src/net/spdy/hpack_encoding_context.cc

   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 #include "net/spdy/hpack_encoding_context.h"
   6
   7 #include <cstddef>
   8
   9 #include "base/logging.h"
  10 #include "base/macros.h"
  11 #include "net/spdy/hpack_constants.h"
  12 #include "net/spdy/hpack_entry.h"
  13
  14 namespace net {
  15
  16 using base::StringPiece;
  17
  18 namespace {
  19
  20 // An entry in the static table. Must be a POD in order to avoid
  21 // static initializers, i.e. no user-defined constructors or
  22 // destructors.
  23 struct StaticEntry {
  24   const char* const name;
  25   const size_t name_len;
  26   const char* const value;
  27   const size_t value_len;
  28 };
  29
  30 // The "constructor" for a StaticEntry that computes the lengths at
  31 // compile time.
  32 #define STATIC_ENTRY(name, value) \
  33   { name, arraysize(name) - 1, value, arraysize(value) - 1 }
  34
  35 const StaticEntry kStaticTable[] = {
  36   STATIC_ENTRY(":authority"                  , ""),             // 1
  37   STATIC_ENTRY(":method"                     , "GET"),          // 2
  38   STATIC_ENTRY(":method"                     , "POST"),         // 3
  39   STATIC_ENTRY(":path"                       , "/"),            // 4
  40   STATIC_ENTRY(":path"                       , "/index.html"),  // 5
  41   STATIC_ENTRY(":scheme"                     , "http"),         // 6
  42   STATIC_ENTRY(":scheme"                     , "https"),        // 7
  43   STATIC_ENTRY(":status"                     , "200"),          // 8
  44   STATIC_ENTRY(":status"                     , "500"),          // 9
  45   STATIC_ENTRY(":status"                     , "404"),          // 10
  46   STATIC_ENTRY(":status"                     , "403"),          // 11
  47   STATIC_ENTRY(":status"                     , "400"),          // 12
  48   STATIC_ENTRY(":status"                     , "401"),          // 13
  49   STATIC_ENTRY("accept-charset"              , ""),             // 14
  50   STATIC_ENTRY("accept-encoding"             , ""),             // 15
  51   STATIC_ENTRY("accept-language"             , ""),             // 16
  52   STATIC_ENTRY("accept-ranges"               , ""),             // 17
  53   STATIC_ENTRY("accept"                      , ""),             // 18
  54   STATIC_ENTRY("access-control-allow-origin" , ""),             // 19
  55   STATIC_ENTRY("age"                         , ""),             // 20
  56   STATIC_ENTRY("allow"                       , ""),             // 21
  57   STATIC_ENTRY("authorization"               , ""),             // 22
  58   STATIC_ENTRY("cache-control"               , ""),             // 23
  59   STATIC_ENTRY("content-disposition"         , ""),             // 24
  60   STATIC_ENTRY("content-encoding"            , ""),             // 25
  61   STATIC_ENTRY("content-language"            , ""),             // 26
  62   STATIC_ENTRY("content-length"              , ""),             // 27
  63   STATIC_ENTRY("content-location"            , ""),             // 28
  64   STATIC_ENTRY("content-range"               , ""),             // 29
  65   STATIC_ENTRY("content-type"                , ""),             // 30
  66   STATIC_ENTRY("cookie"                      , ""),             // 31
  67   STATIC_ENTRY("date"                        , ""),             // 32
  68   STATIC_ENTRY("etag"                        , ""),             // 33
  69   STATIC_ENTRY("expect"                      , ""),             // 34
  70   STATIC_ENTRY("expires"                     , ""),             // 35
  71   STATIC_ENTRY("from"                        , ""),             // 36
  72   STATIC_ENTRY("host"                        , ""),             // 37
  73   STATIC_ENTRY("if-match"                    , ""),             // 38
  74   STATIC_ENTRY("if-modified-since"           , ""),             // 39
  75   STATIC_ENTRY("if-none-match"               , ""),             // 40
  76   STATIC_ENTRY("if-range"                    , ""),             // 41
  77   STATIC_ENTRY("if-unmodified-since"         , ""),             // 42
  78   STATIC_ENTRY("last-modified"               , ""),             // 43
  79   STATIC_ENTRY("link"                        , ""),             // 44
  80   STATIC_ENTRY("location"                    , ""),             // 45
  81   STATIC_ENTRY("max-forwards"                , ""),             // 46
  82   STATIC_ENTRY("proxy-authenticate"          , ""),             // 47
  83   STATIC_ENTRY("proxy-authorization"         , ""),             // 48
  84   STATIC_ENTRY("range"                       , ""),             // 49
  85   STATIC_ENTRY("referer"                     , ""),             // 50
  86   STATIC_ENTRY("refresh"                     , ""),             // 51
  87   STATIC_ENTRY("retry-after"                 , ""),             // 52
  88   STATIC_ENTRY("server"                      , ""),             // 53
  89   STATIC_ENTRY("set-cookie"                  , ""),             // 54
  90   STATIC_ENTRY("strict-transport-security"   , ""),             // 55
  91   STATIC_ENTRY("transfer-encoding"           , ""),             // 56
  92   STATIC_ENTRY("user-agent"                  , ""),             // 57
  93   STATIC_ENTRY("vary"                        , ""),             // 58
  94   STATIC_ENTRY("via"                         , ""),             // 59
  95   STATIC_ENTRY("www-authenticate"            , ""),             // 60
  96 };
  97
  98 #undef STATIC_ENTRY
  99
 100 const size_t kStaticEntryCount = arraysize(kStaticTable);
 101
 102 }  // namespace
 103
 104 // Must match HpackEntry::kUntouched.
 105 const uint32 HpackEncodingContext::kUntouched = 0x7fffffff;
 106
 107 HpackEncodingContext::HpackEncodingContext()
 108     : settings_header_table_size_(kDefaultHeaderTableSizeSetting) {
 109   DCHECK_EQ(HpackEncodingContext::kUntouched, HpackEntry::kUntouched);
 110 }
 111
 112 HpackEncodingContext::~HpackEncodingContext() {}
 113
 114 uint32 HpackEncodingContext::GetMutableEntryCount() const {
 115   return header_table_.GetEntryCount();
 116 }
 117
 118 uint32 HpackEncodingContext::GetEntryCount() const {
 119   return GetMutableEntryCount() + kStaticEntryCount;
 120 }
 121
 122 StringPiece HpackEncodingContext::GetNameAt(uint32 index) const {
 123   CHECK_GE(index, 1u);
 124   CHECK_LE(index, GetEntryCount());
 125   if (index > header_table_.GetEntryCount()) {
 126     const StaticEntry& entry =
 127         kStaticTable[index - header_table_.GetEntryCount() - 1];
 128     return StringPiece(entry.name, entry.name_len);
 129   }
 130   return header_table_.GetEntry(index).name();
 131 }
 132
 133 StringPiece HpackEncodingContext::GetValueAt(uint32 index) const {
 134   CHECK_GE(index, 1u);
 135   CHECK_LE(index, GetEntryCount());
 136   if (index > header_table_.GetEntryCount()) {
 137     const StaticEntry& entry =
 138         kStaticTable[index - header_table_.GetEntryCount() - 1];
 139     return StringPiece(entry.value, entry.value_len);
 140   }
 141   return header_table_.GetEntry(index).value();
 142 }
 143
 144 bool HpackEncodingContext::IsReferencedAt(uint32 index) const {
 145   CHECK_GE(index, 1u);
 146   CHECK_LE(index, GetEntryCount());
 147   if (index > header_table_.GetEntryCount())
 148     return false;
 149   return header_table_.GetEntry(index).IsReferenced();
 150 }
 151
 152 uint32 HpackEncodingContext::GetTouchCountAt(uint32 index) const {
 153   CHECK_GE(index, 1u);
 154   CHECK_LE(index, GetEntryCount());
 155   if (index > header_table_.GetEntryCount())
 156     return 0;
 157   return header_table_.GetEntry(index).TouchCount();
 158 }
 159
 160 void HpackEncodingContext::SetReferencedAt(uint32 index, bool referenced) {
 161   header_table_.GetMutableEntry(index)->SetReferenced(referenced);
 162 }
 163
 164 void HpackEncodingContext::AddTouchesAt(uint32 index, uint32 touch_count) {
 165   header_table_.GetMutableEntry(index)->AddTouches(touch_count);
 166 }
 167
 168 void HpackEncodingContext::ClearTouchesAt(uint32 index) {
 169   header_table_.GetMutableEntry(index)->ClearTouches();
 170 }
 171
 172 void HpackEncodingContext::ApplyHeaderTableSizeSetting(uint32 size) {
 173   settings_header_table_size_ = size;
 174   if (size < header_table_.max_size()) {
 175     // Implicit maximum-size context update.
 176     CHECK(ProcessContextUpdateNewMaximumSize(size));
 177   }
 178 }
 179
 180 bool HpackEncodingContext::ProcessContextUpdateNewMaximumSize(uint32 size) {
 181   if (size > settings_header_table_size_) {
 182     return false;
 183   }
 184   header_table_.SetMaxSize(size);
 185   return true;
 186 }
 187
 188 bool HpackEncodingContext::ProcessContextUpdateEmptyReferenceSet() {
 189   for (size_t i = 1; i <= header_table_.GetEntryCount(); ++i) {
 190     HpackEntry* entry = header_table_.GetMutableEntry(i);
 191     if (entry->IsReferenced()) {
 192       entry->SetReferenced(false);
 193     }
 194   }
 195   return true;
 196 }
 197
 198 bool HpackEncodingContext::ProcessIndexedHeader(uint32 index, uint32* new_index,
 199     std::vector<uint32>* removed_referenced_indices) {
 200   CHECK_GT(index, 0u);
 201   CHECK_LT(index, GetEntryCount());
 202
 203   if (index <= header_table_.GetEntryCount()) {
 204     *new_index = index;
 205     removed_referenced_indices->clear();
 206     HpackEntry* entry = header_table_.GetMutableEntry(index);
 207     entry->SetReferenced(!entry->IsReferenced());
 208   } else {
 209     // TODO(akalin): Make HpackEntry know about owned strings and
 210     // non-owned strings so that it can potentially avoid copies here.
 211     HpackEntry entry(GetNameAt(index), GetValueAt(index));
 212
 213     header_table_.TryAddEntry(entry, new_index, removed_referenced_indices);
 214     if (*new_index >= 1) {
 215       header_table_.GetMutableEntry(*new_index)->SetReferenced(true);
 216     }
 217   }
 218   return true;
 219 }
 220
 221 bool HpackEncodingContext::ProcessLiteralHeaderWithIncrementalIndexing(
 222     StringPiece name,
 223     StringPiece value,
 224     uint32* index,
 225     std::vector<uint32>* removed_referenced_indices) {
 226   HpackEntry entry(name, value);
 227   header_table_.TryAddEntry(entry, index, removed_referenced_indices);
 228   if (*index >= 1) {
 229     header_table_.GetMutableEntry(*index)->SetReferenced(true);
 230   }
 231   return true;
 232 }
 233
 234 }  // namespace net