HPACK changes required for specification draft '07

net/spdy/hpack_constants.h

 // Copyright 2014 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.
 
 #ifndef NET_SPDY_HPACK_CONSTANTS_H_
 #define NET_SPDY_HPACK_CONSTANTS_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "net/base/net_export.h"
 
 // All section references below are to
-// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-06
+// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07
 
 namespace net {
 
 // An HpackPrefix signifies |bits| stored in the top |bit_size| bits
 // of an octet.
 struct HpackPrefix {
   uint8 bits;
   size_t bit_size;
 };
 
@@ skipping 10 matching lines @@
 
 // Largest string literal an HpackDecoder/HpackEncoder will attempt to process
 // before returning an error.
 const uint32 kDefaultMaxStringLiteralSize = 16 * 1024;
 
 // Maximum amount of encoded header buffer HpackDecoder will retain before
 // returning an error.
 // TODO(jgraettinger): Remove with SpdyHeadersHandlerInterface switch.
 const uint32 kMaxDecodeBufferSize = 32 * 1024;
 
-// The marker for a string literal that is stored unmodified (i.e.,
-// without Huffman encoding) (from 4.1.2).
+// 4.1.2: Flag for a string literal that is stored unmodified (i.e.,
+// without Huffman encoding).
 const HpackPrefix kStringLiteralIdentityEncoded = { 0x0, 1 };
 
-// The marker for a string literal that is stored with Huffman
-// encoding (from 4.1.2).
+// 4.1.2: Flag for a Huffman-coded string literal.
 const HpackPrefix kStringLiteralHuffmanEncoded = { 0x1, 1 };
 
-// The opcode for an encoding context update (from 4.2).
-// This is an indexed header representation with special index zero,
-// and as such this opcode must be tested prior to |kIndexedOpcode|.
-const HpackPrefix kEncodingContextOpcode = { 0x80, 8 };
-
-// Follows an |kEncodingContextOpcode| to indicate the reference set should be
-// cleared. (Section 4.4).
-const HpackPrefix kEncodingContextEmptyReferenceSet = { 0x80, 8 };
-
-// Follows an |kEncodingContextOpcode| to indicate the encoder is using a new
-// maximum headers table size. (Section 4.4).
-const HpackPrefix kEncodingContextNewMaximumSize = { 0x0, 1 };
-
-// The opcode for an indexed header field (from 4.2).
+// 4.2: Opcode for an indexed header field.
 const HpackPrefix kIndexedOpcode = { 0x1, 1 };
 
-// The opcode for a literal header field without indexing (from
-// 4.3.1).
-const HpackPrefix kLiteralNoIndexOpcode = { 0x01, 2 };
+// 4.3.1: Opcode for a literal header field with incremental indexing.
+const HpackPrefix kLiteralIncrementalIndexOpcode = { 0x1, 2 };
 
-// The opcode for a literal header field with incremental indexing
-// (from 4.3.2).
-const HpackPrefix kLiteralIncrementalIndexOpcode = { 0x00, 2 };
+// 4.3.2: Opcode for a literal header field without indexing.
+const HpackPrefix kLiteralNoIndexOpcode = { 0x0, 4 };
+
+// 4.3.3: Opcode for a literal header field which is never indexed.
+const HpackPrefix kLiteralNeverIndexOpcode = { 0x1, 4 };
+
+// 4.4: Opcode for an encoding context update.
+const HpackPrefix kEncodingContextOpcode = { 0x1, 3 };
+
+// 4.4: Flag following an |kEncodingContextOpcode|, which indicates
+// the reference set should be cleared.
+const HpackPrefix kEncodingContextEmptyReferenceSet = { 0x10, 5 };
+
+// 4.4: Flag following an |kEncodingContextOpcode|, which indicates
+// the encoder is using a new maximum headers table size. Begins a
+// varint-encoded table size with a 4-bit prefix.
+const HpackPrefix kEncodingContextNewMaximumSize = { 0x0, 1 };
 
 // Returns symbol code table from "Appendix C. Huffman Codes".
 NET_EXPORT_PRIVATE std::vector<HpackHuffmanSymbol> HpackHuffmanCode();
 
 // Returns a HpackHuffmanTable instance initialized with |kHpackHuffmanCode|.
 // The instance is read-only, has static lifetime, and is safe to share amoung
 // threads. This function is thread-safe.
 NET_EXPORT_PRIVATE const HpackHuffmanTable& ObtainHpackHuffmanTable();
 
 }  // namespace net
 
 #endif  // NET_SPDY_HPACK_CONSTANTS_H_