gems.sass-3.2.8.lib.sass.cache_stores.base.rb Maven / Gradle / Ivy
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Sass makes CSS fun again. Sass is an extension of CSS3, adding nested rules, variables, mixins, selector
inheritance, and more. It's translated to well-formatted, standard CSS using the command line tool or a
web-framework plugin.
This is a repackaged GEM in a JAR format of the sass-lang.gem package. The sass-gems package version
follows the sass-lang.gem versions located http://rubyforge.org/frs/?group_id=9702. Simply change
the version of this package to download and repackage the same GEM version.
module Sass
module CacheStores
# An abstract base class for backends for the Sass cache.
# Any key-value store can act as such a backend;
# it just needs to implement the
# \{#_store} and \{#_retrieve} methods.
#
# To use a cache store with Sass,
# use the {file:SASS_REFERENCE.md#cache_store-option `:cache_store` option}.
#
# @abstract
class Base
# Store cached contents for later retrieval
# Must be implemented by all CacheStore subclasses
#
# Note: cache contents contain binary data.
#
# @param key [String] The key to store the contents under
# @param version [String] The current sass version.
# Cached contents must not be retrieved across different versions of sass.
# @param sha [String] The sha of the sass source.
# Cached contents must not be retrieved if the sha has changed.
# @param contents [String] The contents to store.
def _store(key, version, sha, contents)
raise "#{self.class} must implement #_store."
end
# Retrieved cached contents.
# Must be implemented by all subclasses.
#
# Note: if the key exists but the sha or version have changed,
# then the key may be deleted by the cache store, if it wants to do so.
#
# @param key [String] The key to retrieve
# @param version [String] The current sass version.
# Cached contents must not be retrieved across different versions of sass.
# @param sha [String] The sha of the sass source.
# Cached contents must not be retrieved if the sha has changed.
# @return [String] The contents that were previously stored.
# @return [NilClass] when the cache key is not found or the version or sha have changed.
def _retrieve(key, version, sha)
raise "#{self.class} must implement #_retrieve."
end
# Store a {Sass::Tree::RootNode}.
#
# @param key [String] The key to store it under.
# @param sha [String] The checksum for the contents that are being stored.
# @param obj [Object] The object to cache.
def store(key, sha, root)
_store(key, Sass::VERSION, sha, Marshal.dump(root))
rescue TypeError, LoadError => e
Sass::Util.sass_warn "Warning. Error encountered while saving cache #{path_to(key)}: #{e}"
nil
end
# Retrieve a {Sass::Tree::RootNode}.
#
# @param key [String] The key the root element was stored under.
# @param sha [String] The checksum of the root element's content.
# @return [Object] The cached object.
def retrieve(key, sha)
contents = _retrieve(key, Sass::VERSION, sha)
Marshal.load(contents) if contents
rescue EOFError, TypeError, ArgumentError, LoadError => e
Sass::Util.sass_warn "Warning. Error encountered while reading cache #{path_to(key)}: #{e}"
nil
end
# Return the key for the sass file.
#
# The `(sass_dirname, sass_basename)` pair
# should uniquely identify the Sass document,
# but otherwise there are no restrictions on their content.
#
# @param sass_dirname [String]
# The fully-expanded location of the Sass file.
# This corresponds to the directory name on a filesystem.
# @param sass_basename [String] The name of the Sass file that is being referenced.
# This corresponds to the basename on a filesystem.
def key(sass_dirname, sass_basename)
dir = Digest::SHA1.hexdigest(sass_dirname)
filename = "#{sass_basename}c"
"#{dir}/#{filename}"
end
end
end
end