From 7548de61c61d32e8bd9abce5846b836bca26f036 Mon Sep 17 00:00:00 2001
From: fengzero <fengzero@fengzero.com>
Date: Mon, 10 Apr 2023 03:12:12 +0000
Subject: [PATCH] improve(connection): replace old client

---
 src/connection/connection.c | 48 ++++++++++++++++++++++++++++---------
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/src/connection/connection.c b/src/connection/connection.c
index cfd7d092..1b9ad400 100644
--- a/src/connection/connection.c
+++ b/src/connection/connection.c
@@ -69,6 +69,7 @@ struct neu_conn {
 static void conn_tcp_server_add_client(neu_conn_t *conn, int fd,
                                        struct sockaddr_in client);
 static void conn_tcp_server_del_client(neu_conn_t *conn, int fd);
+static void conn_tcp_server_replace_client(neu_conn_t *conn, int fd);
 
 static void conn_tcp_server_listen(neu_conn_t *conn);
 static void conn_tcp_server_stop(neu_conn_t *conn);
@@ -180,16 +181,6 @@ int neu_conn_tcp_server_accept(neu_conn_t *conn)
         return -1;
     }
 
-    if (conn->tcp_server.n_client >= conn->param.params.tcp_server.max_link) {
-        close(fd);
-        zlog_warn(conn->param.log, "%s:%d accpet max link: %d, reject",
-                  conn->param.params.tcp_server.ip,
-                  conn->param.params.tcp_server.port,
-                  conn->param.params.tcp_server.max_link);
-        pthread_mutex_unlock(&conn->mtx);
-        return -1;
-    }
-
     if (conn->block) {
         struct timeval tv = {
             .tv_sec  = conn->param.params.tcp_server.timeout / 1000,
@@ -199,7 +190,23 @@ int neu_conn_tcp_server_accept(neu_conn_t *conn)
         setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
     }
 
-    conn_tcp_server_add_client(conn, fd, client);
+    if (conn->tcp_server.n_client >= conn->param.params.tcp_server.max_link) {
+        int free_fd = conn_tcp_server_del_first_client(conn, fd);
+        if (free_fd > 0) {
+            zlog_warn(conn->param.log, "replace old client %d with %d", free_fd,
+                      fd);
+        } else {
+            close(fd);
+            zlog_warn(conn->param.log, "%s:%d accpet max link: %d, reject",
+                      conn->param.params.tcp_server.ip,
+                      conn->param.params.tcp_server.port,
+                      conn->param.params.tcp_server.max_link);
+            pthread_mutex_unlock(&conn->mtx);
+            return -1;
+        }
+    } else {
+        conn_tcp_server_add_client(conn, fd, client);
+    }
 
     conn->is_connected = true;
     conn->connected(conn->data, fd);
@@ -891,6 +898,25 @@ static void conn_tcp_server_del_client(neu_conn_t *conn, int fd)
     }
 }
 
+static void conn_tcp_server_replace_client(neu_conn_t *conn, int fd)
+{
+    int ret = 0;
+
+    for (int i = 0; i < conn->param.params.tcp_server.max_link; i++) {
+        if (conn->tcp_server.clients[i].fd > 0) {
+            ret = conn->tcp_server.clients[i].fd;
+
+            close(conn->tcp_server.clients[i].fd);
+            conn->tcp_server.clients[i].fd = 0;
+
+            conn->tcp_server.clients[i].fd = fd;
+            return;
+        }
+    }
+
+    return ret;
+}
+
 int neu_conn_stream_consume(neu_conn_t *conn, void *context,
                             neu_conn_stream_consume_fn fn)
 {