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 "update_engine/payload_consumer/file_writer.h"
18 
19 #include <errno.h>
20 
21 namespace chromeos_update_engine {
22 
Open(const char * path,int flags,mode_t mode)23 int DirectFileWriter::Open(const char* path, int flags, mode_t mode) {
24   CHECK_EQ(fd_, -1);
25   fd_ = open(path, flags, mode);
26   if (fd_ < 0)
27     return -errno;
28   return 0;
29 }
30 
Write(const void * bytes,size_t count)31 bool DirectFileWriter::Write(const void* bytes, size_t count) {
32   CHECK_GE(fd_, 0);
33   const char* char_bytes = reinterpret_cast<const char*>(bytes);
34 
35   size_t bytes_written = 0;
36   while (bytes_written < count) {
37     ssize_t rc = write(fd_, char_bytes + bytes_written,
38                        count - bytes_written);
39     if (rc < 0)
40       return false;
41     bytes_written += rc;
42   }
43   CHECK_EQ(bytes_written, count);
44   return bytes_written == count;
45 }
46 
Close()47 int DirectFileWriter::Close() {
48   CHECK_GE(fd_, 0);
49   int rc = close(fd_);
50 
51   // This can be any negative number that's not -1. This way, this FileWriter
52   // won't be used again for another file.
53   fd_ = -2;
54 
55   if (rc < 0)
56     return -errno;
57   return rc;
58 }
59 
60 }  // namespace chromeos_update_engine
61