perf: improve search plugin

Signed-off-by: Jianhui Zhao <zhaojh329@gmail.com>

src/connection.c

@@ -522,7 +522,7 @@ static int on_headers_complete(struct http_parser *parser)
 
     /* match plugin */
     while (p) {
-        if (strlen(p->h->path) == path.len && !strncmp(path.p, p->h->path, path.len)) {
+        if (p->len == path.len && !strncmp(path.p, p->h->path, path.len)) {
             conn->handler = p->h->handler;
             goto done;
         }

src/uhttpd.c

@@ -219,6 +219,7 @@ static int uh_load_plugin(struct uh_server *srv, const char *path)
 
     p->h = h;
     p->dlh = dlh;
+    p->len = strlen(h->path);
 
     if (!srvi->plugins) {
         srvi->plugins = p;

src/uhttpd.h

@@ -128,6 +128,7 @@ struct uh_plugin_handler {
 struct uh_plugin {
     struct uh_plugin_handler *h;
     void *dlh;
+    uint8_t len;
     struct uh_plugin *next;
 };