/* vmop.c - abstracts an operation (instructed) supported by the
 * rsyslog virtual machine
 *
 * Module begun 2008-02-20 by Rainer Gerhards
 *
 * Copyright 2007, 2008 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of rsyslog.
 *
 * Rsyslog is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Rsyslog is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
 *
 * A copy of the GPL can be found in the file "COPYING" in this distribution.
 */

#include "config.h"
#include <stdlib.h>
#include <assert.h>

#include "rsyslog.h"
#include "obj.h"
#include "vmop.h"

/* static data */
DEFobjStaticHelpers
DEFobjCurrIf(var)


/* forward definitions */
static rsRetVal vmopOpcode2Str(vmop_t *pThis, uchar **ppName);

/* Standard-Constructor
 */
BEGINobjConstruct(vmop) /* be sure to specify the object type also in END macro! */
ENDobjConstruct(vmop)


/* ConstructionFinalizer
 * rgerhards, 2008-01-09
 */
rsRetVal vmopConstructFinalize(vmop_t __attribute__((unused)) *pThis)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, vmop);
	RETiRet;
}


/* destructor for the vmop object */
BEGINobjDestruct(vmop) /* be sure to specify the object type also in END and CODESTART macros! */
CODESTARTobjDestruct(vmop)
ENDobjDestruct(vmop)


/* DebugPrint support for the vmop object */
BEGINobjDebugPrint(vmop) /* be sure to specify the object type also in END and CODESTART macros! */
	uchar *pOpcodeName;
CODESTARTobjDebugPrint(vmop)
	vmopOpcode2Str(pThis, &pOpcodeName);
	dbgoprint((obj_t*) pThis, "opcode: %d\t(%s), next %p, var in next line\n", (int) pThis->opcode, pOpcodeName,
		  pThis->pNext);
	if(pThis->operand.pVar != NULL)
		var.DebugPrint(pThis->operand.pVar);
ENDobjDebugPrint(vmop)


/* set operand (variant case)
 * rgerhards, 2008-02-20
 */
static rsRetVal
vmopSetVar(vmop_t *pThis, var_t *pVar)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, vmop);
	ISOBJ_TYPE_assert(pVar, var);
	pThis->operand.pVar = pVar;
	RETiRet;
}


/* set operation
 * rgerhards, 2008-02-20
 */
static rsRetVal
vmopSetOpcode(vmop_t *pThis, opcode_t opcode)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, vmop);
	pThis->opcode = opcode;
	RETiRet;
}


/* a way to turn an opcode into a readable string
 */
static rsRetVal
vmopOpcode2Str(vmop_t *pThis, uchar **ppName)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, vmop);

	switch(pThis->opcode) {
		case opcode_OR:
			*ppName = (uchar*) "or";
			break;
		case opcode_AND:
			*ppName = (uchar*) "and";
			break;
		case opcode_PLUS:
			*ppName = (uchar*) "+";
			break;
		case opcode_MINUS:
			*ppName = (uchar*) "-";
			break;
		case opcode_TIMES:
			*ppName = (uchar*) "*";
			break;
		case opcode_DIV:
			*ppName = (uchar*) "/";
			break;
		case opcode_MOD:
			*ppName = (uchar*) "%";
			break;
		case opcode_NOT:
			*ppName = (uchar*) "not";
			break;
		case opcode_CMP_EQ:
			*ppName = (uchar*) "==";
			break;
		case opcode_CMP_NEQ:
			*ppName = (uchar*) "!=";
			break;
		case opcode_CMP_LT:
			*ppName = (uchar*) "<";
			break;
		case opcode_CMP_GT:
			*ppName = (uchar*) ">";
			break;
		case opcode_CMP_LTEQ:
			*ppName = (uchar*) "<=";
			break;
		case opcode_CMP_CONTAINS:
			*ppName = (uchar*) "contains";
			break;
		case opcode_CMP_STARTSWITH:
			*ppName = (uchar*) "startswith";
			break;
		case opcode_CMP_GTEQ:
			*ppName = (uchar*) ">=";
			break;
		case opcode_PUSHSYSVAR:
			*ppName = (uchar*) "PUSHSYSVAR";
			break;
		case opcode_PUSHMSGVAR:
			*ppName = (uchar*) "PUSHMSGVAR";
			break;
		case opcode_PUSHCONSTANT:
			*ppName = (uchar*) "PUSHCONSTANT";
			break;
		case opcode_POP:
			*ppName = (uchar*) "POP";
			break;
		case opcode_UNARY_MINUS:
			*ppName = (uchar*) "UNARY_MINUS";
			break;
		case opcode_STRADD:
			*ppName = (uchar*) "STRADD";
			break;
		default:
			*ppName = (uchar*) "INVALID opcode";
			break;
	}

	RETiRet;
}


/* queryInterface function
 * rgerhards, 2008-02-21
 */
BEGINobjQueryInterface(vmop)
CODESTARTobjQueryInterface(vmop)
	if(pIf->ifVersion != vmopCURR_IF_VERSION) { /* check for current version, increment on each change */
		ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
	}

	/* ok, we have the right interface, so let's fill it
	 * Please note that we may also do some backwards-compatibility
	 * work here (if we can support an older interface version - that,
	 * of course, also affects the "if" above).
	 */
	pIf->oID = OBJvmop;

	pIf->Construct = vmopConstruct;
	pIf->ConstructFinalize = vmopConstructFinalize;
	pIf->Destruct = vmopDestruct;
	pIf->DebugPrint = vmopDebugPrint;
	pIf->SetOpcode = vmopSetOpcode;
	pIf->SetVar = vmopSetVar;
	pIf->Opcode2Str = vmopOpcode2Str;
finalize_it:
ENDobjQueryInterface(vmop)


/* Initialize the vmop class. Must be called as the very first method
 * before anything else is called inside this class.
 * rgerhards, 2008-02-19
 */
BEGINObjClassInit(vmop, 1) /* class, version */
	/* request objects we use */
	CHKiRet(objUse(var));

	OBJSetMethodHandler(objMethod_DEBUGPRINT, vmopDebugPrint);
	OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, vmopConstructFinalize);
ENDObjClassInit(vmop)

/* vi:set ai:
 */