Initial version of new file wrapper

webrtc/base/file.cc

+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/file.h"
+
+namespace rtc {
+
+File::File(rtc::PlatformFile file) : file_(file) {}
+
+File::~File() {
+  Close();
+}
+
+size_t File::Write(const uint8_t* data, size_t length) {
+  size_t total_written = 0;
+  do {
+    size_t written =
+        WriteNoBestEffort(data + total_written, length - total_written);
+    if (written == 0)
+      break;
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::Read(uint8_t* buffer, size_t length) {
+  size_t total_read = 0;
+  do {
+    size_t read = ReadNoBestEffort(buffer + total_read, length - total_read);
+    if (read == 0)
+      break;
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+size_t File::WriteAt(const uint8_t* data, size_t length, size_t offset) {
+  size_t total_written = 0;
+  do {
+    size_t written = WriteAtNoBestEffort(
+        data + total_written, length - total_written, offset + total_written);
+    if (written == 0)
+      break;
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::ReadAt(uint8_t* buffer, size_t length, size_t offset) {
+  size_t total_read = 0;
+  do {
+    size_t read = ReadAtNoBestEffort(buffer + total_read, length - total_read,
+                                     offset + total_read);
+    if (read == 0)
+      break;
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+}  // namespace rtc