| // Copyright (c) 2009, Google Inc. |
| // All rights reserved. |
| // |
| // 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 Inc. 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. |
| |
| #ifndef CLIENT_LINUX_MINIDUMP_WRITER_LINE_READER_H_ |
| #define CLIENT_LINUX_MINIDUMP_WRITER_LINE_READER_H_ |
| |
| #include <stdint.h> |
| #include <assert.h> |
| #include <string.h> |
| |
| #include "third_party/lss/linux_syscall_support.h" |
| |
| namespace google_breakpad { |
| |
| // A class for reading a file, line by line, without using fopen/fgets or other |
| // functions which may allocate memory. |
| class LineReader { |
| public: |
| LineReader(int fd) |
| : fd_(fd), |
| hit_eof_(false), |
| buf_used_(0) { |
| } |
| |
| // The maximum length of a line. |
| static const size_t kMaxLineLen = 512; |
| |
| // Return the next line from the file. |
| // line: (output) a pointer to the start of the line. The line is NUL |
| // terminated. |
| // len: (output) the length of the line (not inc the NUL byte) |
| // |
| // Returns true iff successful (false on EOF). |
| // |
| // One must call |PopLine| after this function, otherwise you'll continue to |
| // get the same line over and over. |
| bool GetNextLine(const char **line, unsigned *len) { |
| for (;;) { |
| if (buf_used_ == 0 && hit_eof_) |
| return false; |
| |
| for (unsigned i = 0; i < buf_used_; ++i) { |
| if (buf_[i] == '\n' || buf_[i] == 0) { |
| buf_[i] = 0; |
| *len = i; |
| *line = buf_; |
| return true; |
| } |
| } |
| |
| if (buf_used_ == sizeof(buf_)) { |
| // we scanned the whole buffer and didn't find an end-of-line marker. |
| // This line is too long to process. |
| return false; |
| } |
| |
| // We didn't find any end-of-line terminators in the buffer. However, if |
| // this is the last line in the file it might not have one: |
| if (hit_eof_) { |
| assert(buf_used_); |
| // There's room for the NUL because of the buf_used_ == sizeof(buf_) |
| // check above. |
| buf_[buf_used_] = 0; |
| *len = buf_used_; |
| buf_used_ += 1; // since we appended the NUL. |
| *line = buf_; |
| return true; |
| } |
| |
| // Otherwise, we should pull in more data from the file |
| const ssize_t n = sys_read(fd_, buf_ + buf_used_, |
| sizeof(buf_) - buf_used_); |
| if (n < 0) { |
| return false; |
| } else if (n == 0) { |
| hit_eof_ = true; |
| } else { |
| buf_used_ += n; |
| } |
| |
| // At this point, we have either set the hit_eof_ flag, or we have more |
| // data to process... |
| } |
| } |
| |
| void PopLine(unsigned len) { |
| // len doesn't include the NUL byte at the end. |
| |
| assert(buf_used_ >= len + 1); |
| buf_used_ -= len + 1; |
| memmove(buf_, buf_ + len + 1, buf_used_); |
| } |
| |
| private: |
| const int fd_; |
| |
| bool hit_eof_; |
| unsigned buf_used_; |
| char buf_[kMaxLineLen]; |
| }; |
| |
| } // namespace google_breakpad |
| |
| #endif // CLIENT_LINUX_MINIDUMP_WRITER_LINE_READER_H_ |