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
|
// Copyright 2018 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_POSIX_H_
#define BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_POSIX_H_ 1
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string>
#include "src/tools/singlejar/diag.h"
// The implementation is 64-bit Linux or OSX specific.
#if !((defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__)) && \
__SIZEOF_POINTER__ == 8)
#error This code for 64 bit Unix.
#endif
MappedFile::MappedFile()
: mapped_start_(nullptr), mapped_end_(nullptr), fd_(-1) {}
bool MappedFile::Open(const std::string& path) {
if (is_open()) {
diag_errx(1, "%s:%d: This instance is already open", __FILE__, __LINE__);
}
if ((fd_ = open(path.c_str(), O_RDONLY)) < 0) {
diag_warn("%s:%d: open %s:", __FILE__, __LINE__, path.c_str());
return false;
}
// Map the file, even if it is empty (in which case allocate 1 byte to it).
struct stat st;
if (fstat(fd_, &st) ||
(mapped_start_ = static_cast<unsigned char *>(
mmap(nullptr, st.st_size ? st.st_size : 1, PROT_READ, MAP_PRIVATE,
fd_, 0))) == MAP_FAILED) {
if (S_ISDIR(st.st_mode)) {
diag_warn("%s:%d: %s is a directory", __FILE__, __LINE__, path.c_str());
} else {
diag_warn("%s:%d: mmap %s:", __FILE__, __LINE__, path.c_str());
}
close(fd_);
fd_ = -1;
return false;
}
mapped_end_ = mapped_start_ + st.st_size;
return true;
}
void MappedFile::Close() {
if (is_open()) {
munmap(mapped_start_, mapped_end_ - mapped_start_);
mapped_start_ = mapped_end_ = nullptr;
close(fd_);
fd_ = -1;
}
}
#endif // BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_POSIX_H_
|
