Review feedback

Author: rsgowman

firebase-firestore/CHANGELOG.md

@@ -1,5 +1,5 @@
 # Unreleased
-- [fixed] Fixed calculation of SQLite database size on Android 9 (P) devices.
+- [fixed] Fixed calculation of SQLite database size on Android 9 Pie devices.
   Previous method could be off by a few MBs on these devices, potentially
   delaying garbage collection.
 

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLitePersistence.java

@@ -205,7 +205,13 @@ long getByteSize() {
    * @see https://www.sqlite.org/pragma.html#pragma_page_size
    */
   private long getPageSize() {
-    return pragma("page_size");
+    Cursor cursor = db.rawQuery("PRAGMA page_size", null);
+    try {
+      cursor.moveToFirst();
+      return cursor.getLong(/*column=*/ 0);
+    } finally {
+      cursor.close();
+    }
   }
 
   /**
@@ -215,15 +221,7 @@ private long getPageSize() {
    * @see https://www.sqlite.org/pragma.html#pragma_page_count.
    */
   private long getPageCount() {
-    return pragma("page_count");
-  }
-
-  /**
-   * @param pragmaName Must be a valid 'pragma-name' and must refer to a long value.
-   * @see https://www.sqlite.org/pragma.html
-   */
-  private long pragma(String pragmaName) {
-    Cursor cursor = db.rawQuery("PRAGMA " + pragmaName, null);
+    Cursor cursor = db.rawQuery("PRAGMA page_count", null);
     try {
       cursor.moveToFirst();
       return cursor.getLong(/*column=*/ 0);