DO NOT COMMIT: Implement HPACK (draft 03)

net/spdy/http2_encoding_context.h

+// Copyright (c) 2013 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.
+
+#ifndef NET_SPDY_HTTP2_ENCODING_CONTEXT_H_
+#define NET_SPDY_HTTP2_ENCODING_CONTEXT_H_
+
+#include <cstddef>
+#include <deque>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace net {
+
+extern const uint8 kIndexOpcode;
+extern const uint8 kIndexN;
+
+extern const uint8 kLiteralNoIndexOpcode;
+extern const uint8 kLiteralNoIndexN;
+
+extern const uint8 kLiteralIncrementalOpcode;
+extern const uint8 kLiteralIncrementalN;
+
+extern const uint8 kLiteralSubstitutionOpcode;
+extern const uint8 kLiteralSubstitutionN;
+
+extern const uint32 kUntouched;
+
+enum Http2Direction {
+  HTTP2_REQUEST,
+  HTTP2_RESPONSE
+};
+
+bool IsValidHeaderName(const std::string& str);
+
+bool IsValidHeaderValue(const std::string& str);
+
+bool StringsEqualConstantTime(const std::string& str1,
+                              const std::string& str2);
+
+struct HeaderTableEntry {
+  HeaderTableEntry();
+  HeaderTableEntry(const std::string& name, const std::string& value);
+
+  bool Equals(const HeaderTableEntry& other) const;
+
+  size_t Size() const;
+
+  std::string name;
+  std::string value;
+
+  bool referenced;
+  uint32 touch_count;
+};
+
+class HeaderTable {
+ public:
+  HeaderTable();
+
+  ~HeaderTable();
+
+  size_t GetEntryCount() const;
+
+  void SetMaxSize(size_t max_size);
+
+  const HeaderTableEntry* GetEntry(int32 index) const;
+
+  HeaderTableEntry* GetMutableEntry(int32 index);
+
+  void TryAppendEntry(const HeaderTableEntry& entry,
+                      int32* index,
+                      std::vector<uint32>* removed_referenced_indices);
+
+  void TryReplaceEntry(uint32 substituted_index,
+                       const HeaderTableEntry& entry,
+                       int32* index,
+                       std::vector<uint32>* removed_referenced_indices);
+
+ private:
+  void RemoveFirstEntry();
+
+  std::deque<HeaderTableEntry> entries_;
+  size_t size_;
+  size_t max_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(HeaderTable);
+};
+
+class EncodingContext {
+ public:
+  EncodingContext(Http2Direction direction);
+
+  ~EncodingContext();
+
+  size_t GetEntryCount() const;
+
+  bool IsReferenced(uint32 index) const;
+
+  bool GetIndexedHeaderName(uint32 index, std::string* name) const;
+
+  bool GetIndexedHeaderValue(uint32 index, std::string* value) const;
+
+  void ProcessIndexedHeader(uint32 index);
+
+  void ProcessLiteralHeaderWithIncrementalIndexing(
+      const std::string& name,
+      const std::string& value,
+      int32* index,
+      std::vector<uint32>* removed_referenced_indices);
+
+  void ProcessLiteralHeaderWithSubstitutionIndexing(
+      const std::string& name,
+      uint32 substituted_index,
+      const std::string& value,
+      int32* index,
+      std::vector<uint32>* removed_referenced_indices);
+
+  void AddTouches(uint32 index, uint32 touch_count);
+
+  HeaderTableEntry* GetMutableEntry(int32 index);
+
+ private:
+  HeaderTable header_table_;
+
+  DISALLOW_COPY_AND_ASSIGN(EncodingContext);
+};
+
+}  // namespace net
+
+#endif  // NET_SPDY_HTTP2_ENCODING_CONTEXT_H_