Added option to delete locally stored product database and query the size of it

Author: ajungg

core/src/main/java/io/snabble/sdk/ProductDatabase.java

@@ -12,6 +12,7 @@
 import android.os.Handler;
 import android.os.Looper;
 import android.os.SystemClock;
+import android.text.format.Formatter;
 
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
@@ -196,8 +197,9 @@ private boolean open(boolean allowCopyFromBundle) {
                         return false;
                     }
                 } else {
-                    Logger.d("Loaded product database revision %d, schema version %d.%d",
-                            revisionId, schemaVersionMajor, schemaVersionMinor);
+                    Logger.d("Loaded product database revision %d, schema version %d.%d, %s",
+                            revisionId, schemaVersionMajor, schemaVersionMinor,
+                            Formatter.formatFileSize(application, size()));
                 }
 
                 parseLastUpdateTimestamp();
@@ -217,10 +219,12 @@ private void close() {
     }
 
     private void putMetaData(String key, String value) {
-        ContentValues contentValues = new ContentValues();
-        contentValues.put("key", key);
-        contentValues.put("value", value);
-        db.replace("metadata", null, contentValues);
+        if(db != null) {
+            ContentValues contentValues = new ContentValues();
+            contentValues.put("key", key);
+            contentValues.put("value", value);
+            db.replace("metadata", null, contentValues);
+        }
     }
 
     private String getMetaData(String key) {
@@ -478,6 +482,34 @@ protected void onError() {
         });
     }
 
+    /**
+     * Closes and deletes the locally stored database and falls back to online only mode.
+     */
+    public void delete() {
+        if(db != null){
+            close();
+            application.deleteDatabase(dbName);
+            db = null;
+            revisionId = -1;
+            schemaVersionMinor = -1;
+            schemaVersionMajor = -1;
+
+            Logger.d("Deleted database: " + dbName);
+        }
+    }
+
+    /**
+     * @return Size of the database in bytes.
+     */
+    public long size() {
+        if(db == null){
+            return 0;
+        }
+
+        File dbFile = application.getDatabasePath(dbName);
+        return dbFile.length();
+    }
+
     /**
      * Updates the current database in the background by requesting new data from the backend.
      * <p>

sample/src/main/java/io/snabble/testapp/HomeFragment.java

@@ -36,6 +36,13 @@ public void onClick(View v) {
                 App.get().getSnabbleSdk().getProductDatabase().update();
             }
         });
+
+        v.findViewById(R.id.delete_db).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                App.get().getSnabbleSdk().getProductDatabase().delete();
+            }
+        });
         return v;
     }
 }

sample/src/main/res/layout/fragment_home.xml

@@ -24,4 +24,11 @@
         android:padding="8dp"
         android:id="@+id/update_db"
         android:text="Update DB" />
+
+    <Button
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:padding="8dp"
+        android:id="@+id/delete_db"
+        android:text="Delete DB" />
 </LinearLayout>