Source code for wlauto.utils.revent

#    Copyright 2016 ARM Limited
# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import struct
from datetime import datetime
from collections import namedtuple


u16_struct = struct.Struct('<H')
u32_struct = struct.Struct('<I')
u64_struct = struct.Struct('<Q')

# See revent section in WA documentation for the detailed description of
# the recording format.
header_one_struct = struct.Struct('<6sH')
header_two_struct = struct.Struct('<H6x')  # version 2 onwards

devid_struct = struct.Struct('<4H')
devinfo_struct = struct.Struct('<4s96s96s96sI')
absinfo_struct = struct.Struct('<7i')

event_struct = struct.Struct('<HqqHHi')
old_event_struct = struct.Struct("<i4xqqHHi")  # prior to version 2

[docs]def read_struct(fh, struct_spec): data = return struct_spec.unpack(data)
[docs]def read_string(fh): length, = read_struct(fh, u32_struct) str_struct = struct.Struct('<{}s'.format(length)) return read_struct(fh, str_struct)[0]
[docs]def count_bits(bitarr): return sum(bin(b).count('1') for b in bitarr)
[docs]def is_set(bitarr, bit): byte = bit // 8 bytebit = bit % 8 return bitarr[byte] & bytebit
absinfo = namedtuple('absinfo', 'ev_code value min max fuzz flat resolution')
[docs]class UinputDeviceInfo(object): def __init__(self, fh): parts = read_struct(fh, devid_struct) self.bustype = parts[0] self.vendor = parts[1] self.product = parts[2] self.version = parts[3] = read_string(fh) parts = read_struct(fh, devinfo_struct) self.ev_bits = bytearray(parts[0]) self.key_bits = bytearray(parts[1]) self.rel_bits = bytearray(parts[2]) self.abs_bits = bytearray(parts[3]) self.num_absinfo = parts[4] self.absinfo = [absinfo(*read_struct(fh, absinfo_struct)) for _ in xrange(self.num_absinfo)] def __str__(self): return 'UInputInfo({})'.format(self.__dict__)
[docs]class ReventEvent(object): def __init__(self, fh, legacy=False): if not legacy: dev_id, ts_sec, ts_usec, type_, code, value = read_struct(fh, event_struct) else: dev_id, ts_sec, ts_usec, type_, code, value = read_struct(fh, old_event_struct) self.device_id = dev_id self.time = datetime.fromtimestamp(ts_sec + float(ts_usec) / 1000000) self.type = type_ self.code = code self.value = value def __str__(self): return 'InputEvent({})'.format(self.__dict__)
[docs]class ReventRecording(object): """ Represents a parsed revent recording. This contains input events and device descriptions recorded by revent. Two parsing modes are supported. By default, the recording will be parsed in the "streaming" mode. In this mode, initial headers and device descritions are parsed on creation and an open file handle to the recording is saved. Events will be read from the file as they are being iterated over. In this mode, the entire recording is never loaded into memory at once. The underlying file may be "released" by calling ``close`` on the recroding, after which further iteration over the events will not be possible (but would still be possible to access the file description and header information). The alternative is to load the entire recording on creation (in which case the file handle will be closed once the recroding is loaded). This can be enabled by specifying ``streaming=False``. This will make it faster to subsequently iterate over the events, and also will not "hold" the file open. .. note:: When starting a new iteration over the events in streaming mode, the postion in the open file will be automatically reset to the beginning of the event stream. This means it's possible to iterate over the events multiple times without having to re-open the recording, however it is not possible to do so in parallel. If parallel iteration is required, streaming should be disabled. """ @property def duration(self): if self._duration is None: if events = self._iter_events() try: first = last = except StopIteration: self._duration = 0 else: for last in events: pass self._duration = (last.time - first.time).total_seconds() else: # not streaming if not self._events: self._duration = 0 self._duration = (self._events[-1].time - self._events[0].time).total_seconds() return self._duration @property def events(self): if return self._iter_events() else: return self._events def __init__(self, f, stream=True): self.device_paths = [] self.gamepad_device = None self.num_events = None = stream self._events = None self._close_when_done = False self._events_start = None self._duration = None if hasattr(f, 'name'): # file-like object self.filepath = self.fh = f else: # path to file self.filepath = f self.fh = open(self.filepath, 'rb') if not self._close_when_done = True try: self._parse_header_and_devices(self.fh) self._events_start = self.fh.tell() if not self._events = [e for e in self._iter_events()] finally: if self._close_when_done: self.close()
[docs] def close(self): if self.fh is not None: self.fh.close() self.fh = None self._events_start = None
def _parse_header_and_devices(self, fh): magic, version = read_struct(fh, header_one_struct) if magic != 'REVENT': raise ValueError('{} does not appear to be an revent recording'.format(self.filepath)) self.version = version if self.version == 2: self.mode, = read_struct(fh, header_two_struct) if self.mode == GENERAL_MODE: self._read_devices(fh) elif self.mode == GAMEPAD_MODE: self._read_gamepad_info(fh) else: raise ValueError('Unexpected recording mode: {}'.format(self.mode)) self.num_events, = read_struct(fh, u64_struct) elif 2 > self.version >= 0: self.mode = GENERAL_MODE self._read_devices(fh) else: raise ValueError('Invalid recording version: {}'.format(self.version)) def _read_devices(self, fh): num_devices, = read_struct(fh, u32_struct) for _ in xrange(num_devices): self.device_paths.append(read_string(fh)) def _read_gamepad_info(self, fh): self.gamepad_device = UinputDeviceInfo(fh) self.device_paths.append('[GAMEPAD]') def _iter_events(self): if self.fh is None: raise RuntimeError('Attempting to iterate over events of a closed recording') if self.version >= 2: for _ in xrange(self.num_events): yield ReventEvent(self.fh) else: file_size = os.path.getsize(self.filepath) while self.fh.tell() < file_size: yield ReventEvent(self.fh, legacy=True) def __iter__(self): for event in yield event def __enter__(self): return self def __exit__(self, *args): self.close() def __del__(self): self.close()