nested.c

基于ntp协议的网络时间服务程序

                /* FALLTHROUGH */

            case ',':
                dataLen = (pzScan - pzVal) - 1;
            string_done:
                pNV = addStringValue( &(pRes->v.nestVal), pzName, nameLen,
                                      pzVal, dataLen );
                if (pNV != NULL)
                    removeBackslashes( pNV->v.strVal );
                goto leave_scan_name;
            }
        }
        break;
    } leave_scan_name:;

    return pzScan;
}


/*  scanXmlEntry
 *
 *  We've found a '<' character.  We ignore this if it is a comment or a
 *  directive.  If it is something else, then whatever it is we are looking
 *  at is bogus.  Returning NULL stops processing.
 */
static char const*
scanXmlEntry( char const* pzName, tOptionValue* pRes )
{
    size_t nameLen = 1, valLen = 0;
    char const*   pzScan = ++pzName;
    char const*   pzVal;
    tOptionValue  valu;
    tOptionValue* pNewVal;
    tOptionLoadMode save_mode = option_load_mode;

    if (! isalpha((int)*pzName)) {
        switch (*pzName) {
        default:
            pzName = NULL;
            break;

        case '!':
            pzName = strstr( pzName, "-->" );
            if (pzName != NULL)
                pzName += 3;
            break;

        case '?':
            pzName = strchr( pzName, '>' );
            if (pzName != NULL)
                pzName++;
            break;
        }
        return pzName;
    }

    while (isalpha( (int)*++pzScan ))  nameLen++;
    if (nameLen > 64)
        return NULL;
    valu.valType = OPARG_TYPE_STRING;

    switch (*pzScan) {
    case ' ':
    case '\t':
        pzScan = parseAttributes(
            NULL, (char*)pzScan, &option_load_mode, &valu );
        if (*pzScan == '>') {
            pzScan++;
            break;
        }

        if (*pzScan != '/') {
            option_load_mode = save_mode;
            return NULL;
        }
        /* FALLTHROUGH */

    case '/':
        if (*++pzScan != '>') {
            option_load_mode = save_mode;
            return NULL;
        }
        addStringValue(&(pRes->v.nestVal), pzName, nameLen, NULL, (size_t)0);
        option_load_mode = save_mode;
        return pzScan+2;

    default:
        option_load_mode = save_mode;
        return NULL;

    case '>':
        pzScan++;
        break;
    }

    pzVal = pzScan;

    {
        char z[68];
        char* pzD = z;
        int  ct = nameLen;
        char const* pzS = pzName;

        *(pzD++) = '<';
        *(pzD++) = '/';

        do  {
            *(pzD++) = *(pzS++);
        } while (--ct > 0);
        *(pzD++) = '>';
        *pzD = NUL;

        pzScan = strstr( pzScan, z );
        if (pzScan == NULL) {
            option_load_mode = save_mode;
            return NULL;
        }
        valLen = (pzScan - pzVal);
        pzScan += nameLen + 3;
        while (isspace(  (int)*pzScan ))  pzScan++;
    }

    switch (valu.valType) {
    case OPARG_TYPE_NONE:
        addStringValue( &(pRes->v.nestVal), pzName, nameLen, NULL, (size_t)0);
        break;

    case OPARG_TYPE_STRING:
        pNewVal = addStringValue(
            &(pRes->v.nestVal), pzName, nameLen, pzVal, valLen);

        if (option_load_mode == OPTION_LOAD_KEEP)
            break;
        mungeString( pNewVal->v.strVal, option_load_mode );
        break;

    case OPARG_TYPE_BOOLEAN:
        addBoolValue( &(pRes->v.nestVal), pzName, nameLen, pzVal, valLen );
        break;

    case OPARG_TYPE_NUMERIC:
        addNumberValue( &(pRes->v.nestVal), pzName, nameLen, pzVal, valLen );
        break;

    case OPARG_TYPE_HIERARCHY:
    {
        char* pz = AGALOC( valLen+1, "hierarchical scan" );
        if (pz == NULL)
            break;
        memcpy( pz, pzVal, valLen );
        pz[valLen] = NUL;
        addNestedValue( &(pRes->v.nestVal), pzName, nameLen, pz, valLen );
        AGFREE(pz);
        break;
    }

    case OPARG_TYPE_ENUMERATION:
    case OPARG_TYPE_MEMBERSHIP:
    default:
        break;
    }

    option_load_mode = save_mode;
    return pzScan;
}


/*  unloadNestedArglist
 *
 *  Deallocate a list of option arguments.  This must have been gotten from
 *  a hierarchical option argument, not a stacked list of strings.  It is
 *  an internal call, so it is not validated.  The caller is responsible for
 *  knowing what they are doing.
 */
static void
unloadNestedArglist( tArgList* pAL )
{
    int ct = pAL->useCt;
    tCC** ppNV = pAL->apzArgs;

    while (ct-- > 0) {
        tOptionValue* pNV = (tOptionValue*)(void*)*(ppNV++);
        if (pNV->valType == OPARG_TYPE_HIERARCHY)
            unloadNestedArglist( pNV->v.nestVal );
        AGFREE( pNV );
    }

    AGFREE( (void*)pAL );
}


/*=export_func  optionUnloadNested
 *
 * what:  Deallocate the memory for a nested value
 * arg:   + tOptionValue const * + pOptVal + the hierarchical value +
 *
 * doc:
 *  A nested value needs to be deallocated.  The pointer passed in should
 *  have been gotten from a call to @code{configFileLoad()} (See
 *  @pxref{libopts-configFileLoad}).
=*/
void
optionUnloadNested( tOptionValue const * pOV )
{
    if (pOV == NULL) return;
    if (pOV->valType != OPARG_TYPE_HIERARCHY) {
        errno = EINVAL;
        return;
    }

    unloadNestedArglist( pOV->v.nestVal );

    AGFREE( (void*)pOV );
}


/*  sortNestedList
 *
 *  This is a _stable_ sort.  The entries are sorted alphabetically,
 *  but within entries of the same name the ordering is unchanged.
 *  Typically, we also hope the input is sorted.
 */
static void
sortNestedList( tArgList* pAL )
{
    int ix;
    int lm = pAL->useCt;

    /*
     *  This loop iterates "useCt" - 1 times.
     */
    for (ix = 0; ++ix < lm;) {
        int iy = ix-1;
        tOptionValue* pNewNV = (tOptionValue*)(void*)(pAL->apzArgs[ix]);
        tOptionValue* pOldNV = (tOptionValue*)(void*)(pAL->apzArgs[iy]);

        /*
         *  For as long as the new entry precedes the "old" entry,
         *  move the old pointer.  Stop before trying to extract the
         *  "-1" entry.
         */
        while (strcmp( pOldNV->pzName, pNewNV->pzName ) > 0) {
            pAL->apzArgs[iy+1] = (void*)pOldNV;
            pOldNV = (tOptionValue*)(void*)(pAL->apzArgs[--iy]);
            if (iy < 0)
                break;
        }

        /*
         *  Always store the pointer.  Sometimes it is redundant,
         *  but the redundancy is cheaper than a test and branch sequence.
         */
        pAL->apzArgs[iy+1] = (void*)pNewNV;
    }
}


/* optionLoadNested
 * private:
 *
 * what:  parse a hierarchical option argument
 * arg:   + char const*     + pzTxt   + the text to scan +
 * arg:   + char const*     + pzName  + the name for the text +
 * arg:   + size_t          + nameLen + the length of "name"  +
 *
 * ret_type:  tOptionValue*
 * ret_desc:  An allocated, compound value structure
 *
 * doc:
 *  A block of text represents a series of values.  It may be an
 *  entire configuration file, or it may be an argument to an
 *  option that takes a hierarchical value.
 */
LOCAL tOptionValue*
optionLoadNested(char const* pzTxt, char const* pzName, size_t nameLen)
{
    tOptionValue* pRes;
    tArgList*     pAL;

    /*
     *  Make sure we have some data and we have space to put what we find.
     */
    if (pzTxt == NULL) {
        errno = EINVAL;
        return NULL;
    }
    while (isspace( (int)*pzTxt ))  pzTxt++;
    if (*pzTxt == NUL) {
        errno = ENOENT;
        return NULL;
    }
    pRes = AGALOC( sizeof(*pRes) + nameLen + 1, "nested args" );
    if (pRes == NULL) {
        errno = ENOMEM;
        return NULL;
    }
    pRes->valType   = OPARG_TYPE_HIERARCHY;
    pRes->pzName    = (char*)(pRes + 1);
    memcpy( pRes->pzName, pzName, nameLen );
    pRes->pzName[ nameLen ] = NUL;

    pAL = AGALOC( sizeof(*pAL), "nested arg list" );
    if (pAL == NULL) {
        AGFREE( pRes );
        return NULL;
    }
    pRes->v.nestVal = pAL;
    pAL->useCt   = 0;
    pAL->allocCt = MIN_ARG_ALLOC_CT;

    /*
     *  Scan until we hit a NUL.
     */
    do  {
        while (isspace( (int)*pzTxt ))  pzTxt++;
        if (isalpha( (int)*pzTxt )) {
            pzTxt = scanNameEntry( pzTxt, pRes );
        }
        else switch (*pzTxt) {
        case NUL: goto scan_done;
        case '<': pzTxt = scanXmlEntry( pzTxt, pRes );
                  if (*pzTxt == ',') pzTxt++;     break;
        case '#': pzTxt = strchr( pzTxt, '\n' );  break;
        default:  goto woops;
        }
    } while (pzTxt != NULL); scan_done:;

    pAL = pRes->v.nestVal;
    if (pAL->useCt != 0) {
        sortNestedList( pAL );
        return pRes;
    }

 woops:
    AGFREE( pRes->v.nestVal );
    AGFREE( pRes );
    return NULL;
}


/*=export_func  optionNestedVal
 * private:
 *
 * what:  parse a hierarchical option argument
 * arg:   + tOptions* + pOpts    + program options descriptor +
 * arg:   + tOptDesc* + pOptDesc + the descriptor for this arg +
 *
 * doc:
 *  Nested value was found on the command line
=*/
void
optionNestedVal( tOptions* pOpts, tOptDesc* pOD )
{
    tOptionValue* pOV = optionLoadNested(
        pOD->optArg.argString, pOD->pz_Name, strlen(pOD->pz_Name));

    if (pOV != NULL)
        addArgListEntry( &(pOD->optCookie), (void*)pOV );
}
/*
 * Local Variables:
 * mode: C
 * c-file-style: "stroustrup"
 * indent-tabs-mode: nil
 * End:
 * end of autoopts/nested.c */