1 // Copyright 2017 The Chromium OS Authors. All rights reserved.
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 "puffin/src/file_stream.h"
6
7 #include <fcntl.h>
8 #include <unistd.h>
9
10 #include <algorithm>
11 #include <utility>
12
13 #include "puffin/src/include/puffin/common.h"
14 #include "puffin/src/logging.h"
15
16 using std::string;
17
18 namespace puffin {
19
Open(const string & path,bool read,bool write)20 UniqueStreamPtr FileStream::Open(const string& path, bool read, bool write) {
21 TEST_AND_RETURN_VALUE(read || write, nullptr);
22 int flags = O_CLOEXEC;
23 if (read && write) {
24 flags |= O_RDWR | O_CREAT;
25 } else if (read) {
26 flags |= O_RDONLY;
27 } else {
28 flags |= O_WRONLY | O_CREAT;
29 }
30
31 mode_t mode = 0644; // -rw-r--r--
32 int fd = open(path.c_str(), flags, mode);
33 TEST_AND_RETURN_VALUE(fd >= 0, nullptr);
34 return UniqueStreamPtr(new FileStream(fd));
35 }
36
GetSize(uint64_t * size) const37 bool FileStream::GetSize(uint64_t* size) const {
38 auto cur_off = lseek(fd_, 0, SEEK_CUR);
39 TEST_AND_RETURN_FALSE(cur_off >= 0);
40 auto fsize = lseek(fd_, 0, SEEK_END);
41 TEST_AND_RETURN_FALSE(fsize >= 0);
42 cur_off = lseek(fd_, cur_off, SEEK_SET);
43 TEST_AND_RETURN_FALSE(cur_off >= 0);
44 *size = fsize;
45 return true;
46 }
47
GetOffset(uint64_t * offset) const48 bool FileStream::GetOffset(uint64_t* offset) const {
49 auto off = lseek(fd_, 0, SEEK_CUR);
50 TEST_AND_RETURN_FALSE(off >= 0);
51 *offset = off;
52 return true;
53 }
54
Seek(uint64_t offset)55 bool FileStream::Seek(uint64_t offset) {
56 auto off = lseek(fd_, offset, SEEK_SET);
57 TEST_AND_RETURN_FALSE(off == static_cast<off_t>(offset));
58 return true;
59 }
60
Read(void * buffer,size_t length)61 bool FileStream::Read(void* buffer, size_t length) {
62 auto c_bytes = static_cast<uint8_t*>(buffer);
63 size_t total_bytes_read = 0;
64 while (total_bytes_read < length) {
65 auto bytes_read =
66 read(fd_, c_bytes + total_bytes_read, length - total_bytes_read);
67 // if bytes_read is zero then EOF is reached and we should not be here.
68 TEST_AND_RETURN_FALSE(bytes_read > 0);
69 total_bytes_read += bytes_read;
70 }
71 return true;
72 }
73
Write(const void * buffer,size_t length)74 bool FileStream::Write(const void* buffer, size_t length) {
75 auto c_bytes = static_cast<const uint8_t*>(buffer);
76 size_t total_bytes_wrote = 0;
77 while (total_bytes_wrote < length) {
78 auto bytes_wrote =
79 write(fd_, c_bytes + total_bytes_wrote, length - total_bytes_wrote);
80 TEST_AND_RETURN_FALSE(bytes_wrote >= 0);
81 total_bytes_wrote += bytes_wrote;
82 }
83 return true;
84 }
85
Close()86 bool FileStream::Close() {
87 return close(fd_) == 0;
88 }
89
90 } // namespace puffin
91