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 <vector>
18 #include "base/unix_file/random_access_file_utils.h"
19 #include "base/unix_file/random_access_file.h"
20 
21 namespace unix_file {
22 
CopyFile(const RandomAccessFile & src,RandomAccessFile * dst)23 bool CopyFile(const RandomAccessFile& src, RandomAccessFile* dst) {
24   // We don't call src->GetLength because some files (those in /proc, say)
25   // don't know how long they are. We just read until there's nothing left.
26   std::vector<char> buf(4096);
27   int64_t offset = 0;
28   int64_t n;
29   while ((n = src.Read(&buf[0], buf.size(), offset)) > 0) {
30     if (dst->Write(&buf[0], n, offset) != n) {
31       return false;
32     }
33     offset += n;
34   }
35   return n >= 0;
36 }
37 
38 }  // namespace unix_file
39