first;
- }
- } else {
- HashMap.Entry<K,V> entry;
- if (p instanceof HashMap.Entry) {
- entry = (HashMap.Entry<K,V>)p;
- } else {
- entry = (HashMap.Entry<K,V>)((TreeNode)p).entry;
- }
- action.accept(entry.key);
- p = entry.next;
+ else {
+ action.accept(p.key);
+ p = p.next;
}
} while (p != null || i < hi);
if (m.modCount != mc)
@@ -2829,39 +1527,18 @@
}
}
- @SuppressWarnings("unchecked")
public boolean tryAdvance(Consumer<? super K> action) {
int hi;
if (action == null)
throw new NullPointerException();
- Object[] tab = map.table;
- hi = getFence();
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (map.nullKeyEntry != null) {
- action.accept(map.nullKeyEntry.key);
- if (map.modCount != expectedModCount)
- throw new ConcurrentModificationException();
- return true;
- }
- }
- if (tab.length >= hi && index >= 0) {
+ Node<K,V>[] tab = map.table;
+ if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
while (current != null || index < hi) {
- if (current == null) {
+ if (current == null)
current = tab[index++];
- if (current instanceof HashMap.TreeBin) {
- current = ((HashMap.TreeBin)current).first;
- }
- } else {
- HashMap.Entry<K,V> entry;
- if (current instanceof HashMap.Entry) {
- entry = (HashMap.Entry<K,V>)current;
- } else {
- entry = (HashMap.Entry<K,V>)((TreeNode)current).entry;
- }
- K k = entry.key;
- current = entry.next;
+ else {
+ K k = current.key;
+ current = current.next;
action.accept(k);
if (map.modCount != expectedModCount)
throw new ConcurrentModificationException();
@@ -2888,56 +1565,33 @@
public ValueSpliterator<K,V> trySplit() {
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
- if (lo >= mid || current != null) {
- return null;
- } else {
- ValueSpliterator<K,V> retVal = new ValueSpliterator<K,V>(map,
- lo, index = mid, est >>>= 1, expectedModCount);
- // Only 'this' Spliterator chould check for null.
- retVal.acceptedNull = true;
- return retVal;
- }
+ return (lo >= mid || current != null) ? null :
+ new ValueSpliterator<K,V>(map, lo, index = mid, est >>>= 1,
+ expectedModCount);
}
- @SuppressWarnings("unchecked")
public void forEachRemaining(Consumer<? super V> action) {
int i, hi, mc;
if (action == null)
throw new NullPointerException();
HashMap<K,V> m = map;
- Object[] tab = m.table;
+ Node<K,V>[] tab = m.table;
if ((hi = fence) < 0) {
mc = expectedModCount = m.modCount;
- hi = fence = tab.length;
+ hi = fence = (tab == null) ? 0 : tab.length;
}
else
mc = expectedModCount;
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (m.nullKeyEntry != null) {
- action.accept(m.nullKeyEntry.value);
- }
- }
- if (tab.length >= hi && (i = index) >= 0 &&
- (i < (index = hi) || current != null)) {
- Object p = current;
+ if (tab != null && tab.length >= hi &&
+ (i = index) >= 0 && (i < (index = hi) || current != null)) {
+ Node<K,V> p = current;
current = null;
do {
- if (p == null) {
+ if (p == null)
p = tab[i++];
- if (p instanceof HashMap.TreeBin) {
- p = ((HashMap.TreeBin)p).first;
- }
- } else {
- HashMap.Entry<K,V> entry;
- if (p instanceof HashMap.Entry) {
- entry = (HashMap.Entry<K,V>)p;
- } else {
- entry = (HashMap.Entry<K,V>)((TreeNode)p).entry;
- }
- action.accept(entry.value);
- p = entry.next;
+ else {
+ action.accept(p.value);
+ p = p.next;
}
} while (p != null || i < hi);
if (m.modCount != mc)
@@ -2945,39 +1599,18 @@
}
}
- @SuppressWarnings("unchecked")
public boolean tryAdvance(Consumer<? super V> action) {
int hi;
if (action == null)
throw new NullPointerException();
- Object[] tab = map.table;
- hi = getFence();
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (map.nullKeyEntry != null) {
- action.accept(map.nullKeyEntry.value);
- if (map.modCount != expectedModCount)
- throw new ConcurrentModificationException();
- return true;
- }
- }
- if (tab.length >= hi && index >= 0) {
+ Node<K,V>[] tab = map.table;
+ if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
while (current != null || index < hi) {
- if (current == null) {
+ if (current == null)
current = tab[index++];
- if (current instanceof HashMap.TreeBin) {
- current = ((HashMap.TreeBin)current).first;
- }
- } else {
- HashMap.Entry<K,V> entry;
- if (current instanceof HashMap.Entry) {
- entry = (Entry<K,V>)current;
- } else {
- entry = (Entry<K,V>)((TreeNode)current).entry;
- }
- V v = entry.value;
- current = entry.next;
+ else {
+ V v = current.value;
+ current = current.next;
action.accept(v);
if (map.modCount != expectedModCount)
throw new ConcurrentModificationException();
@@ -3003,57 +1636,33 @@
public EntrySpliterator<K,V> trySplit() {
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
- if (lo >= mid || current != null) {
- return null;
- } else {
- EntrySpliterator<K,V> retVal = new EntrySpliterator<K,V>(map,
- lo, index = mid, est >>>= 1, expectedModCount);
- // Only 'this' Spliterator chould check for null.
- retVal.acceptedNull = true;
- return retVal;
- }
+ return (lo >= mid || current != null) ? null :
+ new EntrySpliterator<K,V>(map, lo, index = mid, est >>>= 1,
+ expectedModCount);
}
- @SuppressWarnings("unchecked")
public void forEachRemaining(Consumer<? super Map.Entry<K,V>> action) {
int i, hi, mc;
if (action == null)
throw new NullPointerException();
HashMap<K,V> m = map;
- Object[] tab = m.table;
+ Node<K,V>[] tab = m.table;
if ((hi = fence) < 0) {
mc = expectedModCount = m.modCount;
- hi = fence = tab.length;
+ hi = fence = (tab == null) ? 0 : tab.length;
}
else
mc = expectedModCount;
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (m.nullKeyEntry != null) {
- action.accept(m.nullKeyEntry);
- }
- }
- if (tab.length >= hi && (i = index) >= 0 &&
- (i < (index = hi) || current != null)) {
- Object p = current;
+ if (tab != null && tab.length >= hi &&
+ (i = index) >= 0 && (i < (index = hi) || current != null)) {
+ Node<K,V> p = current;
current = null;
do {
- if (p == null) {
+ if (p == null)
p = tab[i++];
- if (p instanceof HashMap.TreeBin) {
- p = ((HashMap.TreeBin)p).first;
- }
- } else {
- HashMap.Entry<K,V> entry;
- if (p instanceof HashMap.Entry) {
- entry = (HashMap.Entry<K,V>)p;
- } else {
- entry = (HashMap.Entry<K,V>)((TreeNode)p).entry;
- }
- action.accept(entry);
- p = entry.next;
-
+ else {
+ action.accept(p);
+ p = p.next;
}
} while (p != null || i < hi);
if (m.modCount != mc)
@@ -3061,38 +1670,18 @@
}
}
- @SuppressWarnings("unchecked")
public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
int hi;
if (action == null)
throw new NullPointerException();
- Object[] tab = map.table;
- hi = getFence();
-
- if (!acceptedNull) {
- acceptedNull = true;
- if (map.nullKeyEntry != null) {
- action.accept(map.nullKeyEntry);
- if (map.modCount != expectedModCount)
- throw new ConcurrentModificationException();
- return true;
- }
- }
- if (tab.length >= hi && index >= 0) {
+ Node<K,V>[] tab = map.table;
+ if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
while (current != null || index < hi) {
- if (current == null) {
+ if (current == null)
current = tab[index++];
- if (current instanceof HashMap.TreeBin) {
- current = ((HashMap.TreeBin)current).first;
- }
- } else {
- HashMap.Entry<K,V> e;
- if (current instanceof HashMap.Entry) {
- e = (Entry<K,V>)current;
- } else {
- e = (Entry<K,V>)((TreeNode)current).entry;
- }
- current = e.next;
+ else {
+ Node<K,V> e = current;
+ current = current.next;
action.accept(e);
if (map.modCount != expectedModCount)
throw new ConcurrentModificationException();
@@ -3108,4 +1697,664 @@
Spliterator.DISTINCT;
}
}
+
+ /* ------------------------------------------------------------ */
+ // LinkedHashMap support
+
+
+ /*
+ * The following package-protected methods are designed to be
+ * overridden by LinkedHashMap, but not by any other subclass.
+ * Nearly all other internal methods are also package-protected
+ * but are declared final, so can be used by LinkedHashMap, view
+ * classes, and HashSet.
+ */
+
+ // Create a regular (non-tree) node
+ Node<K,V> newNode(int hash, K key, V value, Node<K,V> next) {
+ return new Node<K,V>(hash, key, value, next);
+ }
+
+ // For conversion from TreeNodes to plain nodes
+ Node<K,V> replacementNode(Node<K,V> p, Node<K,V> next) {
+ return new Node<K,V>(p.hash, p.key, p.value, next);
+ }
+
+ // Create a tree bin node
+ TreeNode<K,V> newTreeNode(int hash, K key, V value, Node<K,V> next) {
+ return new TreeNode<K,V>(hash, key, value, next);
+ }
+
+ // For treeifyBin
+ TreeNode<K,V> replacementTreeNode(Node<K,V> p, Node<K,V> next) {
+ return new TreeNode<K,V>(p.hash, p.key, p.value, next);
+ }
+
+ /**
+ * Reset to initial default state. Called by clone and readObject.
+ */
+ void reinitialize() {
+ table = null;
+ entrySet = null;
+ keySet = null;
+ values = null;
+ modCount = 0;
+ threshold = 0;
+ size = 0;
+ }
+
+ // Callbacks to allow LinkedHashMap post-actions
+ void afterNodeAccess(Node<K,V> p) { }
+ void afterNodeInsertion(boolean evict) { }
+ void afterNodeRemoval(Node<K,V> p) { }
+
+ // Called only from writeObject, to ensure compatible ordering.
+ void internalWriteEntries(java.io.ObjectOutputStream s) throws IOException {
+ Node<K,V>[] tab;
+ if (size > 0 && (tab = table) != null) {
+ for (int i = 0; i < tab.length; ++i) {
+ for (Node<K,V> e = tab[i]; e != null; e = e.next) {
+ s.writeObject(e.key);
+ s.writeObject(e.value);
+ }
+ }
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ // Tree bins
+
+ /**
+ * Entry for Tree bins. Extends LinkedHashMap.Entry (which in turn
+ * extends Node) so can be used as extension of either regular or
+ * linked node.
+ */
+ static final class TreeNode<K,V> extends LinkedHashMap.Entry<K,V> {
+ TreeNode<K,V> parent; // red-black tree links
+ TreeNode<K,V> left;
+ TreeNode<K,V> right;
+ TreeNode<K,V> prev; // needed to unlink next upon deletion
+ boolean red;
+ TreeNode(int hash, K key, V val, Node<K,V> next) {
+ super(hash, key, val, next);
+ }
+
+ /**
+ * Returns root of tree containing this node.
+ */
+ final TreeNode<K,V> root() {
+ for (TreeNode<K,V> r = this, p;;) {
+ if ((p = r.parent) == null)
+ return r;
+ r = p;
+ }
+ }
+
+ /**
+ * Ensures that the given root is the first node of its bin.
+ */
+ static <K,V> void moveRootToFront(Node<K,V>[] tab, TreeNode<K,V> root) {
+ int n;
+ if (root != null && tab != null && (n = tab.length) > 0) {
+ int index = (n - 1) & root.hash;
+ TreeNode<K,V> first = (TreeNode<K,V>)tab[index];
+ if (root != first) {
+ Node<K,V> rn;
+ tab[index] = root;
+ TreeNode<K,V> rp = root.prev;
+ if ((rn = root.next) != null)
+ ((TreeNode<K,V>)rn).prev = rp;
+ if (rp != null)
+ rp.next = rn;
+ if (first != null)
+ first.prev = root;
+ root.next = first;
+ root.prev = null;
+ }
+ assert checkInvariants(root);
+ }
+ }
+
+ /**
+ * Finds the node starting at root p with the given hash and key.
+ * The kc argument caches comparableClassFor(key) upon first use
+ * comparing keys.
+ */
+ final TreeNode<K,V> find(int h, Object k, Class<?> kc) {
+ TreeNode<K,V> p = this;
+ do {
+ int ph, dir; K pk;
+ TreeNode<K,V> pl = p.left, pr = p.right, q;
+ if ((ph = p.hash) > h)
+ p = pl;
+ else if (ph < h)
+ p = pr;
+ else if ((pk = p.key) == k || (k != null && k.equals(pk)))
+ return p;
+ else if (pl == null)
+ p = pr;
+ else if (pr == null)
+ p = pl;
+ else if ((kc != null ||
+ (kc = comparableClassFor(k)) != null) &&
+ (dir = compareComparables(kc, k, pk)) != 0)
+ p = (dir < 0) ? pl : pr;
+ else if ((q = pr.find(h, k, kc)) != null)
+ return q;
+ else
+ p = pl;
+ } while (p != null);
+ return null;
+ }
+
+ /**
+ * Calls find for root node.
+ */
+ final TreeNode<K,V> getTreeNode(int h, Object k) {
+ return ((parent != null) ? root() : this).find(h, k, null);
+ }
+
+ /**
+ * Tie-breaking utility for ordering insertions when equal
+ * hashCodes and non-comparable. We don't require a total
+ * order, just a consistent insertion rule to maintain
+ * equivalence across rebalancings. Tie-breaking further than
+ * necessary simplifies testing a bit.
+ */
+ static int tieBreakOrder(Object a, Object b) {
+ int d;
+ if (a == null || b == null ||
+ (d = a.getClass().getName().
+ compareTo(b.getClass().getName())) == 0)
+ d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
+ -1 : 1);
+ return d;
+ }
+
+ /**
+ * Forms tree of the nodes linked from this node.
+ * @return root of tree
+ */
+ final void treeify(Node<K,V>[] tab) {
+ TreeNode<K,V> root = null;
+ for (TreeNode<K,V> x = this, next; x != null; x = next) {
+ next = (TreeNode<K,V>)x.next;
+ x.left = x.right = null;
+ if (root == null) {
+ x.parent = null;
+ x.red = false;
+ root = x;
+ }
+ else {
+ K k = x.key;
+ int h = x.hash;
+ Class<?> kc = null;
+ for (TreeNode<K,V> p = root;;) {
+ int dir, ph;
+ K pk = p.key;
+ if ((ph = p.hash) > h)
+ dir = -1;
+ else if (ph < h)
+ dir = 1;
+ else if ((kc == null &&
+ (kc = comparableClassFor(k)) == null) ||
+ (dir = compareComparables(kc, k, pk)) == 0)
+ dir = tieBreakOrder(k, pk);
+
+ TreeNode<K,V> xp = p;
+ if ((p = (dir <= 0) ? p.left : p.right) == null) {
+ x.parent = xp;
+ if (dir <= 0)
+ xp.left = x;
+ else
+ xp.right = x;
+ root = balanceInsertion(root, x);
+ break;
+ }
+ }
+ }
+ }
+ moveRootToFront(tab, root);
+ }
+
+ /**
+ * Returns a list of non-TreeNodes replacing those linked from
+ * this node.
+ */
+ final Node<K,V> untreeify(HashMap<K,V> map) {
+ Node<K,V> hd = null, tl = null;
+ for (Node<K,V> q = this; q != null; q = q.next) {
+ Node<K,V> p = map.replacementNode(q, null);
+ if (tl == null)
+ hd = p;
+ else
+ tl.next = p;
+ tl = p;
+ }
+ return hd;
+ }
+
+ /**
+ * Tree version of putVal.
+ */
+ final TreeNode<K,V> putTreeVal(HashMap<K,V> map, Node<K,V>[] tab,
+ int h, K k, V v) {
+ Class<?> kc = null;
+ boolean searched = false;
+ TreeNode<K,V> root = (parent != null) ? root() : this;
+ for (TreeNode<K,V> p = root;;) {
+ int dir, ph; K pk;
+ if ((ph = p.hash) > h)
+ dir = -1;
+ else if (ph < h)
+ dir = 1;
+ else if ((pk = p.key) == k || (pk != null && k.equals(pk)))
+ return p;
+ else if ((kc == null &&
+ (kc = comparableClassFor(k)) == null) ||
+ (dir = compareComparables(kc, k, pk)) == 0) {
+ if (!searched) {
+ TreeNode<K,V> q, ch;
+ searched = true;
+ if (((ch = p.left) != null &&
+ (q = ch.find(h, k, kc)) != null) ||
+ ((ch = p.right) != null &&
+ (q = ch.find(h, k, kc)) != null))
+ return q;
+ }
+ dir = tieBreakOrder(k, pk);
+ }
+
+ TreeNode<K,V> xp = p;
+ if ((p = (dir <= 0) ? p.left : p.right) == null) {
+ Node<K,V> xpn = xp.next;
+ TreeNode<K,V> x = map.newTreeNode(h, k, v, xpn);
+ if (dir <= 0)
+ xp.left = x;
+ else
+ xp.right = x;
+ xp.next = x;
+ x.parent = x.prev = xp;
+ if (xpn != null)
+ ((TreeNode<K,V>)xpn).prev = x;
+ moveRootToFront(tab, balanceInsertion(root, x));
+ return null;
+ }
+ }
+ }
+
+ /**
+ * Removes the given node, that must be present before this call.
+ * This is messier than typical red-black deletion code because we
+ * cannot swap the contents of an interior node with a leaf
+ * successor that is pinned by "next" pointers that are accessible
+ * independently during traversal. So instead we swap the tree
+ * linkages. If the current tree appears to have too few nodes,
+ * the bin is converted back to a plain bin. (The test triggers
+ * somewhere between 2 and 6 nodes, depending on tree structure).
+ */
+ final void removeTreeNode(HashMap<K,V> map, Node<K,V>[] tab,
+ boolean movable) {
+ int n;
+ if (tab == null || (n = tab.length) == 0)
+ return;
+ int index = (n - 1) & hash;
+ TreeNode<K,V> first = (TreeNode<K,V>)tab[index], root = first, rl;
+ TreeNode<K,V> succ = (TreeNode<K,V>)next, pred = prev;
+ if (pred == null)
+ tab[index] = first = succ;
+ else
+ pred.next = succ;
+ if (succ != null)
+ succ.prev = pred;
+ if (first == null)
+ return;
+ if (root.parent != null)
+ root = root.root();
+ if (root == null || root.right == null ||
+ (rl = root.left) == null || rl.left == null) {
+ tab[index] = first.untreeify(map); // too small
+ return;
+ }
+ TreeNode<K,V> p = this, pl = left, pr = right, replacement;
+ if (pl != null && pr != null) {
+ TreeNode<K,V> s = pr, sl;
+ while ((sl = s.left) != null) // find successor
+ s = sl;
+ boolean c = s.red; s.red = p.red; p.red = c; // swap colors
+ TreeNode<K,V> sr = s.right;
+ TreeNode<K,V> pp = p.parent;
+ if (s == pr) { // p was s's direct parent
+ p.parent = s;
+ s.right = p;
+ }
+ else {
+ TreeNode<K,V> sp = s.parent;
+ if ((p.parent = sp) != null) {
+ if (s == sp.left)
+ sp.left = p;
+ else
+ sp.right = p;
+ }
+ if ((s.right = pr) != null)
+ pr.parent = s;
+ }
+ p.left = null;
+ if ((p.right = sr) != null)
+ sr.parent = p;
+ if ((s.left = pl) != null)
+ pl.parent = s;
+ if ((s.parent = pp) == null)
+ root = s;
+ else if (p == pp.left)
+ pp.left = s;
+ else
+ pp.right = s;
+ if (sr != null)
+ replacement = sr;
+ else
+ replacement = p;
+ }
+ else if (pl != null)
+ replacement = pl;
+ else if (pr != null)
+ replacement = pr;
+ else
+ replacement = p;
+ if (replacement != p) {
+ TreeNode<K,V> pp = replacement.parent = p.parent;
+ if (pp == null)
+ root = replacement;
+ else if (p == pp.left)
+ pp.left = replacement;
+ else
+ pp.right = replacement;
+ p.left = p.right = p.parent = null;
+ }
+
+ TreeNode<K,V> r = p.red ? root : balanceDeletion(root, replacement);
+
+ if (replacement == p) { // detach
+ TreeNode<K,V> pp = p.parent;
+ p.parent = null;
+ if (pp != null) {
+ if (p == pp.left)
+ pp.left = null;
+ else if (p == pp.right)
+ pp.right = null;
+ }
+ }
+ if (movable)
+ moveRootToFront(tab, r);
+ }
+
+ /**
+ * Splits nodes in a tree bin into lower and upper tree bins,
+ * or untreeifies if now too small. Called only from resize;
+ * see above discussion about split bits and indices.
+ *
+ * @param map the map
+ * @param tab the table for recording bin heads
+ * @param index the index of the table being split
+ * @param bit the bit of hash to split on
+ */
+ final void split(HashMap<K,V> map, Node<K,V>[] tab, int index, int bit) {
+ TreeNode<K,V> b = this;
+ // Relink into lo and hi lists, preserving order
+ TreeNode<K,V> loHead = null, loTail = null;
+ TreeNode<K,V> hiHead = null, hiTail = null;
+ int lc = 0, hc = 0;
+ for (TreeNode<K,V> e = b, next; e != null; e = next) {
+ next = (TreeNode<K,V>)e.next;
+ e.next = null;
+ if ((e.hash & bit) == 0) {
+ if ((e.prev = loTail) == null)
+ loHead = e;
+ else
+ loTail.next = e;
+ loTail = e;
+ ++lc;
+ }
+ else {
+ if ((e.prev = hiTail) == null)
+ hiHead = e;
+ else
+ hiTail.next = e;
+ hiTail = e;
+ ++hc;
+ }
+ }
+
+ if (loHead != null) {
+ if (lc <= UNTREEIFY_THRESHOLD)
+ tab[index] = loHead.untreeify(map);
+ else {
+ tab[index] = loHead;
+ if (hiHead != null) // (else is already treeified)
+ loHead.treeify(tab);
+ }
+ }
+ if (hiHead != null) {
+ if (hc <= UNTREEIFY_THRESHOLD)
+ tab[index + bit] = hiHead.untreeify(map);
+ else {
+ tab[index + bit] = hiHead;
+ if (loHead != null)
+ hiHead.treeify(tab);
+ }
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ // Red-black tree methods, all adapted from CLR
+
+ static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
+ TreeNode<K,V> p) {
+ TreeNode<K,V> r, pp, rl;
+ if (p != null && (r = p.right) != null) {
+ if ((rl = p.right = r.left) != null)
+ rl.parent = p;
+ if ((pp = r.parent = p.parent) == null)
+ (root = r).red = false;
+ else if (pp.left == p)
+ pp.left = r;
+ else
+ pp.right = r;
+ r.left = p;
+ p.parent = r;
+ }
+ return root;
+ }
+
+ static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
+ TreeNode<K,V> p) {
+ TreeNode<K,V> l, pp, lr;
+ if (p != null && (l = p.left) != null) {
+ if ((lr = p.left = l.right) != null)
+ lr.parent = p;
+ if ((pp = l.parent = p.parent) == null)
+ (root = l).red = false;
+ else if (pp.right == p)
+ pp.right = l;
+ else
+ pp.left = l;
+ l.right = p;
+ p.parent = l;
+ }
+ return root;
+ }
+
+ static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
+ TreeNode<K,V> x) {
+ x.red = true;
+ for (TreeNode<K,V> xp, xpp, xppl, xppr;;) {
+ if ((xp = x.parent) == null) {
+ x.red = false;
+ return x;
+ }
+ else if (!xp.red || (xpp = xp.parent) == null)
+ return root;
+ if (xp == (xppl = xpp.left)) {
+ if ((xppr = xpp.right) != null && xppr.red) {
+ xppr.red = false;
+ xp.red = false;
+ xpp.red = true;
+ x = xpp;
+ }
+ else {
+ if (x == xp.right) {
+ root = rotateLeft(root, x = xp);
+ xpp = (xp = x.parent) == null ? null : xp.parent;
+ }
+ if (xp != null) {
+ xp.red = false;
+ if (xpp != null) {
+ xpp.red = true;
+ root = rotateRight(root, xpp);
+ }
+ }
+ }
+ }
+ else {
+ if (xppl != null && xppl.red) {
+ xppl.red = false;
+ xp.red = false;
+ xpp.red = true;
+ x = xpp;
+ }
+ else {
+ if (x == xp.left) {
+ root = rotateRight(root, x = xp);
+ xpp = (xp = x.parent) == null ? null : xp.parent;
+ }
+ if (xp != null) {
+ xp.red = false;
+ if (xpp != null) {
+ xpp.red = true;
+ root = rotateLeft(root, xpp);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
+ TreeNode<K,V> x) {
+ for (TreeNode<K,V> xp, xpl, xpr;;) {
+ if (x == null || x == root)
+ return root;
+ else if ((xp = x.parent) == null) {
+ x.red = false;
+ return x;
+ }
+ else if (x.red) {
+ x.red = false;
+ return root;
+ }
+ else if ((xpl = xp.left) == x) {
+ if ((xpr = xp.right) != null && xpr.red) {
+ xpr.red = false;
+ xp.red = true;
+ root = rotateLeft(root, xp);
+ xpr = (xp = x.parent) == null ? null : xp.right;
+ }
+ if (xpr == null)
+ x = xp;
+ else {
+ TreeNode<K,V> sl = xpr.left, sr = xpr.right;
+ if ((sr == null || !sr.red) &&
+ (sl == null || !sl.red)) {
+ xpr.red = true;
+ x = xp;
+ }
+ else {
+ if (sr == null || !sr.red) {
+ if (sl != null)
+ sl.red = false;
+ xpr.red = true;
+ root = rotateRight(root, xpr);
+ xpr = (xp = x.parent) == null ?
+ null : xp.right;
+ }
+ if (xpr != null) {
+ xpr.red = (xp == null) ? false : xp.red;
+ if ((sr = xpr.right) != null)
+ sr.red = false;
+ }
+ if (xp != null) {
+ xp.red = false;
+ root = rotateLeft(root, xp);
+ }
+ x = root;
+ }
+ }
+ }
+ else { // symmetric
+ if (xpl != null && xpl.red) {
+ xpl.red = false;
+ xp.red = true;
+ root = rotateRight(root, xp);
+ xpl = (xp = x.parent) == null ? null : xp.left;
+ }
+ if (xpl == null)
+ x = xp;
+ else {
+ TreeNode<K,V> sl = xpl.left, sr = xpl.right;
+ if ((sl == null || !sl.red) &&
+ (sr == null || !sr.red)) {
+ xpl.red = true;
+ x = xp;
+ }
+ else {
+ if (sl == null || !sl.red) {
+ if (sr != null)
+ sr.red = false;
+ xpl.red = true;
+ root = rotateLeft(root, xpl);
+ xpl = (xp = x.parent) == null ?
+ null : xp.left;
+ }
+ if (xpl != null) {
+ xpl.red = (xp == null) ? false : xp.red;
+ if ((sl = xpl.left) != null)
+ sl.red = false;
+ }
+ if (xp != null) {
+ xp.red = false;
+ root = rotateRight(root, xp);
+ }
+ x = root;
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Recursive invariant check
+ */
+ static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
+ TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
+ tb = t.prev, tn = (TreeNode<K,V>)t.next;
+ if (tb != null && tb.next != t)
+ return false;
+ if (tn != null && tn.prev != t)
+ return false;
+ if (tp != null && t != tp.left && t != tp.right)
+ return false;
+ if (tl != null && (tl.parent != t || tl.hash > t.hash))
+ return false;
+ if (tr != null && (tr.parent != t || tr.hash < t.hash))
+ return false;
+ if (t.red && tl != null && tl.red && tr != null && tr.red)
+ return false;
+ if (tl != null && !checkInvariants(tl))
+ return false;
+ if (tr != null && !checkInvariants(tr))
+ return false;
+ return true;
+ }
+ }
+
}
--- a/jdk/src/share/classes/java/util/LinkedHashMap.java Mon Aug 12 12:22:10 2013 +0200
+++ b/jdk/src/share/classes/java/util/LinkedHashMap.java Wed Sep 04 09:34:25 2013 +0200
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -24,9 +24,12 @@
*/
package java.util;
-import java.io.*;
+
+import java.util.function.Consumer;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
+import java.io.Serializable;
+import java.io.IOException;
/**
* <p>Hash table and linked list implementation of the <tt>Map</tt> interface,
@@ -57,9 +60,9 @@
* order they were presented.)
*
* <p>A special {@link #LinkedHashMap(int,float,boolean) constructor} is
- * provided to create a <tt>LinkedHashMap</tt> whose order of iteration is the
- * order in which its entries were last accessed, from least-recently accessed
- * to most-recently (<i>access-order</i>). This kind of map is well-suited to
+ * provided to create a linked hash map whose order of iteration is the order
+ * in which its entries were last accessed, from least-recently accessed to
+ * most-recently (<i>access-order</i>). This kind of map is well-suited to
* building LRU caches. Invoking the <tt>put</tt> or <tt>get</tt> method
* results in an access to the corresponding entry (assuming it exists after
* the invocation completes). The <tt>putAll</tt> method generates one entry
@@ -155,18 +158,53 @@
* @see Hashtable
* @since 1.4
*/
-
public class LinkedHashMap<K,V>
extends HashMap<K,V>
implements Map<K,V>
{
+ /*
+ * Implementation note. A previous version of this class was
+ * internally structured a little differently. Because superclass
+ * HashMap now uses trees for some of its nodes, class
+ * LinkedHashMap.Entry is now treated as intermediary node class
+ * that can also be converted to tree form. The name of this
+ * class, LinkedHashMap.Entry, is confusing in several ways in its
+ * current context, but cannot be changed. Otherwise, even though
+ * it is not exported outside this package, some existing source
+ * code is known to have relied on a symbol resolution corner case
+ * rule in calls to removeEldestEntry that suppressed compilation
+ * errors due to ambiguous usages. So, we keep the name to
+ * preserve unmodified compilability.
+ *
+ * The changes in node classes also require using two fields
+ * (head, tail) rather than a pointer to a header node to maintain
+ * the doubly-linked before/after list. This class also
+ * previously used a different style of callback methods upon
+ * access, insertion, and removal.
+ */
+
+ /**
+ * HashMap.Node subclass for normal LinkedHashMap entries.
+ */
+ static class Entry<K,V> extends HashMap.Node<K,V> {
+ Entry<K,V> before, after;
+ Entry(int hash, K key, V value, Node<K,V> next) {
+ super(hash, key, value, next);
+ }
+ }
+
private static final long serialVersionUID = 3801124242820219131L;
/**
- * The head of the doubly linked list.
+ * The head (eldest) of the doubly linked list.
*/
- private transient Entry<K,V> header;
+ transient LinkedHashMap.Entry<K,V> head;
+
+ /**
+ * The tail (youngest) of the doubly linked list.
+ */
+ transient LinkedHashMap.Entry<K,V> tail;
/**
* The iteration ordering method for this linked hash map: <tt>true</tt>
@@ -174,7 +212,125 @@
*
* @serial
*/
- private final boolean accessOrder;
+ final boolean accessOrder;
+
+ // internal utilities
+
+ // link at the end of list
+ private void linkNodeLast(LinkedHashMap.Entry<K,V> p) {
+ LinkedHashMap.Entry<K,V> last = tail;
+ tail = p;
+ if (last == null)
+ head = p;
+ else {
+ p.before = last;
+ last.after = p;
+ }
+ }
+
+ // apply src's links to dst
+ private void transferLinks(LinkedHashMap.Entry<K,V> src,
+ LinkedHashMap.Entry<K,V> dst) {
+ LinkedHashMap.Entry<K,V> b = dst.before = src.before;
+ LinkedHashMap.Entry<K,V> a = dst.after = src.after;
+ if (b == null)
+ head = dst;
+ else
+ b.after = dst;
+ if (a == null)
+ tail = dst;
+ else
+ a.before = dst;
+ }
+
+ // overrides of HashMap hook methods
+
+ void reinitialize() {
+ super.reinitialize();
+ head = tail = null;
+ }
+
+ Node<K,V> newNode(int hash, K key, V value, Node<K,V> e) {
+ LinkedHashMap.Entry<K,V> p =
+ new LinkedHashMap.Entry<K,V>(hash, key, value, e);
+ linkNodeLast(p);
+ return p;
+ }
+
+ Node<K,V> replacementNode(Node<K,V> p, Node<K,V> next) {
+ LinkedHashMap.Entry<K,V> q = (LinkedHashMap.Entry<K,V>)p;
+ LinkedHashMap.Entry<K,V> t =
+ new LinkedHashMap.Entry<K,V>(q.hash, q.key, q.value, next);
+ transferLinks(q, t);
+ return t;
+ }
+
+ TreeNode<K,V> newTreeNode(int hash, K key, V value, Node<K,V> next) {
+ TreeNode<K,V> p = new TreeNode<K,V>(hash, key, value, next);
+ linkNodeLast(p);
+ return p;
+ }
+
+ TreeNode<K,V> replacementTreeNode(Node<K,V> p, Node<K,V> next) {
+ LinkedHashMap.Entry<K,V> q = (LinkedHashMap.Entry<K,V>)p;
+ TreeNode<K,V> t = new TreeNode<K,V>(q.hash, q.key, q.value, next);
+ transferLinks(q, t);
+ return t;
+ }
+
+ void afterNodeRemoval(Node<K,V> e) { // unlink
+ LinkedHashMap.Entry<K,V> p =
+ (LinkedHashMap.Entry<K,V>)e, b = p.before, a = p.after;
+ p.before = p.after = null;
+ if (b == null)
+ head = a;
+ else
+ b.after = a;
+ if (a == null)
+ tail = b;
+ else
+ a.before = b;
+ }
+
+ void afterNodeInsertion(boolean evict) { // possibly remove eldest
+ LinkedHashMap.Entry<K,V> first;
+ if (evict && (first = head) != null && removeEldestEntry(first)) {
+ K key = first.key;
+ removeNode(hash(key), key, null, false, true);
+ }
+ }
+
+ void afterNodeAccess(Node<K,V> e) { // move node to last
+ LinkedHashMap.Entry<K,V> last;
+ if (accessOrder && (last = tail) != e) {
+ LinkedHashMap.Entry<K,V> p =
+ (LinkedHashMap.Entry<K,V>)e, b = p.before, a = p.after;
+ p.after = null;
+ if (b == null)
+ head = a;
+ else
+ b.after = a;
+ if (a != null)
+ a.before = b;
+ else
+ last = b;
+ if (last == null)
+ head = p;
+ else {
+ p.before = last;
+ last.after = p;
+ }
+ tail = p;
+ ++modCount;
+ }
+ }
+
+ void internalWriteEntries(java.io.ObjectOutputStream s) throws IOException {
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after) {
+ s.writeObject(e.key);
+ s.writeObject(e.value);
+ }
+ }
/**
* Constructs an empty insertion-ordered <tt>LinkedHashMap</tt> instance
@@ -221,8 +377,9 @@
* @throws NullPointerException if the specified map is null
*/
public LinkedHashMap(Map<? extends K, ? extends V> m) {
- super(m);
+ super();
accessOrder = false;
+ putMapEntries(m, false);
}
/**
@@ -243,16 +400,6 @@
this.accessOrder = accessOrder;
}
- /**
- * Called by superclass constructors and pseudoconstructors (clone,
- * readObject) before any entries are inserted into the map. Initializes
- * the chain.
- */
- @Override
- void init() {
- header = new Entry<>(-1, null, null, null);
- header.before = header.after = header;
- }
/**
* Returns <tt>true</tt> if this map maps one or more keys to the
@@ -263,15 +410,10 @@
* specified value
*/
public boolean containsValue(Object value) {
- // Overridden to take advantage of faster iterator
- if (value==null) {
- for (Entry<?,?> e = header.after; e != header; e = e.after)
- if (e.value==null)
- return true;
- } else {
- for (Entry<?,?> e = header.after; e != header; e = e.after)
- if (value.equals(e.value))
- return true;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after) {
+ V v = e.value;
+ if (v == value || (value != null && value.equals(v)))
+ return true;
}
return false;
}
@@ -292,10 +434,11 @@
* distinguish these two cases.
*/
public V get(Object key) {
- Entry<K,V> e = (Entry<K,V>)getEntry(key);
- if (e == null)
+ Node<K,V> e;
+ if ((e = getNode(hash(key), key)) == null)
return null;
- e.recordAccess(this);
+ if (accessOrder)
+ afterNodeAccess(e);
return e.value;
}
@@ -305,163 +448,7 @@
*/
public void clear() {
super.clear();
- header.before = header.after = header;
- }
-
- @Override
- public void forEach(BiConsumer<? super K, ? super V> action) {
- Objects.requireNonNull(action);
- int expectedModCount = modCount;
- for (Entry<K, V> entry = header.after; entry != header; entry = entry.after) {
- action.accept(entry.key, entry.value);
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
-
- @Override
- public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
- Objects.requireNonNull(function);
- int expectedModCount = modCount;
- for (Entry<K, V> entry = header.after; entry != header; entry = entry.after) {
- entry.value = function.apply(entry.key, entry.value);
-
- if (expectedModCount != modCount) {
- throw new ConcurrentModificationException();
- }
- }
- }
-
- /**
- * LinkedHashMap entry.
- */
- private static class Entry<K,V> extends HashMap.Entry<K,V> {
- // These fields comprise the doubly linked list used for iteration.
- Entry<K,V> before, after;
-
- Entry(int hash, K key, V value, Object next) {
- super(hash, key, value, next);
- }
-
- /**
- * Removes this entry from the linked list.
- */
- private void remove() {
- before.after = after;
- after.before = before;
- }
-
- /**
- * Inserts this entry before the specified existing entry in the list.
- */
- private void addBefore(Entry<K,V> existingEntry) {
- after = existingEntry;
- before = existingEntry.before;
- before.after = this;
- after.before = this;
- }
-
- /**
- * This method is invoked by the superclass whenever the value
- * of a pre-existing entry is read by Map.get or modified by Map.put.
- * If the enclosing Map is access-ordered, it moves the entry
- * to the end of the list; otherwise, it does nothing.
- */
- void recordAccess(HashMap<K,V> m) {
- LinkedHashMap<K,V> lm = (LinkedHashMap<K,V>)m;
- if (lm.accessOrder) {
- lm.modCount++;
- remove();
- addBefore(lm.header);
- }
- }
-
- void recordRemoval(HashMap<K,V> m) {
- remove();
- }
- }
-
- private abstract class LinkedHashIterator<T> implements Iterator<T> {
- Entry<K,V> nextEntry = header.after;
- Entry<K,V> lastReturned = null;
-
- /**
- * The modCount value that the iterator believes that the backing
- * List should have. If this expectation is violated, the iterator
- * has detected concurrent modification.
- */
- int expectedModCount = modCount;
-
- public boolean hasNext() {
- return nextEntry != header;
- }
-
- public void remove() {
- if (lastReturned == null)
- throw new IllegalStateException();
- if (modCount != expectedModCount)
- throw new ConcurrentModificationException();
-
- LinkedHashMap.this.remove(lastReturned.key);
- lastReturned = null;
- expectedModCount = modCount;
- }
-
- Entry<K,V> nextEntry() {
- if (modCount != expectedModCount)
- throw new ConcurrentModificationException();
- if (nextEntry == header)
- throw new NoSuchElementException();
-
- Entry<K,V> e = lastReturned = nextEntry;
- nextEntry = e.after;
- return e;
- }
- }
-
- private class KeyIterator extends LinkedHashIterator<K> {
- public K next() { return nextEntry().getKey(); }
- }
-
- private class ValueIterator extends LinkedHashIterator<V> {
- public V next() { return nextEntry().value; }
- }
-
- private class EntryIterator extends LinkedHashIterator<Map.Entry<K,V>> {
- public Map.Entry<K,V> next() { return nextEntry(); }
- }
-
- // These Overrides alter the behavior of superclass view iterator() methods
- Iterator<K> newKeyIterator() { return new KeyIterator(); }
- Iterator<V> newValueIterator() { return new ValueIterator(); }
- Iterator<Map.Entry<K,V>> newEntryIterator() { return new EntryIterator(); }
-
- /**
- * This override alters behavior of superclass put method. It causes newly
- * allocated entry to get inserted at the end of the linked list and
- * removes the eldest entry if appropriate.
- */
- @Override
- void addEntry(int hash, K key, V value, int bucketIndex, boolean checkIfNeedTree) {
- super.addEntry(hash, key, value, bucketIndex, checkIfNeedTree);
-
- // Remove eldest entry if instructed
- Entry<K,V> eldest = header.after;
- if (removeEldestEntry(eldest)) {
- removeEntryForKey(eldest.key);
- }
- }
-
- /*
- * Create a new LinkedHashMap.Entry and setup the before/after pointers
- */
- @Override
- HashMap.Entry<K,V> newEntry(int hash, K key, V value, Object next) {
- Entry<K,V> newEntry = new Entry<>(hash, key, value, next);
- newEntry.addBefore(header);
- return newEntry;
+ head = tail = null;
}
/**
@@ -475,13 +462,13 @@
* <p>Sample use: this override will allow the map to grow up to 100
* entries and then delete the eldest entry each time a new entry is
* added, maintaining a steady state of 100 entries.
- * <pre>{@code
+ * <pre>
* private static final int MAX_ENTRIES = 100;
*
* protected boolean removeEldestEntry(Map.Entry eldest) {
- * return size() > MAX_ENTRIES;
+ * return size() > MAX_ENTRIES;
* }
- * }</pre>
+ * </pre>
*
* <p>This method typically does not modify the map in any way,
* instead allowing the map to modify itself as directed by its
@@ -508,4 +495,241 @@
protected boolean removeEldestEntry(Map.Entry<K,V> eldest) {
return false;
}
+
+ /**
+ * Returns a {@link Set} view of the keys contained in this map.
+ * The set is backed by the map, so changes to the map are
+ * reflected in the set, and vice-versa. If the map is modified
+ * while an iteration over the set is in progress (except through
+ * the iterator's own <tt>remove</tt> operation), the results of
+ * the iteration are undefined. The set supports element removal,
+ * which removes the corresponding mapping from the map, via the
+ * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
+ * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
+ * operations. It does not support the <tt>add</tt> or <tt>addAll</tt>
+ * operations.
+ * Its {@link Spliterator} typically provides faster sequential
+ * performance but much poorer parallel performance than that of
+ * {@code HashMap}.
+ *
+ * @return a set view of the keys contained in this map
+ */
+ public Set<K> keySet() {
+ Set<K> ks;
+ return (ks = keySet) == null ? (keySet = new LinkedKeySet()) : ks;
+ }
+
+ final class LinkedKeySet extends AbstractSet<K> {
+ public final int size() { return size; }
+ public final void clear() { LinkedHashMap.this.clear(); }
+ public final Iterator<K> iterator() {
+ return new LinkedKeyIterator();
+ }
+ public final boolean contains(Object o) { return containsKey(o); }
+ public final boolean remove(Object key) {
+ return removeNode(hash(key), key, null, false, true) != null;
+ }
+ public final Spliterator<K> spliterator() {
+ return Spliterators.spliterator(this, Spliterator.SIZED |
+ Spliterator.ORDERED |
+ Spliterator.DISTINCT);
+ }
+ public final void forEach(Consumer<? super K> action) {
+ if (action == null)
+ throw new NullPointerException();
+ int mc = modCount;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after)
+ action.accept(e.key);
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ /**
+ * Returns a {@link Collection} view of the values contained in this map.
+ * The collection is backed by the map, so changes to the map are
+ * reflected in the collection, and vice-versa. If the map is
+ * modified while an iteration over the collection is in progress
+ * (except through the iterator's own <tt>remove</tt> operation),
+ * the results of the iteration are undefined. The collection
+ * supports element removal, which removes the corresponding
+ * mapping from the map, via the <tt>Iterator.remove</tt>,
+ * <tt>Collection.remove</tt>, <tt>removeAll</tt>,
+ * <tt>retainAll</tt> and <tt>clear</tt> operations. It does not
+ * support the <tt>add</tt> or <tt>addAll</tt> operations.
+ * Its {@link Spliterator} typically provides faster sequential
+ * performance but much poorer parallel performance than that of
+ * {@code HashMap}.
+ *
+ * @return a view of the values contained in this map
+ */
+ public Collection<V> values() {
+ Collection<V> vs;
+ return (vs = values) == null ? (values = new LinkedValues()) : vs;
+ }
+
+ final class LinkedValues extends AbstractCollection<V> {
+ public final int size() { return size; }
+ public final void clear() { LinkedHashMap.this.clear(); }
+ public final Iterator<V> iterator() {
+ return new LinkedValueIterator();
+ }
+ public final boolean contains(Object o) { return containsValue(o); }
+ public final Spliterator<V> spliterator() {
+ return Spliterators.spliterator(this, Spliterator.SIZED |
+ Spliterator.ORDERED);
+ }
+ public final void forEach(Consumer<? super V> action) {
+ if (action == null)
+ throw new NullPointerException();
+ int mc = modCount;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after)
+ action.accept(e.value);
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ /**
+ * Returns a {@link Set} view of the mappings contained in this map.
+ * The set is backed by the map, so changes to the map are
+ * reflected in the set, and vice-versa. If the map is modified
+ * while an iteration over the set is in progress (except through
+ * the iterator's own <tt>remove</tt> operation, or through the
+ * <tt>setValue</tt> operation on a map entry returned by the
+ * iterator) the results of the iteration are undefined. The set
+ * supports element removal, which removes the corresponding
+ * mapping from the map, via the <tt>Iterator.remove</tt>,
+ * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and
+ * <tt>clear</tt> operations. It does not support the
+ * <tt>add</tt> or <tt>addAll</tt> operations.
+ * Its {@link Spliterator} typically provides faster sequential
+ * performance but much poorer parallel performance than that of
+ * {@code HashMap}.
+ *
+ * @return a set view of the mappings contained in this map
+ */
+ public Set<Map.Entry<K,V>> entrySet() {
+ Set<Map.Entry<K,V>> es;
+ return (es = entrySet) == null ? (entrySet = new LinkedEntrySet()) : es;
+ }
+
+ final class LinkedEntrySet extends AbstractSet<Map.Entry<K,V>> {
+ public final int size() { return size; }
+ public final void clear() { LinkedHashMap.this.clear(); }
+ public final Iterator<Map.Entry<K,V>> iterator() {
+ return new LinkedEntryIterator();
+ }
+ public final boolean contains(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<?,?> e = (Map.Entry<?,?>) o;
+ Object key = e.getKey();
+ Node<K,V> candidate = getNode(hash(key), key);
+ return candidate != null && candidate.equals(e);
+ }
+ public final boolean remove(Object o) {
+ if (o instanceof Map.Entry) {
+ Map.Entry<?,?> e = (Map.Entry<?,?>) o;
+ Object key = e.getKey();
+ Object value = e.getValue();
+ return removeNode(hash(key), key, value, true, true) != null;
+ }
+ return false;
+ }
+ public final Spliterator<Map.Entry<K,V>> spliterator() {
+ return Spliterators.spliterator(this, Spliterator.SIZED |
+ Spliterator.ORDERED |
+ Spliterator.DISTINCT);
+ }
+ public final void forEach(Consumer<? super Map.Entry<K,V>> action) {
+ if (action == null)
+ throw new NullPointerException();
+ int mc = modCount;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after)
+ action.accept(e);
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ // Map overrides
+
+ public void forEach(BiConsumer<? super K, ? super V> action) {
+ if (action == null)
+ throw new NullPointerException();
+ int mc = modCount;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after)
+ action.accept(e.key, e.value);
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+
+ public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
+ if (function == null)
+ throw new NullPointerException();
+ int mc = modCount;
+ for (LinkedHashMap.Entry<K,V> e = head; e != null; e = e.after)
+ e.value = function.apply(e.key, e.value);
+ if (modCount != mc)
+ throw new ConcurrentModificationException();
+ }
+
+ // Iterators
+
+ abstract class LinkedHashIterator {
+ LinkedHashMap.Entry<K,V> next;
+ LinkedHashMap.Entry<K,V> current;
+ int expectedModCount;
+
+ LinkedHashIterator() {
+ next = head;
+ expectedModCount = modCount;
+ current = null;
+ }
+
+ public final boolean hasNext() {
+ return next != null;
+ }
+
+ final LinkedHashMap.Entry<K,V> nextNode() {
+ LinkedHashMap.Entry<K,V> e = next;
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ if (e == null)
+ throw new NoSuchElementException();
+ current = e;
+ next = e.after;
+ return e;
+ }
+
+ public final void remove() {
+ Node<K,V> p = current;
+ if (p == null)
+ throw new IllegalStateException();
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ current = null;
+ K key = p.key;
+ removeNode(hash(key), key, null, false, false);
+ expectedModCount = modCount;
+ }
+ }
+
+ final class LinkedKeyIterator extends LinkedHashIterator
+ implements Iterator<K> {
+ public final K next() { return nextNode().getKey(); }
+ }
+
+ final class LinkedValueIterator extends LinkedHashIterator
+ implements Iterator<V> {
+ public final V next() { return nextNode().value; }
+ }
+
+ final class LinkedEntryIterator extends LinkedHashIterator
+ implements Iterator<Map.Entry<K,V>> {
+ public final Map.Entry<K,V> next() { return nextNode(); }
+ }
+
+
}