DO NOT COMMIT: Implement HPACK (draft 03)

net/spdy/http2_compressor.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/spdy/http2_compressor.h"
+
+#include "base/logging.h"
+
+namespace net {
+
+Http2Encoder::Http2Encoder() {}
+
+void Http2Encoder::EncodeOctet(uint8 octet) {
+  buffer_.append(1, octet);
+}
+
+void Http2Encoder::EncodeInteger(uint8 op_code, uint8 N, uint32 I) {
+  DCHECK_LT(N, 8u);
+  DCHECK_LT(static_cast<uint16>(op_code), 1u << (8 - N));
+
+  uint8 next_marker = (1 << N) - 1;
+
+  if (I < next_marker) {
+    EncodeOctet((op_code << N) | I);
+    return;
+  }
+
+  if (N > 0) {
+    EncodeOctet((op_code << N) | next_marker);
+  }
+
+  I -= next_marker;
+  while (I >= 128) {
+    EncodeOctet(I % 128 | 128);
+    I /= 128;
+  }
+  EncodeOctet(I);
+}
+
+void Http2Encoder::EncodeOctetSequence(base::StringPiece str) {
+  uint32 size_to_encode = static_cast<uint32>(str.size());
+  DCHECK_EQ(static_cast<size_t>(size_to_encode), str.size());
+  EncodeInteger(0, 0, size_to_encode);
+  buffer_.append(str.data(), str.size());
+}
+
+void Http2Encoder::EncodeIndexedHeader(uint32 index) {
+  EncodeInteger(kIndexOpcode, kIndexN, index);
+}
+
+void Http2Encoder::EncodeLiteralHeaderNoIndexingWithIndex(
+    uint32 index,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralNoIndexOpcode, kLiteralNoIndexN, index + 1);
+  EncodeOctetSequence(value);
+}
+
+void Http2Encoder::EncodeLiteralHeaderNoIndexingWithName(
+    base::StringPiece name,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralNoIndexOpcode, kLiteralNoIndexN, 0);
+  EncodeOctetSequence(name);
+  EncodeOctetSequence(value);
+}
+
+void Http2Encoder::EncodeLiteralHeaderWithIncrementalIndexingWithIndex(
+    uint32 index,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralIncrementalOpcode, kLiteralIncrementalN, index + 1);
+  EncodeOctetSequence(value);
+}
+
+void Http2Encoder::EncodeLiteralHeaderWithIncrementalIndexingWithName(
+    base::StringPiece name,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralIncrementalOpcode, kLiteralIncrementalN, 0);
+  EncodeOctetSequence(name);
+  EncodeOctetSequence(value);
+}
+
+void Http2Encoder::EncodeLiteralHeaderWithSubstitutionIndexingWithIndex(
+    uint32 index,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralSubstitutionOpcode, kLiteralSubstitutionN, index + 1);
+  EncodeOctetSequence(value);
+}
+
+void Http2Encoder::EncodeLiteralHeaderWithSubstitutionIndexingWithName(
+    base::StringPiece name,
+    base::StringPiece value) {
+  EncodeInteger(kLiteralSubstitutionOpcode, kLiteralSubstitutionN, 0);
+  EncodeOctetSequence(name);
+  EncodeOctetSequence(value);
+}
+
+std::string Http2Encoder::Flush() {
+  std::string out;
+  out.swap(buffer_);
+  return out;
+}
+
+Http2Compressor::Http2Compressor() : encoding_context_(HTTP2_REQUEST) {}
+
+Http2Compressor::~Http2Compressor() {}
+
+std::string Http2Compressor::EncodeNameValueBlock(
+    const SpdyNameValueBlock& name_value_block) {
+  Http2Encoder encoder;
+  for (SpdyNameValueBlock::const_iterator it = name_value_block.begin();
+       it != name_value_block.end(); ++it) {
+    encoder.EncodeLiteralHeaderNoIndexingWithName(it->first, it->second);
+  }
+
+  // TODO(akalin): Process unemitted entries in reference set.
+
+  return encoder.Flush();
+}
+
+}  // namespace net