emoji table and cache fix, fixed crash

app/src/main/java/org/nuclearfog/twidda/ClientApplication.java

@@ -2,7 +2,7 @@ package org.nuclearfog.twidda;
 
 import android.app.Application;
 
-import org.nuclearfog.twidda.backend.image.ImageCache;
+import org.nuclearfog.twidda.backend.image.EmojiCache;
 import org.nuclearfog.twidda.backend.image.PicassoBuilder;
 import org.nuclearfog.twidda.backend.utils.BlurHashDecoder;
 import org.nuclearfog.twidda.config.GlobalSettings;
@@ -38,7 +38,7 @@ public class ClientApplication extends Application {
 
 	@Override
 	public void onLowMemory() {
-		ImageCache.clear();
+		EmojiCache.clear();
 		PicassoBuilder.clear();
 		BlurHashDecoder.clearCache();
 		super.onLowMemory();

app/src/main/java/org/nuclearfog/twidda/backend/async/ImageDownloader.java

@@ -49,10 +49,14 @@ public class ImageDownloader extends AsyncExecutor<ImageDownloader.ImageLoaderPa
 			}
 			// create file
 			String ext = '.' + mimeType.substring(mimeType.indexOf('/') + 1);
-			File imageFile = new File(request.cache, StringUtils.getRandomString() + ext);
+			// use deterministic filename depending on the url
-			imageFile.createNewFile();
+			File imageFile = new File(request.cacheFolder, StringUtils.getMD5signature(request.uri.toString()) + ext);
-
+			// if file exists with this signature, use this file
+			if (imageFile.exists()) {
+				return new ImageLoaderResult(Uri.fromFile(imageFile), null);
+			}
 			// copy image to cache folder
+			imageFile.createNewFile();
 			FileOutputStream output = new FileOutputStream(imageFile);
 			int length;
 			byte[] buffer = new byte[4096];
@@ -60,7 +64,6 @@ public class ImageDownloader extends AsyncExecutor<ImageDownloader.ImageLoaderPa
 				output.write(buffer, 0, length);
 			input.close();
 			output.close();
-
 			// create Uri from cached image
 			return new ImageLoaderResult(Uri.fromFile(imageFile), null);
 		} catch (ConnectionException exception) {
@@ -75,11 +78,11 @@ public class ImageDownloader extends AsyncExecutor<ImageDownloader.ImageLoaderPa
 	 */
 	public static class ImageLoaderParam {
 
-		final File cache;
 		final Uri uri;
+		final File cacheFolder;
 
-		public ImageLoaderParam(Uri uri, File cache) {
+		public ImageLoaderParam(Uri uri, File cacheFolder) {
-			this.cache = cache;
+			this.cacheFolder = cacheFolder;
 			this.uri = uri;
 		}
 	}

app/src/main/java/org/nuclearfog/twidda/backend/async/TextEmojiLoader.java

@@ -11,7 +11,7 @@ import androidx.annotation.Nullable;
 import org.nuclearfog.twidda.backend.api.Connection;
 import org.nuclearfog.twidda.backend.api.ConnectionManager;
 import org.nuclearfog.twidda.backend.helper.MediaStatus;
-import org.nuclearfog.twidda.backend.image.ImageCache;
+import org.nuclearfog.twidda.backend.image.EmojiCache;
 import org.nuclearfog.twidda.model.Emoji;
 
 import java.io.InputStream;
@@ -26,14 +26,14 @@ import java.util.TreeMap;
 public class TextEmojiLoader extends AsyncExecutor<TextEmojiLoader.EmojiParam, TextEmojiLoader.EmojiResult> {
 
 	private Connection connection;
-	private ImageCache cache;
+	private EmojiCache cache;
 
 	/**
 	 *
 	 */
 	public TextEmojiLoader(Context context) {
 		connection = ConnectionManager.getDefaultConnection(context);
-		cache = ImageCache.get(context);
+		cache = EmojiCache.get(context);
 	}
 
 
@@ -42,12 +42,12 @@ public class TextEmojiLoader extends AsyncExecutor<TextEmojiLoader.EmojiParam, T
 		try {
 			Map<String, Bitmap> result = new TreeMap<>();
 			for (Emoji emoji : param.emojis) {
-				Bitmap icon = cache.getImage(emoji.getCode());
+				Bitmap icon = cache.getImage(emoji.getUrl());
 				if (icon == null) {
 					MediaStatus media = connection.downloadImage(emoji.getUrl());
 					InputStream input = media.getStream();
 					icon = BitmapFactory.decodeStream(input);
-					cache.putImage(emoji.getCode(), icon);
+					cache.putImage(emoji.getUrl(), icon);
 				}
 				if (icon.getHeight() > 0 && icon.getWidth() > 0) {
 					icon = Bitmap.createScaledBitmap(icon, icon.getWidth() * param.size / icon.getHeight(), param.size, false);

app/src/main/java/org/nuclearfog/twidda/backend/image/EmojiCache.java

@@ -8,6 +8,7 @@ import android.util.LruCache;
 import androidx.annotation.Nullable;
 
 import org.nuclearfog.twidda.BuildConfig;
+import org.nuclearfog.twidda.backend.utils.StringUtils;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -24,7 +25,7 @@ import java.util.concurrent.ConcurrentHashMap;
  *
  * @author nuclearfog
  */
-public class ImageCache {
+public class EmojiCache {
 
 	/**
 	 * size of the lru cache (max entry count)
@@ -41,7 +42,7 @@ public class ImageCache {
 	 */
 	private static final String FOLDER = "images";
 
-	private static ImageCache instance;
+	private static EmojiCache instance;
 
 	private final LruCache<String, Bitmap> cache;
 	private Map<String, File> files;
@@ -50,7 +51,7 @@ public class ImageCache {
 	/**
 	 * @param context context used to determine cache folder path
 	 */
-	private ImageCache(Context context) {
+	private EmojiCache(Context context) {
 		files = new ConcurrentHashMap<>();
 		cache = new LruCache<>(SIZE);
 		try {
@@ -83,9 +84,9 @@ public class ImageCache {
 	 *
 	 * @return singleton instance of this class
 	 */
-	public static ImageCache get(Context context) {
+	public static EmojiCache get(Context context) {
 		if (instance == null)
-			instance = new ImageCache(context);
+			instance = new EmojiCache(context);
 		return instance;
 	}
 
@@ -103,20 +104,21 @@ public class ImageCache {
 	/**
 	 * put image to cache and save as file if not exists
 	 *
-	 * @param key   key of the image (tag)
+	 * @param url   url of the image
 	 * @param image image bitmap
 	 */
-	public void putImage(String key, Bitmap image) {
+	public void putImage(String url, Bitmap image) {
 		synchronized (instance.cache) {
-			cache.put(key, image);
+			String hash = StringUtils.getMD5signature(url);
-			if (!files.containsKey(key)) {
+			cache.put(hash, image);
+			if (!files.containsKey(hash)) {
 				try {
-					File file = new File(imageFolder, key);
+					File file = new File(imageFolder, hash);
 					if ((file.exists() && file.canWrite()) || file.createNewFile()) {
 						FileOutputStream output = new FileOutputStream(file);
 						image.compress(Bitmap.CompressFormat.PNG, 1, output);
 						output.close();
-						files.put(key, file);
+						files.put(hash, file);
 					}
 				} catch (IOException | SecurityException exception) {
 					if (BuildConfig.DEBUG) {
@@ -130,20 +132,21 @@ public class ImageCache {
 	/**
 	 * get image from cache or file
 	 *
-	 * @param key key of the image (tag)
+	 * @param url url of the image
 	 * @return image bitmap or null if not found
 	 */
 	@Nullable
-	public Bitmap getImage(String key) {
+	public Bitmap getImage(String url) {
 		synchronized (instance.cache) {
-			Bitmap result = cache.get(key);
+			String hash = StringUtils.getMD5signature(url);
+			Bitmap result = cache.get(hash);
 			if (result == null) {
 				try {
-					File file = files.get(key);
+					File file = files.get(hash);
 					if (file != null && file.canRead()) {
 						result = BitmapFactory.decodeFile(file.getAbsolutePath());
 						if (result != null) {
-							cache.put(key, result);
+							cache.put(hash, result);
 						}
 					}
 				} catch (SecurityException exception) {
@@ -161,28 +164,30 @@ public class ImageCache {
 	 * and reduce cache size by deleting old image files
 	 */
 	public void trimCache() {
-		File[] files = imageFolder.listFiles();
+		synchronized (instance.cache) {
-		if (files != null) {
+			File[] files = imageFolder.listFiles();
-			long size = 0L;
+			if (files != null) {
-			for (File file : files) {
+				long size = 0L;
-				size += file.length();
-			}
-			if (size > CACHE_SIZE) {
-				Arrays.sort(files, new Comparator<File>() {
-					@Override
-					public int compare(File file1, File file2) {
-						if (file1.lastModified() > file2.lastModified())
-							return 1;
-						else if (file1.lastModified() < file2.lastModified())
-							return -1;
-						return 0;
-					}
-				});
 				for (File file : files) {
-					size -= file.length();
+					size += file.length();
-					file.delete();
+				}
-					if (size < CACHE_SIZE) {
+				if (size > CACHE_SIZE) {
-						break;
+					Arrays.sort(files, new Comparator<File>() {
+						@Override
+						public int compare(File file1, File file2) {
+							if (file1.lastModified() > file2.lastModified())
+								return 1;
+							else if (file1.lastModified() < file2.lastModified())
+								return -1;
+							return 0;
+						}
+					});
+					for (File file : files) {
+						size -= file.length();
+						file.delete();
+						if (size < CACHE_SIZE) {
+							break;
+						}
 					}
 				}
 			}

app/src/main/java/org/nuclearfog/twidda/backend/utils/StringUtils.java

@@ -10,7 +10,10 @@ import org.nuclearfog.twidda.BuildConfig;
 import org.nuclearfog.twidda.R;
 
 import java.io.UnsupportedEncodingException;
+import java.math.BigInteger;
 import java.net.URLEncoder;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.text.NumberFormat;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
@@ -187,6 +190,27 @@ public class StringUtils {
 		return new String(Base64.encode(randomBytes, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP));
 	}
 
+	/**
+	 * generate MD5 hash from string
+	 *
+	 * @param text text to hash
+	 * @return hash string
+	 */
+	public static String getMD5signature(String text) {
+		try {
+			MessageDigest m = MessageDigest.getInstance("MD5");
+			m.reset();
+			m.update(text.getBytes());
+			byte[] digest = m.digest();
+			BigInteger bigInt = new BigInteger(1, digest);
+			return bigInt.toString(16);
+		} catch (NoSuchAlgorithmException exception) {
+			if (text.length() > 200)
+				return text.substring(0, 200);
+			return text;
+		}
+	}
+
 	/**
 	 * convert to percentage string (RFC 3986)
 	 *

app/src/main/java/org/nuclearfog/twidda/config/GlobalSettings.java

@@ -988,10 +988,12 @@ public class GlobalSettings {
 	 * notify listener when settings changes and clear old instances
 	 */
 	private void notifySettingsChange() {
-		for (SettingsChangeObserver observer : settingsChangeObservers) {
+		synchronized (this) {
-			observer.onSettingsChange();
+			for (SettingsChangeObserver observer : settingsChangeObservers) {
+				observer.onSettingsChange();
+			}
+			settingsChangeObservers.clear();
 		}
-		settingsChangeObservers.clear();
 	}
 
 	/**

app/src/main/java/org/nuclearfog/twidda/database/DatabaseAdapter.java

@@ -20,7 +20,7 @@ public class DatabaseAdapter {
 	/**
 	 * database version
 	 */
-	private static final int DB_VERSION = 19;
+	private static final int DB_VERSION = 20;
 
 	/**
 	 * database file name
@@ -137,9 +137,9 @@ public class DatabaseAdapter {
 	 */
 	private static final String TABLE_EMOJI = "CREATE TABLE IF NOT EXISTS "
 			+ EmojiTable.NAME + "("
-			+ EmojiTable.CODE + " TEXT PRIMARY KEY,"
+			+ EmojiTable.URL + " TEXT PRIMARY KEY,"
 			+ EmojiTable.CATEGORY + " TEXT,"
-			+ EmojiTable.URL + " TEXT);";
+			+ EmojiTable.CODE + " TEXT);";
 
 	/**
 	 * SQL query to create a poll table
@@ -412,8 +412,13 @@ public class DatabaseAdapter {
 				db.execSQL(UPDATE_MEDIA_ADD_DESCRIPTION);
 				db.setVersion(18);
 			}
-			if (db.getVersion() < DB_VERSION) {
+			if (db.getVersion() < 19) {
 				db.execSQL(UPDATE_MEDIA_ADD_BLUR_HASH);
+				db.setVersion(19);
+			}
+			if (db.getVersion() < DB_VERSION) {
+				db.delete(EmojiTable.NAME, null, null);
+				db.execSQL(TABLE_EMOJI);
 				db.setVersion(DB_VERSION);
 			}
 		}