Class: Configuration::Thumbnail

Inherits:

HandlerStatement

• Object
• Scope
• HandlerStatement
• Configuration::Thumbnail

Extended by:

Stats

Includes:

ClassLogging, ConditionalInclusion, GlobalConfiguration, ImageName, LocalConfiguration, PerfStats

Defined in:

lib/httpimagestore/configuration/thumbnailer.rb

Defined Under Namespace

Classes: ThumbnailSpec, ThumbnailingError

Class Method Summary

• .match(node) ⇒ Object
• .parse(configuration, node) ⇒ Object

Instance Method Summary

• #included?(request_state) ⇒ Boolean
• #initialize(global, source_image_name, specs, use_multipart_api) ⇒ Thumbnail constructor

  A new instance of Thumbnail.

• #realize(request_state) ⇒ Object

Methods inherited from Scope

node_parsers, #parse, register_node_parser

Constructor Details

#initialize(global, source_image_name, specs, use_multipart_api) ⇒ Thumbnail

Returns a new instance of Thumbnail.

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 249

def initialize(global, source_image_name, specs, use_multipart_api)
	with_global_configuration(global)
	with_image_name(source_image_name)
	@source_image_name = source_image_name
	@specs = specs.freeze
	@use_multipart_api = use_multipart_api
end

Class Method Details

.match(node) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 181

def self.match(node)
	node.name == 'thumbnail'
end

.parse(configuration, node) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 185

def self.parse(configuration, node)
	# if we don't have any subnodes use this node as single subnode and parse as if they were subnodes
	use_multipart_api = node.values.length == 1 ? true : false

	nodes = use_multipart_api ? node.children : [node]
	source_image_name = use_multipart_api ? node.grab_values('source image name').first : nil # parsed later

	general_conditions = []
	if use_multipart_api
		general_conditions, remaining = *ConditionalInclusion.grab_conditions_with_remaining(node.attributes)
		remaining.empty? or raise UnexpectedAttributesError.new(node, remaining)
	end

	nodes.empty? and raise NoValueError.new(node, 'thumbnail image name')

	specs = nodes.map do |node|
		if use_multipart_api
			image_name = node.grab_values('thumbnail image name').first
		else
			source_image_name, image_name = *node.grab_values('source image name', 'thumbnail image name')
		end

		operation, width, height, format, remaining = *node.grab_attributes_with_remaining('operation', 'width', 'height', 'format')

		conditions, remaining = *ConditionalInclusion.grab_conditions_with_remaining(remaining)

		edits = []
		# check for subnodes
		subnodes = node.children.group_by{|node| node.name}
		edit_nodes = subnodes.delete('edit')
		edit_nodes and edit_nodes.each.with_index do |node, edit_no|
			edit_conditions, edit_options = *ConditionalInclusion.grab_conditions_with_remaining(node.attributes)

			args = node.values.dup

			edit = ThumbnailSpec::EditSpec.new(args.shift, args, edit_options, edit_no)
			edit.with_conditions(edit_conditions)

			edits << edit
		end

		subnodes.keys.empty? or raise UnknownThumbnailingDirectiveError.new(source_image_name, image_name, subnodes.keys.join(' and '))

		ThumbnailSpec.new(
			image_name,
			operation || 'fit',
			width || 'input',
			height || 'input',
			format || 'input',
			remaining || {},
			edits
		).with_conditions(conditions)
	end

	thum = self.new(
		configuration.global,
		source_image_name,
		specs,
		use_multipart_api,
	)
	thum.with_conditions(general_conditions)
	configuration.processors << thum
end

Instance Method Details

#included?(request_state) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 332

def included?(request_state)
	# TODO this is to complicated!
	if @use_multipart_api
		super(request_state)
	else
		@specs.any? do |spec|
			spec.included?(request_state)
		end
	end
end

#realize(request_state) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 257

def realize(request_state)
	client = @global.thumbnailer or fail 'thumbnailer configuration'

	specs = @specs.select do |spec|
		spec.included?(request_state)
	end

	if specs.empty?
		# in single part form we are OK to skip the thumbnailing all thogether
		return if not @use_multipart_api
		# in multipart for at least one thumbnail spec should be selected
		raise NoSpecSelectedError.new(@specs.map(&:image_name))
	end

	rendered_specs = specs.map do |spec|
		spec.render(request_state)
	end

	source_image = request_state.images[@source_image_name]

	thumbnails = {}
	input_mime_type = nil
	input_width = nil
	input_height = nil

	log.info "thumbnailing '#{@source_image_name}' to specs: #{rendered_specs.map{|s| "#{s.name} -> #{s.spec}"}.join('; ')}"
	Thumbnail.stats.incr_total_thumbnail_requests
	Thumbnail.stats.incr_total_thumbnail_requests_bytes source_image.data.bytesize

	thumbnails = begin
		measure "thumbnailing image", "'#{@source_image_name}' to specs: #{rendered_specs.map{|s| "#{s.name} -> #{s.spec}"}.join('; ')}" do
			client.with_headers(request_state.forward_headers).thumbnail(source_image.data, *rendered_specs.map(&:spec))
		end
	rescue HTTPThumbnailerClient::HTTPThumbnailerClientError => error
		log.warn 'got thumbnailer error', error
		raise ThumbnailingError.new(@source_image_name, rendered_specs.length == 1 ? rendered_specs.first.name : nil, error)
	end

	input_mime_type = thumbnails.input_mime_type
	input_width = thumbnails.input_width
	input_height = thumbnails.input_height

	# check each thumbnail for errors
	thumbnails = Hash[rendered_specs.map(&:name).zip(thumbnails)]
	thumbnails.each do |name, thumbnail|
		if thumbnail.kind_of? HTTPThumbnailerClient::HTTPThumbnailerClientError
			error = thumbnail
			log.warn 'got single thumbnail error', error
			raise ThumbnailingError.new(@source_image_name, name, error)
		end
	end

	# borrow from memory limit - note that we might have already used too much memory
	thumbnails.each do |name, thumbnail|
		request_state.memory_limit.borrow(thumbnail.data.bytesize, "thumbnail '#{name}'")
	end

	# copy input source path and url
	thumbnails.each do |name, thumbnail|
		thumbnail.extend ImageMetaData
		thumbnail.source_path = source_image.source_path
		thumbnail.source_url = source_image.source_url

		Thumbnail.stats.incr_total_thumbnail_thumbnails
		Thumbnail.stats.incr_total_thumbnail_thumbnails_bytes thumbnail.data.bytesize
	end

	# use httpthumbnailer provided information on input image mime type and size
	source_image.mime_type = input_mime_type if input_mime_type
	source_image.width = input_width if input_width
	source_image.height = input_height if input_height

	request_state.images.merge! thumbnails
end