Class: Configuration::Thumbnail

Inherits:

HandlerStatement

• Object
• HandlerStatement
• Configuration::Thumbnail

Extended by:

Stats

Includes:

ClassLogging, ConditionalInclusion

Defined in:

lib/httpimagestore/configuration/thumbnailer.rb

Defined Under Namespace

Classes: ThumbnailSpec, ThumbnailingError

Instance Attribute Summary

Attributes inherited from HandlerStatement

#config_locals

Class Method Summary

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

Instance Method Summary

• #initialize(global, source_image_name, specs, use_multipart_api, matcher) ⇒ Thumbnail constructor

  A new instance of Thumbnail.

• #realize(request_state) ⇒ Object

Methods inherited from HandlerStatement

#config_local, #path_template

Constructor Details

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

Returns a new instance of Thumbnail.

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 144

def initialize(global, source_image_name, specs, use_multipart_api, matcher)
	super(global, matcher)
	@source_image_name = source_image_name
	@specs = specs
	@use_multipart_api = use_multipart_api
end

Class Method Details

.match(node) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 96

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

.parse(configuration, node) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 100

def self.parse(configuration, node)
	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

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

	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, if_image_name_on, remaining = *node.grab_attributes_with_remaining('operation', 'width', 'height', 'format', 'if-image-name-on')

		matcher = InclusionMatcher.new(image_name, if_image_name_on) if if_image_name_on

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

	matcher = InclusionMatcher.new(source_image_name, node.grab_attributes('if-image-name-on').first) if use_multipart_api

	configuration.processors << self.new(
		configuration.global,
		source_image_name,
		specs,
		use_multipart_api,
		matcher
	)
end

Instance Method Details

#realize(request_state) ⇒ Object

# File 'lib/httpimagestore/configuration/thumbnailer.rb', line 151

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

	rendered_specs = {}
	@specs.select do |spec|
		spec.included?(request_state)
	end.each do |spec|
		rendered_specs.merge! spec.render(request_state)
	end

	rendered_specs.empty? and raise NoSpecSelectedError.new(@specs.map(&:image_name))

	source_image = request_state.images[@source_image_name]

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

	Thumbnail.stats.incr_total_thumbnail_requests
	Thumbnail.stats.incr_total_thumbnail_requests_bytes source_image.data.bytesize

	if @use_multipart_api
		log.info "thumbnailing '#{@source_image_name}' to multiple specs: #{rendered_specs}"

		# need to reference to local so they are available within thumbnail() block context
		source_image_name = @source_image_name
		logger = log

		begin
			thumbnails = client.with_headers(request_state.headers).thumbnail(source_image.data) do
				rendered_specs.each_pair do |name, spec|
					begin
						thumbnail(*spec)
					rescue HTTPThumbnailerClient::HTTPThumbnailerClientError => error
						logger.warn 'got thumbnailer error while passing specs', error
						raise ThumbnailingError.new(source_image_name, name, error)
					end
				end
			end
		rescue HTTPThumbnailerClient::HTTPThumbnailerClientError => error
			logger.warn 'got thumbnailer error while sending input data', error
			raise ThumbnailingError.new(source_image_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.keys.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
	else
		name, rendered_spec = *rendered_specs.first
		log.info "thumbnailing '#{@source_image_name}' to '#{name}' with spec: #{rendered_spec}"

		begin
			thumbnail = client.with_headers(request_state.headers).thumbnail(source_image.data, *rendered_spec)
			request_state.memory_limit.borrow(thumbnail.data.bytesize, "thumbnail '#{name}'")

			input_mime_type = thumbnail.input_mime_type
			input_width = thumbnail.input_width
			input_height = thumbnail.input_height

			thumbnails[name] = thumbnail
		rescue HTTPThumbnailerClient::HTTPThumbnailerClientError => error
			log.warn 'got thumbnailer error', error
			raise ThumbnailingError.new(@source_image_name, name, error)
		end
	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