1# Copyright 2022 The Pigweed Authors 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); you may not 4# use this file except in compliance with the License. You may obtain a copy of 5# the License at 6# 7# https://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12# License for the specific language governing permissions and limitations under 13# the License. 14"""Library to analyze timestamp.""" 15 16from typing import List 17import datetime 18from pw_chrono_protos import chrono_pb2 19 20_UTC_EPOCH = datetime.datetime(1970, 1, 1, 00, 00, 00) 21 22_UNKNOWN = chrono_pb2.EpochType.Enum.UNKNOWN 23_TIME_SINCE_BOOT = chrono_pb2.EpochType.Enum.TIME_SINCE_BOOT 24_UTC_WALL_CLOCK = chrono_pb2.EpochType.Enum.UTC_WALL_CLOCK 25 26 27def process_snapshot(serialized_snapshot: bytes): 28 captured_timestamps = chrono_pb2.SnapshotTimestamps() 29 captured_timestamps.ParseFromString(serialized_snapshot) 30 return timestamp_output(captured_timestamps) 31 32 33def timestamp_output(timestamps: chrono_pb2.SnapshotTimestamps): 34 output: List[str] = [] 35 if not timestamps.timestamps: 36 return '' 37 38 plural = '' if len(timestamps.timestamps) == 1 else 's' 39 output.append(f'Snapshot capture timestamp{plural}') 40 for timepoint in timestamps.timestamps: 41 time = timestamp_snapshot_analyzer(timepoint) 42 clock_epoch_type = timepoint.clock_parameters.epoch_type 43 if clock_epoch_type == _TIME_SINCE_BOOT: 44 output.append(f' Time since boot: {time}') 45 elif clock_epoch_type == _UTC_WALL_CLOCK: 46 utc_time = time + _UTC_EPOCH 47 output.append(f' UTC time: {utc_time}') 48 else: 49 output.append(f' Time since unknown epoch {_UNKNOWN}: unknown') 50 51 return '\n'.join(output) 52 53 54def timestamp_snapshot_analyzer( 55 captured_timepoint: chrono_pb2.TimePoint, 56) -> datetime.timedelta: 57 ticks = captured_timepoint.timestamp 58 clock_period = ( 59 captured_timepoint.clock_parameters.tick_period_seconds_numerator 60 / captured_timepoint.clock_parameters.tick_period_seconds_denominator 61 ) 62 elapsed_seconds = ticks * clock_period 63 64 time_delta = datetime.timedelta(seconds=elapsed_seconds) 65 66 return time_delta 67