broadway: Refcount textures

We want to delay some rendering, and to make that safe we need to correctly
refcount the use of blob uris for the textures so that we don't unref
it while something is scheduled to use it.

diff --git a/gdk/broadway/broadway.js b/gdk/broadway/broadway.js
index 86259aa0a5d3b01c63740875aa71b863b8882190..e246948e11af8ea6775322cef70729d8ad7e9928 100644 (file)
--- a/gdk/broadway/broadway.js
+++ b/gdk/broadway/broadway.js
@@ -128,6 +128,27 @@ function getButtonMask (button) {
     return 0;
 }
 
+function Texture(id, data) {
+    var blob = new Blob([data],{type: "image/png"});
+    this.url = window.URL.createObjectURL(blob);
+    this.refcount = 1;
+    this.id = id;
+    textures[id] = this;
+}
+
+Texture.prototype.ref = function() {
+    this.refcount += 1;
+    return this;
+}
+
+Texture.prototype.unref = function() {
+    this.refcount -= 1;
+    if (this.refcount == 0) {
+        window.URL.revokeObjectURL(this.url);
+        delete textures[this.id];
+    }
+}
+
 function sendConfigureNotify(surface)
 {
     sendInput("w", [surface.id, surface.x, surface.y, surface.width, surface.height]);
@@ -499,8 +520,11 @@ SwapNodes.prototype.insertNode = function(parent, posInParent, oldNode)
             image.height = rect.height;
             image.style["position"] = "absolute";
             set_rect_style(image, rect);
-            var texture_url = textures[texture_id];
-            image.src = texture_url;
+            var texture = textures[texture_id];
+            image.src = texture.url;
+            texture.ref();
+            // Unref blob url when loaded
+            image.onload = function() { texture.unref(); };
             newNode = image;
         }
         break;
@@ -789,16 +813,12 @@ function cmdSurfaceSetNodes(id, node_data)
 
 function cmdUploadTexture(id, data)
 {
-    var blob = new Blob([data],{type: "image/png"});
-    var url = window.URL.createObjectURL(blob);
-    textures[id] = url;
+    new Texture (id, data); // Stores a ref in textures
 }
 
 function cmdReleaseTexture(id)
 {
-    var url = textures[id];
-    window.URL.revokeObjectURL(url);
-    delete textures[id];
+    textures[id].unref();
 }
 
 function cmdGrabPointer(id, ownerEvents)