Class BinaryReader

Lib/profiling/sampling/binary_reader.py:10–90

High-performance binary reader using C implementation. This reader uses memory-mapped I/O (on Unix) for fast replay of profiling data from binary files. Use as a context manager: with BinaryReader('profile.bin') as reader: info = reader.get_info() reader

class BinaryReader:
    """High-performance binary reader using C implementation.

    This reader uses memory-mapped I/O (on Unix) for fast replay of
    profiling data from binary files.

    Use as a context manager:
        with BinaryReader('profile.bin') as reader:
            info = reader.get_info()
            reader.replay_samples(collector, progress_callback)
    """

    def __init__(self, filename):
        """Create a new binary reader.

        Args:
            filename: Path to input binary file
        """
        self.filename = filename
        self._reader = None

    def __enter__(self):
        self._reader = _remote_debugging.BinaryReader(self.filename)
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        if self._reader is not None:
            self._reader.close()
            self._reader = None
        return False

    def get_info(self):
        """Get metadata about the binary file.

        Returns:
            dict: File metadata including:
                - sample_count: Number of samples in the file
                - sample_interval_us: Sampling interval in microseconds
                - start_time_us: Start timestamp in microseconds
                - string_count: Number of unique strings
                - frame_count: Number of unique frames
                - compression: Compression type used
        """
        if self._reader is None:
            raise RuntimeError("Reader not open. Use as context manager.")
        return self._reader.get_info()

    def replay_samples(self, collector, progress_callback=None):
        """Replay samples from binary file through a collector.

        This allows converting binary profiling data to other formats
        (e.g., flamegraph, pstats) by replaying through the appropriate
        collector.

        Args:
            collector: A Collector instance with a collect() method
            progress_callback: Optional callable(current, total) for progress