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_ENTRY_H_ 6 #define NET_SPDY_HPACK_ENTRY_H_ 7 8 #include <cstddef> 9 #include <set> 10 #include <string> 11 12 #include "base/basictypes.h" 13 #include "base/macros.h" 14 #include "base/strings/string_piece.h" 15 #include "net/base/net_export.h" 16 17 // All section references below are to 18 // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07 19 20 namespace net { 21 22 // A structure for an entry in the header table (3.1.2) and the 23 // reference set (3.1.3). 24 class NET_EXPORT_PRIVATE HpackEntry { 25 public: 26 // The constant amount added to name().size() and value().size() to 27 // get the size of an HpackEntry as defined in 3.3.1. 28 static const size_t kSizeOverhead; 29 30 // Creates an entry. Preconditions: 31 // - |is_static| captures whether this entry is a member of the static 32 // or dynamic header table. 33 // - |insertion_index| is this entry's index in the total set of entries ever 34 // inserted into the header table (including static entries). 35 // 36 // The combination of |is_static| and |insertion_index| allows an 37 // HpackEntryTable to determine the index of an HpackEntry in O(1) time. 38 HpackEntry(base::StringPiece name, 39 base::StringPiece value, 40 bool is_static, 41 size_t insertion_index); 42 43 // Create a 'lookup' entry (only) suitable for querying a HpackEntrySet. The 44 // instance InsertionIndex() always returns 0 and IsLookup() returns true. 45 HpackEntry(base::StringPiece name, base::StringPiece value); 46 47 // Creates an entry with empty name and value. Only defined so that 48 // entries can be stored in STL containers. 49 HpackEntry(); 50 51 ~HpackEntry(); 52 name()53 const std::string& name() const { return name_; } value()54 const std::string& value() const { return value_; } 55 56 // Returns whether this entry is a member of the static (as opposed to 57 // dynamic) table. IsStatic()58 bool IsStatic() const { return type_ == STATIC; } 59 60 // Returns whether this entry is a lookup-only entry. IsLookup()61 bool IsLookup() const { return type_ == LOOKUP; } 62 63 // Returns and sets the state of the entry, or zero if never set. 64 // The semantics of |state| are specific to the encoder or decoder. state()65 uint8 state() const { return state_; } set_state(uint8 state)66 void set_state(uint8 state) { state_ = state; } 67 68 // Used to compute the entry's index in the header table. InsertionIndex()69 size_t InsertionIndex() const { return insertion_index_; } 70 71 // Returns the size of an entry as defined in 3.3.1. 72 static size_t Size(base::StringPiece name, base::StringPiece value); 73 size_t Size() const; 74 75 std::string GetDebugString() const; 76 77 private: 78 enum EntryType { 79 LOOKUP, 80 DYNAMIC, 81 STATIC, 82 }; 83 84 // TODO(jgraettinger): Reduce copies, possibly via SpdyPinnableBufferPiece. 85 std::string name_; 86 std::string value_; 87 88 // The entry's index in the total set of entries ever inserted into the header 89 // table. 90 size_t insertion_index_; 91 92 uint8 state_; 93 EntryType type_; 94 }; 95 96 } // namespace net 97 98 #endif // NET_SPDY_HPACK_ENTRY_H_ 99