com.mysql.cj.protocol.a.PacketSplitter Maven / Gradle / Ivy
/*
* Copyright (c) 2015, 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.,
* 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;
}
}