net/spdy/hpack_header_table.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_HEADER_TABLE_H_
   6 #define NET_SPDY_HPACK_HEADER_TABLE_H_
   7
   8 #include <cstddef>
   9 #include <deque>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/macros.h"
  14 #include "net/base/net_export.h"
  15 #include "net/spdy/hpack_entry.h"
  16
  17 namespace net {
  18
  19 // All section references below are to
  20 // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-05
  21 // .
  22
  23 // A data structure for both the header table (described in 3.1.2) and
  24 // the reference set (3.1.3). This structure also keeps track of how
  25 // many times a header has been 'touched', which is useful for both
  26 // encoding and decoding.
  27 class NET_EXPORT_PRIVATE HpackHeaderTable {
  28  public:
  29   HpackHeaderTable();
  30
  31   ~HpackHeaderTable();
  32
  33   uint32 size() const { return size_; }
  34   uint32 max_size() const { return max_size_; }
  35
  36   // Returns the total number of entries.
  37   uint32 GetEntryCount() const;
  38
  39   // The given index must be >= 1 and <= GetEntryCount().
  40   const HpackEntry& GetEntry(uint32 index) const;
  41
  42   // The given index must be >= 1 and <= GetEntryCount().
  43   HpackEntry* GetMutableEntry(uint32 index);
  44
  45   // Sets the maximum size of the header table, evicting entries if
  46   // necessary as described in 3.3.2.
  47   void SetMaxSize(uint32 max_size);
  48
  49   // The given entry must not be one from the header table, since it
  50   // may get evicted. Tries to add the given entry to the header
  51   // table, evicting entries if necessary as described in 3.3.3. index
  52   // will be filled in with the index of the added entry, or 0 if the
  53   // entry could not be added. removed_referenced_indices will be
  54   // filled in with the indices of any removed entries that were in
  55   // the reference set.
  56   void TryAddEntry(const HpackEntry& entry,
  57                    uint32* index,
  58                    std::vector<uint32>* removed_referenced_indices);
  59
  60  private:
  61   std::deque<HpackEntry> entries_;
  62   uint32 size_;
  63   uint32 max_size_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(HpackHeaderTable);
  66 };
  67
  68 }  // namespace net
  69
  70 #endif  // NET_SPDY_HPACK_HEADER_TABLE_H_