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Diffstat (limited to 'Tools/Scripts/webkitpy/style/filter.py')
| -rw-r--r-- | Tools/Scripts/webkitpy/style/filter.py | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/Tools/Scripts/webkitpy/style/filter.py b/Tools/Scripts/webkitpy/style/filter.py new file mode 100644 index 0000000..608a9e6 --- /dev/null +++ b/Tools/Scripts/webkitpy/style/filter.py @@ -0,0 +1,278 @@ +# Copyright (C) 2010 Chris Jerdonek (chris.jerdonek@gmail.com) +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions +# are met: +# 1. Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# 2. Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY +# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +# DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY +# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON +# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +"""Contains filter-related code.""" + + +def validate_filter_rules(filter_rules, all_categories): + """Validate the given filter rules, and raise a ValueError if not valid. + + Args: + filter_rules: A list of boolean filter rules, for example-- + ["-whitespace", "+whitespace/braces"] + all_categories: A list of all available category names, for example-- + ["whitespace/tabs", "whitespace/braces"] + + Raises: + ValueError: An error occurs if a filter rule does not begin + with "+" or "-" or if a filter rule does not match + the beginning of some category name in the list + of all available categories. + + """ + for rule in filter_rules: + if not (rule.startswith('+') or rule.startswith('-')): + raise ValueError('Invalid filter rule "%s": every rule ' + "must start with + or -." % rule) + + for category in all_categories: + if category.startswith(rule[1:]): + break + else: + raise ValueError('Suspected incorrect filter rule "%s": ' + "the rule does not match the beginning " + "of any category name." % rule) + + +class _CategoryFilter(object): + + """Filters whether to check style categories.""" + + def __init__(self, filter_rules=None): + """Create a category filter. + + Args: + filter_rules: A list of strings that are filter rules, which + are strings beginning with the plus or minus + symbol (+/-). The list should include any + default filter rules at the beginning. + Defaults to the empty list. + + Raises: + ValueError: Invalid filter rule if a rule does not start with + plus ("+") or minus ("-"). + + """ + if filter_rules is None: + filter_rules = [] + + self._filter_rules = filter_rules + self._should_check_category = {} # Cached dictionary of category to True/False + + def __str__(self): + return ",".join(self._filter_rules) + + # Useful for unit testing. + def __eq__(self, other): + """Return whether this CategoryFilter instance is equal to another.""" + return self._filter_rules == other._filter_rules + + # Useful for unit testing. + def __ne__(self, other): + # Python does not automatically deduce from __eq__(). + return not (self == other) + + def should_check(self, category): + """Return whether the category should be checked. + + The rules for determining whether a category should be checked + are as follows. By default all categories should be checked. + Then apply the filter rules in order from first to last, with + later flags taking precedence. + + A filter rule applies to a category if the string after the + leading plus/minus (+/-) matches the beginning of the category + name. A plus (+) means the category should be checked, while a + minus (-) means the category should not be checked. + + """ + if category in self._should_check_category: + return self._should_check_category[category] + + should_check = True # All categories checked by default. + for rule in self._filter_rules: + if not category.startswith(rule[1:]): + continue + should_check = rule.startswith('+') + self._should_check_category[category] = should_check # Update cache. + return should_check + + +class FilterConfiguration(object): + + """Supports filtering with path-specific and user-specified rules.""" + + def __init__(self, base_rules=None, path_specific=None, user_rules=None): + """Create a FilterConfiguration instance. + + Args: + base_rules: The starting list of filter rules to use for + processing. The default is the empty list, which + by itself would mean that all categories should be + checked. + + path_specific: A list of (sub_paths, path_rules) pairs + that stores the path-specific filter rules for + appending to the base rules. + The "sub_paths" value is a list of path + substrings. If a file path contains one of the + substrings, then the corresponding path rules + are appended. The first substring match takes + precedence, i.e. only the first match triggers + an append. + The "path_rules" value is a list of filter + rules that can be appended to the base rules. + + user_rules: A list of filter rules that is always appended + to the base rules and any path rules. In other + words, the user rules take precedence over the + everything. In practice, the user rules are + provided by the user from the command line. + + """ + if base_rules is None: + base_rules = [] + if path_specific is None: + path_specific = [] + if user_rules is None: + user_rules = [] + + self._base_rules = base_rules + self._path_specific = path_specific + self._path_specific_lower = None + """The backing store for self._get_path_specific_lower().""" + + self._user_rules = user_rules + + self._path_rules_to_filter = {} + """Cached dictionary of path rules to CategoryFilter instance.""" + + # The same CategoryFilter instance can be shared across + # multiple keys in this dictionary. This allows us to take + # greater advantage of the caching done by + # CategoryFilter.should_check(). + self._path_to_filter = {} + """Cached dictionary of file path to CategoryFilter instance.""" + + # Useful for unit testing. + def __eq__(self, other): + """Return whether this FilterConfiguration is equal to another.""" + if self._base_rules != other._base_rules: + return False + if self._path_specific != other._path_specific: + return False + if self._user_rules != other._user_rules: + return False + + return True + + # Useful for unit testing. + def __ne__(self, other): + # Python does not automatically deduce this from __eq__(). + return not self.__eq__(other) + + # We use the prefix "_get" since the name "_path_specific_lower" + # is already taken up by the data attribute backing store. + def _get_path_specific_lower(self): + """Return a copy of self._path_specific with the paths lower-cased.""" + if self._path_specific_lower is None: + self._path_specific_lower = [] + for (sub_paths, path_rules) in self._path_specific: + sub_paths = map(str.lower, sub_paths) + self._path_specific_lower.append((sub_paths, path_rules)) + return self._path_specific_lower + + def _path_rules_from_path(self, path): + """Determine the path-specific rules to use, and return as a tuple. + + This method returns a tuple rather than a list so the return + value can be passed to _filter_from_path_rules() without change. + + """ + path = path.lower() + for (sub_paths, path_rules) in self._get_path_specific_lower(): + for sub_path in sub_paths: + if path.find(sub_path) > -1: + return tuple(path_rules) + return () # Default to the empty tuple. + + def _filter_from_path_rules(self, path_rules): + """Return the CategoryFilter associated to the given path rules. + + Args: + path_rules: A tuple of path rules. We require a tuple rather + than a list so the value can be used as a dictionary + key in self._path_rules_to_filter. + + """ + # We reuse the same CategoryFilter where possible to take + # advantage of the caching they do. + if path_rules not in self._path_rules_to_filter: + rules = list(self._base_rules) # Make a copy + rules.extend(path_rules) + rules.extend(self._user_rules) + self._path_rules_to_filter[path_rules] = _CategoryFilter(rules) + + return self._path_rules_to_filter[path_rules] + + def _filter_from_path(self, path): + """Return the CategoryFilter associated to a path.""" + if path not in self._path_to_filter: + path_rules = self._path_rules_from_path(path) + filter = self._filter_from_path_rules(path_rules) + self._path_to_filter[path] = filter + + return self._path_to_filter[path] + + def should_check(self, category, path): + """Return whether the given category should be checked. + + This method determines whether a category should be checked + by checking the category name against the filter rules for + the given path. + + For a given path, the filter rules are the combination of + the base rules, the path-specific rules, and the user-provided + rules -- in that order. As we will describe below, later rules + in the list take precedence. The path-specific rules are the + rules corresponding to the first element of the "path_specific" + parameter that contains a string case-insensitively matching + some substring of the path. If there is no such element, + there are no path-specific rules for that path. + + Given a list of filter rules, the logic for determining whether + a category should be checked is as follows. By default all + categories should be checked. Then apply the filter rules in + order from first to last, with later flags taking precedence. + + A filter rule applies to a category if the string after the + leading plus/minus (+/-) matches the beginning of the category + name. A plus (+) means the category should be checked, while a + minus (-) means the category should not be checked. + + Args: + category: The category name. + path: The path of the file being checked. + + """ + return self._filter_from_path(path).should_check(category) + |