Feat[icon]: icon cache cleaner

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/LauncherActivity.java

@@ -32,6 +32,7 @@ import net.kdt.pojavlaunch.extra.ExtraListener;
 
 import net.kdt.pojavlaunch.fragments.SelectAuthFragment;
 import net.kdt.pojavlaunch.modloaders.modpacks.ModloaderInstallTracker;
+import net.kdt.pojavlaunch.modloaders.modpacks.imagecache.IconCacheJanitor;
 import net.kdt.pojavlaunch.multirt.MultiRTConfigDialog;
 import net.kdt.pojavlaunch.prefs.LauncherPreferences;
 import net.kdt.pojavlaunch.prefs.screens.LauncherPreferenceFragment;
@@ -154,6 +155,7 @@ public class LauncherActivity extends BaseActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_pojav_launcher);
+        IconCacheJanitor.runJanitor();
         getWindow().setBackgroundDrawable(null);
         bindViews();
         ProgressKeeper.addTaskCountListener((mProgressServiceKeeper = new ProgressServiceKeeper(this)));

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/modpacks/imagecache/DownloadImageTask.java

@@ -26,6 +26,7 @@ class DownloadImageTask implements Runnable {
 
     public boolean runCatching() {
         try {
+            IconCacheJanitor.waitForJanitorToFinish();
             DownloadUtils.downloadFile(mParentTask.imageUrl, mParentTask.cacheFile);
             return true;
         }catch (IOException e) {

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/modpacks/imagecache/IconCacheJanitor.java

@@ -0,0 +1,86 @@
+package net.kdt.pojavlaunch.modloaders.modpacks.imagecache;
+
+import android.util.Log;
+
+import net.kdt.pojavlaunch.PojavApplication;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+/**
+ * This image is intended to keep the mod icon cache tidy (aka under 100 megabytes)
+ */
+public class IconCacheJanitor implements Runnable{
+    public static final long CACHE_SIZE_LIMIT = 104857600; // The cache size limit, 100 megabytes
+    public static final long CACHE_BRINGDOWN = 52428800; // The size to which the cache should be brought
+    // in case of an overflow, 50 mb
+    private static Future<?> sJanitorFuture;
+    private static boolean sJanitorRan = false;
+    private IconCacheJanitor() {
+        // don't allow others to create this
+    }
+    @Override
+    public void run() {
+        File modIconCachePath = ModIconCache.getImageCachePath();
+        if(!modIconCachePath.isDirectory() || !modIconCachePath.canRead()) return;
+        File[] modIconFiles = modIconCachePath.listFiles();
+        if(modIconFiles == null) return;
+        ArrayList<File> writableModIconFiles = new ArrayList<>(modIconFiles.length);
+        long directoryFileSize = 0;
+        for(File modIconFile : modIconFiles) {
+            if(!modIconFile.isFile() || !modIconFile.canRead()) continue;
+            directoryFileSize += modIconFile.length();
+            if(!modIconFile.canWrite()) continue;
+            writableModIconFiles.add(modIconFile);
+        }
+        if(directoryFileSize < CACHE_SIZE_LIMIT)  {
+            Log.i("IconCacheJanitor", "Skipping cleanup because there's not enough to clean up");
+            return;
+        }
+        Arrays.sort(modIconFiles,
+                (x,y)-> Long.compare(y.lastModified(), x.lastModified())
+        );
+        int filesCleanedUp = 0;
+        for(File modFile : writableModIconFiles) {
+            if(directoryFileSize < CACHE_BRINGDOWN) break;
+            long modFileSize = modFile.length();
+            if(modFile.delete()) {
+                directoryFileSize -= modFileSize;
+                filesCleanedUp++;
+            }
+        }
+        Log.i("IconCacheJanitor", "Cleaned up "+filesCleanedUp+ " files");
+        synchronized (IconCacheJanitor.class) {
+            sJanitorFuture = null;
+            sJanitorRan = true;
+        }
+    }
+
+    /**
+     * Runs the janitor task, unless there was one running already or one has ran already
+     */
+    public static void runJanitor() {
+        synchronized (IconCacheJanitor.class) {
+            if (sJanitorFuture != null || sJanitorRan) return;
+            sJanitorFuture = PojavApplication.sExecutorService.submit(new IconCacheJanitor());
+        }
+    }
+
+    /**
+     * Waits for the janitor task to finish, if there is one running already
+     * Note that the thread waiting must not be interrupted.
+     */
+    public static void waitForJanitorToFinish() {
+        synchronized (IconCacheJanitor.class) {
+            if (sJanitorFuture == null) return;
+            try {
+                sJanitorFuture.get();
+            } catch (ExecutionException | InterruptedException e) {
+                throw new RuntimeException("Should not happen!", e);
+            }
+        }
+    }
+}

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/modpacks/imagecache/ModIconCache.java

@@ -27,13 +27,16 @@ public class ModIconCache {
     File cachePath;
     private final List<WeakReference<ImageReceiver>> mCancelledReceivers = new ArrayList<>();
     public ModIconCache() {
-        cachePath = new File(Tools.DIR_CACHE, "mod_icons");
+        cachePath = getImageCachePath();
         if(!cachePath.exists() && !cachePath.isFile() && Tools.DIR_CACHE.canWrite()) {
             if(!cachePath.mkdirs())
                 throw new RuntimeException("Failed to create icon cache directory");
         }
 
     }
+    static File getImageCachePath() {
+        return new File(Tools.DIR_CACHE, "mod_icons");
+    }
 
     /**
      * Get an image for a mod with the associated tag and URL to download it in case if its not cached

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/modpacks/imagecache/ReadFromDiskTask.java

@@ -30,6 +30,7 @@ public class ReadFromDiskTask implements Runnable {
             return;
         }
         if(cacheFile.canRead()) {
+            IconCacheJanitor.waitForJanitorToFinish();
             Bitmap bitmap = BitmapFactory.decodeFile(cacheFile.getAbsolutePath());
             if(bitmap != null) {
                 Tools.runOnUiThread(()->{