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JDBC Type 4 driver for MySQL.
There is a newer version: 9.1.0
/*
 * Copyright (c) 2015, 2024, 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 designed to work with certain software 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 either included with the program or referenced in the documentation.
 *
 * 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

package com.mysql.cj.protocol.a;

/**
 * Keep track of splitting a large packet into multi-packets segments.
 */
public class PacketSplitter {

    private int totalSize;
    private int currentPacketLen = 0;
    private int offset = 0;

    public PacketSplitter(int totalSize) {
        this.totalSize = totalSize;
    }

    public int getPacketLen() {
        return this.currentPacketLen;
    }

    public int getOffset() {
        return this.offset;
    }

    public boolean nextPacket() {
        this.offset += this.currentPacketLen;
        // need a zero-len packet if final packet len is MAX_PACKET_SIZE
        if (this.currentPacketLen == NativeConstants.MAX_PACKET_SIZE && this.offset == this.totalSize) {
            this.currentPacketLen = 0;
            return true;
        }

        // allow empty packets
        if (this.totalSize == 0) {
            this.totalSize = -1; // to return `false' next iteration
            return true;
        }

        this.currentPacketLen = this.totalSize - this.offset;
        if (this.currentPacketLen > NativeConstants.MAX_PACKET_SIZE) {
            this.currentPacketLen = NativeConstants.MAX_PACKET_SIZE;
        }
        return this.offset < this.totalSize;
    }

}