Hi,
I have problem of freeing the messageTable_head linked list. I found it frees
everytime cache expires by calling messageTable_free(). But I do not want that
to be freed everytime. It will be created at start time and want to be freed at
shutdown.
I have shown this by File* fp. But actually I am making connection to some
fixed
applications and want to retain the connections. The other contents (except
File*)can be freed and updated everytime . I am storing the File* value in
messageTable_head linked list. The linked list also need to be freed at
shutdown.
Even the skeleton code also tells the same . "/* Initialise the contents of the
table here */. but where to free ?
Please give me some idea .
Thanks
Sujata
//global variables
#define FILECOUNT 3
struct messageTable_entry *messageTable_head;
char files[] ={data1.txt, data2.txt, data3.txt }
/** Initializes the abcModule module */
void
init_abcModule(void)
{
/* here we initialize all the tables we're planning on supporting */
initialize_table_messageTable();
}
/** Initialize the messageTable table by defining its contents and how it's
structured */
void
initialize_table_messageTable(void)
{
const oid messageTable_oid[] = {1,3,6,1,4,1,11456,3,3};
const size_t messageTable_oid_len = OID_LENGTH(messageTable_oid);
netsnmp_handler_registration *reg;
netsnmp_iterator_info *iinfo;
netsnmp_table_registration_info *table_info;
int total = 0;
DEBUGMSGTL(("token", "Calculating running total: "));
DEBUGMSG(("token", "\n"));
DEBUGMSGTL(("abcModule:init", "initializing table messageTable\n"));
reg = netsnmp_create_handler_registration(
"messageTable", messageTable_handler,
messageTable_oid, messageTable_oid_len,
HANDLER_CAN_RWRITE
);
table_info = SNMP_MALLOC_TYPEDEF( netsnmp_table_registration_info );
/* netsnmp_table_helper_add_indexes(table_info,
ASN_INTEGER,
ASN_OCTET_STR,
0);
*/
netsnmp_table_helper_add_indexes(table_info, /*ASN_INTEGER,
ASN_OCTET_STR,
ASN_INTEGER,
ASN_INTEGER, */
ASN_INTEGER, 0);
table_info->min_column = COLUMN_MESSAGETYPE;
table_info->max_column = COLUMN_CURRENTMSGID;
iinfo = SNMP_MALLOC_TYPEDEF( netsnmp_iterator_info );
iinfo->get_first_data_point = messageTable_get_first_data_point;
iinfo->get_next_data_point = messageTable_get_next_data_point;
iinfo->table_reginfo = table_info;
netsnmp_register_table_iterator( reg, iinfo );
netsnmp_inject_handler_before( reg,
netsnmp_get_cache_handler(MESSAGETABLE_TIMEOUT,
messageTable_load, messageTable_free,
messageTable_oid, messageTable_oid_len),
TABLE_ITERATOR_NAME);
/* Initialise the contents of the table here */
//////
//Create the messageTable_entry list.
//Open the file pointer and assign to it to messageTable_entry->fp
loadAll();
// where should i close the fp ?
}
/* Typical data structure for a row entry */
struct messageTable_entry {
/* Index values */
long messageIndex;
//connection pointer to the Application
FILE *fp;
/* Column values */
char messageType[10];
long sentMsgCount;
long errorMsgCount;
long currentMsgID;
/* Illustrate using a simple linked list */
int valid;
struct messageTable_entry *next;
};
/* create a new row in the (unsorted) table */
#ifdef jsaj
struct messageTable_entry *
messageTable_createEntry(
long messageIndex
) {
struct messageTable_entry *entry;
entry = SNMP_MALLOC_TYPEDEF(struct messageTable_entry);
if (!entry)
return NULL;
entry->messageIndex = messageIndex;
entry->next = messageTable_head;
messageTable_head = entry;
return entry;
}
/* remove a row from the table */
void
messageTable_removeEntry( struct messageTable_entry *entry ) {
struct messageTable_entry *ptr, *prev;
if (!entry)
return; /* Nothing to remove */
for ( ptr = messageTable_head, prev = NULL;
ptr != NULL;
prev = ptr, ptr = ptr->next ) {
if ( ptr == entry )
break;
}
if ( !ptr )
return; /* Can't find it */
if ( prev == NULL )
messageTable_head = ptr->next;
else
prev->next = ptr->next;
SNMP_FREE( entry ); /* XXX - release any other internal resources */
}
#endif
/* Example cache handling - set up linked list from a suitable file */
loadAll()
{
struct messageTable_entry *this;
char *fileName;
File *fp;
int i =0;
for(i=0; i<FILECOUNT;++i) {
fileName = files[i];
fp = fopen( fileName, "r" );
if ( !fp ) {
return -1;
}
snmp_log(LOG_INFO,"open the connection %s \n",fileName);
this = SNMP_MALLOC_TYPEDEF( struct messageTable_entry );
//store the connection pointer
this->fp = fp;
this->messageIndex = i;
this->next = messageTable_head;
messageTable_head = this; /* Iterate helper is fine with unordered
lists! */
}
}
bool isValidConnection(File* fp) {
//just returning true.
return true;
}
int
messageTable_load( netsnmp_cache *cache, void *vmagic ) {
FILE *fp;
struct messageTable_entry *this;
char buf[STRMAX];
char type[10];
int index = 0;
int msg_id, msg_sent, msg_err = 0;
memset(type,0x00,10);
for ( this = messageTable_head; this; this=that ) {
that = this->next;
fp = this->fp
//is this connection valid.
if ( isValidConnection() && fgets( buf, STRMAX, fp )) {
//populate the values
snmp_log(LOG_INFO,"populating the data.\n\n");
sprintf(type, "%s", strtok(buf, ","));
strcpy(this->messageType, type);
msg_id = atoi(strtok(NULL, ","));
this->currentMsgID = msg_id;
msg_sent = atoi(strtok(NULL, ","));
this->sentMsgCount = msg_sent;
msg_err = atoi(strtok(NULL, ","));
this->errorMsgCount = msg_err;
}
return 0; /* OK */
}
void
messageTable_free( netsnmp_cache *cache, void *vmagic ) {
struct messageTable_entry *this, *that;
for ( this = messageTable_head; this; this=that ) {
that = this->next;
SNMP_FREE( this ); /* XXX - release any other internal resources */
}
messageTable_head = NULL;
}
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