mfd-persistence.m2i

开发snmp的开发包有两个开放的SNMP开发库

########################################################################
## generic include for XXX. Do not use directly.
## $Id: mfd-persistence.m2i 15990 2007-03-23 09:19:51Z dts12 $
########################################################################
@if $m2c_mark_boundary == 1@
/** START code generated by $RCSfile$ $Revision: 15990 $ */
@end@
########################################################################
@if $m2c_processing_type eq 'h'@
/* *********************************************************************
 * Persistent declarations
 */
/*
 * persistence
 */
#define LINE_TERM_CHAR '$'

void ${context}_container_init_persistence( netsnmp_container * container );
int ${context}_container_should_save(${context}_rowreq_ctx * rowreq_ctx);

@end@ // m2c_processing_type eq 'h'
######################################################################
######################################################################
######################################################################
@if $m2c_processing_type eq 'c'@
/************************************************************
 * the *_should_save routine is called to determine if a row
 * should be stored persistently.
 *
 * Note that this is not a 'dirty' check (i.e. if a row has changed),
 * but a check for volatile rows that should not be saved between
 * restarts.
 *
 * return 1 if the row should be stored
 * return 0 if the row should not be stored
 */
int
${context}_container_should_save(${context}_rowreq_ctx * rowreq_ctx)
{
@   foreach $node column@
@      if "$node.syntax" eq "StorageType"@
@         include m2c_setup_node.m2i@
    if (SNMP_STORAGE_VOLATILE == $m2c_ctx_rh    )
        return 0;
@       end@
@   end@
    
    return 1; /* save the row */
}

@end@ // m2c_processing_type eq 'h'
######################################################################
######################################################################
######################################################################
@if $m2c_processing_type eq 'i'@
/***********************************************************************
 *
 * PERSISTENCE
 *
 ***********************************************************************/

static int _${context}_container_save_rows(int majorID, int minorID, void *serverarg, void *clientarg);
static void _${context}_container_row_restore(const char *token, char *buf);
static int _${context}_container_row_save(
            ${context}_rowreq_ctx *rowreq_ctx,
            void *type);
static char * _${context}_container_col_restore(
            ${context}_rowreq_ctx *rowreq_ctx,
            u_int col, char* buf);
static char * _${context}_container_col_save(
            ${context}_rowreq_ctx *rowreq_ctx,
            u_int col, char* buf);

static char row_token[] = "${context}";

/************************************************************
 * *_init_persistence should be called from the main table
 * init routine.
 *
 * If your table depends on rows in another table,
 * you should register your callback after the other table,
 * which should ensure the rows on which you depend are saved
 * (and re-created) before the dependent rows.
 */
void
${context}_container_init_persistence( netsnmp_container * container )
{
    int rc;

    register_config_handler(NULL, row_token,
                            _${context}_container_row_restore, NULL, NULL);
    rc = snmp_register_callback( SNMP_CALLBACK_LIBRARY,
                                     SNMP_CALLBACK_STORE_DATA,
                                     _${context}_container_save_rows,
                                     container);

    if( rc != SNMP_ERR_NOERROR )
        snmp_log(LOG_ERR, "error registering for STORE_DATA callback "
                 "in _${context}_container_init_persistence\n");
}

static int
_${context}_container_save_rows(int majorID, int minorID, void *serverarg, void *clientarg)
{
    char sep[] =
        "##############################################################";
    char buf[] =
        "#\n"
        "# $context persistent data\n"
        "#";
    char *type = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID, 
                                       NETSNMP_DS_LIB_APPTYPE);

    read_config_store((char*)type, sep);
    read_config_store((char*)type, buf);

    /*
     * save all rows
     */
    CONTAINER_FOR_EACH((netsnmp_container*)clientarg,
                       (netsnmp_container_obj_func*)_${context}_container_row_save,
                       type);

    read_config_store((char*)type, sep);
    read_config_store((char*)type, "\n");

    /*
     * never fails 
     */
    return SNMPERR_SUCCESS;
}



/************************************************************
 * _${context}_container_row_save
 */
static int
_${context}_container_row_save(
            ${context}_rowreq_ctx *rowreq_ctx,
            void *type)
{
    /*
     * Allocate space for a line with all data for a row. An
     * attempt is made to come up with a default maximum size, but
     * there is no guarantee it will be enough. It probably will be,
     * unless you are dealing with large values or you have external
     * indexes.
     *
     * 1) allocate space for each column. Comment out columns you don't
     * intend to save. You may also need to add room for any non-
     * column data you want to store. Remeber, data will be stored in
     * ASCII form, so you need to allow for that. Here are some
     * general guidelines:
     *
     *   Object ID   :  12 * len [ASCII len of max int + 1 for .]
     *   Octet String: (2 * len) + 2 [2 ASCII chars per byte + "0x"]
     *   Integers    :  12 [ASCII len for smallest negative number]
     *
     * 2) You also need to allocate space for the row index. This will
     * be stored as an OID, which means that Octet Strings need to
     * be treated a little differently. Specifically, you will need
     * (4 * len) + 4 [3 ASCII chars per byte + 1 for ., + 4 for len].
     *
     * 3) Also, remeber to add space for the identifier and seperator
     * characters (for example, each column is prefixed by the
     * column number and a semicolon. To allow for the maximum
     * column values, 12 bytes [11 for oid + 1 for ':'] per
     * column are added).
     */
        /** xxx: add storage for external index(s)! */
#define MAX_ROW_SIZE (sizeof(row_token) + 1 +  \
@   if $ext_index != 0@
        ( 12 * 128 ) + /* external interfaces - max 128 subids */ \
@   end@
@   foreach $node nonindex@
@      include m2c_setup_node.m2i@
@    if ($node.settable == 1)@
@      if "$node.type" eq "ASN_OBJECT_ID"@
        ( ( 12 * sizeof(${m2c_ctx_rh}) ) + 3 ) + /* $node.type */ \
@      elsif "$node.type" eq "ASN_OCTET_STR"@
        ( ( 2 * sizeof(${m2c_ctx_rh}) ) + 3 ) + /* $node.type */ \
@      else@
        ( 12 ) + /* $node.type $node */ \
@      end@
@    end@
@   end@
        ( $table.uc_MAX_COL * 12 ) + /* column num prefix + : */ \
    2 /* LINE_TERM_CHAR + \n */ )

    char buf[MAX_ROW_SIZE], *pos = buf, *max = &buf[MAX_ROW_SIZE-1];
    char *tmp;
    int i;

    if (${context}_container_should_save(rowreq_ctx) == 0) {
        return SNMP_ERR_NOERROR;
    }

    /*
     * build the line
     */
    pos += sprintf(pos, "%s ", row_token);
    pos = read_config_save_objid(pos, rowreq_ctx->oid_idx.oids,
                                 rowreq_ctx->oid_idx.len);
    if(NULL == pos) {
        snmp_log(LOG_ERR,"error saving ${context} row "
                 "to persistent file\n");
        return SNMP_ERR_GENERR;
    }
    *pos++ = ' ';
    if(pos > max) {
        snmp_log(LOG_ERR,"error saving ${context} row "
                 "to persistent file (too long)\n");
        return SNMP_ERR_GENERR;
    }

    /*
     * add each column
     */
    for(i = $table.uc_MIN_COL; i <= $table.uc_MAX_COL; ++i ) {

        if ((0x1 << (i-1)) & ~$context.uc_SETTABLE_COLS)
           continue;

        tmp = pos;
        pos = _${context}_container_col_save(rowreq_ctx, i, pos);
        if(NULL == pos)
            pos = tmp;
        else
            *pos++ = ' ';        
        if(pos > max) {
            snmp_log(LOG_ERR,"error saving ${context} row "
                     "to persistent file (too long)\n");
            return SNMP_ERR_GENERR;
        }
    }

    /*
     * if you have non-column data, add it here
     */