net/spdy/hpack_input_stream.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_SPDY_HPACK_INPUT_STREAM_H_
   6 #define NET_SPDY_HPACK_INPUT_STREAM_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/macros.h"
  13 #include "base/strings/string_piece.h"
  14 #include "net/base/net_export.h"
  15 #include "net/spdy/hpack_constants.h"  // For HpackPrefix.
  16
  17 // All section references below are to
  18 // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-05
  19 // .
  20
  21 namespace net {
  22
  23 // TODO(akalin): When we use a callback/delegate instead of a vector,
  24 // use StringPiece instead of string.
  25 typedef std::pair<std::string, std::string> HpackHeaderPair;
  26 typedef std::vector<HpackHeaderPair> HpackHeaderPairVector;
  27
  28 // An HpackInputStream handles all the low-level details of decoding
  29 // header fields.
  30 class NET_EXPORT_PRIVATE HpackInputStream {
  31  public:
  32   // |max_string_literal_size| is the largest that any one string
  33   // literal (header name or header value) can be.
  34   HpackInputStream(uint32 max_string_literal_size, base::StringPiece buffer);
  35   ~HpackInputStream();
  36
  37   // Returns whether or not there is more data to process.
  38   bool HasMoreData() const;
  39
  40   // If the next octet has the top |size| bits equal to |bits|,
  41   // consumes it and returns true. Otherwise, consumes nothing and
  42   // returns false.
  43   bool MatchPrefixAndConsume(HpackPrefix prefix);
  44
  45   // The Decode* functions return true and fill in their arguments if
  46   // decoding was successful, or false if an error was encountered.
  47
  48   bool DecodeNextUint32(uint32* I);
  49   bool DecodeNextStringLiteral(base::StringPiece* str);
  50
  51   // Accessors for testing.
  52
  53   void SetBitOffsetForTest(size_t bit_offset) {
  54     bit_offset_ = bit_offset;
  55   }
  56
  57   bool DecodeNextUint32ForTest(uint32* I) {
  58     return DecodeNextUint32(I);
  59   }
  60
  61   bool DecodeNextStringLiteralForTest(base::StringPiece *str) {
  62     return DecodeNextStringLiteral(str);
  63   }
  64
  65  private:
  66   const uint32 max_string_literal_size_;
  67   base::StringPiece buffer_;
  68   size_t bit_offset_;
  69
  70   bool PeekNextOctet(uint8* next_octet);
  71
  72   bool DecodeNextOctet(uint8* next_octet);
  73
  74   DISALLOW_COPY_AND_ASSIGN(HpackInputStream);
  75 };
  76
  77 }  // namespace net
  78
  79 #endif  // NET_SPDY_HPACK_INPUT_STREAM_H_