media/ffmpeg/file_protocol.cc

// Copyright (c) 2011 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 "media/ffmpeg/file_protocol.h"

#include "build/build_config.h"

#if defined(OS_WIN)
#include <io.h>
#else
#include <unistd.h>
#endif
#include <fcntl.h>

#include "base/compiler_specific.h"
#include "base/eintr_wrapper.h"
#include "base/file_util.h"
#include "media/ffmpeg/ffmpeg_common.h"

// warning C4996: 'open': The POSIX name for this item is deprecated.
MSVC_PUSH_DISABLE_WARNING(4996)

static int GetHandle(URLContext *h) {
  return static_cast<int>(reinterpret_cast<intptr_t>(h->priv_data));
}

// FFmpeg protocol interface.
static int OpenContext(URLContext* h, const char* filename, int flags) {
  int access = O_RDONLY;

  if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
    access = O_CREAT | O_TRUNC | O_RDWR;
  } else if (flags & AVIO_FLAG_WRITE) {
    access = O_CREAT | O_TRUNC | O_WRONLY;
  }

#ifdef O_BINARY
  access |= O_BINARY;
#endif

  int f = open(filename, access, 0666);
  if (f == -1)
    return AVERROR(ENOENT);

  h->priv_data = reinterpret_cast<void*>(static_cast<intptr_t>(f));
  h->is_streamed = false;
  return 0;
}

static int ReadContext(URLContext* h, unsigned char* buf, int size) {
  return HANDLE_EINTR(read(GetHandle(h), buf, size));
}

#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(52, 68, 0)
static int WriteContext(URLContext* h, const unsigned char* buf, int size) {
#else
static int WriteContext(URLContext* h, unsigned char* buf, int size) {
#endif
  return HANDLE_EINTR(write(GetHandle(h), buf, size));
}

static int64 SeekContext(URLContext* h, int64 offset, int whence) {
#if defined(OS_WIN)
  return _lseeki64(GetHandle(h), static_cast<__int64>(offset), whence);
#else
  COMPILE_ASSERT(sizeof(off_t) == 8, off_t_not_64_bit);
  return lseek(GetHandle(h), static_cast<off_t>(offset), whence);
#endif
}

static int CloseContext(URLContext* h) {
  return HANDLE_EINTR(close(GetHandle(h)));
}

MSVC_POP_WARNING()

URLProtocol kFFmpegFileProtocol = {
  "file",
  &OpenContext,
  &ReadContext,
  &WriteContext,
  &SeekContext,
  &CloseContext,
  NULL,  // *next
  NULL,  // url_read_pause
  NULL,  // url_read_seek
  &GetHandle
};