diff options
Diffstat (limited to 'externals/breakpad/src/common/linux/scoped_pipe.cc')
-rw-r--r-- | externals/breakpad/src/common/linux/scoped_pipe.cc | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/externals/breakpad/src/common/linux/scoped_pipe.cc b/externals/breakpad/src/common/linux/scoped_pipe.cc new file mode 100644 index 0000000000..8de04ce952 --- /dev/null +++ b/externals/breakpad/src/common/linux/scoped_pipe.cc @@ -0,0 +1,132 @@ +// Copyright 2022 Google LLC +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google LLC nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifdef HAVE_CONFIG_H +#include <config.h> // Must come first +#endif + +#include "common/linux/scoped_pipe.h" + +#include <unistd.h> + +#include "common/linux/eintr_wrapper.h" + +namespace google_breakpad { + +ScopedPipe::ScopedPipe() { + fds_[0] = -1; + fds_[1] = -1; +} + +ScopedPipe::~ScopedPipe() { + CloseReadFd(); + CloseWriteFd(); +} + +bool ScopedPipe::Init() { + return pipe(fds_) == 0; +} + +void ScopedPipe::CloseReadFd() { + if (fds_[0] != -1) { + close(fds_[0]); + fds_[0] = -1; + } +} + +void ScopedPipe::CloseWriteFd() { + if (fds_[1] != -1) { + close(fds_[1]); + fds_[1] = -1; + } +} + +bool ScopedPipe::ReadLine(std::string& line) { + // Simple buffered file read. `read_buffer_` stores previously read bytes, and + // we either return a line from this buffer, or we append blocks of read bytes + // to the buffer until we have a complete line. + size_t eol_index = read_buffer_.find('\n'); + + // While we don't have a full line, and read pipe is valid. + while (eol_index == std::string::npos && GetReadFd() != -1) { + // Read a block of 128 bytes from the read pipe. + char read_buf[128]; + ssize_t read_len = HANDLE_EINTR( + read(GetReadFd(), read_buf, sizeof(read_buf))); + if (read_len <= 0) { + // Pipe error, or pipe has been closed. + CloseReadFd(); + break; + } + + // Append the block, and check if we have a full line now. + read_buffer_.append(read_buf, read_len); + eol_index = read_buffer_.find('\n'); + } + + if (eol_index != std::string::npos) { + // We have a full line to output. + line = read_buffer_.substr(0, eol_index); + if (eol_index < read_buffer_.size()) { + read_buffer_ = read_buffer_.substr(eol_index + 1); + } else { + read_buffer_ = ""; + } + + return true; + } + + if (read_buffer_.size()) { + // We don't have a full line to output, but we can only reach here if the + // pipe has closed and there are some bytes left at the end, so we should + // return those bytes. + line = std::move(read_buffer_); + read_buffer_ = ""; + + return true; + } + + // We don't have any buffered data left, and the pipe has closed. + return false; +} + +int ScopedPipe::Dup2WriteFd(int new_fd) const { + return dup2(fds_[1], new_fd); +} + +bool ScopedPipe::WriteForTesting(const void* bytes, size_t bytes_len) { + ssize_t r = HANDLE_EINTR(write(GetWriteFd(), bytes, bytes_len)); + if (r != static_cast<ssize_t>(bytes_len)) { + CloseWriteFd(); + return false; + } + + return true; +} + +} // namespace google_breakpad |