feat: load a plugin using wildcards

```
struct uh_plugin_handler uh_plugin_handler = {
    .path = "^/test$",
    .wildcard = true,
    .handler = test_handler
};
```

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

example/test_plugin.c

@@ -39,6 +39,7 @@ static void test_handler(struct uh_connection *conn, int event)
 }
 
 struct uh_plugin_handler uh_plugin_handler = {
-    .path = "/test",
+    .path = "^/test$",
+    .wildcard = true,
     .handler = test_handler
 };

src/connection.c

@@ -453,59 +453,79 @@ static int on_header_value_cb(struct http_parser *parser, const char *at, size_t
     return 0;
 }
 
-static bool set_path_handler(struct uh_connection_internal *conn, struct uh_path_handler *h,
-    struct uh_str *path, bool wildcard)
+static bool match_path(struct uh_str *path, const char *needle, int needlelen, uint8_t flags, bool wildcard)
 {
-    while (h) {
-        if (wildcard) {
-            int match = 0;
+    if (wildcard) {
+        int match = 0;
 
-            if (!(h->flags & UH_PATH_WILDCARD))
-                goto next;
+        if (!(flags & UH_PATH_WILDCARD))
+            return false;
 
-            if (path->len < h->len)
-                goto next;
+        if (path->len < needlelen)
+            return false;
 
-            if (h->flags & UH_PATH_MATCH_START) {
-                if (strncmp(path->p, h->path, h->len))
-                    goto next;
-                match++;
-            }
+        if (flags & UH_PATH_MATCH_START) {
+            if (strncmp(path->p, needle, needlelen))
+                return false;
+            match++;
+        }
 
-            if (h->flags & UH_PATH_MATCH_END) {
-                if (strncmp(path->p + (path->len - h->len), h->path, h->len))
-                    goto next;
-                match++;
-            }
+        if (flags & UH_PATH_MATCH_END) {
+            if (strncmp(path->p + (path->len - needlelen), needle, needlelen))
+                return false;
+            match++;
+        }
+
+        if (!match && !memmem(path->p, path->len, needle, needlelen))
+            return false;
+
+        return true;
+    } else {
+        if (flags & UH_PATH_WILDCARD)
+            return false;
 
-            if (!match && !memmem(path->p, path->len, h->path, h->len))
-                goto next;
+        if (needlelen != path->len || strncmp(path->p, needle, path->len))
+            return false;
 
+        return true;
+    }
+}
+
+static bool set_path_handler(struct uh_connection_internal *conn, struct uh_path_handler *h,
+    struct uh_str *path, bool wildcard)
+{
+    while (h) {
+        if (match_path(path, h->path, h->len, h->flags, wildcard)) {
             conn->handler = h->handler;
             return true;
-        } else {
-            if (h->flags & UH_PATH_WILDCARD)
-                goto next;
-
-            if (h->len == path->len && !strncmp(path->p, h->path, path->len)) {
-                conn->handler = h->handler;
-                return true;
-            }
         }
 
-next:
         h = h->next;
     }
 
     return false;
 }
 
+static bool set_plugin_handler(struct uh_connection_internal *conn, struct uh_plugin *p,
+    struct uh_str *path, bool wildcard)
+{
+    while (p) {
+        if (match_path(path, p->path, p->len, p->flags, wildcard)) {
+            conn->handler = p->h->handler;
+            return true;
+        }
+
+        p = p->next;
+    }
+
+    return false;
+}
+
 static int on_headers_complete(struct http_parser *parser)
 {
     struct uh_connection_internal *conn = (struct uh_connection_internal *)parser->data;
     struct uh_server_internal *srv = conn->srv;
     struct uh_request *req = &conn->req;
-    struct uh_plugin *p = srv->plugins;
     struct uh_str path;
 
     http_parser_parse_url(O2D(conn, req->url.offset), req->url.length, false, &conn->url_parser);
@@ -520,14 +540,12 @@ static int on_headers_complete(struct http_parser *parser)
     if (set_path_handler(conn, srv->handlers, &path, true))
         goto done;
 
-    /* match plugin */
-    while (p) {
-        if (p->len == path.len && !strncmp(path.p, p->h->path, path.len)) {
-            conn->handler = p->h->handler;
-            goto done;
-        }
-        p = p->next;
-    }
+    /* match non wildcard plugin */
+    if (set_plugin_handler(conn, srv->plugins, &path, false))
+        goto done;
+
+    /* match wildcard plugin */
+    set_plugin_handler(conn, srv->plugins, &path, true);
 
 done:
     if (!conn->handler)

src/uhttpd.c

@@ -219,8 +219,24 @@ static int uh_load_plugin(struct uh_server *srv, const char *path)
 
     p->h = h;
     p->dlh = dlh;
+    p->path = h->path;
     p->len = strlen(h->path);
 
+    if (h->wildcard) {
+        p->flags |= UH_PATH_WILDCARD;
+
+        if (h->path[0] == '^') {
+            p->flags |= UH_PATH_MATCH_START;
+            p->len--;
+            p->path++;
+        }
+
+        if (p->path[p->len - 1] == '$') {
+            p->flags |= UH_PATH_MATCH_END;
+            p->len--;
+        }
+    }
+
     if (!srvi->plugins) {
         srvi->plugins = p;
         return 0;

src/uhttpd.h

@@ -120,24 +120,27 @@ struct uh_server {
     int (*set_index_page)(struct uh_server *srv, const char *name);
 };
 
+enum {
+    UH_PATH_WILDCARD    = (1 << 0),
+    UH_PATH_MATCH_START = (1 << 1),
+    UH_PATH_MATCH_END   = (1 << 2)
+};
+
 struct uh_plugin_handler {
     const char *path;
+    bool wildcard;
     uh_path_handler_prototype handler;
 };
 
 struct uh_plugin {
     struct uh_plugin_handler *h;
     void *dlh;
+    uint8_t flags;
     uint8_t len;
+    const char *path;
     struct uh_plugin *next;
 };
 
-enum {
-    UH_PATH_WILDCARD    = (1 << 0),
-    UH_PATH_MATCH_START = (1 << 1),
-    UH_PATH_MATCH_END   = (1 << 2)
-};
-
 struct uh_path_handler {
     uh_path_handler_prototype handler;
     struct uh_path_handler *next;