Refactor AppendToFile and WriteFileDescriptor

chrome/browser/media/webrtc_rtp_dump_writer.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 "chrome/browser/media/webrtc_rtp_dump_writer.h"
 
 #include "base/big_endian.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "third_party/zlib/zlib.h"
 
 using content::BrowserThread;
 
 namespace {
 
 static const size_t kMinimumGzipOutputBufferSize = 256;  // In bytes.
 
 const unsigned char kRtpDumpFileHeaderFirstLine[] = "#!rtpplay1.0 0.0.0.0/0\n";
@@ skipping 138 matching lines @@
     std::vector<uint8> compressed_buffer;
     if (!Compress(buffer, &compressed_buffer)) {
       DVLOG(2) << "Compressing buffer failed.";
       *result = FLUSH_RESULT_FAILURE;
       return 0;
     }
 
     int bytes_written = -1;
 
     if (base::PathExists(dump_path_)) {
-      bytes_written = base::AppendToFile(
-          dump_path_,
-          reinterpret_cast<const char*>(&compressed_buffer[0]),
-          compressed_buffer.size());
+      bytes_written =
+          base::AppendToFile(dump_path_,
+                             reinterpret_cast<const char*>(
+                                 vector_as_array(&compressed_buffer)),
+                             compressed_buffer.size())
+              ? compressed_buffer.size()
+              : -1;
     } else {
       bytes_written = base::WriteFile(
           dump_path_,
           reinterpret_cast<const char*>(&compressed_buffer[0]),
           compressed_buffer.size());
     }
 
     if (bytes_written == -1) {
       DVLOG(2) << "Writing file failed: " << dump_path_.value();
       *result = FLUSH_RESULT_FAILURE;
@@ skipping 44 matching lines @@
     DCHECK_EQ(Z_STREAM_END, result);
 
     result = deflateEnd(&stream_);
     DCHECK_EQ(Z_OK, result);
 
     output_buffer.resize(output_buffer.size() - stream_.avail_out);
 
     memset(&stream_, 0, sizeof(z_stream));
 
     DCHECK(!output_buffer.empty());
-    int bytes_written =
-        base::AppendToFile(dump_path_,
-                           reinterpret_cast<const char*>(&output_buffer[0]),
-                           output_buffer.size());
-
-    return bytes_written > 0;
+    return base::AppendToFile(dump_path_,
+                              reinterpret_cast<const char*>(
+                                  vector_as_array(&output_buffer)),
+                              output_buffer.size());
   }
 
   const base::FilePath dump_path_;
 
   z_stream stream_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(FileThreadWorker);
 };
@@ skipping 191 matching lines @@
                 base::Bind(&WebRtcRtpDumpWriter::OnDumpEnded,
                            weak_ptr_factory_.GetWeakPtr(),
                            context,
                            false));
     return;
   }
 
   // This object might be deleted after running the callback.
   context.callback.Run(context.incoming_succeeded, context.outgoing_succeeded);
 }