| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.database.sqlite; |
| |
| import android.database.AbstractWindowedCursor; |
| import android.database.CursorWindow; |
| import android.database.DatabaseUtils; |
| import android.os.StrictMode; |
| import android.util.Log; |
| |
| import com.android.internal.util.Preconditions; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * A Cursor implementation that exposes results from a query on a |
| * {@link SQLiteDatabase}. |
| * |
| * SQLiteCursor is not internally synchronized so code using a SQLiteCursor from multiple |
| * threads should perform its own synchronization when using the SQLiteCursor. |
| */ |
| public class SQLiteCursor extends AbstractWindowedCursor { |
| static final String TAG = "SQLiteCursor"; |
| static final int NO_COUNT = -1; |
| |
| /** The name of the table to edit */ |
| private final String mEditTable; |
| |
| /** The names of the columns in the rows */ |
| private final String[] mColumns; |
| |
| /** The query object for the cursor */ |
| private final SQLiteQuery mQuery; |
| |
| /** The compiled query this cursor came from */ |
| private final SQLiteCursorDriver mDriver; |
| |
| /** The number of rows in the cursor */ |
| private int mCount = NO_COUNT; |
| |
| /** The number of rows that can fit in the cursor window, 0 if unknown */ |
| private int mCursorWindowCapacity; |
| |
| /** A mapping of column names to column indices, to speed up lookups */ |
| private Map<String, Integer> mColumnNameMap; |
| |
| /** Used to find out where a cursor was allocated in case it never got released. */ |
| private final Throwable mStackTrace; |
| |
| /** Controls fetching of rows relative to requested position **/ |
| private boolean mFillWindowForwardOnly; |
| |
| /** |
| * Execute a query and provide access to its result set through a Cursor |
| * interface. For a query such as: {@code SELECT name, birth, phone FROM |
| * myTable WHERE ... LIMIT 1,20 ORDER BY...} the column names (name, birth, |
| * phone) would be in the projection argument and everything from |
| * {@code FROM} onward would be in the params argument. |
| * |
| * @param db a reference to a Database object that is already constructed |
| * and opened. This param is not used any longer |
| * @param editTable the name of the table used for this query |
| * @param query the rest of the query terms |
| * cursor is finalized |
| * @deprecated use {@link #SQLiteCursor(SQLiteCursorDriver, String, SQLiteQuery)} instead |
| */ |
| @Deprecated |
| public SQLiteCursor(SQLiteDatabase db, SQLiteCursorDriver driver, |
| String editTable, SQLiteQuery query) { |
| this(driver, editTable, query); |
| } |
| |
| /** |
| * Execute a query and provide access to its result set through a Cursor |
| * interface. For a query such as: {@code SELECT name, birth, phone FROM |
| * myTable WHERE ... LIMIT 1,20 ORDER BY...} the column names (name, birth, |
| * phone) would be in the projection argument and everything from |
| * {@code FROM} onward would be in the params argument. |
| * |
| * @param editTable the name of the table used for this query |
| * @param query the {@link SQLiteQuery} object associated with this cursor object. |
| */ |
| public SQLiteCursor(SQLiteCursorDriver driver, String editTable, SQLiteQuery query) { |
| if (query == null) { |
| throw new IllegalArgumentException("query object cannot be null"); |
| } |
| if (StrictMode.vmSqliteObjectLeaksEnabled()) { |
| mStackTrace = new DatabaseObjectNotClosedException().fillInStackTrace(); |
| } else { |
| mStackTrace = null; |
| } |
| mDriver = driver; |
| mEditTable = editTable; |
| mColumnNameMap = null; |
| mQuery = query; |
| |
| mColumns = query.getColumnNames(); |
| } |
| |
| /** |
| * Get the database that this cursor is associated with. |
| * @return the SQLiteDatabase that this cursor is associated with. |
| */ |
| public SQLiteDatabase getDatabase() { |
| return mQuery.getDatabase(); |
| } |
| |
| @Override |
| public boolean onMove(int oldPosition, int newPosition) { |
| // Make sure the row at newPosition is present in the window |
| if (mWindow == null || newPosition < mWindow.getStartPosition() || |
| newPosition >= (mWindow.getStartPosition() + mWindow.getNumRows())) { |
| fillWindow(newPosition); |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int getCount() { |
| if (mCount == NO_COUNT) { |
| fillWindow(0); |
| } |
| return mCount; |
| } |
| |
| private void fillWindow(int requiredPos) { |
| clearOrCreateWindow(getDatabase().getPath()); |
| try { |
| Preconditions.checkArgumentNonnegative(requiredPos, |
| "requiredPos cannot be negative, but was " + requiredPos); |
| |
| if (mCount == NO_COUNT) { |
| mCount = mQuery.fillWindow(mWindow, requiredPos, requiredPos, true); |
| mCursorWindowCapacity = mWindow.getNumRows(); |
| if (Log.isLoggable(TAG, Log.DEBUG)) { |
| Log.d(TAG, "received count(*) from native_fill_window: " + mCount); |
| } |
| } else { |
| int startPos = mFillWindowForwardOnly ? requiredPos : DatabaseUtils |
| .cursorPickFillWindowStartPosition(requiredPos, mCursorWindowCapacity); |
| mQuery.fillWindow(mWindow, startPos, requiredPos, false); |
| } |
| } catch (RuntimeException ex) { |
| // Close the cursor window if the query failed and therefore will |
| // not produce any results. This helps to avoid accidentally leaking |
| // the cursor window if the client does not correctly handle exceptions |
| // and fails to close the cursor. |
| closeWindow(); |
| throw ex; |
| } |
| } |
| |
| @Override |
| public int getColumnIndex(String columnName) { |
| // Create mColumnNameMap on demand |
| if (mColumnNameMap == null) { |
| String[] columns = mColumns; |
| int columnCount = columns.length; |
| HashMap<String, Integer> map = new HashMap<String, Integer>(columnCount, 1); |
| for (int i = 0; i < columnCount; i++) { |
| map.put(columns[i], i); |
| } |
| mColumnNameMap = map; |
| } |
| |
| // Hack according to bug 903852 |
| final int periodIndex = columnName.lastIndexOf('.'); |
| if (periodIndex != -1) { |
| Exception e = new Exception(); |
| Log.e(TAG, "requesting column name with table name -- " + columnName, e); |
| columnName = columnName.substring(periodIndex + 1); |
| } |
| |
| Integer i = mColumnNameMap.get(columnName); |
| if (i != null) { |
| return i.intValue(); |
| } else { |
| return -1; |
| } |
| } |
| |
| @Override |
| public String[] getColumnNames() { |
| return mColumns; |
| } |
| |
| @Override |
| public void deactivate() { |
| super.deactivate(); |
| mDriver.cursorDeactivated(); |
| } |
| |
| @Override |
| public void close() { |
| super.close(); |
| synchronized (this) { |
| mQuery.close(); |
| mDriver.cursorClosed(); |
| } |
| } |
| |
| @Override |
| public boolean requery() { |
| if (isClosed()) { |
| return false; |
| } |
| |
| synchronized (this) { |
| if (!mQuery.getDatabase().isOpen()) { |
| return false; |
| } |
| |
| if (mWindow != null) { |
| mWindow.clear(); |
| } |
| mPos = -1; |
| mCount = NO_COUNT; |
| |
| mDriver.cursorRequeried(this); |
| } |
| |
| try { |
| return super.requery(); |
| } catch (IllegalStateException e) { |
| // for backwards compatibility, just return false |
| Log.w(TAG, "requery() failed " + e.getMessage(), e); |
| return false; |
| } |
| } |
| |
| @Override |
| public void setWindow(CursorWindow window) { |
| super.setWindow(window); |
| mCount = NO_COUNT; |
| } |
| |
| /** |
| * Changes the selection arguments. The new values take effect after a call to requery(). |
| */ |
| public void setSelectionArguments(String[] selectionArgs) { |
| mDriver.setBindArguments(selectionArgs); |
| } |
| |
| /** |
| * Controls fetching of rows relative to requested position. |
| * |
| * <p>Calling this method defines how rows will be loaded, but it doesn't affect rows that |
| * are already in the window. This setting is preserved if a new window is |
| * {@link #setWindow(CursorWindow) set} |
| * |
| * @param fillWindowForwardOnly if true, rows will be fetched starting from requested position |
| * up to the window's capacity. Default value is false. |
| */ |
| public void setFillWindowForwardOnly(boolean fillWindowForwardOnly) { |
| mFillWindowForwardOnly = fillWindowForwardOnly; |
| } |
| |
| /** |
| * Release the native resources, if they haven't been released yet. |
| */ |
| @Override |
| protected void finalize() { |
| try { |
| // if the cursor hasn't been closed yet, close it first |
| if (mWindow != null) { |
| if (mStackTrace != null) { |
| String sql = mQuery.getSql(); |
| int len = sql.length(); |
| StrictMode.onSqliteObjectLeaked( |
| "Finalizing a Cursor that has not been deactivated or closed. " + |
| "database = " + mQuery.getDatabase().getLabel() + |
| ", table = " + mEditTable + |
| ", query = " + sql.substring(0, (len > 1000) ? 1000 : len), |
| mStackTrace); |
| } |
| close(); |
| } |
| } finally { |
| super.finalize(); |
| } |
| } |
| } |