/*
Copyright (C) 2002 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.mysql.jdbc;
import java.io.UnsupportedEncodingException;
import java.sql.SQLException;
/**
* Buffer contains code to read and write packets from/to the MySQL server.
*
* @version $Id: Buffer.java,v 1.15.2.12 2004/01/07 01:36:34 mmatthew Exp $
* @author Mark Matthews
*/
class Buffer {
static final int NO_LENGTH_LIMIT = -1;
static final long NULL_LENGTH = -1;
private byte[] byteBuffer;
private boolean wasMultiPacket = false;
private int bufLength = 0;
private int position = 0;
private int sendLength = 0;
Buffer(byte[] buf) {
this.byteBuffer = buf;
setBufLength(buf.length);
}
Buffer(int size) {
this.byteBuffer = new byte[size];
setBufLength(this.byteBuffer.length);
this.position = MysqlIO.HEADER_LENGTH;
}
/**
* Sets the array of bytes to use as a buffer to read from.
*
* @param byteBuffer the array of bytes to use as a buffer
*/
public void setByteBuffer(byte[] byteBuffer) {
this.byteBuffer = byteBuffer;
}
/**
* Returns the array of bytes this Buffer is using to read from.
*
* @return byte array being read from
*/
public byte[] getByteBuffer() {
return this.byteBuffer;
}
/**
* Set the current position to write to/ read from
*
* @param position the position (0-based index)
*/
public void setPosition(int position) {
this.position = position;
}
/**
* Returns the current position to write to/ read from
*
* @return the current position to write to/ read from
*/
public int getPosition() {
return this.position;
}
/**
* Sets whether this packet was part of a multipacket
*
* @param flag was this packet part of a multipacket?
*/
public void setWasMultiPacket(boolean flag) {
wasMultiPacket = flag;
}
/**
* Skip over a length-encoded string
*
* @return The position past the end of the string
*/
public int fastSkipLenString() {
long len = this.readFieldLength();
position += len;
return (int) len; // this is safe, as this is only
}
/**
* Was this packet part of a multipacket?
*
* @return was this packet part of a multipacket?
*/
public boolean wasMultiPacket() {
return wasMultiPacket;
}
protected final byte[] getBufferSource() {
return byteBuffer;
}
final byte[] getBytes(int len) {
byte[] b = new byte[len];
System.arraycopy(this.byteBuffer, this.position, b, 0, len);
this.position += len; // update cursor
return b;
}
// 2000-06-05 Changed
final boolean isLastDataPacket() {
return ((getBufLength() < 9) && ((this.byteBuffer[0] & 0xff) == 254));
}
final void clear() {
this.position = MysqlIO.HEADER_LENGTH;
}
final void dump() {
StringUtils.dumpAsHex(this.byteBuffer, getBufLength());
}
final void dumpHeader() {
for (int i = 0; i < MysqlIO.HEADER_LENGTH; i++) {
String hexVal = Integer.toHexString((int) this.byteBuffer[i] & 0xff);
if (hexVal.length() == 1) {
hexVal = "0" + hexVal;
}
System.out.print(hexVal + " ");
}
}
final void dumpNBytes(int start, int nBytes) {
StringBuffer asciiBuf = new StringBuffer();
for (int i = start;
(i < (start + nBytes)) && (i < this.byteBuffer.length); i++) {
String hexVal = Integer.toHexString((int) this.byteBuffer[i] & 0xff);
if (hexVal.length() == 1) {
hexVal = "0" + hexVal;
}
System.out.print(hexVal + " ");
if ((this.byteBuffer[i] > 32) && (this.byteBuffer[i] < 127)) {
asciiBuf.append((char) this.byteBuffer[i]);
} else {
asciiBuf.append(".");
}
asciiBuf.append(" ");
}
System.out.println(" " + asciiBuf.toString());
}
final void ensureCapacity(int additionalData) throws SQLException {
if ((this.position + additionalData) > getBufLength()) {
if ((this.position + additionalData) < this.byteBuffer.length) {
// byteBuffer.length is != getBufLength() all of the time
// due to re-using of packets (we don't shrink them)
//
// If we can, don't re-alloc, just set buffer length
// to size of current buffer
setBufLength(this.byteBuffer.length);
} else {
//
// Otherwise, re-size, and pad so we can avoid
// allocing again in the near future
//
int newLength = (int) (this.byteBuffer.length * 1.25);
if (newLength < (this.byteBuffer.length + additionalData)) {
newLength = this.byteBuffer.length
+ (int) (additionalData * 1.25);
}
if (newLength < this.byteBuffer.length) {
newLength = this.byteBuffer.length + additionalData;
}
byte[] newBytes = new byte[newLength];
System.arraycopy(this.byteBuffer, 0, newBytes, 0,
this.byteBuffer.length);
this.byteBuffer = newBytes;
setBufLength(this.byteBuffer.length);
}
}
}
final long newReadLength() {
int sw = this.byteBuffer[this.position++] & 0xff;
switch (sw) {
case 251:
return (long) 0;
case 252:
return (long) readInt();
case 253:
return (long) readLongInt();
case 254: // changed for 64 bit lengths
return (long) readLongLong();
default:
return (long) sw;
}
}
final byte readByte() {
return this.byteBuffer[this.position++];
}
final long readFieldLength() {
int sw = this.byteBuffer[this.position++] & 0xff;
switch (sw) {
case 251:
return NULL_LENGTH;
case 252:
return (long) readInt();
case 253:
return (long) readLongInt();
case 254:
return readLongLong();
default:
return (long) sw;
}
}
// 2000-06-05 Changed
final int readInt() {
byte[] b = this.byteBuffer; // a little bit optimization
return (b[this.position++] & 0xff) | ((b[this.position++] & 0xff) << 8);
}
final byte[] readLenByteArray(int offset) {
long len = this.readFieldLength();
if (len == NULL_LENGTH) {
return null;
}
if (len == 0) {
return new byte[0];
}
this.position += offset;
return getBytes((int) len);
}
final long readLength() {
int sw = this.byteBuffer[this.position++] & 0xff;
switch (sw) {
case 251:
return (long) 0;
case 252:
return (long) readInt();
case 253:
return (long) readLongInt();
case 254:
return (long) readLong();
default:
return (long) sw;
}
}
// 2000-06-05 Fixed
final long readLong() {
byte[] b = this.byteBuffer;
return (b[this.position++] & 0xff) | ((b[this.position++] & 0xff) << 8)
| ((b[this.position++] & 0xff) << 16)
| ((b[this.position++] & 0xff) << 24);
}
// 2000-06-05 Changed
final int readLongInt() {
byte[] b = this.byteBuffer;
return (b[this.position++] & 0xff) | ((b[this.position++] & 0xff) << 8)
| ((b[this.position++] & 0xff) << 16);
}
// 2000-06-05 Fixed
final long readLongLong() {
byte[] b = this.byteBuffer;
return (long) (b[this.position++] & 0xff)
| ((long) (b[this.position++] & 0xff) << 8)
| ((long) (b[this.position++] & 0xff) << 16)
| ((long) (b[this.position++] & 0xff) << 24)
| ((long) (b[this.position++] & 0xff) << 32)
| ((long) (b[this.position++] & 0xff) << 40)
| ((long) (b[this.position++] & 0xff) << 48)
| ((long) (b[this.position++] & 0xff) << 56);
}
//
// Read a null-terminated string
//
// To avoid alloc'ing a new byte array, we
// do this by hand, rather than calling getNullTerminatedBytes()
//
final String readString() {
int i = this.position;
int len = 0;
int maxLen = getBufLength();
while ((i < maxLen) && (this.byteBuffer[i] != 0)) {
len++;
i++;
}
String s = new String(this.byteBuffer, this.position, len);
this.position += (len + 1); // update cursor
return s;
}
final String readString(String encoding) throws SQLException {
int i = this.position;
int len = 0;
int maxLen = getBufLength();
while ((i < maxLen) && (this.byteBuffer[i] != 0)) {
len++;
i++;
}
this.position += (len + 1); // update cursor
try {
return new String(this.byteBuffer, this.position, len, encoding);
} catch (UnsupportedEncodingException uEE) {
throw new SQLException("Unsupported character encoding '" + encoding + "'", SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
}
}
final int readnBytes() {
int sw = this.byteBuffer[this.position++] & 0xff;
switch (sw) {
case 1:
return this.byteBuffer[this.position++] & 0xff;
case 2:
return this.readInt();
case 3:
return this.readLongInt();
case 4:
return (int) this.readLong();
default:
return 255;
}
}
final void writeByte(byte b) throws SQLException {
ensureCapacity(1);
this.byteBuffer[this.position++] = b;
}
// Write a byte array
final void writeBytesNoNull(byte[] bytes) throws SQLException {
int len = bytes.length;
ensureCapacity(len);
System.arraycopy(bytes, 0, this.byteBuffer, this.position, len);
this.position += len;
}
// Write a byte array with the given offset and length
final void writeBytesNoNull(byte[] bytes, int offset, int length)
throws SQLException {
ensureCapacity(length);
System.arraycopy(bytes, offset, this.byteBuffer, this.position, length);
this.position += length;
}
final void writeDouble(double d) {
long l = Double.doubleToLongBits(d);
writeLongLong(l);
}
final void writeFloat(float f) {
int i = Float.floatToIntBits(f);
byte[] b = this.byteBuffer;
b[this.position++] = (byte) (i & 0xff);
b[this.position++] = (byte) (i >>> 8);
b[this.position++] = (byte) (i >>> 16);
b[this.position++] = (byte) (i >>> 24);
}
// 2000-06-05 Changed
final void writeInt(int i) {
byte[] b = this.byteBuffer;
b[this.position++] = (byte) (i & 0xff);
b[this.position++] = (byte) (i >>> 8);
}
// 2000-06-05 Changed
final void writeLong(long i) {
byte[] b = this.byteBuffer;
b[this.position++] = (byte) (i & 0xff);
b[this.position++] = (byte) (i >>> 8);
b[this.position++] = (byte) (i >>> 16);
b[this.position++] = (byte) (i >>> 24);
}
// 2000-06-05 Changed
final void writeLongInt(int i) {
byte[] b = this.byteBuffer;
b[this.position++] = (byte) (i & 0xff);
b[this.position++] = (byte) (i >>> 8);
b[this.position++] = (byte) (i >>> 16);
}
final void writeLongLong(long i) {
byte[] b = this.byteBuffer;
b[this.position++] = (byte) (i & 0xff);
b[this.position++] = (byte) (i >>> 8);
b[this.position++] = (byte) (i >>> 16);
b[this.position++] = (byte) (i >>> 24);
b[this.position++] = (byte) (i >>> 32);
b[this.position++] = (byte) (i >>> 40);
b[this.position++] = (byte) (i >>> 48);
b[this.position++] = (byte) (i >>> 56);
}
// Write null-terminated string
final void writeString(String s) throws SQLException {
ensureCapacity(s.length() + 1);
writeStringNoNull(s);
this.byteBuffer[this.position++] = 0;
}
// Write string, with no termination
final void writeStringNoNull(String s) throws SQLException {
int len = s.length();
ensureCapacity(len);
System.arraycopy(s.getBytes(), 0, byteBuffer, position, len);
position += len;
// for (int i = 0; i < len; i++)
// {
// this.byteBuffer[this.position++] = (byte)s.charAt(i);
// }
}
// Write a String using the specified character
// encoding
final void writeStringNoNull(String s, String encoding, SingleByteCharsetConverter converter)
throws UnsupportedEncodingException, SQLException {
byte[] b = null;
if (converter != null) {
b = converter.toBytes(s);
} else {
b = StringUtils.getBytes(s, encoding);
}
int len = b.length;
ensureCapacity(len);
System.arraycopy(b, 0, this.byteBuffer, this.position, len);
this.position += len;
}
void setBufLength(int bufLength) {
this.bufLength = bufLength;
}
int getBufLength() {
return bufLength;
}
void setSendLength(int sendLength) {
this.sendLength = sendLength;
}
}