Merge migration branch

Keep original commit history

Author: krizzu

AsyncLocalStorageUtil.java

@@ -0,0 +1,145 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.modules.storage;
+
+import javax.annotation.Nullable;
+
+import java.util.Arrays;
+import java.util.Iterator;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.text.TextUtils;
+
+import com.facebook.react.bridge.ReadableArray;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import static com.facebook.react.modules.storage.ReactDatabaseSupplier.KEY_COLUMN;
+import static com.facebook.react.modules.storage.ReactDatabaseSupplier.TABLE_CATALYST;
+import static com.facebook.react.modules.storage.ReactDatabaseSupplier.VALUE_COLUMN;
+
+/**
+ * Helper for database operations.
+ */
+public class AsyncLocalStorageUtil {
+
+  /**
+   * Build the String required for an SQL select statement:
+   *  WHERE key IN (?, ?, ..., ?)
+   * without 'WHERE' and with selectionCount '?'
+   */
+  /* package */ static String buildKeySelection(int selectionCount) {
+    String[] list = new String[selectionCount];
+    Arrays.fill(list, "?");
+    return KEY_COLUMN + " IN (" + TextUtils.join(", ", list) + ")";
+  }
+
+  /**
+   * Build the String[] arguments needed for an SQL selection, i.e.:
+   *  {a, b, c}
+   * to be used in the SQL select statement: WHERE key in (?, ?, ?)
+   */
+  /* package */ static String[] buildKeySelectionArgs(ReadableArray keys, int start, int count) {
+    String[] selectionArgs = new String[count];
+    for (int keyIndex = 0; keyIndex < count; keyIndex++) {
+      selectionArgs[keyIndex] = keys.getString(start + keyIndex);
+    }
+    return selectionArgs;
+  }
+
+  /**
+   * Returns the value of the given key, or null if not found.
+   */
+  public static @Nullable String getItemImpl(SQLiteDatabase db, String key) {
+    String[] columns = {VALUE_COLUMN};
+    String[] selectionArgs = {key};
+
+    Cursor cursor = db.query(
+        TABLE_CATALYST,
+        columns,
+        KEY_COLUMN + "=?",
+        selectionArgs,
+        null,
+        null,
+        null);
+
+    try {
+      if (!cursor.moveToFirst()) {
+        return null;
+      } else {
+        return cursor.getString(0);
+      }
+    } finally {
+      cursor.close();
+    }
+  }
+
+  /**
+   * Sets the value for the key given, returns true if successful, false otherwise.
+   */
+  /* package */ static boolean setItemImpl(SQLiteDatabase db, String key, String value) {
+    ContentValues contentValues = new ContentValues();
+    contentValues.put(KEY_COLUMN, key);
+    contentValues.put(VALUE_COLUMN, value);
+
+    long inserted = db.insertWithOnConflict(
+        TABLE_CATALYST,
+        null,
+        contentValues,
+        SQLiteDatabase.CONFLICT_REPLACE);
+
+    return (-1 != inserted);
+  }
+
+  /**
+   * Does the actual merge of the (key, value) pair with the value stored in the database.
+   * NB: This assumes that a database lock is already in effect!
+   * @return the errorCode of the operation
+   */
+  /* package */ static boolean mergeImpl(SQLiteDatabase db, String key, String value)
+      throws JSONException {
+    String oldValue = getItemImpl(db, key);
+    String newValue;
+
+    if (oldValue == null) {
+      newValue = value;
+    } else {
+      JSONObject oldJSON = new JSONObject(oldValue);
+      JSONObject newJSON = new JSONObject(value);
+      deepMergeInto(oldJSON, newJSON);
+      newValue = oldJSON.toString();
+    }
+
+    return setItemImpl(db, key, newValue);
+  }
+
+  /**
+   * Merges two {@link JSONObject}s. The newJSON object will be merged with the oldJSON object by
+   * either overriding its values, or merging them (if the values of the same key in both objects
+   * are of type {@link JSONObject}). oldJSON will contain the result of this merge.
+   */
+  private static void deepMergeInto(JSONObject oldJSON, JSONObject newJSON)
+      throws JSONException {
+    Iterator<?> keys = newJSON.keys();
+    while (keys.hasNext()) {
+      String key = (String) keys.next();
+
+      JSONObject newJSONObject = newJSON.optJSONObject(key);
+      JSONObject oldJSONObject = oldJSON.optJSONObject(key);
+      if (newJSONObject != null && oldJSONObject != null) {
+        deepMergeInto(oldJSONObject, newJSONObject);
+        oldJSON.put(key, oldJSONObject);
+      } else {
+        oldJSON.put(key, newJSON.get(key));
+      }
+    }
+  }
+}