Class: Protocol::Media::Map

Inherits:
Object
  • Object
show all
Defined in:
lib/protocol/media/map.rb

Overview

A map from concrete media types to objects for range-based lookup.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(entries = {}) ⇒ Map

Initialize a new mutable media map with the given entries.

Freezing the map compiles the entries into an efficient immutable index.



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# File 'lib/protocol/media/map.rb', line 29

def initialize(entries = {})
	@entries = {}
	@index = nil
	
	entries.each do |media_type, object|
		self[media_type] = object
	end
end

Class Method Details

.for(entries) ⇒ Object

Convert keyed entries into a media map.

Existing maps are returned unchanged, including their frozen state.



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# File 'lib/protocol/media/map.rb', line 18

def self.for(entries)
	return entries if entries.instance_of?(self)
	
	return new(entries).freeze
end

Instance Method Details

#[](media_range) ⇒ Object

Find the object matching a media type or range.



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# File 'lib/protocol/media/map.rb', line 67

def [](media_range)
	return lookup(Range.for(media_range))
end

#[]=(media_type, object) ⇒ Object

Associate a concrete media type with an object.

Raises:

  • (FrozenError) 


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# File 'lib/protocol/media/map.rb', line 41

def []=(media_type, object)
	raise FrozenError, "can't modify frozen #{self.class}" if frozen?
	
	media_type = Type.for(media_type)
	
	@entries[media_type.name] = [media_type, object]
	@index = nil
end

#for(media_ranges) ⇒ Object

Find the first object matching an ordered sequence of media ranges.



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# File 'lib/protocol/media/map.rb', line 75

def for(media_ranges)
	media_ranges.each do |media_range|
		if object = lookup(Range.for(media_range))
			return [object, media_range]
		end
	end
	
	return nil
end

#freeze ⇒ Object

Freeze the media map, compiling its entries into an efficient index.



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# File 'lib/protocol/media/map.rb', line 52

def freeze
	return self if frozen?
	
	index = self.index
	@entries = nil
	
	index.freeze
	
	return super
end