--- a/src/java.net.http/share/classes/jdk/internal/net/http/hpack/Huffman.java Wed May 02 10:47:16 2018 +0200
+++ b/src/java.net.http/share/classes/jdk/internal/net/http/hpack/Huffman.java Wed May 02 02:36:17 2018 -0700
@@ -27,655 +27,60 @@
import java.io.IOException;
import java.nio.ByteBuffer;
-import static java.lang.String.format;
-
/**
- * Huffman coding table.
- *
- * <p> Instances of this class are safe for use by multiple threads.
+ * Huffman coding.
*
* @since 9
*/
public final class Huffman {
- // TODO: check if reset is done in both reader and writer
-
- static final class Reader {
-
- private Node curr; // position in the trie
- private int len; // length of the path from the root to 'curr'
- private int p; // byte probe
+ public interface Reader {
- {
- reset();
- }
-
- public void read(ByteBuffer source,
- Appendable destination,
- boolean isLast) throws IOException {
- read(source, destination, true, isLast);
- }
-
- // Takes 'isLast' rather than returns whether the reading is done or
- // not, for more informative exceptions.
void read(ByteBuffer source,
Appendable destination,
- boolean reportEOS, /* reportEOS is exposed for tests */
- boolean isLast) throws IOException {
- Node c = curr;
- int l = len;
- /*
- Since ByteBuffer is itself stateful, its position is
- remembered here NOT as a part of Reader's state,
- but to set it back in the case of a failure
- */
- int pos = source.position();
-
- while (source.hasRemaining()) {
- int d = source.get();
- for (; p != 0; p >>= 1) {
- c = c.getChild(p & d);
- l++;
- if (c.isLeaf()) {
- if (reportEOS && c.isEOSPath) {
- throw new IOException("Encountered EOS");
- }
- char ch;
- try {
- ch = c.getChar();
- } catch (IllegalStateException e) {
- source.position(pos); // do we need this?
- throw new IOException(e);
- }
- try {
- destination.append(ch);
- } catch (IOException e) {
- source.position(pos); // do we need this?
- throw e;
- }
- c = INSTANCE.root;
- l = 0;
- }
- curr = c;
- len = l;
- }
- resetProbe();
- pos++;
- }
- if (!isLast) {
- return; // it's too early to jump to any conclusions, let's wait
- }
- if (c.isLeaf()) {
- return; // it's perfectly ok, no extra padding bits
- }
- if (c.isEOSPath && len <= 7) {
- return; // it's ok, some extra padding bits
- }
- if (c.isEOSPath) {
- throw new IOException(
- "Padding is too long (len=" + len + ") " +
- "or unexpected end of data");
- }
- throw new IOException(
- "Not a EOS prefix padding or unexpected end of data");
- }
-
- public void reset() {
- curr = INSTANCE.root;
- len = 0;
- resetProbe();
- }
-
- private void resetProbe() {
- p = 0x80;
- }
- }
+ boolean isLast) throws IOException;
- static final class Writer {
-
- private int pos; // position in 'source'
- private int avail = 8; // number of least significant bits available in 'curr'
- private int curr; // next byte to put to the destination
- private int rem; // number of least significant bits in 'code' yet to be processed
- private int code; // current code being written
-
- private CharSequence source;
- private int end;
-
- public Writer from(CharSequence input, int start, int end) {
- if (start < 0 || end < 0 || end > input.length() || start > end) {
- throw new IndexOutOfBoundsException(
- String.format("input.length()=%s, start=%s, end=%s",
- input.length(), start, end));
- }
- pos = start;
- this.end = end;
- this.source = input;
- return this;
- }
-
- public boolean write(ByteBuffer destination) {
- for (; pos < end; pos++) {
- if (rem == 0) {
- Code desc = INSTANCE.codeOf(source.charAt(pos));
- rem = desc.length;
- code = desc.code;
- }
- while (rem > 0) {
- if (rem < avail) {
- curr |= (code << (avail - rem));
- avail -= rem;
- rem = 0;
- } else {
- int c = (curr | (code >>> (rem - avail)));
- if (destination.hasRemaining()) {
- destination.put((byte) c);
- } else {
- return false;
- }
- curr = c;
- code <<= (32 - rem + avail); // throw written bits off the cliff (is this Sparta?)
- code >>>= (32 - rem + avail); // return to the position
- rem -= avail;
- curr = 0;
- avail = 8;
- }
- }
- }
-
- if (avail < 8) { // have to pad
- if (destination.hasRemaining()) {
- destination.put((byte) (curr | (INSTANCE.EOS.code >>> (INSTANCE.EOS.length - avail))));
- avail = 8;
- } else {
- return false;
- }
- }
-
- return true;
- }
-
- public Writer reset() {
- source = null;
- end = -1;
- pos = -1;
- avail = 8;
- curr = 0;
- code = 0;
- return this;
- }
+ /**
+ * Brings this reader to the state it had upon construction.
+ */
+ void reset();
}
- /**
- * Shared instance.
- */
- public static final Huffman INSTANCE = new Huffman();
+ public interface Writer {
+
+ Writer from(CharSequence input, int start, int end);
+
+ boolean write(ByteBuffer destination);
- private final Code EOS = new Code(0x3fffffff, 30);
- private final Code[] codes = new Code[257];
- private final Node root = new Node() {
- @Override
- public String toString() { return "root"; }
- };
+ /**
+ * Brings this writer to the state it had upon construction.
+ *
+ * @return this writer
+ */
+ Writer reset();
- // TODO: consider builder and immutable trie
- private Huffman() {
- // @formatter:off
- addChar(0, 0x1ff8, 13);
- addChar(1, 0x7fffd8, 23);
- addChar(2, 0xfffffe2, 28);
- addChar(3, 0xfffffe3, 28);
- addChar(4, 0xfffffe4, 28);
- addChar(5, 0xfffffe5, 28);
- addChar(6, 0xfffffe6, 28);
- addChar(7, 0xfffffe7, 28);
- addChar(8, 0xfffffe8, 28);
- addChar(9, 0xffffea, 24);
- addChar(10, 0x3ffffffc, 30);
- addChar(11, 0xfffffe9, 28);
- addChar(12, 0xfffffea, 28);
- addChar(13, 0x3ffffffd, 30);
- addChar(14, 0xfffffeb, 28);
- addChar(15, 0xfffffec, 28);
- addChar(16, 0xfffffed, 28);
- addChar(17, 0xfffffee, 28);
- addChar(18, 0xfffffef, 28);
- addChar(19, 0xffffff0, 28);
- addChar(20, 0xffffff1, 28);
- addChar(21, 0xffffff2, 28);
- addChar(22, 0x3ffffffe, 30);
- addChar(23, 0xffffff3, 28);
- addChar(24, 0xffffff4, 28);
- addChar(25, 0xffffff5, 28);
- addChar(26, 0xffffff6, 28);
- addChar(27, 0xffffff7, 28);
- addChar(28, 0xffffff8, 28);
- addChar(29, 0xffffff9, 28);
- addChar(30, 0xffffffa, 28);
- addChar(31, 0xffffffb, 28);
- addChar(32, 0x14, 6);
- addChar(33, 0x3f8, 10);
- addChar(34, 0x3f9, 10);
- addChar(35, 0xffa, 12);
- addChar(36, 0x1ff9, 13);
- addChar(37, 0x15, 6);
- addChar(38, 0xf8, 8);
- addChar(39, 0x7fa, 11);
- addChar(40, 0x3fa, 10);
- addChar(41, 0x3fb, 10);
- addChar(42, 0xf9, 8);
- addChar(43, 0x7fb, 11);
- addChar(44, 0xfa, 8);
- addChar(45, 0x16, 6);
- addChar(46, 0x17, 6);
- addChar(47, 0x18, 6);
- addChar(48, 0x0, 5);
- addChar(49, 0x1, 5);
- addChar(50, 0x2, 5);
- addChar(51, 0x19, 6);
- addChar(52, 0x1a, 6);
- addChar(53, 0x1b, 6);
- addChar(54, 0x1c, 6);
- addChar(55, 0x1d, 6);
- addChar(56, 0x1e, 6);
- addChar(57, 0x1f, 6);
- addChar(58, 0x5c, 7);
- addChar(59, 0xfb, 8);
- addChar(60, 0x7ffc, 15);
- addChar(61, 0x20, 6);
- addChar(62, 0xffb, 12);
- addChar(63, 0x3fc, 10);
- addChar(64, 0x1ffa, 13);
- addChar(65, 0x21, 6);
- addChar(66, 0x5d, 7);
- addChar(67, 0x5e, 7);
- addChar(68, 0x5f, 7);
- addChar(69, 0x60, 7);
- addChar(70, 0x61, 7);
- addChar(71, 0x62, 7);
- addChar(72, 0x63, 7);
- addChar(73, 0x64, 7);
- addChar(74, 0x65, 7);
- addChar(75, 0x66, 7);
- addChar(76, 0x67, 7);
- addChar(77, 0x68, 7);
- addChar(78, 0x69, 7);
- addChar(79, 0x6a, 7);
- addChar(80, 0x6b, 7);
- addChar(81, 0x6c, 7);
- addChar(82, 0x6d, 7);
- addChar(83, 0x6e, 7);
- addChar(84, 0x6f, 7);
- addChar(85, 0x70, 7);
- addChar(86, 0x71, 7);
- addChar(87, 0x72, 7);
- addChar(88, 0xfc, 8);
- addChar(89, 0x73, 7);
- addChar(90, 0xfd, 8);
- addChar(91, 0x1ffb, 13);
- addChar(92, 0x7fff0, 19);
- addChar(93, 0x1ffc, 13);
- addChar(94, 0x3ffc, 14);
- addChar(95, 0x22, 6);
- addChar(96, 0x7ffd, 15);
- addChar(97, 0x3, 5);
- addChar(98, 0x23, 6);
- addChar(99, 0x4, 5);
- addChar(100, 0x24, 6);
- addChar(101, 0x5, 5);
- addChar(102, 0x25, 6);
- addChar(103, 0x26, 6);
- addChar(104, 0x27, 6);
- addChar(105, 0x6, 5);
- addChar(106, 0x74, 7);
- addChar(107, 0x75, 7);
- addChar(108, 0x28, 6);
- addChar(109, 0x29, 6);
- addChar(110, 0x2a, 6);
- addChar(111, 0x7, 5);
- addChar(112, 0x2b, 6);
- addChar(113, 0x76, 7);
- addChar(114, 0x2c, 6);
- addChar(115, 0x8, 5);
- addChar(116, 0x9, 5);
- addChar(117, 0x2d, 6);
- addChar(118, 0x77, 7);
- addChar(119, 0x78, 7);
- addChar(120, 0x79, 7);
- addChar(121, 0x7a, 7);
- addChar(122, 0x7b, 7);
- addChar(123, 0x7ffe, 15);
- addChar(124, 0x7fc, 11);
- addChar(125, 0x3ffd, 14);
- addChar(126, 0x1ffd, 13);
- addChar(127, 0xffffffc, 28);
- addChar(128, 0xfffe6, 20);
- addChar(129, 0x3fffd2, 22);
- addChar(130, 0xfffe7, 20);
- addChar(131, 0xfffe8, 20);
- addChar(132, 0x3fffd3, 22);
- addChar(133, 0x3fffd4, 22);
- addChar(134, 0x3fffd5, 22);
- addChar(135, 0x7fffd9, 23);
- addChar(136, 0x3fffd6, 22);
- addChar(137, 0x7fffda, 23);
- addChar(138, 0x7fffdb, 23);
- addChar(139, 0x7fffdc, 23);
- addChar(140, 0x7fffdd, 23);
- addChar(141, 0x7fffde, 23);
- addChar(142, 0xffffeb, 24);
- addChar(143, 0x7fffdf, 23);
- addChar(144, 0xffffec, 24);
- addChar(145, 0xffffed, 24);
- addChar(146, 0x3fffd7, 22);
- addChar(147, 0x7fffe0, 23);
- addChar(148, 0xffffee, 24);
- addChar(149, 0x7fffe1, 23);
- addChar(150, 0x7fffe2, 23);
- addChar(151, 0x7fffe3, 23);
- addChar(152, 0x7fffe4, 23);
- addChar(153, 0x1fffdc, 21);
- addChar(154, 0x3fffd8, 22);
- addChar(155, 0x7fffe5, 23);
- addChar(156, 0x3fffd9, 22);
- addChar(157, 0x7fffe6, 23);
- addChar(158, 0x7fffe7, 23);
- addChar(159, 0xffffef, 24);
- addChar(160, 0x3fffda, 22);
- addChar(161, 0x1fffdd, 21);
- addChar(162, 0xfffe9, 20);
- addChar(163, 0x3fffdb, 22);
- addChar(164, 0x3fffdc, 22);
- addChar(165, 0x7fffe8, 23);
- addChar(166, 0x7fffe9, 23);
- addChar(167, 0x1fffde, 21);
- addChar(168, 0x7fffea, 23);
- addChar(169, 0x3fffdd, 22);
- addChar(170, 0x3fffde, 22);
- addChar(171, 0xfffff0, 24);
- addChar(172, 0x1fffdf, 21);
- addChar(173, 0x3fffdf, 22);
- addChar(174, 0x7fffeb, 23);
- addChar(175, 0x7fffec, 23);
- addChar(176, 0x1fffe0, 21);
- addChar(177, 0x1fffe1, 21);
- addChar(178, 0x3fffe0, 22);
- addChar(179, 0x1fffe2, 21);
- addChar(180, 0x7fffed, 23);
- addChar(181, 0x3fffe1, 22);
- addChar(182, 0x7fffee, 23);
- addChar(183, 0x7fffef, 23);
- addChar(184, 0xfffea, 20);
- addChar(185, 0x3fffe2, 22);
- addChar(186, 0x3fffe3, 22);
- addChar(187, 0x3fffe4, 22);
- addChar(188, 0x7ffff0, 23);
- addChar(189, 0x3fffe5, 22);
- addChar(190, 0x3fffe6, 22);
- addChar(191, 0x7ffff1, 23);
- addChar(192, 0x3ffffe0, 26);
- addChar(193, 0x3ffffe1, 26);
- addChar(194, 0xfffeb, 20);
- addChar(195, 0x7fff1, 19);
- addChar(196, 0x3fffe7, 22);
- addChar(197, 0x7ffff2, 23);
- addChar(198, 0x3fffe8, 22);
- addChar(199, 0x1ffffec, 25);
- addChar(200, 0x3ffffe2, 26);
- addChar(201, 0x3ffffe3, 26);
- addChar(202, 0x3ffffe4, 26);
- addChar(203, 0x7ffffde, 27);
- addChar(204, 0x7ffffdf, 27);
- addChar(205, 0x3ffffe5, 26);
- addChar(206, 0xfffff1, 24);
- addChar(207, 0x1ffffed, 25);
- addChar(208, 0x7fff2, 19);
- addChar(209, 0x1fffe3, 21);
- addChar(210, 0x3ffffe6, 26);
- addChar(211, 0x7ffffe0, 27);
- addChar(212, 0x7ffffe1, 27);
- addChar(213, 0x3ffffe7, 26);
- addChar(214, 0x7ffffe2, 27);
- addChar(215, 0xfffff2, 24);
- addChar(216, 0x1fffe4, 21);
- addChar(217, 0x1fffe5, 21);
- addChar(218, 0x3ffffe8, 26);
- addChar(219, 0x3ffffe9, 26);
- addChar(220, 0xffffffd, 28);
- addChar(221, 0x7ffffe3, 27);
- addChar(222, 0x7ffffe4, 27);
- addChar(223, 0x7ffffe5, 27);
- addChar(224, 0xfffec, 20);
- addChar(225, 0xfffff3, 24);
- addChar(226, 0xfffed, 20);
- addChar(227, 0x1fffe6, 21);
- addChar(228, 0x3fffe9, 22);
- addChar(229, 0x1fffe7, 21);
- addChar(230, 0x1fffe8, 21);
- addChar(231, 0x7ffff3, 23);
- addChar(232, 0x3fffea, 22);
- addChar(233, 0x3fffeb, 22);
- addChar(234, 0x1ffffee, 25);
- addChar(235, 0x1ffffef, 25);
- addChar(236, 0xfffff4, 24);
- addChar(237, 0xfffff5, 24);
- addChar(238, 0x3ffffea, 26);
- addChar(239, 0x7ffff4, 23);
- addChar(240, 0x3ffffeb, 26);
- addChar(241, 0x7ffffe6, 27);
- addChar(242, 0x3ffffec, 26);
- addChar(243, 0x3ffffed, 26);
- addChar(244, 0x7ffffe7, 27);
- addChar(245, 0x7ffffe8, 27);
- addChar(246, 0x7ffffe9, 27);
- addChar(247, 0x7ffffea, 27);
- addChar(248, 0x7ffffeb, 27);
- addChar(249, 0xffffffe, 28);
- addChar(250, 0x7ffffec, 27);
- addChar(251, 0x7ffffed, 27);
- addChar(252, 0x7ffffee, 27);
- addChar(253, 0x7ffffef, 27);
- addChar(254, 0x7fffff0, 27);
- addChar(255, 0x3ffffee, 26);
- addEOS (256, EOS.code, EOS.length);
- // @formatter:on
- }
+ /**
+ * Calculates the number of bytes required to represent a subsequence of
+ * the given {@code CharSequence} using the Huffman coding.
+ *
+ * @param value
+ * characters
+ * @param start
+ * the start index, inclusive
+ * @param end
+ * the end index, exclusive
+ *
+ * @return number of bytes
+ * @throws NullPointerException
+ * if the value is null
+ * @throws IndexOutOfBoundsException
+ * if any invocation of {@code value.charAt(i)}, where
+ * {@code start <= i < end}, throws an IndexOutOfBoundsException
+ */
+ int lengthOf(CharSequence value, int start, int end);
-
- /**
- * Calculates the number of bytes required to represent the given {@code
- * CharSequence} with the Huffman coding.
- *
- * @param value
- * characters
- *
- * @return number of bytes
- *
- * @throws NullPointerException
- * if the value is null
- */
- public int lengthOf(CharSequence value) {
- return lengthOf(value, 0, value.length());
- }
-
- /**
- * Calculates the number of bytes required to represent a subsequence of the
- * given {@code CharSequence} with the Huffman coding.
- *
- * @param value
- * characters
- * @param start
- * the start index, inclusive
- * @param end
- * the end index, exclusive
- *
- * @return number of bytes
- *
- * @throws NullPointerException
- * if the value is null
- * @throws IndexOutOfBoundsException
- * if any invocation of {@code value.charAt(i)}, where
- * {@code start <= i < end} would throw an IndexOutOfBoundsException
- */
- public int lengthOf(CharSequence value, int start, int end) {
- int len = 0;
- for (int i = start; i < end; i++) {
- char c = value.charAt(i);
- len += INSTANCE.codeOf(c).length;
- }
- // Integer division with ceiling, assumption:
- assert (len / 8 + (len % 8 != 0 ? 1 : 0)) == (len + 7) / 8 : len;
- return (len + 7) / 8;
- }
-
- private void addChar(int c, int code, int bitLength) {
- addLeaf(c, code, bitLength, false);
- codes[c] = new Code(code, bitLength);
- }
-
- private void addEOS(int c, int code, int bitLength) {
- addLeaf(c, code, bitLength, true);
- codes[c] = new Code(code, bitLength);
- }
-
- private void addLeaf(int c, int code, int bitLength, boolean isEOS) {
- if (bitLength < 1) {
- throw new IllegalArgumentException("bitLength < 1");
- }
- Node curr = root;
- for (int p = 1 << bitLength - 1; p != 0 && !curr.isLeaf(); p = p >> 1) {
- curr.isEOSPath |= isEOS; // If it's already true, it can't become false
- curr = curr.addChildIfAbsent(p & code);
- }
- curr.isEOSPath |= isEOS; // The last one needs to have this property as well
- if (curr.isLeaf()) {
- throw new IllegalStateException("Specified code is already taken");
- }
- curr.setChar((char) c);
- }
-
- private Code codeOf(char c) {
- if (c > 255) {
- throw new IllegalArgumentException("char=" + ((int) c));
- }
- return codes[c];
- }
-
- //
- // For debugging/testing purposes
- //
- Node getRoot() {
- return root;
- }
-
- //
- // Guarantees:
- //
- // if (isLeaf() == true) => getChar() is a legal call
- // if (isLeaf() == false) => getChild(i) is a legal call (though it can
- // return null)
- //
- static class Node {
-
- Node left;
- Node right;
- boolean isEOSPath;
-
- boolean charIsSet;
- char c;
-
- Node getChild(int selector) {
- if (isLeaf()) {
- throw new IllegalStateException("This is a leaf node");
- }
- Node result = selector == 0 ? left : right;
- if (result == null) {
- throw new IllegalStateException(format(
- "Node doesn't have a child (selector=%s)", selector));
- }
- return result;
- }
-
- boolean isLeaf() {
- return charIsSet;
- }
-
- char getChar() {
- if (!isLeaf()) {
- throw new IllegalStateException("This node is not a leaf node");
- }
- return c;
- }
-
- void setChar(char c) {
- if (charIsSet) {
- throw new IllegalStateException(
- "This node has been taken already");
- }
- if (left != null || right != null) {
- throw new IllegalStateException("The node cannot be made "
- + "a leaf as it's already has a child");
- }
- this.c = c;
- charIsSet = true;
- }
-
- Node addChildIfAbsent(int i) {
- if (charIsSet) {
- throw new IllegalStateException("The node cannot have a child "
- + "as it's already a leaf node");
- }
- Node child;
- if (i == 0) {
- if ((child = left) == null) {
- child = left = new Node();
- }
- } else {
- if ((child = right) == null) {
- child = right = new Node();
- }
- }
- return child;
- }
-
- @Override
- public String toString() {
- if (isLeaf()) {
- if (isEOSPath) {
- return "EOS";
- } else {
- return format("char: (%3s) '%s'", (int) c, c);
- }
- }
- return "/\\";
- }
- }
-
- // TODO: value-based class?
- // FIXME: can we re-use Node instead of this class?
- private static final class Code {
-
- final int code;
- final int length;
-
- private Code(int code, int length) {
- this.code = code;
- this.length = length;
- }
-
- public int getCode() {
- return code;
- }
-
- public int getLength() {
- return length;
- }
-
- @Override
- public String toString() {
- long p = 1 << length;
- return Long.toBinaryString(code + p).substring(1)
- + ", length=" + length;
+ default int lengthOf(CharSequence value) {
+ return lengthOf(value, 0, value.length());
}
}
}