[EasyUnlock] Port Connection class to native code.

components/proximity_auth/permit_message.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 "components/proximity_auth/permit_message.h"
+
+#include "base/logging.h"
+
+namespace proximity_auth {
+namespace {
+
+// The length of the message header, in bytes.
+const int kHeaderLength = 3;
+
+// TODO(isherman): Uncomment this once code that uses it lands.
+// The protocol version of the message format.
+//const int kMessageFormatVersion = 3;
+
+// Parses the |message|'s header and returns the full length of the message
+// (i.e. the sum of the lengths of the message header and body), as recorded in
+// the header. Returns -1 if the header is incomplete or malformed.
+int ReadLengthFromHeader(const char* message, int size) {
+  if (size < kHeaderLength)
+    return -1;
+
+  int body_length =
+      static_cast<int>(message[1]) << 8 | static_cast<int>(message[2]);
+  return kHeaderLength + body_length;
+}
+
+}  // namespace
+
+PermitMessage::~PermitMessage() {
+}
+
+// static
+bool PermitMessage::IsCompleteMessage(const char* bytes, int size) {
+  int message_length = ReadLengthFromHeader(bytes, size);
+  return message_length != -1 && size >= message_length;
+}
+
+// static
+scoped_ptr<PermitMessage> PermitMessage::FromBytes(const char* bytes,
+                                                   int size) {
+  if (!IsCompleteMessage(bytes, size)) {
+    VLOG(1) << "Error: Cannot parse incomplete received message.";
+    return scoped_ptr<PermitMessage>();
+  }
+
+  int message_length = ReadLengthFromHeader(bytes, size);
+  scoped_ptr<PermitMessage> message = FromBytesImpl(bytes, message_length);
+  if (!message)
+    VLOG(1) << "Error: Unable to parse message.";
+
+  return message.Pass();
+}
+
+PermitMessage::PermitMessage() {
+  // TODO(isherman): Implement.
+}
+
+// static
+scoped_ptr<PermitMessage> PermitMessage::FromBytesImpl(const char* bytes,

[Tim Song, 2014/09/05 00:30:34]

Why not put this in the namespace above?

[Ilya Sherman, 2014/09/05 01:02:11]

I've since decided that this method isn't needed; dropping it instead.

+                                                       int size) {
+  // TODO(isherman): Implement.
+  return scoped_ptr<PermitMessage>();
+}
+
+}  // namespace proximity_auth