root/net/spdy/hpack_encoding_context.cc

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DEFINITIONS

This source file includes following definitions.
  1. GetMutableEntryCount
  2. GetEntryCount
  3. GetNameAt
  4. GetValueAt
  5. IsReferencedAt
  6. GetTouchCountAt
  7. SetReferencedAt
  8. AddTouchesAt
  9. ClearTouchesAt
  10. ApplyHeaderTableSizeSetting
  11. ProcessContextUpdateNewMaximumSize
  12. ProcessContextUpdateEmptyReferenceSet
  13. ProcessIndexedHeader
  14. ProcessLiteralHeaderWithIncrementalIndexing

// 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.

#include "net/spdy/hpack_encoding_context.h"

#include <cstddef>

#include "base/logging.h"
#include "base/macros.h"
#include "net/spdy/hpack_constants.h"
#include "net/spdy/hpack_entry.h"

namespace net {

using base::StringPiece;

namespace {

// An entry in the static table. Must be a POD in order to avoid
// static initializers, i.e. no user-defined constructors or
// destructors.
struct StaticEntry {
  const char* const name;
  const size_t name_len;
  const char* const value;
  const size_t value_len;
};

// The "constructor" for a StaticEntry that computes the lengths at
// compile time.
#define STATIC_ENTRY(name, value) \
  { name, arraysize(name) - 1, value, arraysize(value) - 1 }

const StaticEntry kStaticTable[] = {
  STATIC_ENTRY(":authority"                  , ""),             // 1
  STATIC_ENTRY(":method"                     , "GET"),          // 2
  STATIC_ENTRY(":method"                     , "POST"),         // 3
  STATIC_ENTRY(":path"                       , "/"),            // 4
  STATIC_ENTRY(":path"                       , "/index.html"),  // 5
  STATIC_ENTRY(":scheme"                     , "http"),         // 6
  STATIC_ENTRY(":scheme"                     , "https"),        // 7
  STATIC_ENTRY(":status"                     , "200"),          // 8
  STATIC_ENTRY(":status"                     , "500"),          // 9
  STATIC_ENTRY(":status"                     , "404"),          // 10
  STATIC_ENTRY(":status"                     , "403"),          // 11
  STATIC_ENTRY(":status"                     , "400"),          // 12
  STATIC_ENTRY(":status"                     , "401"),          // 13
  STATIC_ENTRY("accept-charset"              , ""),             // 14
  STATIC_ENTRY("accept-encoding"             , ""),             // 15
  STATIC_ENTRY("accept-language"             , ""),             // 16
  STATIC_ENTRY("accept-ranges"               , ""),             // 17
  STATIC_ENTRY("accept"                      , ""),             // 18
  STATIC_ENTRY("access-control-allow-origin" , ""),             // 19
  STATIC_ENTRY("age"                         , ""),             // 20
  STATIC_ENTRY("allow"                       , ""),             // 21
  STATIC_ENTRY("authorization"               , ""),             // 22
  STATIC_ENTRY("cache-control"               , ""),             // 23
  STATIC_ENTRY("content-disposition"         , ""),             // 24
  STATIC_ENTRY("content-encoding"            , ""),             // 25
  STATIC_ENTRY("content-language"            , ""),             // 26
  STATIC_ENTRY("content-length"              , ""),             // 27
  STATIC_ENTRY("content-location"            , ""),             // 28
  STATIC_ENTRY("content-range"               , ""),             // 29
  STATIC_ENTRY("content-type"                , ""),             // 30
  STATIC_ENTRY("cookie"                      , ""),             // 31
  STATIC_ENTRY("date"                        , ""),             // 32
  STATIC_ENTRY("etag"                        , ""),             // 33
  STATIC_ENTRY("expect"                      , ""),             // 34
  STATIC_ENTRY("expires"                     , ""),             // 35
  STATIC_ENTRY("from"                        , ""),             // 36
  STATIC_ENTRY("host"                        , ""),             // 37
  STATIC_ENTRY("if-match"                    , ""),             // 38
  STATIC_ENTRY("if-modified-since"           , ""),             // 39
  STATIC_ENTRY("if-none-match"               , ""),             // 40
  STATIC_ENTRY("if-range"                    , ""),             // 41
  STATIC_ENTRY("if-unmodified-since"         , ""),             // 42
  STATIC_ENTRY("last-modified"               , ""),             // 43
  STATIC_ENTRY("link"                        , ""),             // 44
  STATIC_ENTRY("location"                    , ""),             // 45
  STATIC_ENTRY("max-forwards"                , ""),             // 46
  STATIC_ENTRY("proxy-authenticate"          , ""),             // 47
  STATIC_ENTRY("proxy-authorization"         , ""),             // 48
  STATIC_ENTRY("range"                       , ""),             // 49
  STATIC_ENTRY("referer"                     , ""),             // 50
  STATIC_ENTRY("refresh"                     , ""),             // 51
  STATIC_ENTRY("retry-after"                 , ""),             // 52
  STATIC_ENTRY("server"                      , ""),             // 53
  STATIC_ENTRY("set-cookie"                  , ""),             // 54
  STATIC_ENTRY("strict-transport-security"   , ""),             // 55
  STATIC_ENTRY("transfer-encoding"           , ""),             // 56
  STATIC_ENTRY("user-agent"                  , ""),             // 57
  STATIC_ENTRY("vary"                        , ""),             // 58
  STATIC_ENTRY("via"                         , ""),             // 59
  STATIC_ENTRY("www-authenticate"            , ""),             // 60
};

#undef STATIC_ENTRY

const size_t kStaticEntryCount = arraysize(kStaticTable);

}  // namespace

// Must match HpackEntry::kUntouched.
const uint32 HpackEncodingContext::kUntouched = 0x7fffffff;

HpackEncodingContext::HpackEncodingContext()
    : settings_header_table_size_(kDefaultHeaderTableSizeSetting) {
  DCHECK_EQ(HpackEncodingContext::kUntouched, HpackEntry::kUntouched);
}

HpackEncodingContext::~HpackEncodingContext() {}

uint32 HpackEncodingContext::GetMutableEntryCount() const {
  return header_table_.GetEntryCount();
}

uint32 HpackEncodingContext::GetEntryCount() const {
  return GetMutableEntryCount() + kStaticEntryCount;
}

StringPiece HpackEncodingContext::GetNameAt(uint32 index) const {
  CHECK_GE(index, 1u);
  CHECK_LE(index, GetEntryCount());
  if (index > header_table_.GetEntryCount()) {
    const StaticEntry& entry =
        kStaticTable[index - header_table_.GetEntryCount() - 1];
    return StringPiece(entry.name, entry.name_len);
  }
  return header_table_.GetEntry(index).name();
}

StringPiece HpackEncodingContext::GetValueAt(uint32 index) const {
  CHECK_GE(index, 1u);
  CHECK_LE(index, GetEntryCount());
  if (index > header_table_.GetEntryCount()) {
    const StaticEntry& entry =
        kStaticTable[index - header_table_.GetEntryCount() - 1];
    return StringPiece(entry.value, entry.value_len);
  }
  return header_table_.GetEntry(index).value();
}

bool HpackEncodingContext::IsReferencedAt(uint32 index) const {
  CHECK_GE(index, 1u);
  CHECK_LE(index, GetEntryCount());
  if (index > header_table_.GetEntryCount())
    return false;
  return header_table_.GetEntry(index).IsReferenced();
}

uint32 HpackEncodingContext::GetTouchCountAt(uint32 index) const {
  CHECK_GE(index, 1u);
  CHECK_LE(index, GetEntryCount());
  if (index > header_table_.GetEntryCount())
    return 0;
  return header_table_.GetEntry(index).TouchCount();
}

void HpackEncodingContext::SetReferencedAt(uint32 index, bool referenced) {
  header_table_.GetMutableEntry(index)->SetReferenced(referenced);
}

void HpackEncodingContext::AddTouchesAt(uint32 index, uint32 touch_count) {
  header_table_.GetMutableEntry(index)->AddTouches(touch_count);
}

void HpackEncodingContext::ClearTouchesAt(uint32 index) {
  header_table_.GetMutableEntry(index)->ClearTouches();
}

void HpackEncodingContext::ApplyHeaderTableSizeSetting(uint32 size) {
  settings_header_table_size_ = size;
  if (size < header_table_.max_size()) {
    // Implicit maximum-size context update.
    CHECK(ProcessContextUpdateNewMaximumSize(size));
  }
}

bool HpackEncodingContext::ProcessContextUpdateNewMaximumSize(uint32 size) {
  if (size > settings_header_table_size_) {
    return false;
  }
  header_table_.SetMaxSize(size);
  return true;
}

bool HpackEncodingContext::ProcessContextUpdateEmptyReferenceSet() {
  for (size_t i = 1; i <= header_table_.GetEntryCount(); ++i) {
    HpackEntry* entry = header_table_.GetMutableEntry(i);
    if (entry->IsReferenced()) {
      entry->SetReferenced(false);
    }
  }
  return true;
}

bool HpackEncodingContext::ProcessIndexedHeader(uint32 index, uint32* new_index,
    std::vector<uint32>* removed_referenced_indices) {
  CHECK_GT(index, 0u);
  CHECK_LT(index, GetEntryCount());

  if (index <= header_table_.GetEntryCount()) {
    *new_index = index;
    removed_referenced_indices->clear();
    HpackEntry* entry = header_table_.GetMutableEntry(index);
    entry->SetReferenced(!entry->IsReferenced());
  } else {
    // TODO(akalin): Make HpackEntry know about owned strings and
    // non-owned strings so that it can potentially avoid copies here.
    HpackEntry entry(GetNameAt(index), GetValueAt(index));

    header_table_.TryAddEntry(entry, new_index, removed_referenced_indices);
    if (*new_index >= 1) {
      header_table_.GetMutableEntry(*new_index)->SetReferenced(true);
    }
  }
  return true;
}

bool HpackEncodingContext::ProcessLiteralHeaderWithIncrementalIndexing(
    StringPiece name,
    StringPiece value,
    uint32* index,
    std::vector<uint32>* removed_referenced_indices) {
  HpackEntry entry(name, value);
  header_table_.TryAddEntry(entry, index, removed_referenced_indices);
  if (*index >= 1) {
    header_table_.GetMutableEntry(*index)->SetReferenced(true);
  }
  return true;
}

}  // namespace net

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