Moving some utility classes to icon lib

Change-Id: I0cc19ea02fb0732e9e1778a18c0d2c229232d179
2018-11-07 13:15:46 -08:00
parent 8b8ff994d2
commit 9a4c5be23e
12 changed files with 29 additions and 24 deletions
@@ -0,0 +1,125 @@
+package com.android.launcher3.util;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteException;
+import android.database.sqlite.SQLiteFullException;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.util.Log;
+
+/**
+ * An extension of {@link SQLiteOpenHelper} with utility methods for a single table cache DB.
+ * Any exception during write operations are ignored, and any version change causes a DB reset.
+ */
+public abstract class SQLiteCacheHelper {
+    private static final String TAG = "SQLiteCacheHelper";
+
+    private static final boolean IN_MEMORY_CACHE = false;
+
+    private final String mTableName;
+    private final MySQLiteOpenHelper mOpenHelper;
+
+    private boolean mIgnoreWrites;
+
+    public SQLiteCacheHelper(Context context, String name, int version, String tableName) {
+        if (IN_MEMORY_CACHE) {
+            name = null;
+        }
+        mTableName = tableName;
+        mOpenHelper = new MySQLiteOpenHelper(context, name, version);
+
+        mIgnoreWrites = false;
+    }
+
+    /**
+     * @see SQLiteDatabase#delete(String, String, String[])
+     */
+    public void delete(String whereClause, String[] whereArgs) {
+        if (mIgnoreWrites) {
+            return;
+        }
+        try {
+            mOpenHelper.getWritableDatabase().delete(mTableName, whereClause, whereArgs);
+        } catch (SQLiteFullException e) {
+            onDiskFull(e);
+        } catch (SQLiteException e) {
+            Log.d(TAG, "Ignoring sqlite exception", e);
+        }
+    }
+
+    /**
+     * @see SQLiteDatabase#insertWithOnConflict(String, String, ContentValues, int)
+     */
+    public void insertOrReplace(ContentValues values) {
+        if (mIgnoreWrites) {
+            return;
+        }
+        try {
+            mOpenHelper.getWritableDatabase().insertWithOnConflict(
+                    mTableName, null, values, SQLiteDatabase.CONFLICT_REPLACE);
+        } catch (SQLiteFullException e) {
+            onDiskFull(e);
+        } catch (SQLiteException e) {
+            Log.d(TAG, "Ignoring sqlite exception", e);
+        }
+    }
+
+    private void onDiskFull(SQLiteFullException e) {
+        Log.e(TAG, "Disk full, all write operations will be ignored", e);
+        mIgnoreWrites = true;
+    }
+
+    /**
+     * @see SQLiteDatabase#query(String, String[], String, String[], String, String, String)
+     */
+    public Cursor query(String[] columns, String selection, String[] selectionArgs) {
+        return mOpenHelper.getReadableDatabase().query(
+                mTableName, columns, selection, selectionArgs, null, null, null);
+    }
+
+    public void clear() {
+        mOpenHelper.clearDB(mOpenHelper.getWritableDatabase());
+    }
+
+    public void close() {
+        mOpenHelper.close();
+    }
+
+    protected abstract void onCreateTable(SQLiteDatabase db);
+
+    /**
+     * A private inner class to prevent direct DB access.
+     */
+    private class MySQLiteOpenHelper extends NoLocaleSQLiteHelper {
+
+        public MySQLiteOpenHelper(Context context, String name, int version) {
+            super(context, name, version);
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            onCreateTable(db);
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            if (oldVersion != newVersion) {
+                clearDB(db);
+            }
+        }
+
+        @Override
+        public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            if (oldVersion != newVersion) {
+                clearDB(db);
+            }
+        }
+
+        private void clearDB(SQLiteDatabase db) {
+            db.execSQL("DROP TABLE IF EXISTS " + mTableName);
+            onCreate(db);
+        }
+    }
+}