1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "net/disk_cache/blockfile/mapped_file.h"
6
7 #include <errno.h>
8 #include <sys/mman.h>
9
10 #include "base/files/file_path.h"
11 #include "base/logging.h"
12 #include "net/disk_cache/disk_cache.h"
13
14 namespace disk_cache {
15
Init(const base::FilePath & name,size_t size)16 void* MappedFile::Init(const base::FilePath& name, size_t size) {
17 DCHECK(!init_);
18 if (init_ || !File::Init(name))
19 return nullptr;
20
21 size_t temp_len = size ? size : 4096;
22 if (!size)
23 size = GetLength();
24
25 buffer_ = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED,
26 platform_file(), 0);
27 init_ = true;
28 view_size_ = size;
29 DPLOG_IF(ERROR, buffer_ == MAP_FAILED) << "Failed to mmap " << name.value();
30 if (buffer_ == MAP_FAILED)
31 buffer_ = nullptr;
32
33 // Make sure we detect hardware failures reading the headers.
34 auto temp = std::make_unique<char[]>(temp_len);
35 if (!Read(temp.get(), temp_len, 0))
36 return nullptr;
37
38 return buffer_;
39 }
40
Flush()41 void MappedFile::Flush() {
42 }
43
~MappedFile()44 MappedFile::~MappedFile() {
45 if (!init_)
46 return;
47
48 if (buffer_) {
49 int ret = munmap(buffer_, view_size_);
50 DCHECK_EQ(0, ret);
51 }
52 }
53
54 } // namespace disk_cache
55