/*
* TeleStax, Open Source Cloud Communications Copyright 2012.
* and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This 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 software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.mobicents.protocols.ss7.map.datacoding;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.util.BitSet;
/**
*
* @author amit bhayani
* @author sergey vetyutnev
*
*/
public class GSMCharsetEncoder extends CharsetEncoder {
private int bitpos = 0;
private int carryOver;
private GSMCharset cs;
private GSMCharsetEncodingData encodingData;
// The mask to check if corresponding bit in read byte is 1 or 0 and hence
// store it i BitSet accordingly
byte[] mask = new byte[] { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40 };
// BitSet to hold the bits of passed char to be encoded
BitSet bitSet = new BitSet();
static final byte ESCAPE = 0x1B;
protected GSMCharsetEncoder(Charset cs, float averageBytesPerChar, float maxBytesPerChar) {
super(cs, averageBytesPerChar, maxBytesPerChar);
implReset();
this.cs = (GSMCharset) cs;
}
public void setGSMCharsetEncodingData(GSMCharsetEncodingData encodingData) {
this.encodingData = encodingData;
}
public GSMCharsetEncodingData getGSMCharsetEncodingData() {
return this.encodingData;
}
@Override
protected void implReset() {
bitpos = 0;
carryOver = 0;
bitSet.clear();
if (encodingData != null) {
encodingData.totalSeptetCount = 0;
encodingData.leadingBufferIsEncoded = false;
}
}
/**
* TODO :
*/
@Override
protected CoderResult implFlush(ByteBuffer out) {
if (!out.hasRemaining()) {
return CoderResult.OVERFLOW;
}
return CoderResult.UNDERFLOW;
}
byte rawData = 0;
@Override
protected CoderResult encodeLoop(CharBuffer in, ByteBuffer out) {
if (this.encodingData != null && this.encodingData.leadingBuffer != null && !this.encodingData.leadingBufferIsEncoded) {
if (out.limit() - out.position() >= this.encodingData.leadingBuffer.length) {
if (this.encodingData.encodingStyle != Gsm7EncodingStyle.bit8_smpp_style) {
int septetCount = (this.encodingData.leadingBuffer.length * 8 + 6) / 7;
bitpos = septetCount % 8;
this.encodingData.totalSeptetCount = septetCount;
}
for (int ind = 0; ind < this.encodingData.leadingBuffer.length; ind++) {
out.put(this.encodingData.leadingBuffer[ind]);
}
this.encodingData.leadingBufferIsEncoded = true;
} else {
// not enough size in the target buffer - return CoderResult.OVERFLOW for out buffer encreasing
return CoderResult.OVERFLOW;
}
}
char lastChar = ' ';
while (in.hasRemaining()) {
if (out.limit() - out.position() < 3) {
// not enough size in the target buffer - return CoderResult.OVERFLOW for out buffer encreasing
return CoderResult.OVERFLOW;
}
// Read the first char
char c = in.get();
lastChar = c;
boolean found = false;
// searching a char in the main character table
for (int i = 0; i < this.cs.mainTable.length; i++) {
if (this.cs.mainTable[i] == c) {
found = true;
this.putByte(i, out);
break;
}
}
// searching a char in the extension character table
if (!found && this.cs.extensionTable != null) {
for (int i = 0; i < this.cs.mainTable.length; i++) {
if (this.cs.extensionTable[i] == c) {
found = true;
this.putByte(GSMCharsetEncoder.ESCAPE, out);
this.putByte(i, out);
break;
}
}
}
if (!found) {
// found no suitable symbol - encode a space char
this.putByte(0x20, out);
}
}
if (out.limit() - out.position() < 1) {
// not enough size in the target buffer - return CoderResult.OVERFLOW for out buffer encreasing
return CoderResult.OVERFLOW;
}
if (this.encodingData == null || this.encodingData.encodingStyle != Gsm7EncodingStyle.bit8_smpp_style) {
if (bitpos != 0) {
// USSD: replace 7-bit pad with <CR>
if (this.encodingData != null && this.encodingData.encodingStyle == Gsm7EncodingStyle.bit7_ussd_style
&& bitpos == 7)
carryOver |= 0x1A;
// writing a carryOver data
out.put((byte) carryOver);
} else {
// USSD: adding extra <CR> if the last symbol is <CR> and no padding
if (this.encodingData != null && this.encodingData.encodingStyle == Gsm7EncodingStyle.bit7_ussd_style
&& lastChar == '\r')
out.put((byte) 0x0D);
}
}
return CoderResult.UNDERFLOW;
}
private void putByte(int data, ByteBuffer out) {
if (this.encodingData != null && this.encodingData.encodingStyle == Gsm7EncodingStyle.bit8_smpp_style) {
out.put((byte) data);
} else {
if (bitpos == 0) {
carryOver = data;
} else {
int i1 = data << (8 - bitpos);
out.put((byte) (i1 | carryOver));
carryOver = data >>> bitpos;
}
bitpos++;
if (bitpos == 8) {
bitpos = 0;
}
if (this.encodingData != null)
this.encodingData.totalSeptetCount++;
}
}
}