DataStreamRequestHandler::AbstractDataStreamRequestHandler Class Reference

this class implements a chunked request handler supporting the DataStream protocol More...

Inherits AbstractRestStreamRequestHandler.

Public Member Functions
	constructor (hash cx, *hash ah)
	creates the chunked request handler according to the arguments
*hash	getErrorResponse ()
	if an error occurred, then return a hash giving an error response, otherwise return nothing More...
hash	getResponseHeaderMessageImpl ()
	returns the response header to the request More...
nothing	recvImpl (hash v)
	calls the receive callback as returned by the DataStreamUtil module, which in turn calls recvDataImpl() to deliver deserialized data
any	sendImpl ()
	calls the send callback as returned by the DataStreamUtil module, which in turn calls sendDataImpl() to get the data to serialize and encode and send as a response

Public Attributes
code	rcb
	the receive callback as returned by the DataStreamUtil module
code	scb
	the send callback as returned by the DataStreamUtil module
bool	recv_done = False
	flag for when all data has been received
bool	send_done = False
	flag for when all data has been sent
int	err
	HTTP status code for error response sent.
*string	send_error
	send error string received

Private Member Functions
nothing	recvDataDone (*string err)
	this method is called when all data has been received
nothing	recvData (any data)
	This is the concrete method called when data is received; it calls recvDataImpl() in turn. More...
any	sendData ()
	This is the concrete method called when data is received; it calls recvDataImpl() in turn. More...
nothing	recvDataDoneImpl (*string err)
	this method is called when all data has been received
abstract nothing	recvDataImpl (any data)
	reimplement this method in subclasses to receive decoded and deserialized data More...
abstract any	sendDataImpl ()
	reimplement this method in subclasses to support streamed data transfers; when this method returns no value, it signifies the end of the streamed data transfer More...

Detailed Description

this class implements a chunked request handler supporting the DataStream protocol

this class must be subclassed and then the recvDataImpl() and sendDataImpl() methods reimplemented to provide data receiving and sending support, respectively.

Member Function Documentation

*hash DataStreamRequestHandler::AbstractDataStreamRequestHandler::getErrorResponse

(

)

if an error occurred, then return a hash giving an error response, otherwise return nothing

this method is meant to be called by getResponseHeaderMessageImpl()

hash DataStreamRequestHandler::AbstractDataStreamRequestHandler::getResponseHeaderMessageImpl

(

)

returns the response header to the request

Returns

a hash with the following keys:

• "code": the HTTP return code (see HttpServer::HttpCodes)
• "body": the message body to return in the response; if this key is returned, then the reply is sent immediately; a chunked reply is not made, and send() and sendImpl() are not called
• "close": (optional) set this key to True if the connection should be unconditionally closed when the handler returns
• "hdr": (optional) set this key to a hash of extra header information to be returned with the response

Note

this method is called after the message body has been received

nothing DataStreamRequestHandler::AbstractDataStreamRequestHandler::recvData ( any  data )

private

This is the concrete method called when data is received; it calls recvDataImpl() in turn.

Parameters

data	the data received

abstract nothing DataStreamRequestHandler::AbstractDataStreamRequestHandler::recvDataImpl ( any  data )

privatepure virtual

reimplement this method in subclasses to receive decoded and deserialized data

Parameters

data	the argument passed to this callback is the decoded and deserialized data in the message

any DataStreamRequestHandler::AbstractDataStreamRequestHandler::sendData ( )

private

This is the concrete method called when data is received; it calls recvDataImpl() in turn.

Returns

data the data to be sent over the link

abstract any DataStreamRequestHandler::AbstractDataStreamRequestHandler::sendDataImpl ( )

privatepure virtual

reimplement this method in subclasses to support streamed data transfers; when this method returns no value, it signifies the end of the streamed data transfer

Returns

the data returned by this callback will be serialized to YAML and send via the DataStream protocol to the remote HTTP REST server in HTTP chunked format; when all data has been send then this callback should return nothing, which will close the chunked message and terminate the request