experimental: textures_get_key() caching for embedded in binary path strings

src/textures.c

@@ -361,7 +361,39 @@ void textures_update_atlas(struct texture_cache *cache) {
     arrfree(rects);
 }
 
+/* EXPERIMANTAL: LIKELY TO BE REMOVED! */
+/* todo: If it's proven to be useful: add runtime checking for .rodata > .data */
+#ifdef __unix__ /* use rodata elf section for fast lookups of repeating textures */
 
+extern const char start_rodata_address[];
+extern const char stop_rodata_heuristic[];
+
+asm(".set start_rodata_address, .rodata");
+asm(".set stop_rodata_heuristic, .data"); /* there's nothing in default linker script to know the size of .rodata */
+
+t_texture_key textures_get_key(struct texture_cache *cache, const char *path) {
+    static const char *last_path = NULL;
+    static t_texture_key last_texture;
+
+    /* fast path */
+    if (path == last_path && path >= start_rodata_address && path < stop_rodata_heuristic)
+        return last_texture;
+
+    /* hash tables are assumed to be stable, so we just return indices */
+    int texture = (int)shgeti(cache->hash, path);
+
+    /* load it if it isn't */
+    if (texture == -1) {
+        last_texture = textures_load(cache, path);
+    } else
+        last_texture = (t_texture_key){ texture };
+
+    last_path = path;
+
+    return last_texture;
+}
+
+#else
 t_texture_key textures_get_key(struct texture_cache *cache, const char *path) {
     /* hash tables are assumed to be stable, so we just return indices */
     ptrdiff_t texture = shgeti(cache->hash, path);