ospxmlenc.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.                                      
*                                     
*
*
*
*
*
*
*#########################################################################
*#########################################################################
*#########################################################################
*/


/*
 * ospxmlenc.c - Generic XML document encoding functions.
 */

#include "osp.h"
#include "ospbfr.h"
#include "osperrno.h"
#include "ospxmlattr.h"
#include "ospxmlelem.h"
#include "ospxmltype.h"
#include "ospxmldoc.h"

/**/
/*-----------------------------------------------------------------------*
 * OSPPXMLDocCreate() - create a linear document from a root element
 *-----------------------------------------------------------------------*/

int                                       /* returns error code */
OSPPXMLDocCreate(
    OSPTXMLELEM  *ospvElem,               /* root element for document */
    OSPTBFR     **ospvBfrAddr             /* buffer in which to put doc */
)
{
    int ospvErrCode = OSPC_ERR_NO_ERROR;
    unsigned cnt = 0;

    if (ospvElem     == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_XML_NO_ELEMENT;
    }
    if (ospvBfrAddr  == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_BUF_EMPTY;
    }
    if (*ospvBfrAddr == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_BUF_EMPTY;
    }

    /*
     * First start off with the XML declaration. This is not technically
     * required by the XML specification since we're not doing anything
     * other than XML version 1.0, nor are we using any fancy character
     * encodings.
     */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        cnt = OSPPBfrWriteBlock(ospvBfrAddr, OSPC_XMLDOC_DECL, OSPC_XMLDOC_DECLLEN);
        if (cnt == OSPC_XMLDOC_DECLLEN)
        {
            /*
             * If the declaration was successfully added, go ahead and
             * construct the root element.
             */

            ospvErrCode = OSPC_ERR_BUF_INCOMPLETE;

            ospvErrCode = OSPPXMLDocAddElem(ospvElem, ospvBfrAddr);

            /* re-add this code later (maybe) */
            /*
                ospvErrCode = OSPPXMLDocAddElem(ospvElem, ospvBfrAddr);
            */
        }
        else
        {
            ospvErrCode = OSPC_ERR_BUF_EMPTY;
        }
    }

    return (ospvErrCode);
}

/**/
/*-----------------------------------------------------------------------*
 * OSPPXMLDocAddElem() - add an element to a document
 *-----------------------------------------------------------------------*/

int                                  /* returns error code */
OSPPXMLDocAddElem(
    OSPTXMLELEM  *ospvElem,               /* element to add */
    OSPTBFR     **ospvBfrAddr             /* buffer to add to */
)
{
    int         ospvErrCode = OSPC_ERR_NO_ERROR;
    OSPTXMLELEM *child = OSPC_OSNULL;
    OSPTXMLATTR *attr = OSPC_OSNULL;
    const char  *val = OSPC_OSNULL;
    unsigned     vallen = 0;
    unsigned     cnt;

    /*
     * Because of the length of this routine, it's broken up into the
     * eight major steps involved in encoding an element. Look for the
     * "**** STEP n:" comments that emphasize these steps.
     */

    if (ospvElem     == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_XML_NO_ELEMENT;
    }
    if (ospvBfrAddr  == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_BUF_EMPTY;
    }
    if (*ospvBfrAddr == OSPC_OSNULL)
    {
        ospvErrCode = OSPC_ERR_BUF_EMPTY;
    }

    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /*
         * Pre-calculate some useful variables; we might need them in several
         * places in the following code. We're pre-calculating the element
         * value, and the element value's length.
         */
        val   = OSPPXMLElemGetValue(ospvElem);
        if (val != OSPC_OSNULL)
        {
            vallen = OSPM_STRLEN(val);
        }
        else
        {
            vallen = 0;
        }
    }
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /**** STEP 1: begin with the opening bracket */
        ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_OPEN);
    }

    /**** STEP 2: add the element name */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        ospvErrCode = OSPPXMLDocAddElemName(ospvElem, ospvBfrAddr);
    }

    /**** STEP 3: if no children or contents, add trailer */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /*
         * Empty elements have neither children or content; they
         * can, however, include attributes (so we don't bother to
         * check for attributes or not).
         */
        child = (OSPTXMLELEM *)OSPPXMLElemFirstChild(ospvElem);
        if ((child == OSPC_OSNULL) && (vallen == 0))
        {
            /* if the element is empty, go ahead and add the trailer */
            ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_TRAILER);
        }
    }

    /**** STEP 4: add the attributes */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /* the "for" loop steps through each attribute */
        for (attr = (OSPTXMLATTR *)OSPPXMLElemFirstAttr(ospvElem);
            ((attr != OSPC_OSNULL) && (ospvErrCode == OSPC_ERR_NO_ERROR));
            attr = (OSPTXMLATTR *)OSPPXMLElemNextAttr(ospvElem, attr)
            )
        {
            /*
             * Attributes are separated by spaces, and we add a space
             * first in order to separate the first attribute from the
             * element name. That also means that we won't end up with
             * any extra trailing space, which is correct.
             */
            ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_SPACE);

            /* now add the attributes themselves */
            if (ospvErrCode == OSPC_ERR_NO_ERROR)
            {
                ospvErrCode = OSPPXMLDocAddAttr(attr, ospvBfrAddr);
            }
        }
    }

    /**** STEP 5: add the closing bracket (for the opening tag) */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_CLOSE);
        /* add newline for readability */
        ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_LF);
    }

    /**** STEP 6: add the child elements */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /* the "for" loop walks through all child elements */
        for (child = (OSPTXMLELEM *)OSPPXMLElemFirstChild(ospvElem);
            ((child != OSPC_OSNULL) && (ospvErrCode == OSPC_ERR_NO_ERROR));
            child = (OSPTXMLELEM *)OSPPXMLElemNextChild(ospvElem, child)
            )
        {
            /*
             * Call ourselves recursively. Since OSP documents aren't
             * terribly deep in structure, this shouldn't cause too
             * much grief with stack space, etc.. Still, there is a
             * possible optimization here.
             */
            ospvErrCode = OSPPXMLDocAddElem(child, ospvBfrAddr );
        }
    }

    /**** STEP 7: add the value itself */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /* of course, make sure there's something to add */
        if (vallen > 0)
        {
            cnt = OSPPBfrWriteBlock(ospvBfrAddr, (const void *)val, vallen);
            if (cnt != vallen)
            {
                ospvErrCode = OSPC_ERR_BUF_EMPTY;
            }
        }
    }

    /**** STEP 8: add the closing tag (but only if there was some content) */
    if (ospvErrCode == OSPC_ERR_NO_ERROR)
    {
        /*
         * Empty elements have neither children or content; they
         * can, however, include attributes (so we don't bother to
         * check for attributes or not).
         */
        child = (OSPTXMLELEM *)OSPPXMLElemFirstChild(ospvElem);
        if ((child != OSPC_OSNULL) || (vallen != 0))
        {
            /* first is the opening bracket */
            ospvErrCode = OSPPXMLDocAddChar(ospvBfrAddr, OSPC_XMLDOC_OPEN);

            /* then the trailing slash */