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- // Copyright 2015 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.
- #include <errno.h>
- #include <fcntl.h>
- #include <stdio.h>
- #include <sys/mman.h>
- #include <unistd.h>
- #include <algorithm>
- #include <limits>
- #include "third_party/ijar/mapped_file.h"
- #define MAX_ERROR 2048
- namespace devtools_ijar {
- static char errmsg[MAX_ERROR];
- struct MappedInputFileImpl {
- size_t discarded_;
- int fd_;
- };
- MappedInputFile::MappedInputFile(const char* name) {
- impl_ = NULL;
- opened_ = false;
- int fd = open(name, O_RDONLY);
- if (fd < 0) {
- snprintf(errmsg, MAX_ERROR, "open(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- off_t length = lseek(fd, 0, SEEK_END);
- if (length < 0) {
- snprintf(errmsg, MAX_ERROR, "lseek(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- void* buffer = mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, 0);
- if (buffer == MAP_FAILED) {
- snprintf(errmsg, MAX_ERROR, "mmap(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- impl_ = new MappedInputFileImpl();
- impl_->fd_ = fd;
- impl_->discarded_ = 0;
- buffer_ = reinterpret_cast<u1*>(buffer);
- length_ = length;
- opened_ = true;
- }
- MappedInputFile::~MappedInputFile() {
- delete impl_;
- }
- void MappedInputFile::Discard(size_t bytes) {
- munmap(buffer_ + impl_->discarded_, bytes);
- impl_->discarded_ += bytes;
- }
- int MappedInputFile::Close() {
- if (close(impl_->fd_) < 0) {
- snprintf(errmsg, MAX_ERROR, "close(): %s", strerror(errno));
- errmsg_ = errmsg;
- return -1;
- }
- return 0;
- }
- struct MappedOutputFileImpl {
- int fd_;
- int mmap_length_;
- };
- MappedOutputFile::MappedOutputFile(const char* name, size_t estimated_size)
- : estimated_size_(estimated_size) {
- impl_ = NULL;
- opened_ = false;
- int fd = open(name, O_CREAT|O_RDWR|O_TRUNC, 0644);
- if (fd < 0) {
- snprintf(errmsg, MAX_ERROR, "open(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- // Create mmap-able sparse file
- if (ftruncate(fd, estimated_size) < 0) {
- snprintf(errmsg, MAX_ERROR, "ftruncate(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- // Ensure that any buffer overflow in JarStripper will result in
- // SIGSEGV or SIGBUS by over-allocating beyond the end of the file.
- size_t mmap_length =
- std::min(static_cast<size_t>(estimated_size + sysconf(_SC_PAGESIZE)),
- std::numeric_limits<size_t>::max());
- void* mapped =
- mmap(NULL, mmap_length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
- if (mapped == MAP_FAILED) {
- snprintf(errmsg, MAX_ERROR, "mmap(): %s", strerror(errno));
- errmsg_ = errmsg;
- return;
- }
- impl_ = new MappedOutputFileImpl();
- impl_->fd_ = fd;
- impl_->mmap_length_ = mmap_length;
- buffer_ = reinterpret_cast<u1*>(mapped);
- opened_ = true;
- }
- MappedOutputFile::~MappedOutputFile() {
- delete impl_;
- }
- int MappedOutputFile::Close(size_t size) {
- if (size > estimated_size_) {
- snprintf(errmsg, MAX_ERROR, "size %zu > estimated size %zu", size,
- estimated_size_);
- errmsg_ = errmsg;
- return -1;
- }
- munmap(buffer_, impl_->mmap_length_);
- if (ftruncate(impl_->fd_, size) < 0) {
- snprintf(errmsg, MAX_ERROR, "ftruncate(): %s", strerror(errno));
- errmsg_ = errmsg;
- return -1;
- }
- if (close(impl_->fd_) < 0) {
- snprintf(errmsg, MAX_ERROR, "close(): %s", strerror(errno));
- errmsg_ = errmsg;
- return -1;
- }
- return 0;
- }
- } // namespace devtools_ijar
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