Cast channel: Add cast.channel.getLogs extension API.

extensions/browser/api/cast_channel/logger.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 51 matching lines @@
 
   // For AUTH_CHALLENGE_REPLY event.
   void LogSocketChallengeReplyEvent(int channel_id,
                                     const AuthResult& auth_result);
 
   void LogSocketEventForMessage(int channel_id,
                                 proto::EventType event_type,
                                 const std::string& message_namespace,
                                 const std::string& details);
 
-  // Assembles logs collected so far and return it as a serialized Log proto.
-  // |output|: Where serialized contents will be assigned to.
-  // Returns true if serialization is successful.
-  // Contents in |output| is valid only if function returns true.
-  // TODO(imcheng): Add compression.
-  bool LogToString(std::string* output) const;
+  // Assembles logs collected so far and return it as a serialized Log proto,
+  // compressed in gzip format.
+  // If serialization or compression failed, returns a NULL pointer.
+  // |length|: If successful, assigned with size of compressed content.
+  scoped_ptr<char[]> GetLogs(int* length) const;

[Wez, 2014/08/13 20:32:25]

What's the rationale for changing this API from having returning data in
std::string (or via scoped_ptr<std::string>)?

[imcheng, 2014/08/13 20:46:04]

The rationale is to avoid an extra copy when constructing the base::BinaryValue
in cast_channel_api.cc, by passing ownership of the char[] in the constructor.

[Wez, 2014/08/14 18:51:23]

Would it make sense to have GetLogs() return a scoped_ptr<base::BinaryValue>
then?

[imcheng, 2014/08/14 21:12:34]

I think either way is fine. We can change it to base::BinaryValue in a later
patch.

 
   // Clears the internal map.
   void Reset();
 
  private:
   friend class base::RefCounted<Logger>;
   ~Logger();
 
   struct AggregatedSocketEventLog {
    public:
@@ skipping 35 matching lines @@
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(Logger);
 };
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_LOGGER_H_