Rework image cache

meson.build

@@ -41,9 +41,9 @@ sources = files(
     'src/Services/Accounts/Mastodon/Account.vala',
     'src/Services/Streams/Streams.vala',
     'src/Services/Streams/Streamable.vala',
-    'src/Services/Cache.vala',
     'src/Services/Cache/AbstractCache.vala',
     'src/Services/Cache/EntityCache.vala',
+    'src/Services/Cache/ImageCache.vala',
     'src/Services/Network/Network.vala',
     'src/Services/Network/Request.vala',
     'src/Services/Settings.vala',
@@ -69,8 +69,6 @@ sources = files(
     'src/Widgets/Conversation.vala',
     'src/Widgets/VisibilityPopover.vala',
     'src/Widgets/Attachment/Box.vala',
-    'src/Widgets/Attachment/Slot.vala',
-    'src/Widgets/Attachment/Picture.vala',
     'src/Widgets/AdaptiveButton.vala',
     'src/Widgets/MarkupView.vala',
     'src/Dialogs/Saveable.vala',

src/Application.vala

@@ -14,10 +14,10 @@ namespace Tootle {
 	public static Settings settings;
 	public static AccountStore accounts;
 	public static Network network;
-	public static Cache cache;
 	public static Streams streams;
 
 	public static EntityCache entity_cache;
+	public static ImageCache image_cache;
 
 	public static bool start_hidden = false;
 
@@ -30,7 +30,6 @@ namespace Tootle {
 		public Settings app_settings { get {return Tootle.settings; } }
 		public AccountStore app_accounts { get {return Tootle.accounts; } }
 		public Network app_network { get {return Tootle.network; } }
-		public Cache app_cache { get {return Tootle.cache; } }
 		public Streams app_streams { get {return Tootle.streams; } }
 
 		public signal void refresh ();
@@ -87,8 +86,8 @@ namespace Tootle {
 				settings = new Settings ();
 				streams = new Streams ();
 				network = new Network ();
-				cache = new Cache ();
 				entity_cache = new EntityCache ();
+				image_cache = new ImageCache ();
 				accounts = new SecretAccountStore();
 				accounts.init ();
 

src/Services/Cache/AbstractCache.vala

@@ -28,10 +28,13 @@ public class Tootle.AbstractCache : Object {
 			while (iter.has_next ()) {
 				iter.next ();
 				var obj = iter.get_value ();
-				var min_ref_count = obj.get_data<uint> (DATA_MIN_REF_COUNT);
-				var remove = obj.ref_count <= min_ref_count;
+				assert (obj != null);
 
-				if (remove) {
+				var min_ref_count = obj.get_data<uint> (DATA_MIN_REF_COUNT);
+				if ("jpg" in iter.get_key ()) {
+					warning (@"Key \"$(iter.get_key ())\": $(obj.ref_count)/$(min_ref_count)");
+				}
+				if (obj.ref_count <= min_ref_count) {
 					cleared++;
 					Value url = Value (typeof (string));
 					obj.get_property ("url", ref url);
@@ -61,13 +64,21 @@ public class Tootle.AbstractCache : Object {
 		return items.has_key (get_key (id));
 	}
 
-	public void insert (string id, owned Object obj) {
+	public string insert (string id, owned Object obj) {
 		var key = get_key (id);
 		message ("Inserting: "+key);
 		items.@set (key, (owned) obj);
 
 		var nobj = items.@get (key);
 		nobj.set_data<uint> (DATA_MIN_REF_COUNT, nobj.ref_count);
+
+		return key;
+	}
+
+	public void nuke () {
+		message ("Clearing cache");
+		items.clear ();
+		items_in_progress.clear ();
 	}
 
 }

src/Services/Cache/ImageCache.vala

@@ -0,0 +1,88 @@
+using Gdk;
+
+public class Tootle.ImageCache : AbstractCache {
+
+	// [Signal (detailed = true)]
+	// public signal void on_item_changed (bool is_loaded, owned Pixbuf? data);
+
+	public delegate void OnItemChangedFn (bool is_loaded, owned Pixbuf? data);
+
+	protected Pixbuf decode_image (owned Soup.Message msg) throws Error {
+		Pixbuf? pixbuf = null;
+		var code = msg.status_code;
+		if (code != Soup.Status.OK) {
+			var error = network.describe_error (code);
+			throw new Oopsie.INSTANCE (@"Server returned $error");
+		}
+
+        var data = msg.response_body.flatten ().data;
+        var stream = new MemoryInputStream.from_data (data);
+        pixbuf = new Pixbuf.from_stream (stream);
+        stream.close ();
+
+        if (pixbuf == null)
+        	throw new Oopsie.INSTANCE ("Returned pixbuf is null");
+
+        return pixbuf;
+	}
+
+	public void request_pixbuf (string? url, owned OnItemChangedFn cb) {
+		if (url == null)
+			return;
+
+		var key = get_key (url);
+		if (contains (key)) {
+			cb (true, lookup (key) as Pixbuf);
+			return;
+		}
+
+		var download_msg = items_in_progress.@get (key);
+		if (download_msg == null) {
+			// This image isn't cached, so we need to download it first.
+
+            download_msg = new Soup.Message ("GET", url);
+            ulong id = 0;
+            id = download_msg.finished.connect (() => {
+                Pixbuf? pixbuf = null;
+                try {
+                    pixbuf = decode_image (download_msg);
+                }
+                catch (Error e) {
+                    warning (@"Failed to download image at \"$url\". $(e.message).");
+                    cb (true, null);
+                    return;
+                }
+
+                // message (@"[*] $key");
+                insert (url, pixbuf);
+                items_in_progress.unset (key);
+
+                cb (true, pixbuf);
+
+                download_msg.disconnect (id);
+            });
+
+            network.queue (download_msg, (sess, mess) => {
+                // no one cares
+            },
+            (code, reason) => {
+                cb (true, null);
+            });
+
+            cb (false, null);
+
+            items_in_progress.@set (key, download_msg);
+		}
+		else {
+			// This image is either cached or already downloading, so we can serve the result immediately.
+
+            //message ("[/]: %s", key);
+            ulong id = 0;
+            id = download_msg.finished.connect_after (() => {
+                cb (true, lookup (key) as Pixbuf);
+                download_msg.disconnect (id);
+            });
+        }
+	}
+
+}