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 "base/unix_file/string_file.h"
18 #include <errno.h>
19 #include <algorithm>
20 #include "base/logging.h"
21
22 namespace unix_file {
23
StringFile()24 StringFile::StringFile() {
25 }
26
~StringFile()27 StringFile::~StringFile() {
28 }
29
Close()30 int StringFile::Close() {
31 return 0;
32 }
33
Flush()34 int StringFile::Flush() {
35 return 0;
36 }
37
Read(char * buf,int64_t byte_count,int64_t offset) const38 int64_t StringFile::Read(char *buf, int64_t byte_count, int64_t offset) const {
39 CHECK(buf);
40 CHECK_GE(byte_count, 0);
41
42 if (offset < 0) {
43 return -EINVAL;
44 }
45
46 const int64_t available_bytes = std::min(byte_count, GetLength() - offset);
47 if (available_bytes < 0) {
48 return 0; // Not an error, but nothing for us to do, either.
49 }
50 memcpy(buf, data_.data() + offset, available_bytes);
51 return available_bytes;
52 }
53
SetLength(int64_t new_length)54 int StringFile::SetLength(int64_t new_length) {
55 if (new_length < 0) {
56 return -EINVAL;
57 }
58 data_.resize(new_length);
59 return 0;
60 }
61
GetLength() const62 int64_t StringFile::GetLength() const {
63 return data_.size();
64 }
65
Write(const char * buf,int64_t byte_count,int64_t offset)66 int64_t StringFile::Write(const char *buf, int64_t byte_count, int64_t offset) {
67 CHECK(buf);
68 CHECK_GE(byte_count, 0);
69
70 if (offset < 0) {
71 return -EINVAL;
72 }
73
74 if (byte_count == 0) {
75 return 0;
76 }
77
78 // FUSE seems happy to allow writes past the end. (I'd guess it doesn't
79 // synthesize a write of zero bytes so that we're free to implement sparse
80 // files.) GNU as(1) seems to require such writes. Those files are small.
81 const int64_t bytes_past_end = offset - GetLength();
82 if (bytes_past_end > 0) {
83 data_.append(bytes_past_end, '\0');
84 }
85
86 data_.replace(offset, byte_count, buf, byte_count);
87 return byte_count;
88 }
89
Assign(const art::StringPiece & new_data)90 void StringFile::Assign(const art::StringPiece &new_data) {
91 data_.assign(new_data.data(), new_data.size());
92 }
93
ToStringPiece() const94 const art::StringPiece StringFile::ToStringPiece() const {
95 return data_;
96 }
97
98 } // namespace unix_file
99