// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.chrome.browser.database;
import android.database.AbstractCursor;
import android.database.CursorWindow;
import android.util.Log;
import org.chromium.base.CalledByNative;
import java.sql.Types;
/**
* This class exposes the query result from native side.
*/
public class SQLiteCursor extends AbstractCursor {
private static final String TAG = "SQLiteCursor";
// Used by JNI.
private int mNativeSQLiteCursor;
// The count of result rows.
private int mCount = -1;
private int[] mColumnTypes;
private final Object mColumnTypeLock = new Object();
// The belows are the locks for those methods that need wait for
// the callback result in native side.
private final Object mMoveLock = new Object();
private final Object mGetBlobLock = new Object();
private SQLiteCursor(int nativeSQLiteCursor) {
mNativeSQLiteCursor = nativeSQLiteCursor;
}
@CalledByNative
private static SQLiteCursor create(int nativeSQLiteCursor) {
return new SQLiteCursor(nativeSQLiteCursor);
}
@Override
public int getCount() {
synchronized (mMoveLock) {
if (mCount == -1)
mCount = nativeGetCount(mNativeSQLiteCursor);
}
return mCount;
}
@Override
public String[] getColumnNames() {
return nativeGetColumnNames(mNativeSQLiteCursor);
}
@Override
public String getString(int column) {
return nativeGetString(mNativeSQLiteCursor, column);
}
@Override
public short getShort(int column) {
return (short) nativeGetInt(mNativeSQLiteCursor, column);
}
@Override
public int getInt(int column) {
return nativeGetInt(mNativeSQLiteCursor, column);
}
@Override
public long getLong(int column) {
return nativeGetLong(mNativeSQLiteCursor, column);
}
@Override
public float getFloat(int column) {
return (float)nativeGetDouble(mNativeSQLiteCursor, column);
}
@Override
public double getDouble(int column) {
return nativeGetDouble(mNativeSQLiteCursor, column);
}
@Override
public boolean isNull(int column) {
return nativeIsNull(mNativeSQLiteCursor, column);
}
@Override
public void close() {
super.close();
nativeDestroy(mNativeSQLiteCursor);
mNativeSQLiteCursor = 0;
}
@Override
public boolean onMove(int oldPosition, int newPosition) {
synchronized (mMoveLock) {
nativeMoveTo(mNativeSQLiteCursor, newPosition);
}
return super.onMove(oldPosition, newPosition);
}
@Override
public byte[] getBlob(int column) {
synchronized (mGetBlobLock) {
return nativeGetBlob(mNativeSQLiteCursor, column);
}
}
@Deprecated
public boolean supportsUpdates() {
return false;
}
@Override
protected void finalize() {
super.finalize();
if (!isClosed()) {
Log.w(TAG, "Cursor hasn't been closed");
close();
}
}
@Override
public void fillWindow(int position, CursorWindow window) {
if (position < 0 || position > getCount()) {
return;
}
window.acquireReference();
try {
int oldpos = mPos;
mPos = position - 1;
window.clear();
window.setStartPosition(position);
int columnNum = getColumnCount();
window.setNumColumns(columnNum);
while (moveToNext() && window.allocRow()) {
for (int i = 0; i < columnNum; i++) {
boolean hasRoom = true;
switch (getColumnType(i)) {
case Types.DOUBLE:
hasRoom = fillRow(window, Double.valueOf(getDouble(i)), mPos, i);
break;
case Types.NUMERIC:
hasRoom = fillRow(window, Long.valueOf(getLong(i)), mPos, i);
break;
case Types.BLOB:
hasRoom = fillRow(window, getBlob(i), mPos, i);
break;
case Types.LONGVARCHAR:
hasRoom = fillRow(window, getString(i), mPos, i);
break;
case Types.NULL:
hasRoom = fillRow(window, null, mPos, i);
break;
}
if (!hasRoom) {
break;
}
}
}
mPos = oldpos;
} catch (IllegalStateException e) {
// simply ignore it
} finally {
window.releaseReference();
}
}
/**
* Fill row with the given value. If the value type is other than Long,
* String, byte[] or Double, the NULL will be filled.
*
* @return true if succeeded, false if window is full.
*/
private boolean fillRow(CursorWindow window, Object value, int pos, int column) {
if (putValue(window, value, pos, column)) {
return true;
} else {
window.freeLastRow();
return false;
}
}
/**
* Put the value in given window. If the value type is other than Long,
* String, byte[] or Double, the NULL will be filled.
*
* @return true if succeeded.
*/
private boolean putValue(CursorWindow window, Object value, int pos, int column) {
if (value == null) {
return window.putNull(pos, column);
} else if (value instanceof Long) {
return window.putLong((Long) value, pos, column);
} else if (value instanceof String) {
return window.putString((String) value, pos, column);
} else if (value instanceof byte[] && ((byte[]) value).length > 0) {
return window.putBlob((byte[]) value, pos, column);
} else if (value instanceof Double) {
return window.putDouble((Double) value, pos, column);
} else {
return window.putNull(pos, column);
}
}
/**
* @param index the column index.
* @return the column type from cache or native side.
*/
private int getColumnType(int index) {
synchronized (mColumnTypeLock) {
if (mColumnTypes == null) {
int columnCount = getColumnCount();
mColumnTypes = new int[columnCount];
for (int i = 0; i < columnCount; i++) {
mColumnTypes[i] = nativeGetColumnType(mNativeSQLiteCursor, i);
}
}
}
return mColumnTypes[index];
}
private native void nativeDestroy(int nativeSQLiteCursor);
private native int nativeGetCount(int nativeSQLiteCursor);
private native String[] nativeGetColumnNames(int nativeSQLiteCursor);
private native int nativeGetColumnType(int nativeSQLiteCursor, int column);
private native String nativeGetString(int nativeSQLiteCursor, int column);
private native byte[] nativeGetBlob(int nativeSQLiteCursor, int column);
private native boolean nativeIsNull(int nativeSQLiteCursor, int column);
private native long nativeGetLong(int nativeSQLiteCursor, int column);
private native int nativeGetInt(int nativeSQLiteCursor, int column);
private native double nativeGetDouble(int nativeSQLiteCursor, int column);
private native int nativeMoveTo(int nativeSQLiteCursor, int newPosition);
}