class Sprockets::Manifest

The Manifest logs the contents of assets compiled to a single directory. It records basic attributes about the asset for fast lookup without having to compile. A pointer from each logical path indicates which fingerprinted asset is the current one.

The JSON is part of the public API and should be considered stable. This should make it easy to read from other programming languages and processes that don’t have sprockets loaded. See ‘#assets` and `#files` for more information about the structure.

Attributes

dir[R]
directory[R]
environment[R]
filename[R]

Returns String path to manifest.json file.

path[R]

Returns String path to manifest.json file.

Public Class Methods

new(*args) click to toggle source

Create new Manifest associated with an ‘environment`. `filename` is a full path to the manifest json file. The file may or may not already exist. The dirname of the `filename` will be used to write compiled assets to. Otherwise, if the path is a directory, the filename will default a random “.sprockets-manifest-*.json” file in that directory.

Manifest.new(environment, "./public/assets/manifest.json")
# File lib/sprockets/manifest.rb, line 32
def initialize(*args)
  if args.first.is_a?(Base) || args.first.nil?
    @environment = args.shift
  end

  @directory, @filename = args[0], args[1]

  # Whether the manifest file is using the old manifest-*.json naming convention
  @legacy_manifest = false

  # Expand paths
  @directory = File.expand_path(@directory) if @directory
  @filename  = File.expand_path(@filename) if @filename

  # If filename is given as the second arg
  if @directory && File.extname(@directory) != ""
    @directory, @filename = nil, @directory
  end

  # Default dir to the directory of the filename
  @directory ||= File.dirname(@filename) if @filename

  # If directory is given w/o filename, pick a random manifest location
  if @directory && @filename.nil?
    @filename = find_directory_manifest(@directory, logger)
  end

  unless @directory && @filename
    raise ArgumentError, "manifest requires output filename"
  end

  data = {}

  begin
    if File.exist?(@filename)
      data = json_decode(File.read(@filename))
    end
  rescue JSON::ParserError => e
    logger.error "#{@filename} is invalid: #{e.class} #{e.message}"
  end

  @data = data
end

Public Instance Methods

assets() click to toggle source

Returns internal assets mapping. Keys are logical paths which map to the latest fingerprinted filename.

Logical path (String): Fingerprint path (String)

{ "application.js" => "application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js",
  "jquery.js"      => "jquery-ae0908555a245f8266f77df5a8edca2e.js" }
# File lib/sprockets/manifest.rb, line 91
def assets
  @data['assets'] ||= {}
end
clean(count = 2, age = 3600) click to toggle source

Cleanup old assets in the compile directory. By default it will keep the latest version, 2 backups and any created within the past hour.

Examples

To force only 1 backup to be kept, set count=1 and age=0.

To only keep files created within the last 10 minutes, set count=0 and
age=600.
# File lib/sprockets/manifest.rb, line 246
def clean(count = 2, age = 3600)
  asset_versions = files.group_by { |_, attrs| attrs['logical_path'] }

  asset_versions.each do |logical_path, versions|
    current = assets[logical_path]

    versions.reject { |path, _|
      path == current
    }.sort_by { |_, attrs|
      # Sort by timestamp
      Time.parse(attrs['mtime'])
    }.reverse.each_with_index.drop_while { |(_, attrs), index|
      _age = [0, Time.now - Time.parse(attrs['mtime'])].max
      # Keep if under age or within the count limit
      _age < age || index < count
    }.each { |(path, _), _|
       # Remove old assets
      remove(path)
    }
  end
end
clobber() click to toggle source

Wipe directive

# File lib/sprockets/manifest.rb, line 269
def clobber
  FileUtils.rm_r(directory) if File.exist?(directory)
  logger.info "Removed #{directory}"
  # if we have an environment clear the cache too
  environment.cache.clear if environment
  nil
end
compile(*args) click to toggle source

Compile asset to directory. The asset is written to a fingerprinted filename like ‘application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js`. An entry is also inserted into the manifest file.

compile("application.js")
# File lib/sprockets/manifest.rb, line 161
def compile(*args)
  unless environment
    raise Error, "manifest requires environment for compilation"
  end

  filenames            = []
  concurrent_exporters = []

  assets_to_export = Concurrent::Array.new
  find(*args) do |asset|
    assets_to_export << asset
  end

  assets_to_export.each do |asset|
    mtime = Time.now.iso8601
    files[asset.digest_path] = {
      'logical_path' => asset.logical_path,
      'mtime'        => mtime,
      'size'         => asset.bytesize,
      'digest'       => asset.hexdigest,

      # Deprecated: Remove beta integrity attribute in next release.
      # Callers should DigestUtils.hexdigest_integrity_uri to compute the
      # digest themselves.
      'integrity'    => DigestUtils.hexdigest_integrity_uri(asset.hexdigest)
    }
    assets[asset.logical_path] = asset.digest_path

    filenames << asset.filename

    promise      = nil
    exporters_for_asset(asset) do |exporter|
      next if exporter.skip?(logger)

      if promise.nil?
        promise = Concurrent::Promise.new(executor: executor) { exporter.call }
        concurrent_exporters << promise.execute
      else
        concurrent_exporters << promise.then { exporter.call }
      end
    end
  end

  # make sure all exporters have finished before returning the main thread
  concurrent_exporters.each(&:wait!)
  save

  filenames
end
files() click to toggle source

Returns internal file directory listing. Keys are filenames which map to an attributes array.

 Fingerprint path (String):
   logical_path: Logical path (String)
   mtime: ISO8601 mtime (String)
   digest: Base64 hex digest (String)

{ "application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js" =>
    { 'logical_path' => "application.js",
      'mtime' => "2011-12-13T21:47:08-06:00",
      'digest' => "2e8e9a7c6b0aafa0c9bdeec90ea30213" } }
# File lib/sprockets/manifest.rb, line 108
def files
  @data['files'] ||= {}
end
find(*args, &block) click to toggle source

Public: Find all assets matching pattern set in environment.

Returns Enumerator of Assets.

# File lib/sprockets/manifest.rb, line 115
def find(*args, &block)
  unless environment
    raise Error, "manifest requires environment for compilation"
  end

  return to_enum(__method__, *args) unless block_given?

  environment = self.environment.cached
  promises = args.flatten.map do |path|
    Concurrent::Promise.execute(executor: executor) do
      environment.find_all_linked_assets(path).to_a
    end
  end

  promises.each do |promise|
    promise.value!.each(&block)
  end

  nil
end
find_sources(*args) { |source| ... } click to toggle source

Public: Find the source of assets by paths.

Returns Enumerator of assets file content.

# File lib/sprockets/manifest.rb, line 139
def find_sources(*args)
  return to_enum(__method__, *args) unless block_given?

  if environment
    find(*args).each do |asset|
      yield asset.source
    end
  else
    args.each do |path|
      asset = assets[path]
      yield File.binread(File.join(dir, asset)) if asset
    end
  end
end
remove(filename) click to toggle source

Removes file from directory and from manifest. ‘filename` must be the name with any directory path.

manifest.remove("application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js")
# File lib/sprockets/manifest.rb, line 216
def remove(filename)
  path = File.join(dir, filename)
  gzip = "#{path}.gz"
  logical_path = files[filename]['logical_path']

  if assets[logical_path] == filename
    assets.delete(logical_path)
  end

  files.delete(filename)
  FileUtils.rm(path) if File.exist?(path)
  FileUtils.rm(gzip) if File.exist?(gzip)

  save

  logger.info "Removed #{filename}"

  nil
end
save() click to toggle source

Persist manifest back to FS

# File lib/sprockets/manifest.rb, line 278
def save
  data = json_encode(@data)
  FileUtils.mkdir_p File.dirname(@filename)
  PathUtils.atomic_write(@filename) do |f|
    f.write(data)
  end
end

Private Instance Methods

executor() click to toggle source
# File lib/sprockets/manifest.rb, line 335
def executor
  @executor ||= environment.export_concurrent ? :fast : :immediate
end
exporters_for_asset(asset) { |exporter(asset: asset, environment: environment, directory: dir)| ... } click to toggle source

Given an asset, finds all exporters that match its mime-type.

Will yield each expoter to the passed in block.

array = []
puts asset.content_type # => "application/javascript"
exporters_for_asset(asset) do |exporter|
  array << exporter
end
# puts array => [Exporters::FileExporter, Exporters::ZlibExporter]
# File lib/sprockets/manifest.rb, line 299
def exporters_for_asset(asset)
  exporters = [Exporters::FileExporter]

  environment.exporters.each do |mime_type, exporter_list|
    next unless asset.content_type
    next unless environment.match_mime_type? asset.content_type, mime_type
    exporter_list.each do |exporter|
      exporters << exporter
    end
  end

  exporters.uniq!

  exporters.each do |exporter|
    yield exporter.new(asset: asset, environment: environment, directory: dir)
  end
end
json_decode(obj) click to toggle source
# File lib/sprockets/manifest.rb, line 317
def json_decode(obj)
  JSON.parse(obj, create_additions: false)
end
json_encode(obj) click to toggle source
# File lib/sprockets/manifest.rb, line 321
def json_encode(obj)
  JSON.generate(obj)
end
logger() click to toggle source
# File lib/sprockets/manifest.rb, line 325
def logger
  if environment
    environment.logger
  else
    logger = Logger.new($stderr)
    logger.level = Logger::FATAL
    logger
  end
end