dragonpilot/tools/lib/logreader.py

#!/usr/bin/env python3
import os
import sys
import bz2
import urllib.parse
import capnp
import warnings

from typing import Iterable, Iterator

from cereal import log as capnp_log
from openpilot.tools.lib.filereader import FileReader

LogIterable = Iterable[capnp._DynamicStructReader]


class LogReader:
  def __init__(self, fn, canonicalize=True, only_union_types=False, sort_by_time=False, dat=None):
    self.data_version = None
    self._only_union_types = only_union_types

    ext = None
    if not dat:
      _, ext = os.path.splitext(urllib.parse.urlparse(fn).path)
      if ext not in ('', '.bz2'):
        # old rlogs weren't bz2 compressed
        raise Exception(f"unknown extension {ext}")

      with FileReader(fn) as f:
        dat = f.read()

    if ext == ".bz2" or dat.startswith(b'BZh9'):
      dat = bz2.decompress(dat)

    ents = capnp_log.Event.read_multiple_bytes(dat)

    _ents = []
    try:
      for e in ents:
        _ents.append(e)
    except capnp.KjException:
      warnings.warn("Corrupted events detected", RuntimeWarning, stacklevel=1)

    self._ents = list(sorted(_ents, key=lambda x: x.logMonoTime) if sort_by_time else _ents)
    self._ts = [x.logMonoTime for x in self._ents]

  @classmethod
  def from_bytes(cls, dat):
    return cls("", dat=dat)

  def __iter__(self) -> Iterator[capnp._DynamicStructReader]:
    for ent in self._ents:
      if self._only_union_types:
        try:
          ent.which()
          yield ent
        except capnp.lib.capnp.KjException:
          pass
      else:
        yield ent


if __name__ == "__main__":
  import codecs
  # capnproto <= 0.8.0 throws errors converting byte data to string
  # below line catches those errors and replaces the bytes with \x__
  codecs.register_error("strict", codecs.backslashreplace_errors)
  log_path = sys.argv[1]
  lr = LogReader(log_path, sort_by_time=True)
  for msg in lr:
    print(msg)