util.c

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/****************************** Module Header ******************************\
* Module Name: util.c
*
* Copyright (c) 1985 - 1999, Microsoft Corporation
*
* DDE Manager general utility functions
*
* Created: 11/3/91 Sanford Staab
\***************************************************************************/

#include "precomp.h"
#pragma hdrstop

/***************************************************************************\
* AddLink
*
* Description:
* Adds an advise link to the conversation's info.
*
* History:
* 11-19-91 sanfords Created.
\***************************************************************************/
BOOL AddLink(
PCONV_INFO pcoi,
GATOM gaItem,
WORD wFmt,
WORD wType)
{
    PADVISE_LINK aLinkNew;
    int cLinks;
    LATOM la;
    PCL_INSTANCE_INFO pcii;

    /*
     * if the link already exists, update its flags, otherwise create a
     * new one.
     */

    aLinkNew = pcoi->aLinks;
    cLinks = pcoi->cLinks;
    la = GlobalToLocalAtom(gaItem);     // aLinkNew copy
    while (cLinks) {
        if (aLinkNew->laItem == la && aLinkNew->wFmt == wFmt) {
            aLinkNew->wType = wType;
            aLinkNew->state = 0;
            DeleteAtom(la);
            return TRUE;
        }
        aLinkNew++;
        cLinks--;
    }

    if (pcoi->aLinks == NULL) {
        aLinkNew = (PADVISE_LINK)DDEMLAlloc(sizeof(ADVISE_LINK));
    } else {
        aLinkNew = (PADVISE_LINK)DDEMLReAlloc(pcoi->aLinks,
                sizeof(ADVISE_LINK) * (pcoi->cLinks + 1));
    }
    if (aLinkNew == NULL) {
        SetLastDDEMLError(pcoi->pcii, DMLERR_MEMORY_ERROR);
        DeleteAtom(la);
        return FALSE;
    }
    pcoi->aLinks = aLinkNew;
    aLinkNew += pcoi->cLinks;
    pcoi->cLinks++;

    aLinkNew->laItem = la;
    aLinkNew->wFmt = wFmt;
    aLinkNew->wType = wType;
    aLinkNew->state = 0;

    if (!(pcoi->state & ST_CLIENT)) {
        /*
         * Add count for this link
         */
        pcii = pcoi->pcii;

        for (aLinkNew->pLinkCount = pcii->pLinkCount;
                aLinkNew->pLinkCount;
                    aLinkNew->pLinkCount = aLinkNew->pLinkCount->next) {
            if (aLinkNew->pLinkCount->laTopic == pcoi->laTopic &&
                    aLinkNew->pLinkCount->gaItem == gaItem &&
                    aLinkNew->pLinkCount->wFmt == wFmt) {
                aLinkNew->pLinkCount->Total++;
                return(TRUE);
            }
        }

        /*
         * Not found - add an entry
         */
        aLinkNew->pLinkCount = (PLINK_COUNT)DDEMLAlloc(sizeof(LINK_COUNT));
        if (aLinkNew->pLinkCount == NULL) {
            SetLastDDEMLError(pcoi->pcii, DMLERR_MEMORY_ERROR);
            return FALSE;
        }
        aLinkNew->pLinkCount->next = pcii->pLinkCount;
        pcii->pLinkCount = aLinkNew->pLinkCount;

        aLinkNew->pLinkCount->laTopic = IncLocalAtomCount(pcoi->laTopic); // LinkCount copy
        aLinkNew->pLinkCount->gaItem = IncGlobalAtomCount(gaItem); // LinkCount copy
        aLinkNew->pLinkCount->laItem = IncLocalAtomCount(la); // LinkCount copy

        aLinkNew->pLinkCount->wFmt = wFmt;
        aLinkNew->pLinkCount->Total = 1;
        // doesn't matter: aLinkNew->pLinkCount->Count = 0;
    }

    return TRUE;
}



/*
 * The LinkCount array is a list of all active links grouped by topic
 * and item.  The Total field is the number of active links total for
 * that particular topic/item pair for the entire instance.  The count
 * field is used to properly set up the links to go field of the XTYP_ADVREQ
 * callback.  Whenever links are added or removed, DeleteLinkCount or
 * AddLink need to be called to keep thses counts correct.
 */
VOID DeleteLinkCount(
PCL_INSTANCE_INFO pcii,
PLINK_COUNT pLinkCountDelete)
{
    PLINK_COUNT pLinkCount, pLinkCountPrev;

    if (--pLinkCountDelete->Total != 0) {
        return;
    }
    pLinkCountPrev = NULL;
    pLinkCount     = pcii->pLinkCount;
    while (pLinkCount) {

        if (pLinkCount == pLinkCountDelete) {
            GlobalDeleteAtom(pLinkCount->gaItem);
            DeleteAtom(pLinkCount->laItem);
            DeleteAtom(pLinkCount->laTopic);
            if (pLinkCountPrev == NULL) {
                pcii->pLinkCount = pLinkCount->next;
            } else {
                pLinkCountPrev->next = pLinkCount->next;
            }
            DDEMLFree(pLinkCount);
            return;
        }

        pLinkCountPrev = pLinkCount;
        pLinkCount = pLinkCount->next;
    }
}

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