class Sprockets::Cache::FileStore
Public: A file system cache store that automatically cleans up old keys.
Assign the instance to the Environment#cache
.
environment.cache = Sprockets::Cache::FileStore.new("/tmp")
See Also
ActiveSupport::Cache::FileStore
Constants
- DEFAULT_MAX_SIZE
Internal: Default key limit for store.
- EXCLUDED_DIRS
- GITKEEP_FILES
Public Class Methods
Internal: Default standard error fatal logger.
Returns a Logger.
# File lib/sprockets/cache/file_store.rb, line 29 def self.default_logger logger = Logger.new($stderr) logger.level = Logger::FATAL logger end
Public: Initialize the cache store.
root - A String path to a directory to persist cached values to. max_size - A Integer of the maximum size the store will hold (in bytes).
(default: 25MB).
logger - The logger to which some info will be printed.
(default logger level is FATAL and won't output anything).
# File lib/sprockets/cache/file_store.rb, line 42 def initialize(root, max_size = DEFAULT_MAX_SIZE, logger = self.class.default_logger) @root = root @max_size = max_size @gc_size = max_size * 0.75 @logger = logger end
Public Instance Methods
Public: Clear the cache
adapted from ActiveSupport::Cache::FileStore#clear
Deletes all items from the cache. In this case it deletes all the entries in the specified file store directory except for .keep or .gitkeep. Be careful which directory is specified as @root because everything in that directory will be deleted.
Returns true
# File lib/sprockets/cache/file_store.rb, line 139 def clear(options=nil) if File.exist?(@root) root_dirs = Dir.entries(@root).reject { |f| (EXCLUDED_DIRS + GITKEEP_FILES).include?(f) } FileUtils.rm_r(root_dirs.collect{ |f| File.join(@root, f) }) end true end
Public: Retrieve value from cache.
This API should not be used directly, but via the Cache
wrapper API.
key - String cache key.
Returns Object or nil or the value is not set.
# File lib/sprockets/cache/file_store.rb, line 56 def get(key) path = File.join(@root, "#{key}.cache") value = safe_open(path) do |f| begin EncodingUtils.unmarshaled_deflated(f.read, Zlib::MAX_WBITS) rescue Exception => e @logger.error do "#{self.class}[#{path}] could not be unmarshaled: " + "#{e.class}: #{e.message}" end nil end end if value FileUtils.touch(path) value end end
Public: Pretty inspect
Returns String.
# File lib/sprockets/cache/file_store.rb, line 126 def inspect "#<#{self.class} size=#{size}/#{@max_size}>" end
Public: Set a key and value in the cache.
This API should not be used directly, but via the Cache
wrapper API.
key - String cache key. value - Object value.
Returns Object value.
# File lib/sprockets/cache/file_store.rb, line 85 def set(key, value) path = File.join(@root, "#{key}.cache") # Ensure directory exists FileUtils.mkdir_p File.dirname(path) # Check if cache exists before writing exists = File.exist?(path) # Serialize value marshaled = Marshal.dump(value) # Compress if larger than 4KB if marshaled.bytesize > 4 * 1024 deflater = Zlib::Deflate.new( Zlib::BEST_COMPRESSION, Zlib::MAX_WBITS, Zlib::MAX_MEM_LEVEL, Zlib::DEFAULT_STRATEGY ) deflater << marshaled raw = deflater.finish else raw = marshaled end # Write data PathUtils.atomic_write(path) do |f| f.write(raw) @size = size + f.size unless exists end # GC if necessary gc! if size > @max_size value end
Private Instance Methods
# File lib/sprockets/cache/file_store.rb, line 166 def compute_size(caches) caches.inject(0) { |sum, (_, stat)| sum + stat.size } end
Internal: Get all cache files along with stats.
Returns an Array of [String filename, File::Stat] pairs sorted by mtime.
# File lib/sprockets/cache/file_store.rb, line 152 def find_caches Dir.glob(File.join(@root, '**/*.cache')).reduce([]) { |stats, filename| stat = safe_stat(filename) # stat maybe nil if file was removed between the time we called # dir.glob and the next stat stats << [filename, stat] if stat stats }.sort_by { |_, stat| stat.mtime.to_i } end
# File lib/sprockets/cache/file_store.rb, line 183 def gc! start_time = Time.now caches = find_caches size = compute_size(caches) delete_caches, keep_caches = caches.partition { |filename, stat| deleted = size > @gc_size size -= stat.size deleted } return if delete_caches.empty? FileUtils.remove(delete_caches.map(&:first), force: true) @size = compute_size(keep_caches) @logger.warn do secs = Time.now.to_f - start_time.to_f "#{self.class}[#{@root}] garbage collected " + "#{delete_caches.size} files (#{(secs * 1000).to_i}ms)" end end
# File lib/sprockets/cache/file_store.rb, line 176 def safe_open(path, &block) if File.exist?(path) File.open(path, 'rb', &block) end rescue Errno::ENOENT end
# File lib/sprockets/cache/file_store.rb, line 170 def safe_stat(fn) File.stat(fn) rescue Errno::ENOENT nil end
# File lib/sprockets/cache/file_store.rb, line 162 def size @size ||= compute_size(find_caches) end