`class Digestable`

Invokes a callback once the body has finished reading.

Definitions

`def self.wrap(message, digest = Digest::SHA256.new, &block)`

Wrap a message body with a callback. If the body is empty, the callback is not invoked, as there is no data to digest.

Signature

parameter　message　Request | Response: the message body.
parameter　digest　Digest: the digest to use.
parameter　block　Proc: the callback to invoke when the body is closed.

Implementation

def self.wrap(message, digest = Digest::SHA256.new, &block)
	if body = message&.body and !body.empty?
		message.body = self.new(message.body, digest, block)
	end
end

`def initialize(body, digest = Digest::SHA256.new, callback = nil)`

Initialize the digestable body with a callback.

Signature

parameter　body　Readable: the body to wrap.
parameter　digest　Digest: the digest to use.
parameter　callback　Block: The callback is invoked when the digest is complete.

Implementation

def initialize(body, digest = Digest::SHA256.new, callback = nil)
	super(body)
	
	@digest = digest
	@callback = callback
end

`attr :digest`

Signature

attribute　Digest: digest the digest object.

`def etag(weak: false)`

Generate an appropriate ETag for the digest, assuming it is complete. If you call this method before the body is fully read, the ETag will be incorrect.

Signature

parameter　weak　Boolean: If true, the ETag is marked as weak.
returns　String: the ETag.

Implementation

def etag(weak: false)
	if weak
		"W/\"#{digest.hexdigest}\""
	else
		"\"#{digest.hexdigest}\""
	end
end

`def read`

Read the body and update the digest. When the body is fully read, the callback is invoked with self as the argument.

Signature

returns　String | Nil: the next chunk of data, or nil if the body is fully read.

Implementation

def read
	if chunk = super
		@digest.update(chunk)
		
		return chunk
	else
		@callback&.call(self)
		
		return nil
	end
end