src/messaging/message.cpp

// vi: ts=4 sw=4 noet:
/*
==================================================================================
	Copyright (c) 2020 Nokia
	Copyright (c) 2020 AT&T Intellectual Property.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================================
*/

/*
	Mnemonic:	message.cpp
	Abstract:	A message wrapper. This should completely hide the
				underlying transport (RMR) message structure from
				the user application. For the most part, the getters
				are used by the framwork; it is unlikely that other
				than adding/extracting the MEID, the user app will
				be completely unaware of information that is not
				presented in the callback parms.

	Date:		12 March 2020
	Author:		E. Scott Daniels
*/

#include <string.h>
#include <unistd.h>

#include <rmr/rmr.h>

#include <iostream>

#include "message.hpp"

// --------------- private ------------------------------------------------

// --------------- builders -----------------------------------------------

/*
	Create a new message wrapper for an existing RMR msg buffer.
*/
Message::Message( rmr_mbuf_t* mbuf, void* mrc ) {
	this->mrc = mrc;			// the message router context for sends
	this->mbuf = mbuf;
}

Message::Message( void* mrc, int payload_len ) {
	this->mrc = mrc;
	this->mbuf = rmr_alloc_msg( mrc, payload_len );
}

/*
	Destroyer.
*/
Message::~Message() {
	if( mbuf != NULL ) {
		rmr_free_msg( mbuf );
	}

	mbuf = NULL;
}


// --- getters/setters -----------------------------------------------------
/*
	Copy the payload bytes, and return a smart pointer (unique) to it.
	If the application needs to update the payload in place for a return
	to sender call, or just to access the payload in a more efficent manner
	(without the copy), the Get_payload() function should be considered.

	This function will return a NULL pointer if malloc fails.
*/
//char* Message::Copy_payload( ){
std::unique_ptr<unsigned char> Message::Copy_payload( ){
	unsigned char*	new_payload = NULL;

	if( mbuf != NULL ) {
		new_payload = (unsigned char *) malloc( sizeof( unsigned char ) * mbuf->len );
		memcpy( new_payload, mbuf->payload, mbuf->len );
	}

	return std::unique_ptr<unsigned char>( new_payload );
}

/*
	Makes a copy of the MEID and returns a smart pointer to it.
*/
std::unique_ptr<unsigned char> Message::Get_meid(){
	unsigned char* m = NULL;

	if( m != NULL ) {
		m = (unsigned char *) malloc( sizeof( unsigned char ) * RMR_MAX_MEID );
		rmr_get_meid( mbuf, m );
	}

	return std::unique_ptr<unsigned char>( m );
}

int Message::Get_available_size(){
	if( mbuf != NULL ) {
		return rmr_payload_size( mbuf );
	}

	return 0;
}

int	Message::Get_mtype(){
	if( mbuf != NULL ) {
		return mbuf->mtype;
	}

	return INVALID_MTYPE;
}

/*
	Makes a copy of the source field and returns a smart pointer to it.
*/
std::unique_ptr<unsigned char> Message::Get_src(){
	unsigned char* m = NULL;

	m = (unsigned char *) malloc( sizeof( unsigned char ) * RMR_MAX_SRC );
	if( m != NULL ) {
		rmr_get_src( mbuf, m );
	}

	return std::unique_ptr<unsigned char>( m );
}

int	Message::Get_state( ){
	if( mbuf != NULL ) {
		return mbuf->state;
	}

	return INVALID_STATUS;
}

int	Message::Get_subid(){
	if( mbuf != NULL ) {
		return mbuf->sub_id;
	}

	return INVALID_SUBID;
}

int	Message::Get_len(){
	if( mbuf != NULL ) {
		return mbuf->len;
	}

	return 0;
}

/*
	This returns a smart (unique) pointer to the payload portion of the
	message. This provides the user application with the means to
	update the payload in place to avoid multiple copies.  The
	user programme is responsible to determing the usable payload
	length by calling Message:Get_available_size(), and ensuring that
	writing beyond the indicated size does not happen.
*/
Msg_component Message::Get_payload(){
	if( mbuf != NULL ) {
		return std::unique_ptr<unsigned char, unfreeable>( mbuf->payload );
	}

	return NULL;
}

void Message::Set_meid( std::unique_ptr<unsigned char> new_meid ) {
	if( mbuf != NULL ) {
		rmr_str2meid( mbuf, (unsigned char *) new_meid.get() );
	}
}

void Message::Set_mtype( int new_type ){
	if( mbuf != NULL ) {
		mbuf->mtype = new_type;
	}
}

void Message::Set_subid( int new_subid ){
	if( mbuf != NULL ) {
		mbuf->sub_id = new_subid;
	}
}


// -------------- send functions ---------------------------------

/*
	This assumes that the contents of the mbuf were set by either a send attempt that
	failed with a retry and thus is ready to be processed by RMR.
	Exposed to the user, but not expected to be frequently used.
*/
bool Message::Send( ) {
	if( mbuf == NULL ) {
		return false;
	}

	mbuf =  rmr_send_msg( mrc, mbuf );
	return mbuf->state == RMR_OK;
}

/*
	Similar to Send(), this assumes that the message is already set up and this is a retry.
	Exposed to the user, but not expected to be frequently used.
*/
bool Message::Reply( ) {
	if( mbuf == NULL ) {
		return false;
	}

	mbuf =  rmr_rts_msg( mrc, mbuf );
	return mbuf->state == RMR_OK;
}

/*
	Send workhorse.
	This will setup the message (type etc.) ensure the message payload space is
	large enough and copy in the payload (if a new payload is given), then will
	either send or rts the message based on the stype parm.

	If payload is nil, then we assume the user updated the payload in place and
	no copy is needed.

	This is public, but most users should use Send_msg or Send_response functions.
*/
bool Message::Send( int mtype, int subid, int payload_len, unsigned char* payload, int stype ) {

	if( mbuf == NULL ) {
		return false;
	}

	mbuf->mtype = mtype;
	mbuf->sub_id = subid;
	mbuf->len = payload_len;

	if( payload != NULL ) {			// if we have a payload, ensure msg has room, realloc if needed, then copy
		mbuf = rmr_realloc_payload( mbuf, payload_len, RMR_NO_COPY, RMR_NO_CLONE );		// ensure message is large enough
		if( mbuf == NULL ) {
			return false;
		}

		memcpy( mbuf->payload, payload, mbuf->len );
	}

	if( stype == RESPONSE ) {
		mbuf = rmr_rts_msg( mrc, mbuf );
	} else {
		mbuf = rmr_send_msg( mrc, mbuf );
	}

	return mbuf->state == RMR_OK;
}

/*
	Send a response to the endpoint that sent the original message.

	Response can be null and the assumption will be that the message payload
	was updated in place and no additional copy is needed before sending the message.

	The second form of the call allows for a stack allocated buffer (e.g. char foo[120]) to
	be passed as the payload.
*/
bool Message::Send_response(  int mtype, int subid, int response_len, std::unique_ptr<unsigned char> response ) {
	return Send( mtype, subid, response_len, response.get(), RESPONSE );
}

bool Message::Send_response(  int mtype, int subid, int response_len, unsigned char* response ) {
	return Send( mtype, subid, response_len, response, RESPONSE );
}

/*
	These allow a response message to be sent without changing the mtype/subid.
*/
bool Message::Send_response(  int response_len, std::unique_ptr<unsigned char> response ) {
	return Send( NOCHANGE, NOCHANGE, response_len, response.get(), RESPONSE );
}

bool Message::Send_response(  int response_len, unsigned char* response ) {
	return Send( NOCHANGE, NOCHANGE, response_len, response, RESPONSE );
}


/*
	Send a message based on message type routing.

	Payload can be null and the assumption will be that the message payload
	was updated in place and no additional copy is needed before sending the message.

	Return is a new mbuf suitable for sending another message, or the original buffer with
	a bad state sent if there was a failure.
*/
bool Message::Send_msg(  int mtype, int subid, int payload_len, std::unique_ptr<unsigned char> payload ) {
	return Send( mtype, subid, payload_len, payload.get(), MESSAGE );
}

bool Message::Send_msg(  int mtype, int subid, int payload_len, unsigned char* payload ) {
	return Send( mtype, subid, payload_len, payload, MESSAGE );
}

/*
	Similar send functions that allow the message type/subid to remain unchanged
*/
bool Message::Send_msg(  int payload_len, std::unique_ptr<unsigned char> payload ) {
	return Send( NOCHANGE, NOCHANGE, payload_len, payload.get(), MESSAGE );
}

bool Message::Send_msg(  int payload_len, unsigned char* payload ) {
	return Send( NOCHANGE, NOCHANGE, payload_len, payload, MESSAGE );
}