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Diffstat (limited to 'chromium/third_party/skia/tools/misc_utils.py')
| -rw-r--r-- | chromium/third_party/skia/tools/misc_utils.py | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/chromium/third_party/skia/tools/misc_utils.py b/chromium/third_party/skia/tools/misc_utils.py new file mode 100644 index 00000000000..13978a47421 --- /dev/null +++ b/chromium/third_party/skia/tools/misc_utils.py @@ -0,0 +1,224 @@ +# Copyright 2014 Google Inc. +# +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + + +"""Module to host the VerboseSubprocess, ChangeDir, and ReSearch classes. +""" + +import os +import re +import subprocess + + +def print_subprocess_args(prefix, *args, **kwargs): + """Print out args in a human-readable manner.""" + def quote_and_escape(string): + """Quote and escape a string if necessary.""" + if ' ' in string or '\n' in string: + string = '"%s"' % string.replace('"', '\\"') + return string + if 'cwd' in kwargs: + print '%scd %s' % (prefix, kwargs['cwd']) + print prefix + ' '.join(quote_and_escape(arg) for arg in args[0]) + if 'cwd' in kwargs: + print '%scd -' % prefix + + +class VerboseSubprocess(object): + """Call subprocess methods, but print out command before executing. + + Attributes: + verbose: (boolean) should we print out the command or not. If + not, this is the same as calling the subprocess method + quiet: (boolean) suppress stdout on check_call and call. + prefix: (string) When verbose, what to print before each command. + """ + + def __init__(self, verbose): + self.verbose = verbose + self.quiet = not verbose + self.prefix = '~~$ ' + + def check_call(self, *args, **kwargs): + """Wrapper for subprocess.check_call(). + + Args: + *args: to be passed to subprocess.check_call() + **kwargs: to be passed to subprocess.check_call() + Returns: + Whatever subprocess.check_call() returns. + Raises: + OSError or subprocess.CalledProcessError: raised by check_call. + """ + if self.verbose: + print_subprocess_args(self.prefix, *args, **kwargs) + if self.quiet: + with open(os.devnull, 'w') as devnull: + return subprocess.check_call(*args, stdout=devnull, **kwargs) + else: + return subprocess.check_call(*args, **kwargs) + + def call(self, *args, **kwargs): + """Wrapper for subprocess.check(). + + Args: + *args: to be passed to subprocess.check_call() + **kwargs: to be passed to subprocess.check_call() + Returns: + Whatever subprocess.call() returns. + Raises: + OSError or subprocess.CalledProcessError: raised by call. + """ + if self.verbose: + print_subprocess_args(self.prefix, *args, **kwargs) + if self.quiet: + with open(os.devnull, 'w') as devnull: + return subprocess.call(*args, stdout=devnull, **kwargs) + else: + return subprocess.call(*args, **kwargs) + + def check_output(self, *args, **kwargs): + """Wrapper for subprocess.check_output(). + + Args: + *args: to be passed to subprocess.check_output() + **kwargs: to be passed to subprocess.check_output() + Returns: + Whatever subprocess.check_output() returns. + Raises: + OSError or subprocess.CalledProcessError: raised by check_output. + """ + if self.verbose: + print_subprocess_args(self.prefix, *args, **kwargs) + return subprocess.check_output(*args, **kwargs) + + def strip_output(self, *args, **kwargs): + """Wrap subprocess.check_output and str.strip(). + + Pass the given arguments into subprocess.check_output() and return + the results, after stripping any excess whitespace. + + Args: + *args: to be passed to subprocess.check_output() + **kwargs: to be passed to subprocess.check_output() + + Returns: + The output of the process as a string without leading or + trailing whitespace. + Raises: + OSError or subprocess.CalledProcessError: raised by check_output. + """ + if self.verbose: + print_subprocess_args(self.prefix, *args, **kwargs) + return str(subprocess.check_output(*args, **kwargs)).strip() + + def popen(self, *args, **kwargs): + """Wrapper for subprocess.Popen(). + + Args: + *args: to be passed to subprocess.Popen() + **kwargs: to be passed to subprocess.Popen() + Returns: + The output of subprocess.Popen() + Raises: + OSError or subprocess.CalledProcessError: raised by Popen. + """ + if self.verbose: + print_subprocess_args(self.prefix, *args, **kwargs) + return subprocess.Popen(*args, **kwargs) + + +class ChangeDir(object): + """Use with a with-statement to temporarily change directories.""" + # pylint: disable=I0011,R0903 + + def __init__(self, directory, verbose=False): + self._directory = directory + self._verbose = verbose + + def __enter__(self): + if self._directory != os.curdir: + if self._verbose: + print '~~$ cd %s' % self._directory + cwd = os.getcwd() + os.chdir(self._directory) + self._directory = cwd + + def __exit__(self, etype, value, traceback): + if self._directory != os.curdir: + if self._verbose: + print '~~$ cd %s' % self._directory + os.chdir(self._directory) + + +class ReSearch(object): + """A collection of static methods for regexing things.""" + + @staticmethod + def search_within_stream(input_stream, pattern, default=None): + """Search for regular expression in a file-like object. + + Opens a file for reading and searches line by line for a match to + the regex and returns the parenthesized group named return for the + first match. Does not search across newlines. + + For example: + pattern = '^root(:[^:]*){4}:(?P<return>[^:]*)' + with open('/etc/passwd', 'r') as stream: + return search_within_file(stream, pattern) + should return root's home directory (/root on my system). + + Args: + input_stream: file-like object to be read + pattern: (string) to be passed to re.compile + default: what to return if no match + + Returns: + A string or whatever default is + """ + pattern_object = re.compile(pattern) + for line in input_stream: + match = pattern_object.search(line) + if match: + return match.group('return') + return default + + @staticmethod + def search_within_string(input_string, pattern, default=None): + """Search for regular expression in a string. + + Args: + input_string: (string) to be searched + pattern: (string) to be passed to re.compile + default: what to return if no match + + Returns: + A string or whatever default is + """ + match = re.search(pattern, input_string) + return match.group('return') if match else default + + @staticmethod + def search_within_output(verbose, pattern, default, *args, **kwargs): + """Search for regular expression in a process output. + + Does not search across newlines. + + Args: + verbose: (boolean) shoule we call print_subprocess_args? + pattern: (string) to be passed to re.compile + default: what to return if no match + *args: to be passed to subprocess.Popen() + **kwargs: to be passed to subprocess.Popen() + + Returns: + A string or whatever default is + """ + if verbose: + print_subprocess_args('~~$ ', *args, **kwargs) + proc = subprocess.Popen(*args, stdout=subprocess.PIPE, **kwargs) + return ReSearch.search_within_stream(proc.stdout, pattern, default) + + |