com.mysql.cj.protocol.a.result.AbstractBufferRow Maven / Gradle / Ivy
/*
* Copyright (c) 2016, 2020, Oracle and/or its affiliates.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 2.0, as published by the
* Free Software Foundation.
*
* This program is also distributed with certain software (including but not
* limited to OpenSSL) that is licensed under separate terms, as designated in a
* particular file or component or in included license documentation. The
* authors of MySQL hereby grant you an additional permission to link the
* program and your derivative works with the separately licensed software that
* they have included with MySQL.
*
* Without limiting anything contained in the foregoing, this file, which is
* part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
* version 1.0, a copy of which can be found at
* http://oss.oracle.com/licenses/universal-foss-exception.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
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*/
package com.mysql.cj.protocol.a.result;
import com.mysql.cj.exceptions.ExceptionInterceptor;
import com.mysql.cj.protocol.a.NativePacketPayload;
import com.mysql.cj.protocol.result.AbstractResultsetRow;
/**
* A ResultSetRow implementation that holds one row packet (which is re-used by the driver, and thus saves memory allocations), and tries when possible to avoid
* allocations to break out the results as individual byte[]s.
*
* (this isn't possible when doing things like reading floating point values).
*/
public abstract class AbstractBufferRow extends AbstractResultsetRow {
protected NativePacketPayload rowFromServer;
/**
* The beginning of the row packet
*/
protected int homePosition = 0;
/**
* The last-requested index, used as an optimization, if you ask for the same index, we won't seek to find it. If you ask for an index that is greater
* than the last one requested, we start seeking from the last requested index.
*/
protected int lastRequestedIndex = -1;
/**
* The position of the last-requested index, optimization in concert with lastRequestedIndex.
*/
protected int lastRequestedPos;
protected AbstractBufferRow(ExceptionInterceptor exceptionInterceptor) {
super(exceptionInterceptor);
}
abstract int findAndSeekToOffset(int index);
}