ospmsgdesc.c

mgcp协议源代码。支持多种编码：g711

/*
*########################################################################
*########################################################################
*########################################################################
*                                                               
*   COPYRIGHT (c) 1998, 1999 by TransNexus, LLC                          
*                                                                    
*   This software contains proprietary and confidential information  
*   of TransNexus, LLC. Except as may be set forth in the license    
*   agreement under which this software is supplied, use, disclosure, 
*   or reproduction is prohibited without the prior, express, written
*   consent of TransNexus, LLC.                                      
*                                     
*
*
*
*
*
*
*#########################################################################
*#########################################################################
*#########################################################################
*/


/*
 * ospmsgdesc.c - generic message descriptor processing functions.
 */

#include "osp.h"
#include "ospmsgdesc.h"

/**/
/*-----------------------------------------------------------------------*
 * OSPPMsgDescGetPart() - find a part from a name
 *-----------------------------------------------------------------------*/
OSPTMSGPART
    OSPPMsgDescGetPart(
    const char        *ospvName,           /* name for which to find tag */
    const OSPTMSGDESC *ospvDesc,       /* array of descriptors to search */
    unsigned           ospvNumDesc                      /* size of array */
    )
{
    unsigned    cnt;
    OSPTMSGPART ospvPart = OSPC_MSGPARTUNKNOWN;

    if (ospvName != OSPC_OSNULL) 
    {
        /* now just search through the array looking for the name */
        for (cnt=0; cnt<ospvNumDesc; cnt++)
        {
            if (OSPM_STRCMP(ospvDesc->ospmMsgDescName, ospvName) == 0)
            {
                ospvPart = ospvDesc->ospmMsgDescPart;
                break;
            }
            ospvDesc++;
        }
    }
    return(ospvPart);
}

#ifdef OSPC_DEBUG
/**/
/*-----------------------------------------------------------------------*
 * OSPPMsgDescGetName() - find a name from a part
 *-----------------------------------------------------------------------*/
const char *                           /* returns the name found or NULL */
OSPPMsgDescGetName(
    OSPTMSGPART        ospvPart,          /* part for which to find name */
    const OSPTMSGDESC *ospvDesc,       /* array of descriptors to search */
    unsigned           ospvNumDesc                      /* size of array */
)
{
    const char *ospvName = OSPC_OSNULL;

    if (ospvPart != OSPC_MSGPARTUNKNOWN) 
    {

        /*
         * The OSPPMsgDescGetName includes two different implementations: the
         * first is safer and the second has higher performance. The safer option
         * does an exhaustive search through the descriptors array. The second
         * simply uses the part ID as an index into that array. The risk with the
         * second approach is that it requires that the array be built correctly,
         * with elements in the precise, right order. If you enable the second
         * approach, it is essential to test the array ordering using the the code
         * in the included main() procedures in the individual components.
         */

#ifndef OSPC_FASTMSG_DESC

        /* safest approach - slower but harder to mess up */

        /* now just search through the array looking for the part */
        for (cnt=0; cnt<ospvNumDesc; cnt++)
        {
            if (ospvDesc->ospmMsgDescPart == ospvPart)
            {
                ospvName = ospvDesc->ospmMsgDescName;
                break;
            }
            ospvDesc++;
        }

#else

        /* alternate approach - faster, but array must be built appropriately */
        if ((unsigned)ospvPart < ospvNumDesc) 
        {
            ospvName = ospvDesc[(int)ospvPart].ospmMsgDescName;
        }

#endif
    }
    return(ospvName);
}
#endif /* PSOC_DEBUG */