Update HPACK implementation to draft 05

net/spdy/hpack_header_table.cc

 // 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_header_table.h"
 
 #include "base/logging.h"
 #include "net/spdy/hpack_string_util.h"
 
 namespace net {
 
 HpackHeaderTable::HpackHeaderTable() : size_(0), max_size_(4096) {}
 
 HpackHeaderTable::~HpackHeaderTable() {}
 
 uint32 HpackHeaderTable::GetEntryCount() const {
   size_t size = entries_.size();
   DCHECK_LE(size, kuint32max);
   return static_cast<uint32>(size);
 }
 
 const HpackEntry& HpackHeaderTable::GetEntry(uint32 index) const {
-  CHECK_LT(index, GetEntryCount());
-  return entries_[index];
+  CHECK_GE(index, 1u);
+  CHECK_LE(index, GetEntryCount());
+  return entries_[index-1];
 }
 
 HpackEntry* HpackHeaderTable::GetMutableEntry(uint32 index) {
-  CHECK_LT(index, GetEntryCount());
-  return &entries_[index];
+  CHECK_GE(index, 1u);
+  CHECK_LE(index, GetEntryCount());
+  return &entries_[index-1];
 }
 
 void HpackHeaderTable::SetMaxSize(uint32 max_size) {
   max_size_ = max_size;
   while (size_ > max_size_) {
     CHECK(!entries_.empty());
     size_ -= entries_.back().Size();
     entries_.pop_back();
   }
 }
 
 void HpackHeaderTable::TryAddEntry(
     const HpackEntry& entry,
-    int32* index,
+    uint32* index,
     std::vector<uint32>* removed_referenced_indices) {
-  *index = -1;
+  *index = 0;
   removed_referenced_indices->clear();
 
   // The algorithm used here is described in 3.3.3. We're assuming
   // that the given entry is caching the name/value.
   size_t target_size = 0;
   size_t size_t_max_size = static_cast<size_t>(max_size_);
   if (entry.Size() <= size_t_max_size) {
     // The conditional implies the difference can fit in 32 bits.
     target_size = size_t_max_size - entry.Size();
   }
-  while ((static_cast<size_t>(size_) > target_size) && !entries_.empty()) {
+  while (static_cast<size_t>(size_) > target_size) {
+    DCHECK(!entries_.empty());
     if (entries_.back().IsReferenced()) {
-      removed_referenced_indices->push_back(entries_.size() - 1);
+      removed_referenced_indices->push_back(entries_.size());
     }
     size_ -= entries_.back().Size();
     entries_.pop_back();
   }
 
   if (entry.Size() <= size_t_max_size) {
     // Implied by the exit condition of the while loop above and the
     // condition of the if.
     DCHECK_LE(static_cast<size_t>(size_) + entry.Size(), size_t_max_size);
     size_ += entry.Size();
-    *index = 0;
+    *index = 1;
     entries_.push_front(entry);
   }
 }
 
 }  // namespace net