--- a/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/hpack/Encoder.java Tue Feb 06 19:37:56 2018 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,525 +0,0 @@
-/*
- * Copyright (c) 2014, 2018, 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
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-package jdk.incubator.http.internal.hpack;
-
-import jdk.incubator.http.internal.hpack.HPACK.Logger;
-
-import java.nio.ByteBuffer;
-import java.nio.ReadOnlyBufferException;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicLong;
-
-import static java.lang.String.format;
-import static java.util.Objects.requireNonNull;
-import static jdk.incubator.http.internal.hpack.HPACK.Logger.Level.EXTRA;
-import static jdk.incubator.http.internal.hpack.HPACK.Logger.Level.NORMAL;
-
-/**
- * Encodes headers to their binary representation.
- *
- * <p> Typical lifecycle looks like this:
- *
- * <p> {@link #Encoder(int) new Encoder}
- * ({@link #setMaxCapacity(int) setMaxCapacity}?
- * {@link #encode(ByteBuffer) encode})*
- *
- * <p> Suppose headers are represented by {@code Map<String, List<String>>}.
- * A supplier and a consumer of {@link ByteBuffer}s in forms of
- * {@code Supplier<ByteBuffer>} and {@code Consumer<ByteBuffer>} respectively.
- * Then to encode headers, the following approach might be used:
- *
- * <pre>{@code
- * for (Map.Entry<String, List<String>> h : headers.entrySet()) {
- * String name = h.getKey();
- * for (String value : h.getValue()) {
- * encoder.header(name, value); // Set up header
- * boolean encoded;
- * do {
- * ByteBuffer b = buffersSupplier.get();
- * encoded = encoder.encode(b); // Encode the header
- * buffersConsumer.accept(b);
- * } while (!encoded);
- * }
- * }
- * }</pre>
- *
- * <p> Though the specification <a href="https://tools.ietf.org/html/rfc7541#section-2">does not define</a>
- * how an encoder is to be implemented, a default implementation is provided by
- * the method {@link #header(CharSequence, CharSequence, boolean)}.
- *
- * <p> To provide a custom encoding implementation, {@code Encoder} has to be
- * extended. A subclass then can access methods for encoding using specific
- * representations (e.g. {@link #literal(int, CharSequence, boolean) literal},
- * {@link #indexed(int) indexed}, etc.)
- *
- * @apiNote
- *
- * <p> An Encoder provides an incremental way of encoding headers.
- * {@link #encode(ByteBuffer)} takes a buffer a returns a boolean indicating
- * whether, or not, the buffer was sufficiently sized to hold the
- * remaining of the encoded representation.
- *
- * <p> This way, there's no need to provide a buffer of a specific size, or to
- * resize (and copy) the buffer on demand, when the remaining encoded
- * representation will not fit in the buffer's remaining space. Instead, an
- * array of existing buffers can be used, prepended with a frame that encloses
- * the resulting header block afterwards.
- *
- * <p> Splitting the encoding operation into header set up and header encoding,
- * separates long lived arguments ({@code name}, {@code value},
- * {@code sensitivity}, etc.) from the short lived ones (e.g. {@code buffer}),
- * simplifying each operation itself.
- *
- * @implNote
- *
- * <p> The default implementation does not use dynamic table. It reports to a
- * coupled Decoder a size update with the value of {@code 0}, and never changes
- * it afterwards.
- *
- * @since 9
- */
-public class Encoder {
-
- private static final AtomicLong ENCODERS_IDS = new AtomicLong();
-
- // TODO: enum: no huffman/smart huffman/always huffman
- private static final boolean DEFAULT_HUFFMAN = true;
-
- private final Logger logger;
- private final long id;
- private final IndexedWriter indexedWriter = new IndexedWriter();
- private final LiteralWriter literalWriter = new LiteralWriter();
- private final LiteralNeverIndexedWriter literalNeverIndexedWriter
- = new LiteralNeverIndexedWriter();
- private final LiteralWithIndexingWriter literalWithIndexingWriter
- = new LiteralWithIndexingWriter();
- private final SizeUpdateWriter sizeUpdateWriter = new SizeUpdateWriter();
- private final BulkSizeUpdateWriter bulkSizeUpdateWriter
- = new BulkSizeUpdateWriter();
-
- private BinaryRepresentationWriter writer;
- private final HeaderTable headerTable;
-
- private boolean encoding;
-
- private int maxCapacity;
- private int currCapacity;
- private int lastCapacity;
- private long minCapacity;
- private boolean capacityUpdate;
- private boolean configuredCapacityUpdate;
-
- /**
- * Constructs an {@code Encoder} with the specified maximum capacity of the
- * header table.
- *
- * <p> The value has to be agreed between decoder and encoder out-of-band,
- * e.g. by a protocol that uses HPACK
- * (see <a href="https://tools.ietf.org/html/rfc7541#section-4.2">4.2. Maximum Table Size</a>).
- *
- * @param maxCapacity
- * a non-negative integer
- *
- * @throws IllegalArgumentException
- * if maxCapacity is negative
- */
- public Encoder(int maxCapacity) {
- id = ENCODERS_IDS.incrementAndGet();
- this.logger = HPACK.getLogger().subLogger("Encoder#" + id);
- if (logger.isLoggable(NORMAL)) {
- logger.log(NORMAL, () -> format("new encoder with maximum table size %s",
- maxCapacity));
- }
- if (logger.isLoggable(EXTRA)) {
- /* To correlate with logging outside HPACK, knowing
- hashCode/toString is important */
- logger.log(EXTRA, () -> {
- String hashCode = Integer.toHexString(
- System.identityHashCode(this));
- /* Since Encoder can be subclassed hashCode AND identity
- hashCode might be different. So let's print both. */
- return format("toString='%s', hashCode=%s, identityHashCode=%s",
- toString(), hashCode(), hashCode);
- });
- }
- if (maxCapacity < 0) {
- throw new IllegalArgumentException(
- "maxCapacity >= 0: " + maxCapacity);
- }
- // Initial maximum capacity update mechanics
- minCapacity = Long.MAX_VALUE;
- currCapacity = -1;
- setMaxCapacity0(maxCapacity);
- headerTable = new HeaderTable(lastCapacity, logger.subLogger("HeaderTable"));
- }
-
- /**
- * Sets up the given header {@code (name, value)}.
- *
- * <p> Fixates {@code name} and {@code value} for the duration of encoding.
- *
- * @param name
- * the name
- * @param value
- * the value
- *
- * @throws NullPointerException
- * if any of the arguments are {@code null}
- * @throws IllegalStateException
- * if the encoder hasn't fully encoded the previous header, or
- * hasn't yet started to encode it
- * @see #header(CharSequence, CharSequence, boolean)
- */
- public void header(CharSequence name, CharSequence value)
- throws IllegalStateException {
- header(name, value, false);
- }
-
- /**
- * Sets up the given header {@code (name, value)} with possibly sensitive
- * value.
- *
- * <p> If the {@code value} is sensitive (think security, secrecy, etc.)
- * this encoder will compress it using a special representation
- * (see <a href="https://tools.ietf.org/html/rfc7541#section-6.2.3">6.2.3. Literal Header Field Never Indexed</a>).
- *
- * <p> Fixates {@code name} and {@code value} for the duration of encoding.
- *
- * @param name
- * the name
- * @param value
- * the value
- * @param sensitive
- * whether or not the value is sensitive
- *
- * @throws NullPointerException
- * if any of the arguments are {@code null}
- * @throws IllegalStateException
- * if the encoder hasn't fully encoded the previous header, or
- * hasn't yet started to encode it
- * @see #header(CharSequence, CharSequence)
- * @see DecodingCallback#onDecoded(CharSequence, CharSequence, boolean)
- */
- public void header(CharSequence name,
- CharSequence value,
- boolean sensitive) throws IllegalStateException {
- if (logger.isLoggable(NORMAL)) {
- logger.log(NORMAL, () -> format("encoding ('%s', '%s'), sensitive: %s",
- name, value, sensitive));
- }
- // Arguably a good balance between complexity of implementation and
- // efficiency of encoding
- requireNonNull(name, "name");
- requireNonNull(value, "value");
- HeaderTable t = getHeaderTable();
- int index = t.indexOf(name, value);
- if (index > 0) {
- indexed(index);
- } else if (index < 0) {
- if (sensitive) {
- literalNeverIndexed(-index, value, DEFAULT_HUFFMAN);
- } else {
- literal(-index, value, DEFAULT_HUFFMAN);
- }
- } else {
- if (sensitive) {
- literalNeverIndexed(name, DEFAULT_HUFFMAN, value, DEFAULT_HUFFMAN);
- } else {
- literal(name, DEFAULT_HUFFMAN, value, DEFAULT_HUFFMAN);
- }
- }
- }
-
- /**
- * Sets a maximum capacity of the header table.
- *
- * <p> The value has to be agreed between decoder and encoder out-of-band,
- * e.g. by a protocol that uses HPACK
- * (see <a href="https://tools.ietf.org/html/rfc7541#section-4.2">4.2. Maximum Table Size</a>).
- *
- * <p> May be called any number of times after or before a complete header
- * has been encoded.
- *
- * <p> If the encoder decides to change the actual capacity, an update will
- * be encoded before a new encoding operation starts.
- *
- * @param capacity
- * a non-negative integer
- *
- * @throws IllegalArgumentException
- * if capacity is negative
- * @throws IllegalStateException
- * if the encoder hasn't fully encoded the previous header, or
- * hasn't yet started to encode it
- */
- public void setMaxCapacity(int capacity) {
- if (logger.isLoggable(NORMAL)) {
- logger.log(NORMAL, () -> format("setting maximum table size to %s",
- capacity));
- }
- setMaxCapacity0(capacity);
- }
-
- private void setMaxCapacity0(int capacity) {
- checkEncoding();
- if (capacity < 0) {
- throw new IllegalArgumentException("capacity >= 0: " + capacity);
- }
- int calculated = calculateCapacity(capacity);
- if (logger.isLoggable(NORMAL)) {
- logger.log(NORMAL, () -> format("actual maximum table size will be %s",
- calculated));
- }
- if (calculated < 0 || calculated > capacity) {
- throw new IllegalArgumentException(
- format("0 <= calculated <= capacity: calculated=%s, capacity=%s",
- calculated, capacity));
- }
- capacityUpdate = true;
- // maxCapacity needs to be updated unconditionally, so the encoder
- // always has the newest one (in case it decides to update it later
- // unsolicitedly)
- // Suppose maxCapacity = 4096, and the encoder has decided to use only
- // 2048. It later can choose anything else from the region [0, 4096].
- maxCapacity = capacity;
- lastCapacity = calculated;
- minCapacity = Math.min(minCapacity, lastCapacity);
- }
-
- /**
- * Calculates actual capacity to be used by this encoder in response to
- * a request to update maximum table size.
- *
- * <p> Default implementation does not add anything to the headers table,
- * hence this method returns {@code 0}.
- *
- * <p> It is an error to return a value {@code c}, where {@code c < 0} or
- * {@code c > maxCapacity}.
- *
- * @param maxCapacity
- * upper bound
- *
- * @return actual capacity
- */
- protected int calculateCapacity(int maxCapacity) {
- return 0;
- }
-
- /**
- * Encodes the {@linkplain #header(CharSequence, CharSequence) set up}
- * header into the given buffer.
- *
- * <p> The encoder writes as much as possible of the header's binary
- * representation into the given buffer, starting at the buffer's position,
- * and increments its position to reflect the bytes written. The buffer's
- * mark and limit will not be modified.
- *
- * <p> Once the method has returned {@code true}, the current header is
- * deemed encoded. A new header may be set up.
- *
- * @param headerBlock
- * the buffer to encode the header into, may be empty
- *
- * @return {@code true} if the current header has been fully encoded,
- * {@code false} otherwise
- *
- * @throws NullPointerException
- * if the buffer is {@code null}
- * @throws ReadOnlyBufferException
- * if this buffer is read-only
- * @throws IllegalStateException
- * if there is no set up header
- */
- public final boolean encode(ByteBuffer headerBlock) {
- if (!encoding) {
- throw new IllegalStateException("A header hasn't been set up");
- }
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("writing to %s", headerBlock));
- }
- if (!prependWithCapacityUpdate(headerBlock)) { // TODO: log
- return false;
- }
- boolean done = writer.write(headerTable, headerBlock);
- if (done) {
- writer.reset(); // FIXME: WHY?
- encoding = false;
- }
- return done;
- }
-
- private boolean prependWithCapacityUpdate(ByteBuffer headerBlock) {
- if (capacityUpdate) {
- if (!configuredCapacityUpdate) {
- List<Integer> sizes = new LinkedList<>();
- if (minCapacity < currCapacity) {
- sizes.add((int) minCapacity);
- if (minCapacity != lastCapacity) {
- sizes.add(lastCapacity);
- }
- } else if (lastCapacity != currCapacity) {
- sizes.add(lastCapacity);
- }
- bulkSizeUpdateWriter.maxHeaderTableSizes(sizes);
- configuredCapacityUpdate = true;
- }
- boolean done = bulkSizeUpdateWriter.write(headerTable, headerBlock);
- if (done) {
- minCapacity = lastCapacity;
- currCapacity = lastCapacity;
- bulkSizeUpdateWriter.reset();
- capacityUpdate = false;
- configuredCapacityUpdate = false;
- }
- return done;
- }
- return true;
- }
-
- protected final void indexed(int index) throws IndexOutOfBoundsException {
- checkEncoding();
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("indexed %s", index));
- }
- encoding = true;
- writer = indexedWriter.index(index);
- }
-
- protected final void literal(int index,
- CharSequence value,
- boolean useHuffman)
- throws IndexOutOfBoundsException {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("literal without indexing ('%s', '%s')",
- index, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalWriter
- .index(index).value(value, useHuffman);
- }
-
- protected final void literal(CharSequence name,
- boolean nameHuffman,
- CharSequence value,
- boolean valueHuffman) {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("literal without indexing ('%s', '%s')",
- name, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalWriter
- .name(name, nameHuffman).value(value, valueHuffman);
- }
-
- protected final void literalNeverIndexed(int index,
- CharSequence value,
- boolean valueHuffman)
- throws IndexOutOfBoundsException {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("literal never indexed ('%s', '%s')",
- index, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalNeverIndexedWriter
- .index(index).value(value, valueHuffman);
- }
-
- protected final void literalNeverIndexed(CharSequence name,
- boolean nameHuffman,
- CharSequence value,
- boolean valueHuffman) {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("literal never indexed ('%s', '%s')",
- name, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalNeverIndexedWriter
- .name(name, nameHuffman).value(value, valueHuffman);
- }
-
- protected final void literalWithIndexing(int index,
- CharSequence value,
- boolean valueHuffman)
- throws IndexOutOfBoundsException {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("literal with incremental indexing ('%s', '%s')",
- index, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalWithIndexingWriter
- .index(index).value(value, valueHuffman);
- }
-
- protected final void literalWithIndexing(CharSequence name,
- boolean nameHuffman,
- CharSequence value,
- boolean valueHuffman) {
- if (logger.isLoggable(EXTRA)) { // TODO: include huffman info?
- logger.log(EXTRA, () -> format("literal with incremental indexing ('%s', '%s')",
- name, value));
- }
- checkEncoding();
- encoding = true;
- writer = literalWithIndexingWriter
- .name(name, nameHuffman).value(value, valueHuffman);
- }
-
- protected final void sizeUpdate(int capacity)
- throws IllegalArgumentException {
- if (logger.isLoggable(EXTRA)) {
- logger.log(EXTRA, () -> format("dynamic table size update %s",
- capacity));
- }
- checkEncoding();
- // Ensure subclass follows the contract
- if (capacity > this.maxCapacity) {
- throw new IllegalArgumentException(
- format("capacity <= maxCapacity: capacity=%s, maxCapacity=%s",
- capacity, maxCapacity));
- }
- writer = sizeUpdateWriter.maxHeaderTableSize(capacity);
- }
-
- protected final int getMaxCapacity() {
- return maxCapacity;
- }
-
- protected final HeaderTable getHeaderTable() {
- return headerTable;
- }
-
- protected final void checkEncoding() { // TODO: better name e.g. checkIfEncodingInProgress()
- if (encoding) {
- throw new IllegalStateException(
- "Previous encoding operation hasn't finished yet");
- }
- }
-}