altoslib: Fix map preloading callbacks, run in separate thread

The map storage and tile callbacks were muddled together. Create
clearly separate states for map data and have status updates be
delivered when registering for new status events so that registration
is sufficient to track the state without an explicit call to get the
current state.

Run the map tile creation in a separate thread so that even checking
status of files on disk runs out of the UI thread.

These fixes serve to make the pacifier update more smoothly, and also
not over/under count tile loading so that the loading actually
completes when all of the tiles are loaded.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 24 insertions, 23 deletions

diff --git a/altoslib/AltosMapStore.java b/altoslib/AltosMapStore.java
index eebef310..aed365ca 100644
--- a/altoslib/AltosMapStore.java
+++ b/altoslib/AltosMapStore.java
@@ -35,6 +35,7 @@ public class AltosMapStore {
 	public synchronized void add_listener(AltosMapStoreListener listener) {
 		if (!listeners.contains(listener))
 			listeners.add(listener);
+		listener.notify_store(this, status);
 	}
 
 	public synchronized void remove_listener(AltosMapStoreListener listener) {
@@ -110,7 +111,7 @@ public class AltosMapStore {
 				file.delete();
 			return AltosMapTile.bad_request;
 		}
-		return AltosMapTile.success;
+		return AltosMapTile.fetched;
 	}
 
 	static Object	fetch_lock = new Object();
@@ -118,42 +119,42 @@ public class AltosMapStore {
 	static final long	forbidden_interval = 60l * 1000l * 1000l * 1000l;
 	static final long 	google_maps_ratelimit_ms = 1200;
 
-	static Object	loader_lock = new Object();
+	static Object	fetcher_lock = new Object();
 
 	static LinkedList<AltosMapStore> waiting = new LinkedList<AltosMapStore>();
 	static LinkedList<AltosMapStore> running = new LinkedList<AltosMapStore>();
 
-	static final int concurrent_loaders = 128;
+	static final int concurrent_fetchers = 128;
 
-	static void start_loaders() {
-		while (!waiting.isEmpty() && running.size() < concurrent_loaders) {
+	static void start_fetchers() {
+		while (!waiting.isEmpty() && running.size() < concurrent_fetchers) {
 			AltosMapStore 	s = waiting.remove();
 			running.add(s);
-			Thread lt = s.make_loader_thread();
+			Thread lt = s.make_fetcher_thread();
 			lt.start();
 		}
 	}
 
-	void finish_loader() {
-		synchronized(loader_lock) {
+	void finish_fetcher() {
+		synchronized(fetcher_lock) {
 			running.remove(this);
-			start_loaders();
+			start_fetchers();
 		}
 	}
 
-	void add_loader() {
-		synchronized(loader_lock) {
+	void add_fetcher() {
+		synchronized(fetcher_lock) {
 			waiting.add(this);
-			start_loaders();
+			start_fetchers();
 		}
 	}
 
-	class loader implements Runnable {
+	class fetcher implements Runnable {
 
 		public void run() {
 			try {
 				if (file.exists()) {
-					notify_listeners(AltosMapTile.success);
+					notify_listeners(AltosMapTile.fetched);
 					return;
 				}
 
@@ -170,7 +171,7 @@ public class AltosMapStore {
 					synchronized (fetch_lock) {
 						long startTime = System.nanoTime();
 						new_status = fetch_url();
-						if (new_status == AltosMapTile.success) {
+						if (new_status == AltosMapTile.fetched) {
 							long duration_ms = (System.nanoTime() - startTime) / 1000000;
 							if (duration_ms < google_maps_ratelimit_ms) {
 								try {
@@ -186,17 +187,17 @@ public class AltosMapStore {
 				}
 				notify_listeners(new_status);
 			} finally {
-				finish_loader();
+				finish_fetcher();
 			}
 		}
 	}
 
-	private Thread make_loader_thread() {
-		return new Thread(new loader());
+	private Thread make_fetcher_thread() {
+		return new Thread(new fetcher());
 	}
 
-	private void load() {
-		add_loader();
+	private void fetch() {
+		add_fetcher();
 	}
 
 	private AltosMapStore (String url, File file) {
@@ -204,10 +205,10 @@ public class AltosMapStore {
 		this.file = file;
 
 		if (file.exists())
-			status = AltosMapTile.success;
+			status = AltosMapTile.fetched;
 		else {
-			status = AltosMapTile.loading;
-			load();
+			status = AltosMapTile.fetching;
+			fetch();
 		}
 	}