Store: add dbSize and dbSizeOnDisk, deprecate sizeOnDisk #203

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/BoxStore.java

@@ -194,7 +194,9 @@ static native void nativeRegisterCustomType(long store, int entityId, int proper
 
     static native boolean nativeIsObjectBrowserAvailable();
 
-    native long nativeSizeOnDisk(long store);
+    native long nativeDbSize(long store);
+
+    native long nativeDbSizeOnDisk(long store);
 
     native long nativeValidate(long store, long pageLimit, boolean checkLeafLevel);
 
@@ -484,9 +486,31 @@ public static long sysProcStatusKb(String key) {
      * The size in bytes occupied by the data file on disk.
      *
      * @return 0 if the size could not be determined (does not throw unless this store was already closed)
+     * @deprecated Use {@link #dbSize()} or {@link #dbSizeOnDisk()} instead which properly handle in-memory databases.
      */
+    @Deprecated
     public long sizeOnDisk() {
-        return nativeSizeOnDisk(getNativeStore());
+        return dbSize();
+    }
+
+    /**
+     * Get the size of this store. For a disk-based store type, this corresponds to the size on disk, and for the
+     * in-memory store type, this is roughly the used memory bytes occupied by the data.
+     *
+     * @return The size in bytes of the database, or 0 if the file does not exist or some error occurred.
+     */
+    public long dbSize() {
+        return nativeDbSize(getNativeStore());
+    }
+
+    /**
+     * The size in bytes occupied by the database on disk (if any).
+     *
+     * @return The size in bytes of the database on disk, or 0 if the underlying database is in-memory only
+     * or the size could not be determined.
+     */
+    public long dbSizeOnDisk() {
+        return nativeDbSizeOnDisk(getNativeStore());
     }
 
     /**

tests/objectbox-java-test/src/test/java/io/objectbox/BoxStoreTest.java

@@ -114,6 +114,8 @@ public void testClose() {
 
         // Methods using the native store should throw.
         assertThrowsStoreIsClosed(store::sizeOnDisk);
+        assertThrowsStoreIsClosed(store::dbSize);
+        assertThrowsStoreIsClosed(store::dbSizeOnDisk);
         assertThrowsStoreIsClosed(store::beginTx);
         assertThrowsStoreIsClosed(store::beginReadTx);
         assertThrowsStoreIsClosed(store::isReadOnly);
@@ -306,9 +308,18 @@ private Callable<String> createTestCallable(final int[] countHolder) {
 
     @Test
     public void testSizeOnDisk() {
-        long size = store.sizeOnDisk();
         // Note: initial database does have a non-zero (file) size.
-        assertTrue(size > 0);
+        long legacySizeOnDisk = store.sizeOnDisk();
+        assertTrue(legacySizeOnDisk > 0);
+
+        assertTrue(store.dbSize() > 0);
+
+        long sizeOnDisk = store.dbSizeOnDisk();
+        if (IN_MEMORY) {
+            assertEquals(0, sizeOnDisk);
+        } else {
+            assertTrue(sizeOnDisk > 0);
+        }
     }
 
     @Test