1 #!/usr/bin/env python 2 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3 # 4 # Use of this source code is governed by a BSD-style license 5 # that can be found in the LICENSE file in the root of the source 6 # tree. An additional intellectual property rights grant can be found 7 # in the file PATENTS. All contributing project authors may 8 # be found in the AUTHORS file in the root of the source tree. 9 10 import multiprocessing 11 import os 12 import subprocess 13 import sys 14 15 _DEFAULT_PADDING = 4 16 17 18 class HelperError(Exception): 19 """Exception raised for errors in the helper.""" 20 pass 21 22 23 def zero_pad(number, padding=_DEFAULT_PADDING): 24 """Converts an int into a zero padded string. 25 26 Args: 27 number(int): The number to convert. 28 padding(int): The number of chars in the output. Note that if you pass for 29 example number=23456 and padding=4, the output will still be '23456', 30 i.e. it will not be cropped. If you pass number=2 and padding=4, the 31 return value will be '0002'. 32 Return: 33 (string): The zero padded number converted to string. 34 """ 35 return str(number).zfill(padding) 36 37 38 def run_shell_command(cmd_list, fail_msg=None): 39 """Executes a command. 40 41 Args: 42 cmd_list(list): Command list to execute. 43 fail_msg(string): Message describing the error in case the command fails. 44 45 Return: 46 (string): The standard output from running the command. 47 48 Raise: 49 HelperError: If command fails. 50 """ 51 process = subprocess.Popen(cmd_list, stdout=subprocess.PIPE, 52 stderr=subprocess.PIPE) 53 output, error = process.communicate() 54 if process.returncode != 0: 55 if fail_msg: 56 print >> sys.stderr, fail_msg 57 raise HelperError('Failed to run %s: command returned %d and printed ' 58 '%s and %s' % (' '.join(cmd_list), process.returncode, 59 output, error)) 60 return output.strip() 61 62 63 def perform_action_on_all_files(directory, file_pattern, file_extension, 64 start_number, action, **kwargs): 65 """Function that performs a given action on all files matching a pattern. 66 67 It is assumed that the files are named file_patternxxxx.file_extension, where 68 xxxx are digits starting from start_number. 69 70 Args: 71 directory(string): The directory where the files live. 72 file_pattern(string): The name pattern of the files. 73 file_extension(string): The files' extension. 74 start_number(int): From where to start to count frames. 75 action(function): The action to be performed over the files. Must return 76 False if the action failed, True otherwise. It should take a file name 77 as the first argument and **kwargs as arguments. The function must be 78 possible to pickle, so it cannot be a bound function (for instance). 79 80 Return: 81 (bool): Whether performing the action over all files was successful or not. 82 """ 83 file_prefix = os.path.join(directory, file_pattern) 84 file_number = start_number 85 86 process_pool = multiprocessing.Pool(processes=multiprocessing.cpu_count()) 87 results = [] 88 while True: 89 zero_padded_file_number = zero_pad(file_number) 90 file_name = file_prefix + zero_padded_file_number + '.' + file_extension 91 if not os.path.isfile(file_name): 92 break 93 future = process_pool.apply_async(action, args=(file_name,), kwds=kwargs) 94 results.append(future) 95 file_number += 1 96 97 successful = True 98 for result in results: 99 if not result.get(): 100 print "At least one action %s failed for files %sxxxx.%s." % ( 101 action, file_pattern, file_extension) 102 successful = False 103 104 process_pool.close() 105 return successful 106
