random_access_file_utils.cc revision 8f4b056427a9d2321e3aa4f21ca8ffb18b3e5ae6
1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "base/unix_file/random_access_file_utils.h"
18
19#include <vector>
20
21#include "base/unix_file/random_access_file.h"
22
23namespace unix_file {
24
25bool CopyFile(const RandomAccessFile& src, RandomAccessFile* dst) {
26  // We don't call src->GetLength because some files (those in /proc, say)
27  // don't know how long they are. We just read until there's nothing left.
28  std::vector<char> buf(4096);
29  int64_t offset = 0;
30  int64_t n;
31  while ((n = src.Read(&buf[0], buf.size(), offset)) > 0) {
32    if (dst->Write(&buf[0], n, offset) != n) {
33      return false;
34    }
35    offset += n;
36  }
37  return n >= 0;
38}
39
40}  // namespace unix_file
41