1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
// Copyright 2017 The Chromium OS 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 "puffin/file_stream.h"
#include <fcntl.h>
#include <unistd.h>
#include <algorithm>
#include <utility>
#include "puffin/src/include/puffin/common.h"
#include "puffin/src/logging.h"
using std::string;
namespace puffin {
UniqueStreamPtr FileStream::Open(const string& path, bool read, bool write) {
TEST_AND_RETURN_VALUE(read || write, nullptr);
int flags = O_CLOEXEC;
if (read && write) {
flags |= O_RDWR | O_CREAT;
} else if (read) {
flags |= O_RDONLY;
} else {
flags |= O_WRONLY | O_CREAT;
}
mode_t mode = 0644; // -rw-r--r--
int fd = open(path.c_str(), flags, mode);
TEST_AND_RETURN_VALUE(fd >= 0, nullptr);
return UniqueStreamPtr(new FileStream(fd));
}
bool FileStream::GetSize(uint64_t* size) const {
auto cur_off = lseek(fd_, 0, SEEK_CUR);
TEST_AND_RETURN_FALSE(cur_off >= 0);
auto fsize = lseek(fd_, 0, SEEK_END);
TEST_AND_RETURN_FALSE(fsize >= 0);
cur_off = lseek(fd_, cur_off, SEEK_SET);
TEST_AND_RETURN_FALSE(cur_off >= 0);
*size = fsize;
return true;
}
bool FileStream::GetOffset(uint64_t* offset) const {
auto off = lseek(fd_, 0, SEEK_CUR);
TEST_AND_RETURN_FALSE(off >= 0);
*offset = off;
return true;
}
bool FileStream::Seek(uint64_t offset) {
auto off = lseek(fd_, offset, SEEK_SET);
TEST_AND_RETURN_FALSE(off == static_cast<off_t>(offset));
return true;
}
bool FileStream::Read(void* buffer, size_t length) {
auto c_bytes = static_cast<uint8_t*>(buffer);
size_t total_bytes_read = 0;
while (total_bytes_read < length) {
auto bytes_read =
read(fd_, c_bytes + total_bytes_read, length - total_bytes_read);
// if bytes_read is zero then EOF is reached and we should not be here.
TEST_AND_RETURN_FALSE(bytes_read > 0);
total_bytes_read += bytes_read;
}
return true;
}
bool FileStream::Write(const void* buffer, size_t length) {
auto c_bytes = static_cast<const uint8_t*>(buffer);
size_t total_bytes_wrote = 0;
while (total_bytes_wrote < length) {
auto bytes_wrote =
write(fd_, c_bytes + total_bytes_wrote, length - total_bytes_wrote);
TEST_AND_RETURN_FALSE(bytes_wrote >= 0);
total_bytes_wrote += bytes_wrote;
}
return true;
}
bool FileStream::Close() {
return close(fd_) == 0;
}
} // namespace puffin
|
