class Protocol::HTTP::Body::Rewindable

As the body is buffered in memory, you may want to ensure your server has sufficient (virtual) memory available to buffer the entire body.
A body which buffers all its contents as it is read.

def self.wrap(message)

@parameter message [Request | Response] the message to wrap.

Wrap the given message body in a rewindable body, if it is not already rewindable. 
def self.wrap(message)
	if body = message.body
		if body.rewindable?
			body
		else
			message.body = self.new(body)
		end
	end
end

def buffered

@returns [Buffered] the buffered body.

A rewindable body wraps some other body. Convert it to a buffered body. The buffered body will share the same chunks as the rewindable body. 
def buffered
	Buffered.new(@chunks)
end

def empty?

@returns [Boolean] Whether the body is empty. 
def empty?
	(@index >= @chunks.size) && super
end

def initialize(body)

@parameter body [Readable] the body to wrap.

Initialize the body with the given body. 
def initialize(body)
	super(body)
	
	@chunks = []
	@index = 0
end

def inspect

@returns [String] a string representation of the body.

Inspect the rewindable body. 
def inspect
	"\#<#{self.class} #{@index}/#{@chunks.size} chunks read>"
end

def read

@returns [String | Nil] The chunk of data, or `nil` if the stream has finished.

Read the next available chunk. This may return a buffered chunk if the stream has been rewound, or a chunk from the underlying stream, if available. 
def read
	if @index < @chunks.size
		chunk = @chunks[@index]
		@index += 1
	else
		if chunk = super
			@chunks << -chunk
			@index += 1
		end
	end
	
	# We dup them on the way out, so that if someone modifies the string, it won't modify the rewindability.
	return chunk
end

def ready?

@returns [Boolean] Whether the body is ready to be read. 
def ready?
	(@index < @chunks.size) || super
end

def rewind

Rewind the stream to the beginning. 
def rewind
	@index = 0
end

def rewindable?

@returns [Boolean] Whether the stream is rewindable, which it is. 
def rewindable?
	true
end