class Sass::CacheStores::Base
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
Public Instance Methods
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.
# File lib/sass/cache_stores/base.rb, line 41 def _retrieve(key, version, sha) raise "#{self.class} must implement #_retrieve." end
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.
# File lib/sass/cache_stores/base.rb, line 24 def _store(key, version, sha, contents) raise "#{self.class} must implement #_store." 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.
# File lib/sass/cache_stores/base.rb, line 81 def key(sass_dirname, sass_basename) dir = Digest::SHA1.hexdigest(sass_dirname) filename = "#{sass_basename}c" "#{dir}/#{filename}" 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.
# File lib/sass/cache_stores/base.rb, line 62 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
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 root [Object] The root node to cache.
# File lib/sass/cache_stores/base.rb, line 50 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