* NEW [hook] Update the key to exchange. key=hash(clientid+topic+id).

Signed-off-by: wanghaemq <wangwei@emqx.io>

nanomq/webhook_post.c

@@ -246,7 +246,24 @@ webhook_client_disconnect(nng_socket *sock, conf_web_hook *hook_conf,
 	return rv;
 }
 
-// uint64_t g_index = 0;
+static inline uint64_t
+gen_hash_nearby_key(char *clientid, char *topic, uint32_t pid)
+{
+	uint64_t res = 0;
+	char buf[10]; // should be enough put a u32
+	sprintf(buf, "%ld", pid);
+
+	char buf2[100]; // should be enough put the clienid and topic and pid
+	sprintf(buf2, "%s%s%s", clientid, topic, buf);
+
+	uint32_t key32 = DJBHash(buf2);
+	res = key32; res = res << 32; res += key32;
+	// log_info("%s - %s - %s => %lx %llx", clientid, topic, buf, key32, res);
+	// nng_time ts = nng_timestamp();
+	return res;
+}
+
+static uint32_t g_inc_id = 0;
 
 inline int
 hook_entry(nano_work *work, uint8_t reason)
@@ -267,13 +284,23 @@ hook_entry(nano_work *work, uint8_t reason)
 		nng_msg_alloc(&msg, 0);
 		nng_msg_header_append(msg, nng_msg_header(work->msg), nng_msg_header_len(work->msg));
 		nng_msg_append(msg, nng_msg_body(work->msg), nng_msg_len(work->msg));
+
 		uint8_t *body_ptr = nng_msg_body(work->msg);
 		ptrdiff_t offset = (ptrdiff_t)(nng_msg_payload_ptr(work->msg) - body_ptr);
 		nng_msg_set_payload_ptr(msg, (uint8_t *)nng_msg_body(msg) + offset);
-		nng_time ts = nng_timestamp();
-		// nng_mtx_lock(hook_conf->ex_mtx);
-		// nng_time ts = g_index ++;
-		// nng_mtx_unlock(hook_conf->ex_mtx);
+
+		// cparam has cloned at outside of hook_entry
+		char *clientid = (char *)conn_param_get_clientid(work->cparam);
+		if (clientid == NULL)
+			goto done;
+		char *topic = work->pub_packet->var_header.publish.topic_name.body;
+		if (topic == NULL)
+			goto done;
+		nng_mtx_lock(hook_conf->ex_mtx);
+		uint32_t pid = g_inc_id ++;
+		nng_mtx_unlock(hook_conf->ex_mtx);
+
+		nng_time ts = (nng_time)gen_hash_nearby_key(clientid, topic, pid);
 		nng_msg_set_timestamp(msg, ts);
 
 		for (size_t i = 0; i < ex_conf->count; i++) {
@@ -325,6 +352,8 @@ hook_entry(nano_work *work, uint8_t reason)
 	default:
 		break;
 	}
+
+done:
 	// Do not let online event msg trigger webhook
 	work->flag = 0;
 	return rv;