Add QuicFramer and friends.

net/quic/crypto/crypto_framer.h

Index: net/quic/crypto/crypto_framer.h
diff --git a/net/quic/crypto/crypto_framer.h b/net/quic/crypto/crypto_framer.h
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+// Copyright (c) 2012 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_QUIC_CRYPTO_CRYPTO_FRAMER_H_
+#define NET_QUIC_CRYPTO_CRYPTO_FRAMER_H_
+
+#include <map>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/string_piece.h"
+#include "net/base/net_export.h"
+#include "net/quic/crypto/crypto_protocol.h"
+#include "net/quic/quic_protocol.h"
+
+namespace net {
+
+class CryptoFramer;
+class QuicDataReader;
+class QuicData;
+
+class NET_EXPORT_PRIVATE CryptoFramerVisitorInterface {
+ public:
+  virtual ~CryptoFramerVisitorInterface() {}
+
+  // Called if an error is detected.
+  virtual void OnError(CryptoFramer* framer) = 0;
+
+  // Called when a complete handshake message has been parsed.
+  virtual void OnHandshakeMessage(const CryptoHandshakeMessage& message) = 0;
+};
+
+// A class for framing the crypto message that are exchanged in a QUIC session.
+class NET_EXPORT_PRIVATE CryptoFramer {
+ public:
+  CryptoFramer();
+
+  virtual ~CryptoFramer();
+
+  // Set callbacks to be called from the framer.  A visitor must be set, or
+  // else the framer will likely crash.  It is acceptable for the visitor
+  // to do nothing.  If this is called multiple times, only the last visitor
+  // will be used.  |visitor| will be owned by the framer.
+  void set_visitor(CryptoFramerVisitorInterface* visitor) {
+    visitor_ = visitor;
+  }
+
+  QuicErrorCode error() const {
+    return error_;
+  }
+
+  // Processes input data, which must be delievered in order.  Returns
+  // false if there was an error, and true otherwise.
+  bool ProcessInput(base::StringPiece input);
+
+  // Serializes |message| into |packet|.  Returns false if there was an
+  // error, and true otherwise.
+  bool ConstructHandshakeMessage(const CryptoHandshakeMessage& message,
+                                 QuicData** packet);
+
+ private:
+  // Clears per-message state.  Does not clear the visitor.
+  void Clear();
+
+  void set_error(QuicErrorCode error) {
+    error_ = error;
+  }
+
+  enum CryptoFramerState {
+    STATE_READING_TAG,
+    STATE_READING_NUM_ENTRIES,
+    STATE_READING_KEY_TAGS,
+    STATE_READING_LENGTHS,
+    STATE_READING_VALUES
+  };
+
+  // Visitor to send invoke when messages are parsed.
+  CryptoFramerVisitorInterface* visitor_;
+  // Last error.
+  QuicErrorCode error_;
+  // Remaining unparsed data.
+  std::string buffer_;
+  // Current state of the parsing.
+  CryptoFramerState state_;
+  // Tag of the message currently being parsed.
+  CryptoTag message_tag_;
+  // Number of entires in the message currently being parsed.
+  uint16 num_entries_;
+  // Vector of tags in the message currently being parsed.
+  std::vector<CryptoTag> tags_;
+  // Length of the data associated with each tag in the message currently
+  // being parsed.
+  std::map<CryptoTag, size_t> tag_length_map_;
+  // Length of the data associated with each tag in the message currently
+  // being parsed.
+  CryptoTagValueMap tag_value_map_;
+  // Cumulative length of all values in the message currently being parsed.
+  size_t values_len_;
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_CRYPTO_CRYPTO_FRAMER_H_