ndb_mongodb: added mongodb_find_one()

- find first matching document and return it
- faster when knowing it is supposed to be only one, or needing only one

modules/ndb_mongodb/mongodb_client.c

@@ -217,6 +217,7 @@ int mongodbc_exec_cmd(str *srv, str *dname, str *cname, str *cmd, str *res, int
 	bson_t reply;
 	const bson_t *cdoc;
 	char c;
+	int nres;
 	int ret;
 
 	if(srv==NULL || cmd==NULL || res==NULL)
@@ -283,10 +284,12 @@ int mongodbc_exec_cmd(str *srv, str *dname, str *cname, str *cmd, str *res, int
 					NULL,
 					0);
 		} else {
+			nres = 0;
+			if(emode==3) nres = 1; /* return one result */
 			rpl->cursor = mongoc_collection_find (rpl->collection,
 					MONGOC_QUERY_NONE,
 					0,
-					0,
+					nres,
 					0,
 					&command,
 					NULL,
@@ -340,6 +343,14 @@ int mongodbc_find(str *srv, str *dname, str *cname, str *cmd, str *res)
 	return mongodbc_exec_cmd(srv, dname, cname, cmd, res, 2);
 }
 
+/**
+ *
+ */
+int mongodbc_find_one(str *srv, str *dname, str *cname, str *cmd, str *res)
+{
+	return mongodbc_exec_cmd(srv, dname, cname, cmd, res, 3);
+}
+
 /**
  *
  */

modules/ndb_mongodb/mongodb_client.h

@@ -35,6 +35,7 @@ int mongodbc_add_server(char *spec);
 int mongodbc_exec_simple(str *srv, str *dname, str *cname, str *cmd, str *res);
 int mongodbc_exec(str *srv, str *dname, str *cname, str *cmd, str *res);
 int mongodbc_find(str *srv, str *dname, str *cname, str *cmd, str *res);
+int mongodbc_find_one(str *srv, str *dname, str *cname, str *cmd, str *res);
 
 typedef struct mongodbc_server {
 	str *sname;

modules/ndb_mongodb/ndb_mongodb_mod.c

@@ -39,6 +39,8 @@ MODULE_VERSION
 int mongodb_srv_param(modparam_t type, void *val);
 static int w_mongodb_find(sip_msg_t* msg, char* ssrv, char *sdname, char *scname,
 		char* scmd, char* sres);
+static int w_mongodb_find_one(sip_msg_t* msg, char* ssrv, char *sdname, char *scname,
+		char* scmd, char* sres);
 static int w_mongodb_cmd_simple(sip_msg_t* msg, char* ssrv, char *sdname, char *scname,
 		char* scmd, char* sres);
 static int w_mongodb_cmd(sip_msg_t* msg, char* ssrv, char *sdname, char *scname,
@@ -64,6 +66,8 @@ static pv_export_t mod_pvs[] = {
 static cmd_export_t cmds[]={
 	{"mongodb_find", (cmd_function)w_mongodb_find, 5, fixup_mongodb_cmd,
 		0, ANY_ROUTE},
+	{"mongodb_find_one", (cmd_function)w_mongodb_find_one, 5, fixup_mongodb_cmd,
+		0, ANY_ROUTE},
 	{"mongodb_cmd_simple", (cmd_function)w_mongodb_cmd_simple, 5, fixup_mongodb_cmd,
 		0, ANY_ROUTE},
 	{"mongodb_cmd", (cmd_function)w_mongodb_cmd, 5, fixup_mongodb_cmd,
@@ -155,12 +159,15 @@ static int w_mongodb_do_cmd(sip_msg_t* msg, char* ssrv, char *sdname, char *scna
 		LM_ERR("no mongodb reply name\n");
 		return -1;
 	}
+	ret = -1;
 	if(ctype==0) {
 		ret = mongodbc_exec_simple(&s[0], &s[1], &s[2], &s[3], &s[4]);
 	} else if(ctype==1) {
 		ret = mongodbc_exec(&s[0], &s[1], &s[2], &s[3], &s[4]);
-	} else {
+	} else if(ctype==2) {
 		ret = mongodbc_find(&s[0], &s[1], &s[2], &s[3], &s[4]);
+	} else if(ctype==3) {
+		ret = mongodbc_find_one(&s[0], &s[1], &s[2], &s[3], &s[4]);
 	}
 	if(ret<0)
 		return -1;
@@ -194,6 +201,15 @@ static int w_mongodb_find(sip_msg_t* msg, char* ssrv, char *sdname, char *scname
 	return w_mongodb_do_cmd(msg, ssrv, sdname, scname, scmd, sres, 2);
 }
 
+/**
+ *
+ */
+static int w_mongodb_find_one(sip_msg_t* msg, char* ssrv, char *sdname, char *scname,
+		char* scmd, char* sres)
+{
+	return w_mongodb_do_cmd(msg, ssrv, sdname, scname, scmd, sres, 3);
+}
+
 /**
  *
  */