keymap: Keep keymap fd management in one place

At the same time, reduce the distance between this and the Xwayland handling branch.

eek/eek-keyboard.c

@@ -28,33 +28,24 @@
 #include <sys/random.h> // TODO: this is Linux-specific
 #include <xkbcommon/xkbcommon.h>
 
-
 #include "eek-keyboard.h"
 
-void level_keyboard_free(LevelKeyboard *self) {
-    xkb_keymap_unref(self->keymap);
-    close(self->keymap_fd);
-    squeek_layout_free(self->layout);
-    g_free(self);
+
+static void eek_key_map_deinit(struct keymap *self) {
+    if (self->fd < 0) {
+        g_error("Deinit called multiple times on KeyMap");
+    } else {
+        close(self->fd);
+    }
+    self->fd = -1;
 }
 
-LevelKeyboard*
-level_keyboard_new (struct squeek_layout *layout)
-{
-    LevelKeyboard *keyboard = g_new0(LevelKeyboard, 1);
-
-    if (!keyboard) {
-        g_error("Failed to create a keyboard");
-    }
-    keyboard->layout = layout;
-
+static struct keymap eek_key_map_from_str(const char *keymap_str) {
     struct xkb_context *context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
     if (!context) {
         g_error("No context created");
     }
 
-    const gchar *keymap_str = squeek_layout_get_keymap(keyboard->layout);
-
     struct xkb_keymap *keymap = xkb_keymap_new_from_string(context, keymap_str,
         XKB_KEYMAP_FORMAT_TEXT_V1, XKB_KEYMAP_COMPILE_NO_FLAGS);
 
@@ -62,10 +53,9 @@ level_keyboard_new (struct squeek_layout *layout)
         g_error("Bad keymap:\n%s", keymap_str);
 
     xkb_context_unref(context);
-    keyboard->keymap = keymap;
 
-    char * xkb_keymap_str = xkb_keymap_get_as_string(keymap, XKB_KEYMAP_FORMAT_TEXT_V1);
-    keyboard->keymap_len = strlen(xkb_keymap_str) + 1;
+    char *xkb_keymap_str = xkb_keymap_get_as_string(keymap, XKB_KEYMAP_FORMAT_TEXT_V1);
+    size_t keymap_len = strlen(xkb_keymap_str) + 1;
 
     g_autofree char *path = strdup("/eek_keymap-XXXXXX");
     char *r = &path[strlen(path) - 6];
@@ -79,18 +69,42 @@ level_keyboard_new (struct squeek_layout *layout)
     if (keymap_fd < 0) {
         g_error("Failed to set up keymap fd");
     }
-    keyboard->keymap_fd = keymap_fd;
+
     shm_unlink(path);
-    if (ftruncate(keymap_fd, (off_t)keyboard->keymap_len)) {
+    if (ftruncate(keymap_fd, (off_t)keymap_len)) {
         g_error("Failed to increase keymap fd size");
     }
-    char *ptr = mmap(NULL, keyboard->keymap_len, PROT_WRITE, MAP_SHARED,
+    char *ptr = mmap(NULL, keymap_len, PROT_WRITE, MAP_SHARED,
         keymap_fd, 0);
     if ((void*)ptr == (void*)-1) {
         g_error("Failed to set up mmap");
     }
-    strncpy(ptr, xkb_keymap_str, keyboard->keymap_len);
+    strncpy(ptr, xkb_keymap_str, keymap_len);
+    munmap(ptr, keymap_len);
     free(xkb_keymap_str);
-    munmap(ptr, keyboard->keymap_len);
+    xkb_keymap_unref(keymap);
+    struct keymap km = {
+        .fd = keymap_fd,
+        .fd_len = keymap_len,
+    };
+    return km;
+}
+
+void level_keyboard_free(LevelKeyboard *self) {
+    eek_key_map_deinit(&self->keymap);
+    squeek_layout_free(self->layout);
+    g_free(self);
+}
+
+LevelKeyboard*
+level_keyboard_new (struct squeek_layout *layout)
+{
+    LevelKeyboard *keyboard = g_new0(LevelKeyboard, 1);
+    if (!keyboard) {
+        g_error("Failed to create a keyboard");
+    }
+    keyboard->layout = layout;
+    const gchar *keymap_str = squeek_layout_get_keymap(keyboard->layout);
+    keyboard->keymap = eek_key_map_from_str(keymap_str);
     return keyboard;
 }

eek/eek-keyboard.h

@@ -32,19 +32,20 @@
 
 G_BEGIN_DECLS
 
+/// Keymap container for Rust interoperability.
+struct keymap {
+    uint32_t fd; // keymap formatted as XKB string
+    size_t fd_len; // length of the data inside keymap_fd
+};
+
 /// Keyboard state holder
 struct _LevelKeyboard {
     struct squeek_layout *layout; // owned
-    struct xkb_keymap *keymap; // owned
-    int keymap_fd; // keymap formatted as XKB string
-    size_t keymap_len; // length of the data inside keymap_fd
-
-    guint id; // as a key to layout choices
+    struct keymap keymap; // owned
 };
 typedef struct _LevelKeyboard LevelKeyboard;
 
-gchar *             eek_keyboard_get_keymap
-                                     (LevelKeyboard *keyboard);
+gchar *eek_keyboard_get_keymap(LevelKeyboard *keyboard);
 
 LevelKeyboard*
 level_keyboard_new (struct squeek_layout *layout);

src/wayland.c

@@ -17,7 +17,7 @@ eek_virtual_keyboard_v1_key(struct zwp_virtual_keyboard_v1 *zwp_virtual_keyboard
 void eek_virtual_keyboard_update_keymap(struct zwp_virtual_keyboard_v1 *zwp_virtual_keyboard_v1, const LevelKeyboard *keyboard) {
     zwp_virtual_keyboard_v1_keymap(zwp_virtual_keyboard_v1,
         WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1,
-        keyboard->keymap_fd, keyboard->keymap_len);
+        keyboard->keymap.fd, keyboard->keymap.fd_len);
 }
 
 void