File size: 2,554 Bytes
dbf8921 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | # Copyright (c) Meta Platforms, Inc. and affiliates.
#
# 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
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import bisect
from typing import Dict, List, Optional
def find_closest(sorted_input_list: List[int], target: int) -> int:
"""
Find the closest value in a sorted list to a target value
"""
index = bisect.bisect_left(sorted_input_list, target)
if index == 0:
closest = sorted_input_list[0]
elif index == len(sorted_input_list):
closest = sorted_input_list[-1]
else:
before = sorted_input_list[index - 1]
after = sorted_input_list[index]
if abs(target - after) > abs(target - before):
closest = before
else:
closest = after
return closest
def compute_frameset_for_timestamp(
stream_timestamps_sorted: Dict[str, List[int]],
target_timestamp: int,
frameset_acceptable_time_diff: int,
) -> Dict[str, Optional[int]]:
"""
Compute the frameset for a given timestamp.
The frameset consists of the closest timestamps for each stream that are within the acceptable time difference.
Args:
stream_timestamps_sorted: A dictionary containing lists of sorted timestamps indexed by str(StreamId).
target_timestamp: The target timestamp to compute the frameset for.
frameset_acceptable_time_diff: The maximum difference between the target timestamp and the closest timestamp in each stream.
Returns:
A dictionary of str(StreamId) to timestamps which defines a frameset at the target timestamp.
"""
stream_id_strs = list(stream_timestamps_sorted.keys())
frameset = {}
for stream_id_str in stream_id_strs:
closest_timestamp = find_closest(
sorted_input_list=stream_timestamps_sorted[stream_id_str],
target=target_timestamp,
)
if abs(closest_timestamp - target_timestamp) < frameset_acceptable_time_diff:
frameset[stream_id_str] = closest_timestamp
else:
frameset[stream_id_str] = None
return frameset
|