zstd/tests/rateLimiter.py
Yann Collet 09c9cf3f51 simplified rateLimiter
resists better to changing in/out conditions
limits risks of "catching up"
2018-08-13 12:13:47 -07:00

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1.1 KiB
Python
Executable File

#!/usr/bin/env python3
# ################################################################
# Copyright (c) 2018-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under both the BSD-style license (found in the
# LICENSE file in the root directory of this source tree) and the GPLv2 (found
# in the COPYING file in the root directory of this source tree).
# ##########################################################################
# Rate limiter, replacement for pv
# this rate limiter does not "catch up" after a blocking period
# Limitations:
# - only accepts limit speed in MB/s
import sys
import time
MB = 1024 * 1024
rate = float(sys.argv[1]) * MB
start = time.time()
total_read = 0
# sys.stderr.close() # remove error message, for Ctrl+C
try:
buf = " "
while len(buf):
now = time.time()
to_read = max(int(rate * (now - start)), 1)
max_buf_size = 1 * MB
to_read = min(to_read, max_buf_size)
start = now
buf = sys.stdin.buffer.read(to_read)
sys.stdout.buffer.write(buf)
except (KeyboardInterrupt, BrokenPipeError) as e:
pass