platform_system_core/libmemunreachable/LineBuffer.cpp

67 lines
2.0 KiB
C++

/*
* Copyright (C) 2015 The Android Open Source Project
*
* 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.
*/
// Copied from system/extras/memory_replay/LineBuffer.cpp
// TODO(ccross): find a way to share between libmemunreachable and memory_replay?
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "LineBuffer.h"
namespace android {
LineBuffer::LineBuffer(int fd, char* buffer, size_t buffer_len)
: fd_(fd), buffer_(buffer), buffer_len_(buffer_len) {}
bool LineBuffer::GetLine(char** line, size_t* line_len) {
while (true) {
if (bytes_ > 0) {
char* newline = reinterpret_cast<char*>(memchr(buffer_ + start_, '\n', bytes_));
if (newline != nullptr) {
*newline = '\0';
*line = buffer_ + start_;
start_ = newline - buffer_ + 1;
bytes_ -= newline - *line + 1;
*line_len = newline - *line;
return true;
}
}
if (start_ > 0) {
// Didn't find anything, copy the current to the front of the buffer.
memmove(buffer_, buffer_ + start_, bytes_);
start_ = 0;
}
ssize_t bytes = TEMP_FAILURE_RETRY(read(fd_, buffer_ + bytes_, buffer_len_ - bytes_ - 1));
if (bytes <= 0) {
if (bytes_ > 0) {
// The read data might not contain a nul terminator, so add one.
buffer_[bytes_] = '\0';
*line = buffer_ + start_;
*line_len = bytes_;
bytes_ = 0;
start_ = 0;
return true;
}
return false;
}
bytes_ += bytes;
}
}
} // namespace android