restore.c

基于ntp协议的网络时间服务程序

/*
 *  restore.c  $Id: restore.c,v 4.10 2007/02/04 17:44:12 bkorb Exp $
 * Time-stamp:      "2007-01-13 14:13:17 bkorb"
 *
 *  This module's routines will save the current option state to memory
 *  and restore it.  If saved prior to the initial optionProcess call,
 *  then the initial state will be restored.
 */

/*
 *  Automated Options copyright 1992-2007 Bruce Korb
 *
 *  Automated Options is free software.
 *  You may redistribute it and/or modify it under the terms of the
 *  GNU General Public License, as published by the Free Software
 *  Foundation; either version 2, or (at your option) any later version.
 *
 *  Automated Options 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 Automated Options.  See the file "COPYING".  If not,
 *  write to:  The Free Software Foundation, Inc.,
 *             51 Franklin Street, Fifth Floor,
 *             Boston, MA  02110-1301, USA.
 *
 * As a special exception, Bruce Korb gives permission for additional
 * uses of the text contained in his release of AutoOpts.
 *
 * The exception is that, if you link the AutoOpts library with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the AutoOpts library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by Bruce Korb under
 * the name AutoOpts.  If you copy code from other sources under the
 * General Public License into a copy of AutoOpts, as the General Public
 * License permits, the exception does not apply to the code that you add
 * in this way.  To avoid misleading anyone as to the status of such
 * modified files, you must delete this exception notice from them.
 *
 * If you write modifications of your own for AutoOpts, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 */

/*
 *  optionFixupSavedOpts  Really, it just wipes out option state for
 *  options that are troublesome to copy.  viz., stacked strings and
 *  hierarcicaly valued option args.  We do duplicate string args that
 *  have been marked as allocated though.
 */
static void
fixupSavedOptionArgs(tOptions* pOpts)
{
    tOptions* p   = pOpts->pSavedState;
    tOptDesc* pOD = pOpts->pOptDesc;
    int       ct  = pOpts->optCt;

    /*
     *  Make sure that allocated stuff is only referenced in the
     *  archived copy of the data.
     */
    for (; ct-- > 0; pOD++)  {
        switch (OPTST_GET_ARGTYPE(pOD->fOptState)) {
        case OPARG_TYPE_STRING:
            if (pOD->fOptState & OPTST_STACKED) {
                tOptDesc* q = p->pOptDesc + (pOD - pOpts->pOptDesc);
                q->optCookie = NULL;
            }
            if (pOD->fOptState & OPTST_ALLOC_ARG) {
                tOptDesc* q = p->pOptDesc + (pOD - pOpts->pOptDesc);
                AGDUPSTR(q->optArg.argString, pOD->optArg.argString, "arg");
            }
            break;

        case OPARG_TYPE_HIERARCHY:
        {
            tOptDesc* q = p->pOptDesc + (pOD - pOpts->pOptDesc);
            q->optCookie = NULL;
        }
        }
    }
}

/*=export_func optionSaveState
 *
 * what:  saves the option state to memory
 * arg:   tOptions*, pOpts, program options descriptor
 *
 * doc:
 *
 *  This routine will allocate enough memory to save the current option
 *  processing state.  If this routine has been called before, that memory
 *  will be reused.  You may only save one copy of the option state.  This
 *  routine may be called before optionProcess(3AO).  If you do call it
 *  before the first call to optionProcess, then you may also change the
 *  contents of argc/argv after you call optionRestore(3AO)
 *
 *  In fact, more strongly put: it is safest to only use this function
 *  before having processed any options.  In particular, the saving and
 *  restoring of stacked string arguments and hierarchical values is
 *  disabled.  The values are not saved.
 *
 * err:   If it fails to allocate the memory,
 *        it will print a message to stderr and exit.
 *        Otherwise, it will always succeed.
=*/
void
optionSaveState(tOptions* pOpts)
{
    tOptions* p = (tOptions*)pOpts->pSavedState;

    if (p == NULL) {
        size_t sz = sizeof( *pOpts ) + (pOpts->optCt * sizeof( tOptDesc ));
        p = AGALOC( sz, "saved option state" );
        if (p == NULL) {
            tCC* pzName = pOpts->pzProgName;
            if (pzName == NULL) {
                pzName = pOpts->pzPROGNAME;
                if (pzName == NULL)
                    pzName = zNil;
            }
            fprintf( stderr, zCantSave, pzName, sz );
            exit( EXIT_FAILURE );
        }

        pOpts->pSavedState = p;
    }

    memcpy( p, pOpts, sizeof( *p ));
    memcpy( p + 1, pOpts->pOptDesc, p->optCt * sizeof( tOptDesc ));

    fixupSavedOptionArgs(pOpts);
}


/*=export_func optionRestore
 *
 * what:  restore option state from memory copy
 * arg:   tOptions*, pOpts, program options descriptor
 *
 * doc:  Copy back the option state from saved memory.
 *       The allocated memory is left intact, so this routine can be
 *       called repeatedly without having to call optionSaveState again.
 *       If you are restoring a state that was saved before the first call
 *       to optionProcess(3AO), then you may change the contents of the
 *       argc/argv parameters to optionProcess.
 *
 * err:  If you have not called @code{optionSaveState} before, a diagnostic is
 *       printed to @code{stderr} and exit is called.
=*/
void
optionRestore( tOptions* pOpts )
{
    tOptions* p = (tOptions*)pOpts->pSavedState;

    if (p == NULL) {
        tCC* pzName = pOpts->pzProgName;
        if (pzName == NULL) {
            pzName = pOpts->pzPROGNAME;
            if (pzName == NULL)
                pzName = zNil;
        }
        fprintf( stderr, zNoState, pzName );
        exit( EXIT_FAILURE );
    }

    pOpts->pSavedState = NULL;
    optionFree(pOpts);

    memcpy( pOpts, p, sizeof( *p ));
    memcpy( pOpts->pOptDesc, p+1, p->optCt * sizeof( tOptDesc ));
    pOpts->pSavedState = p;

    fixupSavedOptionArgs(pOpts);
}

/* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = */

/*=export_func optionFree
 *
 * what:  free allocated option processing memory
 * arg:   tOptions*, pOpts, program options descriptor
 *
 * doc:   AutoOpts sometimes allocates memory and puts pointers to it in the
 *        option state structures.  This routine deallocates all such memory.
 *
 * err:   As long as memory has not been corrupted,
 *        this routine is always successful.
=*/
void
optionFree( tOptions* pOpts )
{
 free_saved_state:
    {
        tOptDesc* p = pOpts->pOptDesc;
        int ct = pOpts->optCt;
        do  {
            if (p->fOptState & OPTST_ALLOC_ARG) {
                AGFREE(p->optArg.argString);
                p->optArg.argString = NULL;
                p->fOptState &= ~OPTST_ALLOC_ARG;
            }

            switch (OPTST_GET_ARGTYPE(p->fOptState)) {
            case OPARG_TYPE_STRING:
#ifdef WITH_LIBREGEX
                if (  (p->fOptState & OPTST_STACKED)
                   && (p->optCookie != NULL)) {
                    p->optArg.argString = ".*";
                    optionUnstackArg(pOpts, p);
                }
#else
                /* leak memory */;
#endif
                break;

            case OPARG_TYPE_HIERARCHY:
                if (p->optCookie != NULL)
                    unloadNestedArglist(p->optCookie);
                break;
            }

            p->optCookie = NULL;
        } while (p++, --ct > 0);
    }
    if (pOpts->pSavedState != NULL) {
        tOptions * p = (tOptions*)pOpts->pSavedState;
        memcpy( pOpts, p, sizeof( *p ));
        memcpy( pOpts->pOptDesc, p+1, p->optCt * sizeof( tOptDesc ));
        AGFREE( pOpts->pSavedState );
        pOpts->pSavedState = NULL;
        goto free_saved_state;
    }
}
/*
 * Local Variables:
 * mode: C
 * c-file-style: "stroustrup"
 * indent-tabs-mode: nil
 * End:
 * end of autoopts/restore.c */