Rename struct mg_connection::label -> data. Make its size configurable

src/config.h

@@ -81,14 +81,16 @@
 #define MG_ENABLE_PACKED_FS 0
 #endif
 
-// Granularity of the send/recv IO buffer growth
 #ifndef MG_IO_SIZE
-#define MG_IO_SIZE 2048
+#define MG_IO_SIZE 2048  // Granularity of the send/recv IO buffer growth
 #endif
 
-// Maximum size of the recv IO buffer
 #ifndef MG_MAX_RECV_SIZE
-#define MG_MAX_RECV_SIZE (3 * 1024 * 1024)
+#define MG_MAX_RECV_SIZE (3 * 1024 * 1024)  // Maximum recv IO buffer size
+#endif
+
+#ifndef MG_DATA_SIZE
+#define MG_DATA_SIZE 32  // struct mg_connection :: data size
 #endif
 
 #ifndef MG_MAX_HTTP_HEADERS

src/http.c

@@ -355,7 +355,7 @@ static void static_cb(struct mg_connection *c, int ev, void *ev_data,
     struct mg_fd *fd = (struct mg_fd *) fn_data;
     // Read to send IO buffer directly, avoid extra on-stack buffer
     size_t n, max = MG_IO_SIZE, space;
-    size_t *cl = (size_t *) &c->label[(sizeof(c->label) - sizeof(size_t)) /
+    size_t *cl = (size_t *) &c->data[(sizeof(c->data) - sizeof(size_t)) /
                                       sizeof(size_t) * sizeof(size_t)];
     if (c->send.size < max) mg_iobuf_resize(&c->send, max);
     if (c->send.len >= c->send.size) return;  // Rate limit
@@ -527,8 +527,8 @@ void mg_http_serve_file(struct mg_connection *c, struct mg_http_message *hm,
       c->is_resp = 0;
       mg_fs_close(fd);
     } else {
-      // Track to-be-sent content length at the end of c->label, aligned
-      size_t *clp = (size_t *) &c->label[(sizeof(c->label) - sizeof(size_t)) /
+      // Track to-be-sent content length at the end of c->data, aligned
+      size_t *clp = (size_t *) &c->data[(sizeof(c->data) - sizeof(size_t)) /
                                          sizeof(size_t) * sizeof(size_t)];
       c->pfn = static_cb;
       c->pfn_data = fd;
@@ -982,7 +982,7 @@ static void mg_hfn(struct mg_connection *c, int ev, void *ev_data, void *fnd) {
     if (mg_http_match_uri(hm, "/quit")) {
       mg_http_reply(c, 200, "", "ok\n");
       c->is_draining = 1;
-      c->label[0] = 'X';
+      c->data[0] = 'X';
     } else if (mg_http_match_uri(hm, "/debug")) {
       int level = (int) mg_json_get_long(hm->body, "$.level", MG_LL_DEBUG);
       mg_log_set(level);
@@ -991,7 +991,7 @@ static void mg_hfn(struct mg_connection *c, int ev, void *ev_data, void *fnd) {
       mg_http_reply(c, 200, "", "hi\n");
     }
   } else if (ev == MG_EV_CLOSE) {
-    if (c->label[0] == 'X') *(bool *) fnd = true;
+    if (c->data[0] == 'X') *(bool *) fnd = true;
   }
 }
 

src/net.h

@@ -52,7 +52,7 @@ struct mg_connection {
   void *fn_data;               // User-specified function parameter
   mg_event_handler_t pfn;      // Protocol-specific handler function
   void *pfn_data;              // Protocol-specific function parameter
-  char label[50];              // Arbitrary label
+  char data[MG_DATA_SIZE];     // Arbitrary connection data
   void *tls;                   // TLS specific data
   unsigned is_listening : 1;   // Listening connection
   unsigned is_client : 1;      // Outbound (client) connection

src/sock.c

@@ -101,8 +101,8 @@ static void iolog(struct mg_connection *c, char *buf, long n, bool r) {
       union usa usa;
       socklen_t slen = sizeof(usa.sin);
       if (getsockname(FD(c), &usa.sa, &slen) < 0) (void) 0;  // Ignore result
-      MG_INFO(("\n-- %lu %I %s %I %s %ld", c->id, 4, &usa.sin.sin_addr,
-               r ? "<-" : "->", 4, &c->rem.ip, c->label, n));
+      MG_INFO(("\n-- %lu %I %s %I %ld", c->id, 4, &usa.sin.sin_addr,
+               r ? "<-" : "->", 4, &c->rem.ip, n));
 
       mg_hexdump(buf, (size_t) n);
     }