shaka-packager/tools/python/google/process_utils.py

222 lines
7.3 KiB
Python

# Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Shared process-related utility functions."""
import errno
import os
import subprocess
import sys
class CommandNotFound(Exception): pass
TASKKILL = os.path.join(os.environ['WINDIR'], 'system32', 'taskkill.exe')
TASKKILL_PROCESS_NOT_FOUND_ERR = 128
# On windows 2000 there is no taskkill.exe, we need to have pskill somewhere
# in the path.
PSKILL = 'pskill.exe'
PSKILL_PROCESS_NOT_FOUND_ERR = -1
def KillAll(executables):
"""Tries to kill all copies of each process in the processes list. Returns
an error if any running processes couldn't be killed.
"""
result = 0
if os.path.exists(TASKKILL):
command = [TASKKILL, '/f', '/im']
process_not_found_err = TASKKILL_PROCESS_NOT_FOUND_ERR
else:
command = [PSKILL, '/t']
process_not_found_err = PSKILL_PROCESS_NOT_FOUND_ERR
for name in executables:
new_error = RunCommand(command + [name])
# Ignore "process not found" error.
if new_error != 0 and new_error != process_not_found_err:
result = new_error
return result
def RunCommandFull(command, verbose=True, collect_output=False,
print_output=True):
"""Runs the command list.
Prints the given command (which should be a list of one or more strings).
If specified, prints its stderr (and optionally stdout) to stdout,
line-buffered, converting line endings to CRLF (see note below). If
specified, collects the output as a list of lines and returns it. Waits
for the command to terminate and returns its status.
Args:
command: the full command to run, as a list of one or more strings
verbose: if True, combines all output (stdout and stderr) into stdout.
Otherwise, prints only the command's stderr to stdout.
collect_output: if True, collects the output of the command as a list of
lines and returns it
print_output: if True, prints the output of the command
Returns:
A tuple consisting of the process's exit status and output. If
collect_output is False, the output will be [].
Raises:
CommandNotFound if the command executable could not be found.
"""
print '\n' + subprocess.list2cmdline(command).replace('\\', '/') + '\n', ###
if verbose:
out = subprocess.PIPE
err = subprocess.STDOUT
else:
out = file(os.devnull, 'w')
err = subprocess.PIPE
try:
proc = subprocess.Popen(command, stdout=out, stderr=err, bufsize=1)
except OSError, e:
if e.errno == errno.ENOENT:
raise CommandNotFound('Unable to find "%s"' % command[0])
raise
output = []
if verbose:
read_from = proc.stdout
else:
read_from = proc.stderr
line = read_from.readline()
while line:
line = line.rstrip()
if collect_output:
output.append(line)
if print_output:
# Windows Python converts \n to \r\n automatically whenever it
# encounters it written to a text file (including stdout). The only
# way around it is to write to a binary file, which isn't feasible for
# stdout. So we end up with \r\n here even though we explicitly write
# \n. (We could write \r instead, which doesn't get converted to \r\n,
# but that's probably more troublesome for people trying to read the
# files.)
print line + '\n',
# Python on windows writes the buffer only when it reaches 4k. This is
# not fast enough for all purposes.
sys.stdout.flush()
line = read_from.readline()
# Make sure the process terminates.
proc.wait()
if not verbose:
out.close()
return (proc.returncode, output)
def RunCommand(command, verbose=True):
"""Runs the command list, printing its output and returning its exit status.
Prints the given command (which should be a list of one or more strings),
then runs it and prints its stderr (and optionally stdout) to stdout,
line-buffered, converting line endings to CRLF. Waits for the command to
terminate and returns its status.
Args:
command: the full command to run, as a list of one or more strings
verbose: if True, combines all output (stdout and stderr) into stdout.
Otherwise, prints only the command's stderr to stdout.
Returns:
The process's exit status.
Raises:
CommandNotFound if the command executable could not be found.
"""
return RunCommandFull(command, verbose)[0]
def RunCommandsInParallel(commands, verbose=True, collect_output=False,
print_output=True):
"""Runs a list of commands in parallel, waits for all commands to terminate
and returns their status. If specified, the ouput of commands can be
returned and/or printed.
Args:
commands: the list of commands to run, each as a list of one or more
strings.
verbose: if True, combines stdout and stderr into stdout.
Otherwise, prints only the command's stderr to stdout.
collect_output: if True, collects the output of the each command as a list
of lines and returns it.
print_output: if True, prints the output of each command.
Returns:
A list of tuples consisting of each command's exit status and output. If
collect_output is False, the output will be [].
Raises:
CommandNotFound if any of the command executables could not be found.
"""
command_num = len(commands)
outputs = [[] for i in xrange(command_num)]
procs = [None for i in xrange(command_num)]
eofs = [False for i in xrange(command_num)]
for command in commands:
print '\n' + subprocess.list2cmdline(command).replace('\\', '/') + '\n',
if verbose:
out = subprocess.PIPE
err = subprocess.STDOUT
else:
out = file(os.devnull, 'w')
err = subprocess.PIPE
for i in xrange(command_num):
try:
command = commands[i]
procs[i] = subprocess.Popen(command, stdout=out, stderr=err, bufsize=1)
except OSError, e:
if e.errno == errno.ENOENT:
raise CommandNotFound('Unable to find "%s"' % command[0])
raise
# We could consider terminating the processes already started.
# But Popen.kill() is only available in version 2.6.
# For now the clean up is done by KillAll.
while True:
eof_all = True
for i in xrange(command_num):
if eofs[i]:
continue
if verbose:
read_from = procs[i].stdout
else:
read_from = procs[i].stderr
line = read_from.readline()
if line:
eof_all = False
line = line.rstrip()
outputs[i].append(line)
if print_output:
# Windows Python converts \n to \r\n automatically whenever it
# encounters it written to a text file (including stdout). The only
# way around it is to write to a binary file, which isn't feasible
# for stdout. So we end up with \r\n here even though we explicitly
# write \n. (We could write \r instead, which doesn't get converted
# to \r\n, but that's probably more troublesome for people trying to
# read the files.)
print line + '\n',
else:
eofs[i] = True
if eof_all:
break
# Make sure the process terminates.
for i in xrange(command_num):
procs[i].wait()
if not verbose:
out.close()
return [(procs[i].returncode, outputs[i]) for i in xrange(command_num)]