Class Logcat

Lib/_android_support.py:159–192

class Logcat:
    def __init__(self, android_log_write):
        self.android_log_write = android_log_write
        self._lock = RLock()
        self._bucket_level = 0
        self._prev_write_time = time()

    def write(self, prio, tag, message):
        # Encode null bytes using "modified UTF-8" to avoid them truncating the
        # message.
        message = message.replace(b"\x00", b"\xc0\x80")

        # On API level 30 and higher, Logcat will strip any number of leading
        # newlines. This is visible in all `logcat` modes, even --binary. Work
        # around this by adding a leading space, which shouldn't make any
        # difference to the log's usability.
        if message.startswith(b"\n"):
            message = b" " + message

        with self._lock:
            now = time()
            self._bucket_level += (
                (now - self._prev_write_time) * MAX_BYTES_PER_SECOND)

            # If the bucket level is still below zero, the clock must have gone
            # backwards, so reset it to zero and continue.
            self._bucket_level = max(0, min(self._bucket_level, BUCKET_SIZE))
            self._prev_write_time = now

            self._bucket_level -= PER_MESSAGE_OVERHEAD + len(tag) + len(message)
            if self._bucket_level < 0:
                sleep(-self._bucket_level / MAX_BYTES_PER_SECOND)

            self.android_log_write(prio, tag, message)