| // 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 <algorithm> |
| |
| #include "base/logging.h" |
| #include "net/spdy/hpack_constants.h" |
| #include "net/spdy/hpack_static_table.h" |
| #include "net/spdy/hpack_string_util.h" |
| |
| namespace net { |
| |
| using base::StringPiece; |
| |
| bool HpackHeaderTable::EntryComparator::operator() ( |
| const HpackEntry* lhs, const HpackEntry* rhs) const { |
| int result = lhs->name().compare(rhs->name()); |
| if (result != 0) |
| return result < 0; |
| result = lhs->value().compare(rhs->value()); |
| if (result != 0) |
| return result < 0; |
| const size_t lhs_index = lhs->IsLookup() ? 0 : 1 + lhs->InsertionIndex(); |
| const size_t rhs_index = rhs->IsLookup() ? 0 : 1 + rhs->InsertionIndex(); |
| DCHECK(lhs == rhs || lhs_index != rhs_index) |
| << "lhs: (" << lhs->name() << ", " << rhs->value() << ") rhs: (" |
| << rhs->name() << ", " << rhs->value() << ")" |
| << " lhs index: " << lhs_index << " rhs index: " << rhs_index; |
| return lhs_index < rhs_index; |
| } |
| |
| HpackHeaderTable::HpackHeaderTable() |
| : static_entries_(ObtainHpackStaticTable().GetStaticEntries()), |
| static_index_(ObtainHpackStaticTable().GetStaticIndex()), |
| settings_size_bound_(kDefaultHeaderTableSizeSetting), |
| size_(0), |
| max_size_(kDefaultHeaderTableSizeSetting), |
| total_insertions_(static_entries_.size()) {} |
| |
| HpackHeaderTable::~HpackHeaderTable() {} |
| |
| const HpackEntry* HpackHeaderTable::GetByIndex(size_t index) { |
| if (index == 0) { |
| return NULL; |
| } |
| index -= 1; |
| if (index < static_entries_.size()) { |
| return &static_entries_[index]; |
| } |
| index -= static_entries_.size(); |
| if (index < dynamic_entries_.size()) { |
| return &dynamic_entries_[index]; |
| } |
| return NULL; |
| } |
| |
| const HpackEntry* HpackHeaderTable::GetByName(StringPiece name) { |
| HpackEntry query(name, ""); |
| { |
| OrderedEntrySet::const_iterator it = static_index_.lower_bound(&query); |
| if (it != static_index_.end() && (*it)->name() == name) { |
| return *it; |
| } |
| } |
| { |
| OrderedEntrySet::const_iterator it = dynamic_index_.lower_bound(&query); |
| if (it != dynamic_index_.end() && (*it)->name() == name) { |
| return *it; |
| } |
| } |
| return NULL; |
| } |
| |
| const HpackEntry* HpackHeaderTable::GetByNameAndValue(StringPiece name, |
| StringPiece value) { |
| HpackEntry query(name, value); |
| { |
| OrderedEntrySet::const_iterator it = static_index_.lower_bound(&query); |
| if (it != static_index_.end() && |
| (*it)->name() == name && |
| (*it)->value() == value) { |
| return *it; |
| } |
| } |
| { |
| OrderedEntrySet::const_iterator it = dynamic_index_.lower_bound(&query); |
| if (it != dynamic_index_.end() && |
| (*it)->name() == name && |
| (*it)->value() == value) { |
| return *it; |
| } |
| } |
| return NULL; |
| } |
| |
| size_t HpackHeaderTable::IndexOf(const HpackEntry* entry) const { |
| if (entry->IsLookup()) { |
| return 0; |
| } else if (entry->IsStatic()) { |
| return 1 + entry->InsertionIndex(); |
| } else { |
| return total_insertions_ - entry->InsertionIndex() + static_entries_.size(); |
| } |
| } |
| |
| void HpackHeaderTable::SetMaxSize(size_t max_size) { |
| CHECK_LE(max_size, settings_size_bound_); |
| |
| max_size_ = max_size; |
| if (size_ > max_size_) { |
| Evict(EvictionCountToReclaim(size_ - max_size_)); |
| CHECK_LE(size_, max_size_); |
| } |
| } |
| |
| void HpackHeaderTable::SetSettingsHeaderTableSize(size_t settings_size) { |
| settings_size_bound_ = settings_size; |
| if (settings_size_bound_ < max_size_) { |
| SetMaxSize(settings_size_bound_); |
| } |
| } |
| |
| void HpackHeaderTable::EvictionSet(StringPiece name, |
| StringPiece value, |
| EntryTable::iterator* begin_out, |
| EntryTable::iterator* end_out) { |
| size_t eviction_count = EvictionCountForEntry(name, value); |
| *begin_out = dynamic_entries_.end() - eviction_count; |
| *end_out = dynamic_entries_.end(); |
| } |
| |
| size_t HpackHeaderTable::EvictionCountForEntry(StringPiece name, |
| StringPiece value) const { |
| size_t available_size = max_size_ - size_; |
| size_t entry_size = HpackEntry::Size(name, value); |
| |
| if (entry_size <= available_size) { |
| // No evictions are required. |
| return 0; |
| } |
| return EvictionCountToReclaim(entry_size - available_size); |
| } |
| |
| size_t HpackHeaderTable::EvictionCountToReclaim(size_t reclaim_size) const { |
| size_t count = 0; |
| for (EntryTable::const_reverse_iterator it = dynamic_entries_.rbegin(); |
| it != dynamic_entries_.rend() && reclaim_size != 0; ++it, ++count) { |
| reclaim_size -= std::min(reclaim_size, it->Size()); |
| } |
| return count; |
| } |
| |
| void HpackHeaderTable::Evict(size_t count) { |
| for (size_t i = 0; i != count; ++i) { |
| CHECK(!dynamic_entries_.empty()); |
| HpackEntry* entry = &dynamic_entries_.back(); |
| |
| size_ -= entry->Size(); |
| CHECK_EQ(1u, dynamic_index_.erase(entry)); |
| dynamic_entries_.pop_back(); |
| } |
| } |
| |
| const HpackEntry* HpackHeaderTable::TryAddEntry(StringPiece name, |
| StringPiece value) { |
| Evict(EvictionCountForEntry(name, value)); |
| |
| size_t entry_size = HpackEntry::Size(name, value); |
| if (entry_size > (max_size_ - size_)) { |
| // Entire table has been emptied, but there's still insufficient room. |
| DCHECK(dynamic_entries_.empty()); |
| DCHECK_EQ(0u, size_); |
| return NULL; |
| } |
| dynamic_entries_.push_front(HpackEntry(name, |
| value, |
| false, // is_static |
| total_insertions_)); |
| CHECK(dynamic_index_.insert(&dynamic_entries_.front()).second); |
| |
| size_ += entry_size; |
| ++total_insertions_; |
| |
| return &dynamic_entries_.front(); |
| } |
| |
| void HpackHeaderTable::DebugLogTableState() const { |
| DVLOG(2) << "Dynamic table:"; |
| for (EntryTable::const_iterator it = dynamic_entries_.begin(); |
| it != dynamic_entries_.end(); ++it) { |
| DVLOG(2) << " " << it->GetDebugString(); |
| } |
| DVLOG(2) << "Full Static Index:"; |
| for (OrderedEntrySet::const_iterator it = static_index_.begin(); |
| it != static_index_.end(); ++it) { |
| DVLOG(2) << " " << (*it)->GetDebugString(); |
| } |
| DVLOG(2) << "Full Dynamic Index:"; |
| for (OrderedEntrySet::const_iterator it = dynamic_index_.begin(); |
| it != dynamic_index_.end(); ++it) { |
| DVLOG(2) << " " << (*it)->GetDebugString(); |
| } |
| } |
| |
| } // namespace net |