Motown in-proc streaming framework used to implement media services.

services/media/framework/parts/file_reader.cc

+// Copyright 2016 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 <cstdio>
+
+#include "base/files/file_util.h"
+#include "services/media/framework/parts/file_reader.h"
+#include "url/gurl.h"
+
+namespace mojo {
+namespace media {
+
+FileReader::~FileReader() {
+  if (file_ != nullptr) {
+    fclose(file_);
+    file_ = nullptr;
+  }
+}
+
+Result FileReader::Init(const GURL& gurl) {
+  // TODO(dalesat): Assumes the authority is localhost.
+  std::string path = gurl.path();
+  file_ = base::OpenFile(base::FilePath(path), "rb");
+  if (file_ == nullptr) {
+    return Result::kNotFound;
+  }
+
+  if (fseek(file_, 0, SEEK_END) == 0) {
+    size_ = ftell(file_);
+    if (fseek(file_, 0, SEEK_SET) < 0) {
+      fclose(file_);
+      file_ = nullptr;
+      return Result::kUnsupportedOperation;
+    }
+  } else {
+    size_ = -1;
+  }
+
+  return Result::kOk;
+}
+
+size_t FileReader::Read(uint8* buffer, int bytes_to_read) {
+  return fread(buffer, 1, bytes_to_read, file_);
+}
+
+int64_t FileReader::GetPosition() const {
+  return ftell(file_);
+}
+
+int64_t FileReader::SetPosition(int64 position) {
+  if (fseek(file_, position, SEEK_SET) < 0) {
+    return -1;
+  }
+  return position;
+}
+
+size_t FileReader::GetSize() const {
+  return size_;
+}
+
+bool FileReader::CanSeek() const {
+  return true;
+}
+
+} // namespace media
+} // namespace mojo