Implement basic classes for HPACK (HTTP/2 compression)

net/spdy/hpack_entry.cc

+// Copyright (c) 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_entry.h"
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "net/spdy/hpack_string_util.h"
+
+namespace net {
+
+namespace {
+
+const uint32 kReferencedMask = 0x80000000;
+const uint32 kTouchCountMask = 0x7fffffff;
+
+}  // namespace
+
+const uint32 HpackEntry::kSizeOverhead = 32;
+
+const uint32 HpackEntry::kUntouched = 0x7fffffff;
+
+HpackEntry::HpackEntry() : referenced_and_touch_count_(kUntouched) {}
+
+HpackEntry::HpackEntry(base::StringPiece name, base::StringPiece value)
+    : name_(name.as_string()),
+      value_(value.as_string()),
+      referenced_and_touch_count_(kUntouched) {}
+
+bool HpackEntry::IsReferenced() const {
+  return ((referenced_and_touch_count_ & kReferencedMask) != 0);
+}
+
+uint32 HpackEntry::TouchCount() const {
+  return referenced_and_touch_count_ & kTouchCountMask;
+}
+
+size_t HpackEntry::Size() const {
+  return name_.size() + value_.size() + kSizeOverhead;
+}
+
+std::string HpackEntry::GetDebugString() const {
+  const char* is_referenced_str = (IsReferenced() ? "true" : "false");
+  std::string touch_count_str = "(untouched)";
+  if (TouchCount() != kUntouched)
+    touch_count_str = base::IntToString(TouchCount());
+  return "{ name: \"" + name_ + "\", value: \"" + value_ +
+      "\", referenced: " + is_referenced_str + ", touch_count: " +
+      touch_count_str + " }";
+}
+
+bool HpackEntry::Equals(const HpackEntry& other) const {
+  return
+      StringPiecesEqualConstantTime(name_, other.name_) &&
+      StringPiecesEqualConstantTime(value_, other.value_) &&
+      (referenced_and_touch_count_ == other.referenced_and_touch_count_);
+}
+
+void HpackEntry::SetReferenced(bool referenced) {
+  referenced_and_touch_count_ &= kTouchCountMask;
+  if (referenced)
+    referenced_and_touch_count_ |= kReferencedMask;
+}
+
+void HpackEntry::AddTouches(uint32 additional_touch_count) {
+  uint32 new_touch_count = TouchCount();
+  if (new_touch_count == kUntouched)
+    new_touch_count = 0;
+  new_touch_count += additional_touch_count;
+  DCHECK_LT(new_touch_count, kUntouched);
+  referenced_and_touch_count_ &= kReferencedMask;
+  referenced_and_touch_count_ |= new_touch_count;
+}
+
+void HpackEntry::ClearTouches() {
+  referenced_and_touch_count_ &= kReferencedMask;
+  referenced_and_touch_count_ |= kUntouched;
+}
+
+}  // namespace net