net.sourceforge.jtds.jdbc.RequestStream Maven / Gradle / Ivy
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// jTDS JDBC Driver for Microsoft SQL Server and Sybase
// Copyright (C) 2004 The jTDS Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
package net.sourceforge.jtds.jdbc;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.io.InputStream;
import java.io.Reader;
import java.math.BigDecimal;
import java.math.BigInteger;
import net.sourceforge.jtds.util.*;
/**
* Class to implement an output stream for the server request.
*
* Implementation note:
*
* - This class contains methods to write different types of data to the
* server request stream in TDS format.
*
- Character translation of String items is carried out.
*
*
* @author Mike Hutchinson.
* @version $Id: RequestStream.java,v 1.18 2005-09-21 21:50:34 ddkilzer Exp $
*/
public class RequestStream {
/** The shared network socket. */
private final SharedSocket socket;
/** The output packet buffer. */
private byte[] buffer;
/** The offset of the next byte to write. */
private int bufferPtr;
/** The request packet type. */
private byte pktType;
/** The unique stream id. */
private final int streamId;
/** True if stream is closed. */
private boolean isClosed;
/** The current output buffer size*/
private int bufferSize;
/** The maximum decimal precision. */
private int maxPrecision;
/**
* Construct a RequestStream object.
*
* @param socket the shared socket object to write to
* @param streamId the unique id for this stream
* @param bufferSize the initial buffer size to use (the current network
* packet size)
* @param maxPrecision the maximum precision for numeric/decimal types
*/
RequestStream(SharedSocket socket, int streamId, int bufferSize, int maxPrecision) {
this.streamId = streamId;
this.socket = socket;
this.bufferSize = bufferSize;
this.buffer = new byte[bufferSize];
this.bufferPtr = TdsCore.PKT_HDR_LEN;
this.maxPrecision = maxPrecision;
}
/**
* Set the output buffer size
*
* @param size The new buffer size (>= {@link TdsCore#MIN_PKT_SIZE} <= {@link TdsCore#MAX_PKT_SIZE}).
*/
void setBufferSize(int size) {
if (size < bufferPtr || size == bufferSize) {
return; // Can't shrink buffer size;
}
if (size < TdsCore.MIN_PKT_SIZE || size > TdsCore.MAX_PKT_SIZE) {
throw new IllegalArgumentException("Invalid buffer size parameter " + size);
}
byte[] tmp = new byte[size];
System.arraycopy(buffer, 0, tmp, 0, bufferPtr);
buffer = tmp;
}
/**
* Retrieve the current output packet size.
*
* @return the packet size as an int.
*/
int getBufferSize() {
return bufferSize;
}
/**
* Retrive the maximum decimal precision.
*
* @return The precision as an int.
*/
int getMaxPrecision() {
return this.maxPrecision;
}
/**
* Returns the maximum number of bytes required to output a decimal
* given the current {@link #maxPrecision}.
*
* @return the maximum number of bytes required to output a decimal.
*/
byte getMaxDecimalBytes() {
return (byte) ((maxPrecision <= TdsData.DEFAULT_PRECISION_28) ? 13 : 17);
}
/**
* Retrieve the unique stream id.
*
* @return the unique stream id as an int.
*/
int getStreamId() {
return this.streamId;
}
/**
* Set the current output packet type.
*
* @param pktType The packet type eg TdsCore.QUERY_PKT.
*/
void setPacketType(byte pktType) {
this.pktType = pktType;
}
/**
* Write a byte to the output stream.
*
* @param b The byte value to write.
* @throws IOException
*/
void write(byte b) throws IOException {
if (bufferPtr == buffer.length) {
putPacket(0);
}
buffer[bufferPtr++] = b;
}
/**
* Write an array of bytes to the output stream.
*
* @param b The byte array to write.
* @throws IOException
*/
void write(byte[] b) throws IOException {
int bytesToWrite = b.length;
int off = 0;
while (bytesToWrite > 0) {
int available = buffer.length - bufferPtr;
if (available == 0) {
putPacket(0);
continue;
}
int bc = (available > bytesToWrite) ? bytesToWrite : available;
System.arraycopy(b, off, buffer, bufferPtr, bc);
off += bc;
bufferPtr += bc;
bytesToWrite -= bc;
}
}
/**
* Write a partial byte buffer to the output stream.
*
* @param b The byte array buffer.
* @param off The offset into the byte array.
* @param len The number of bytes to write.
* @throws IOException
*/
void write(byte[] b, int off, int len) throws IOException {
int limit = (off + len) > b.length? b.length: off + len;
int bytesToWrite = limit - off;
int i = len - bytesToWrite;
while (bytesToWrite > 0) {
int available = buffer.length - bufferPtr;
if (available == 0) {
putPacket(0);
continue;
}
int bc = (available > bytesToWrite)? bytesToWrite: available;
System.arraycopy(b, off, buffer, bufferPtr, bc);
off += bc;
bufferPtr += bc;
bytesToWrite -= bc;
}
for (; i > 0; i--) {
write((byte) 0);
}
}
/**
* Write an int value to the output stream.
*
* @param i The int value to write.
* @throws IOException
*/
void write(int i) throws IOException {
write((byte) i);
write((byte) (i >> 8));
write((byte) (i >> 16));
write((byte) (i >> 24));
}
/**
* Write a short value to the output stream.
*
* @param s The short value to write.
* @throws IOException
*/
void write(short s) throws IOException {
write((byte) s);
write((byte) (s >> 8));
}
/**
* Write a long value to the output stream.
*
* @param l The long value to write.
* @throws IOException
*/
void write(long l) throws IOException {
write((byte) l);
write((byte) (l >> 8));
write((byte) (l >> 16));
write((byte) (l >> 24));
write((byte) (l >> 32));
write((byte) (l >> 40));
write((byte) (l >> 48));
write((byte) (l >> 56));
}
/**
* Write a double value to the output stream.
*
* @param f The double value to write.
* @throws IOException
*/
void write(double f) throws IOException {
long l = Double.doubleToLongBits(f);
write((byte) l);
write((byte) (l >> 8));
write((byte) (l >> 16));
write((byte) (l >> 24));
write((byte) (l >> 32));
write((byte) (l >> 40));
write((byte) (l >> 48));
write((byte) (l >> 56));
}
/**
* Write a float value to the output stream.
*
* @param f The float value to write.
* @throws IOException
*/
void write(float f) throws IOException {
int l = Float.floatToIntBits(f);
write((byte) l);
write((byte) (l >> 8));
write((byte) (l >> 16));
write((byte) (l >> 24));
}
/**
* Write a String object to the output stream.
* If the TDS version is >= 7.0 write a UNICODE string otherwise
* wrote a translated byte stream.
*
* @param s The String to write.
* @throws IOException
*/
void write(String s) throws IOException {
if (socket.getTdsVersion() >= Driver.TDS70) {
int len = s.length();
for (int i = 0; i < len; ++i) {
int c = s.charAt(i);
if (bufferPtr == buffer.length) {
putPacket(0);
}
buffer[bufferPtr++] = (byte) c;
if (bufferPtr == buffer.length) {
putPacket(0);
}
buffer[bufferPtr++] = (byte) (c >> 8);
}
} else {
writeAscii(s);
}
}
/**
* Write a char array object to the output stream.
*
* @param s The char[] to write.
* @throws IOException
*/
void write(char s[], int off, int len) throws IOException {
int i = off;
int limit = (off + len) > s.length ? s.length : off + len;
for ( ; i < limit; i++) {
char c = s[i];
if (bufferPtr == buffer.length) {
putPacket(0);
}
buffer[bufferPtr++] = (byte) c;
if (bufferPtr == buffer.length) {
putPacket(0);
}
buffer[bufferPtr++] = (byte) (c >> 8);
}
}
/**
* Write a String to the output stream as translated bytes.
*
* @param s The String to write.
* @throws IOException
*/
void writeAscii(String s) throws IOException {
String charsetName = socket.getCharset();
if (charsetName != null) {
try {
write(s.getBytes(charsetName));
} catch (UnsupportedEncodingException e) {
write(s.getBytes());
}
} else {
write(s.getBytes());
}
}
/**
* Copy the contents of an InputStream to the server.
*
* @param in The InputStream to read.
* @param length The length of the stream.
* @throws IOException
*/
void writeStreamBytes(InputStream in, int length) throws IOException {
byte buffer[] = new byte[1024];
while (length > 0) {
int res = in.read(buffer);
if (res < 0) {
throw new java.io.IOException(
"Data in stream less than specified by length");
}
write(buffer, 0, res);
length -= res;
}
// XXX Not sure that this is actually an error
if (length < 0 || in.read() >= 0) {
throw new java.io.IOException(
"More data in stream than specified by length");
}
}
/**
* Copy the contents of a Reader stream to the server.
*
* @param in The Reader object with the data.
* @param length The length of the data in characters.
* @throws IOException
*/
void writeReaderChars(Reader in, int length) throws IOException {
char cbuffer[] = new char[512];
byte bbuffer[] = new byte[1024];
while (length > 0) {
int res = in.read(cbuffer);
if (res < 0) {
throw new java.io.IOException(
"Data in stream less than specified by length");
}
for (int i = 0, j = -1; i < res; i++) {
bbuffer[++j] = (byte) cbuffer[i];
bbuffer[++j] = (byte) (cbuffer[i] >> 8);
}
write(bbuffer, 0, res * 2);
length -= res;
}
// XXX Not sure that this is actually an error
if (length < 0 || in.read() >= 0) {
throw new java.io.IOException(
"More data in stream than specified by length");
}
}
/**
* Copy the contents of a Reader stream to the server as bytes.
*
* NB. Only reliable where the charset is single byte.
*
* @param in The Reader object with the data.
* @param length The length of the data in bytes.
* @throws IOException
*/
void writeReaderBytes(Reader in, int length) throws IOException {
char buffer[] = new char[1024];
for (int i = 0; i < length;) {
int result = in.read(buffer);
if (result == -1) {
throw new java.io.IOException(
"Data in stream less than specified by length");
} else if (i + result > length) {
throw new java.io.IOException(
"More data in stream than specified by length");
}
write(Support.encodeString(socket.getCharset(), new String(buffer, 0, result)));
i += result;
}
}
/**
* Write a BigDecimal value to the output stream.
*
* @param value The BigDecimal value to write.
* @throws IOException
*/
void write(BigDecimal value) throws IOException {
if (value == null) {
write((byte) 0);
} else {
byte signum = (byte) (value.signum() < 0 ? 0 : 1);
BigInteger bi = value.unscaledValue();
byte mantisse[] = bi.abs().toByteArray();
byte len = (byte) (mantisse.length + 1);
if (len > getMaxDecimalBytes()) {
// Should never happen now as value is normalized elsewhere
throw new IOException("BigDecimal to big to send");
}
if (socket.serverType == Driver.SYBASE) {
write((byte) len);
// Sybase TDS5 stores MSB first opposite sign!
// length, prec, scale already sent in parameter descriptor.
write((byte) ((signum == 0) ? 1 : 0));
for (int i = 0; i < mantisse.length; i++) {
write((byte) mantisse[i]);
}
} else {
write((byte) len);
write((byte) signum);
for (int i = mantisse.length - 1; i >= 0; i--) {
write((byte) mantisse[i]);
}
}
}
}
/**
* Flush the packet to the output stream setting the last packet flag.
*
* @throws IOException
*/
void flush() throws IOException {
putPacket(1);
}
/**
* Close the output stream.
*/
void close() {
isClosed = true;
}
/**
* Retrieve the TDS version number.
*
* @return The TDS version as an int.
*/
int getTdsVersion() {
return socket.getTdsVersion();
}
/**
* Retrieve the Server type.
*
* @return The Server type as an int.
*/
int getServerType() {
return socket.serverType;
}
/**
* Write the TDS packet to the network.
*
* @param last Set to 1 if this is the last packet else 0.
* @throws IOException
*/
private void putPacket(int last) throws IOException {
if (isClosed) {
throw new IOException("RequestStream is closed");
}
buffer[0] = pktType;
buffer[1] = (byte) last; // last segment indicator
buffer[2] = (byte) (bufferPtr >> 8);
buffer[3] = (byte) bufferPtr;
buffer[4] = 0;
buffer[5] = 0;
buffer[6] = (byte) ((socket.getTdsVersion() >= Driver.TDS70) ? 1 : 0);
buffer[7] = 0;
if (Logger.isActive()) {
Logger.logPacket(streamId, false, buffer);
}
buffer = socket.sendNetPacket(streamId, buffer);
bufferPtr = TdsCore.PKT_HDR_LEN;
}
}