AppRTCDemo file logging.

talk/app/webrtc/objc/public/RTCFileLogger.h

 /*
  * libjingle
  * Copyright 2015 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
  *     this list of conditions and the following disclaimer in the documentation
  *     and/or other materials provided with the distribution.
  *  3. The name of the author may not be used to endorse or promote products
  *     derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #import <Foundation/Foundation.h>
 
-@class RTCSessionDescription;
+// TODO(tkchin): Move this to a common location.
+#ifndef NS_DESIGNATED_INITIALIZER
+#define NS_DESIGNATED_INITIALIZER
+#endif
 
-@interface ARDSDPUtils : NSObject
+// This class intercepts WebRTC logs and saves them to a file. The file size
+// will not exceed the given maximum bytesize. When the maximum bytesize is
+// reached logs from the beginning and the end are preserved while the middle
+// section is overwritten instead.
+@interface RTCFileLogger : NSObject
 
-// Updates the original SDP description to instead prefer the specified video
-// codec. We do this by placing the specified codec at the beginning of the
-// codec list if it exists in the sdp.
-+ (RTCSessionDescription *)
-    descriptionForDescription:(RTCSessionDescription *)description
-          preferredVideoCodec:(NSString *)codec;
+// Default constructor provides default settings for file path and file size.
+- (instancetype)init;
+
+- (instancetype)initWithFilePath:(NSString *)filePath
+                     maxFileSize:(NSUInteger)maxFileSize NS_DESIGNATED_INITIALIZER;
+
+// Starts writing WebRTC logs to file if not already started. Overwrites any
+// existing file.
+- (void)start;
+
+// Stops writing WebRTC logs to file.
+- (void)stop;
+
+// Returns the contents of the written log file.
+- (NSString *)log;
 
 @end