Class | Sass::Plugin::StalenessChecker |
In: |
lib/sass/plugin/staleness_checker.rb
|
Parent: | Object |
The class handles `.s[ca]ss` file staleness checks via their mtime timestamps.
To speed things up two level of caches are employed:
Usage:
DELETED | = | 1.0/0.0 |
dependencies_cache | [RW] | @private |
Creates a new StalenessChecker for checking the staleness of several stylesheets at once.
# File lib/sass/plugin/staleness_checker.rb, line 35 35: def initialize 36: @dependencies = self.class.dependencies_cache 37: 38: # Entries in the following instance-level caches are never explicitly expired. 39: # Instead they are supposed to automaticaly go out of scope when a series of staleness checks 40: # (this instance of StalenessChecker was created for) is finished. 41: @mtimes, @dependencies_stale = {}, {} 42: end
Returns whether or not a given CSS file is out of date and needs to be regenerated.
The distinction between this method and the instance-level \{stylesheet_needs_update?} is that the instance method preserves mtime and stale-dependency caches, so it‘s better to use when checking multiple stylesheets at once.
@param css_file [String] The location of the CSS file to check. @param template_file [String] The location of the Sass or SCSS template
that is compiled to `css_file`.
# File lib/sass/plugin/staleness_checker.rb, line 66 66: def self.stylesheet_needs_update?(css_file, template_file) 67: new.stylesheet_needs_update?(css_file, template_file) 68: end
Returns whether or not a given CSS file is out of date and needs to be regenerated.
@param css_file [String] The location of the CSS file to check. @param template_file [String] The location of the Sass or SCSS template
that is compiled to `css_file`.
# File lib/sass/plugin/staleness_checker.rb, line 50 50: def stylesheet_needs_update?(css_file, template_file) 51: template_file, css_mtime = File.expand_path(template_file), mtime(css_file) 52: 53: css_mtime == DELETED || dependency_updated?(css_mtime).call(template_file) 54: end
# File lib/sass/plugin/staleness_checker.rb, line 114 114: def compute_dependencies(filename) 115: Files.tree_for(filename, Plugin.engine_options).grep(Tree::ImportNode) do |n| 116: File.expand_path(n.full_filename) unless n.full_filename =~ /\.css$/ 117: end.compact 118: rescue Sass::SyntaxError => e 119: [] # If the file has an error, we assume it has no dependencies 120: end
# File lib/sass/plugin/staleness_checker.rb, line 93 93: def dependencies(filename) 94: stored_mtime, dependencies = @dependencies[filename] 95: 96: if !stored_mtime || stored_mtime < mtime(filename) 97: @dependencies[filename] = [mtime(filename), dependencies = compute_dependencies(filename)] 98: end 99: 100: dependencies 101: end
# File lib/sass/plugin/staleness_checker.rb, line 72 72: def dependencies_stale?(template_file, css_mtime) 73: timestamps = @dependencies_stale[template_file] ||= {} 74: timestamps.each_pair do |checked_css_mtime, is_stale| 75: if checked_css_mtime <= css_mtime && !is_stale 76: return false 77: elsif checked_css_mtime > css_mtime && is_stale 78: return true 79: end 80: end 81: timestamps[css_mtime] = dependencies(template_file).any?(&dependency_updated?(css_mtime)) 82: end
# File lib/sass/plugin/staleness_checker.rb, line 103 103: def dependency_updated?(css_mtime) 104: lambda do |dep| 105: begin 106: mtime(dep) > css_mtime || dependencies_stale?(dep, css_mtime) 107: rescue Sass::SyntaxError 108: # If there's an error finding depenencies, default to recompiling. 109: true 110: end 111: end 112: end