*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/pgtclCmds.c,v 1.7 1996/11/11 12:14:42 scrappy Exp $
+ * $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/pgtclCmds.c,v 1.8 1996/12/19 05:02:49 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
#include "pgtclCmds.h"
#include "pgtclId.h"
+static Tcl_HashTable notifyTable = { NULL };
+
#ifdef TCL_ARRAYS
#define ISOCTAL(c) (((c) >= '0') && ((c) <= '7'))
#define DIGIT(c) ((c) - '0')
return TCL_OK;
}
+int
+Pg_listen(ClientData cData, Tcl_Interp *interp, int argc, char* argv[])
+{
+ int new;
+ char *relname;
+ char *callback = NULL;
+ Tcl_HashEntry *entry;
+ PGconn *conn;
+ PGresult *result;
+
+ if ((argc < 3) || (argc > 4)) {
+ Tcl_AppendResult(interp, "wrong # args, should be \"",
+ argv[0], " connection relname ?callback?\"", 0);
+ return TCL_ERROR;
+ }
+
+ /*
+ * Initialize the notify hash table if not already done.
+ */
+ if (notifyTable.buckets == NULL) {
+ Tcl_InitHashTable(¬ifyTable, TCL_STRING_KEYS);
+ }
+
+ /*
+ * Get the command arguments. Note that relname will copied by
+ * Tcl_CreateHashEntry while callback must be allocated.
+ */
+ if (!PgValidId(argv[1])) {
+ Tcl_AppendResult(interp, "not a valid connection\n", 0);
+ return TCL_ERROR;
+ }
+ conn = (PGconn*)PgGetId(argv[1]);
+ relname = argv[2];
+ if ((argc > 3) && *argv[3]) {
+ callback = (char *) ckalloc((unsigned) (strlen(argv[3])+1));
+ strcpy(callback, argv[3]);
+ }
+
+ /*
+ * Set or update a callback for a relation;
+ */
+ if (callback) {
+ entry = Tcl_CreateHashEntry(¬ifyTable, relname, &new);
+ if (new) {
+ /* New callback, execute a listen command on the relation */
+ char *cmd = (char *) ckalloc((unsigned) (strlen(argv[2])+8));
+ sprintf(cmd, "LISTEN %s", relname);
+ result = PQexec(conn, cmd);
+ ckfree(cmd);
+ if (!result || (result->resultStatus != PGRES_COMMAND_OK)) {
+ /* Error occurred during the execution of command */
+ if (result) PQclear(result);
+ ckfree(callback);
+ Tcl_DeleteHashEntry(entry);
+ Tcl_SetResult(interp, conn->errorMessage, TCL_STATIC);
+ return TCL_ERROR;
+ }
+ PQclear(result);
+ } else {
+ /* Free the old callback string */
+ ckfree((char *) Tcl_GetHashValue(entry));
+ }
+ /* Store the new callback command */
+ Tcl_SetHashValue(entry, callback);
+ }
+
+ /*
+ * Remove a callback for a relation. There is no way to
+ * un-listen a relation, simply remove the callback from
+ * the notify hash table.
+ */
+ if (callback == NULL) {
+ entry = Tcl_FindHashEntry(¬ifyTable, relname);
+ if (entry == NULL) {
+ Tcl_AppendResult(interp, "not listening on ", relname, 0);
+ return TCL_ERROR;
+ }
+ ckfree((char *) Tcl_GetHashValue(entry));
+ Tcl_DeleteHashEntry(entry);
+ }
+
+ return TCL_OK;
+}
+
+Pg_notifies(ClientData cData, Tcl_Interp *interp, int argc, char* argv[])
+{
+ int count;
+ char buff[12];
+ char *relname;
+ char *callback;
+ Tcl_HashEntry *entry;
+ PGconn *conn;
+ PGresult *result;
+ PGnotify *notify;
+
+ if (argc != 2) {
+ Tcl_AppendResult(interp, "wrong # args, should be \"",
+ argv[0], " connection\"", 0);
+ return TCL_ERROR;
+ }
+
+ /*
+ * Initialize the notify hash table if not already done.
+ */
+ if (notifyTable.buckets == NULL) {
+ Tcl_InitHashTable(¬ifyTable, TCL_STRING_KEYS);
+ }
+
+ /*
+ * Get the connection argument.
+ */
+ if (!PgValidId(argv[1])) {
+ Tcl_AppendResult(interp, "not a valid connection\n", 0);
+ return TCL_ERROR;
+ }
+ conn = (PGconn*)PgGetId(argv[1]);
+
+ /* Execute an empty command to retrieve asynchronous notifications */
+ result = PQexec(conn, " ");
+ if (result == NULL) {
+ /* Error occurred during the execution of command */
+ Tcl_SetResult(interp, conn->errorMessage, TCL_STATIC);
+ return TCL_ERROR;
+ }
+ PQclear(result);
+
+ /*
+ * Loop while there are pending notifies.
+ */
+ for (count=0; count < 999; count++) {
+ /* See if there is a pending notification */
+ notify = PQnotifies(conn);
+ if (notify == NULL) {
+ break;
+ }
+ entry = Tcl_FindHashEntry(¬ifyTable, notify->relname);
+ if (entry != NULL) {
+ callback = Tcl_GetHashValue(entry);
+ if (callback) {
+ Tcl_Eval(interp, callback);
+ }
+ }
+ free(notify);
+ }
+
+ /*
+ * Return the number of notifications processed.
+ */
+ sprintf(buff, "%d", count);
+ Tcl_SetResult(interp, buff, TCL_VOLATILE);
+ return TCL_OK;
+}