/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Ant" and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/*
 * This package is based on the work done by Keiron Liddle, Aftex Software
 * <keiron@aftexsw.com> to whom the Ant project is very grateful for his
 * great code.
 */

package org.apache.tools.bzip2;

import java.io.IOException;
import java.io.OutputStream;

/**
 * An output stream that compresses into the BZip2 format (without the file header chars) into another stream.
 *
 * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a>
 *
 * TODO: Update to BZip2 1.0.1
 */
public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
	protected static final int SETMASK = (1 << 21);
	protected static final int CLEARMASK = (~SETMASK);
	protected static final int GREATER_ICOST = 15;
	protected static final int LESSER_ICOST = 0;
	protected static final int SMALL_THRESH = 20;
	protected static final int DEPTH_THRESH = 10;

	/*
	 * If you are ever unlucky/improbable enough to get a stack overflow whilst sorting, increase the following constant and try
	 * again. In practice I have never seen the stack go above 27 elems, so the following limit seems very generous.
	 */
	protected static final int QSORT_STACK_SIZE = 1000;

	private static void panic() {
		System.out.println("panic");
		// throw new CError();
	}

	private void makeMaps() {
		int i;
		nInUse = 0;
		for (i = 0; i < 256; i++) {
			if (inUse[i]) {
				seqToUnseq[nInUse] = (char) i;
				unseqToSeq[i] = (char) nInUse;
				nInUse++;
			}
		}
	}

	protected static void hbMakeCodeLengths(char[] len, int[] freq, int alphaSize, int maxLen) {
		/*
		 * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel.
		 */
		int nNodes, nHeap, n1, n2, i, j, k;
		boolean tooLong;

		int[] heap = new int[MAX_ALPHA_SIZE + 2];
		int[] weight = new int[MAX_ALPHA_SIZE * 2];
		int[] parent = new int[MAX_ALPHA_SIZE * 2];

		for (i = 0; i < alphaSize; i++) {
			weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8;
		}

		while (true) {
			nNodes = alphaSize;
			nHeap = 0;

			heap[0] = 0;
			weight[0] = 0;
			parent[0] = -2;

			for (i = 1; i <= alphaSize; i++) {
				parent[i] = -1;
				nHeap++;
				heap[nHeap] = i;
				{
					int zz, tmp;
					zz = nHeap;
					tmp = heap[zz];
					while (weight[tmp] < weight[heap[zz >> 1]]) {
						heap[zz] = heap[zz >> 1];
						zz >>= 1;
					}
					heap[zz] = tmp;
				}
			}
			if (!(nHeap < (MAX_ALPHA_SIZE + 2))) {
				panic();
			}

			while (nHeap > 1) {
				n1 = heap[1];
				heap[1] = heap[nHeap];
				nHeap--;
				{
					int zz = 0, yy = 0, tmp = 0;
					zz = 1;
					tmp = heap[zz];
					while (true) {
						yy = zz << 1;
						if (yy > nHeap) {
							break;
						}
						if (yy < nHeap && weight[heap[yy + 1]] < weight[heap[yy]]) {
							yy++;
						}
						if (weight[tmp] < weight[heap[yy]]) {
							break;
						}
						heap[zz] = heap[yy];
						zz = yy;
					}
					heap[zz] = tmp;
				}
				n2 = heap[1];
				heap[1] = heap[nHeap];
				nHeap--;
				{
					int zz = 0, yy = 0, tmp = 0;
					zz = 1;
					tmp = heap[zz];
					while (true) {
						yy = zz << 1;
						if (yy > nHeap) {
							break;
						}
						if (yy < nHeap && weight[heap[yy + 1]] < weight[heap[yy]]) {
							yy++;
						}
						if (weight[tmp] < weight[heap[yy]]) {
							break;
						}
						heap[zz] = heap[yy];
						zz = yy;
					}
					heap[zz] = tmp;
				}
				nNodes++;
				parent[n1] = parent[n2] = nNodes;

				weight[nNodes] = ((weight[n1] & 0xffffff00) + (weight[n2] & 0xffffff00)) | (1 + (((weight[n1] & 0x000000ff) > (weight[n2] & 0x000000ff)) ? (weight[n1] & 0x000000ff) : (weight[n2] & 0x000000ff)));

				parent[nNodes] = -1;
				nHeap++;
				heap[nHeap] = nNodes;
				{
					int zz = 0, tmp = 0;
					zz = nHeap;
					tmp = heap[zz];
					while (weight[tmp] < weight[heap[zz >> 1]]) {
						heap[zz] = heap[zz >> 1];
						zz >>= 1;
					}
					heap[zz] = tmp;
				}
			}
			if (!(nNodes < (MAX_ALPHA_SIZE * 2))) {
				panic();
			}

			tooLong = false;
			for (i = 1; i <= alphaSize; i++) {
				j = 0;
				k = i;
				while (parent[k] >= 0) {
					k = parent[k];
					j++;
				}
				len[i - 1] = (char) j;
				if (j > maxLen) {
					tooLong = true;
				}
			}

			if (!tooLong) {
				break;
			}

			for (i = 1; i < alphaSize; i++) {
				j = weight[i] >> 8;
				j = 1 + (j / 2);
				weight[i] = j << 8;
			}
		}
	}

	/*
	 * index of the last char in the block, so the block size == last + 1.
	 */
	int last;

	/*
	 * index in zptr[] of original string after sorting.
	 */
	int origPtr;

	/*
	 * always: in the range 0 .. 9. The current block size is 100000 * this number.
	 */
	int blockSize100k;

	boolean blockRandomised;

	int bytesOut;
	int bsBuff;
	int bsLive;
	CRC mCrc = new CRC();

	private boolean[] inUse = new boolean[256];
	private int nInUse;

	private char[] seqToUnseq = new char[256];
	private char[] unseqToSeq = new char[256];

	private char[] selector = new char[MAX_SELECTORS];
	private char[] selectorMtf = new char[MAX_SELECTORS];

	private char[] block;
	private int[] quadrant;
	private int[] zptr;
	private short[] szptr;
	private int[] ftab;

	private int nMTF;

	private int[] mtfFreq = new int[MAX_ALPHA_SIZE];

	/*
	 * Used when sorting. If too many long comparisons happen, we stop sorting, randomise the block slightly, and try again.
	 */
	private int workFactor;
	private int workDone;
	private int workLimit;
	private boolean firstAttempt;
	@SuppressWarnings("unused")
	private int nBlocksRandomised;

	private int currentChar = -1;
	private int runLength = 0;

	public CBZip2OutputStream(OutputStream inStream) throws IOException {
		this(inStream, 9);
	}

	public CBZip2OutputStream(OutputStream inStream, int inBlockSize) throws IOException {
		block = null;
		quadrant = null;
		zptr = null;
		ftab = null;

		bsSetStream(inStream);

		workFactor = 50;
		if (inBlockSize > 9) {
			inBlockSize = 9;
		}
		if (inBlockSize < 1) {
			inBlockSize = 1;
		}
		blockSize100k = inBlockSize;
		allocateCompressStructures();
		initialize();
		initBlock();
	}

	/**
	 *
	 * modified by Oliver Merkel, 010128
	 *
	 */
	@Override
	public void write(int bv) throws IOException {
		int b = (256 + bv) % 256;
		if (currentChar != -1) {
			if (currentChar == b) {
				runLength++;
				if (runLength > 254) {
					writeRun();
					currentChar = -1;
					runLength = 0;
				}
			} else {
				writeRun();
				runLength = 1;
				currentChar = b;
			}
		} else {
			currentChar = b;
			runLength++;
		}
	}

	private void writeRun() throws IOException {
		if (last < allowableBlockSize) {
			inUse[currentChar] = true;
			for (int i = 0; i < runLength; i++) {
				mCrc.updateCRC((char) currentChar);
			}
			switch (runLength) {
			case 1:
				last++;
				block[last + 1] = (char) currentChar;
				break;
			case 2:
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				break;
			case 3:
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				break;
			default:
				inUse[runLength - 4] = true;
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) currentChar;
				last++;
				block[last + 1] = (char) (runLength - 4);
				break;
			}
		} else {
			endBlock();
			initBlock();
			writeRun();
		}
	}

	boolean closed = false;

	@Override
	protected void finalize() throws Throwable {
		close();
		super.finalize();
	}

	@Override
	public void close() throws IOException {
		if (closed) {
			return;
		}

		if (runLength > 0) {
			writeRun();
		}
		currentChar = -1;
		endBlock();
		endCompression();
		closed = true;
		super.close();
		bsStream.close();
	}

	@Override
	public void flush() throws IOException {
		super.flush();
		bsStream.flush();
	}

	private int blockCRC, combinedCRC;

	private void initialize() throws IOException {
		bytesOut = 0;
		nBlocksRandomised = 0;

		/*
		 * Write `magic' bytes h indicating file-format == huffmanised, followed by a digit indicating blockSize100k.
		 */
		bsPutUChar('h');
		bsPutUChar('0' + blockSize100k);

		combinedCRC = 0;
	}

	private int allowableBlockSize;

	private void initBlock() {
		// blockNo++;
		mCrc.initialiseCRC();
		last = -1;
		// ch = 0;

		for (int i = 0; i < 256; i++) {
			inUse[i] = false;
		}

		/* 20 is just a paranoia constant */
		allowableBlockSize = baseBlockSize * blockSize100k - 20;
	}

	private void endBlock() throws IOException {
		blockCRC = mCrc.getFinalCRC();
		combinedCRC = (combinedCRC << 1) | (combinedCRC >>> 31);
		combinedCRC ^= blockCRC;

		/* sort the block and establish posn of original string */
		doReversibleTransformation();

		/*
		 * A 6-byte block header, the value chosen arbitrarily as 0x314159265359 :-). A 32 bit value does not really give a strong
		 * enough guarantee that the value will not appear by chance in the compressed datastream. Worst-case probability of this
		 * event, for a 900k block, is about 2.0e-3 for 32 bits, 1.0e-5 for 40 bits and 4.0e-8 for 48 bits. For a compressed file of
		 * size 100Gb -- about 100000 blocks -- only a 48-bit marker will do. NB: normal compression/ decompression do *not* rely on
		 * these statistical properties. They are only important when trying to recover blocks from damaged files.
		 */
		bsPutUChar(0x31);
		bsPutUChar(0x41);
		bsPutUChar(0x59);
		bsPutUChar(0x26);
		bsPutUChar(0x53);
		bsPutUChar(0x59);

		/* Now the block's CRC, so it is in a known place. */
		bsPutint(blockCRC);

		/* Now a single bit indicating randomisation. */
		if (blockRandomised) {
			bsW(1, 1);
			nBlocksRandomised++;
		} else {
			bsW(1, 0);
		}

		/* Finally, block's contents proper. */
		moveToFrontCodeAndSend();
	}

	private void endCompression() throws IOException {
		/*
		 * Now another magic 48-bit number, 0x177245385090, to indicate the end of the last block. (sqrt(pi), if you want to know. I
		 * did want to use e, but it contains too much repetition -- 27 18 28 18 28 46 -- for me to feel statistically comfortable.
		 * Call me paranoid.)
		 */
		bsPutUChar(0x17);
		bsPutUChar(0x72);
		bsPutUChar(0x45);
		bsPutUChar(0x38);
		bsPutUChar(0x50);
		bsPutUChar(0x90);

		bsPutint(combinedCRC);

		bsFinishedWithStream();
	}

	private void hbAssignCodes(int[] code, char[] length, int minLen, int maxLen, int alphaSize) {
		int n, vec, i;

		vec = 0;
		for (n = minLen; n <= maxLen; n++) {
			for (i = 0; i < alphaSize; i++) {
				if (length[i] == n) {
					code[i] = vec;
					vec++;
				}
			}
			;
			vec <<= 1;
		}
	}

	private void bsSetStream(OutputStream f) {
		bsStream = f;
		bsLive = 0;
		bsBuff = 0;
		bytesOut = 0;
	}

	private void bsFinishedWithStream() throws IOException {
		while (bsLive > 0) {
			int ch = (bsBuff >> 24);
			try {
				bsStream.write(ch); // write 8-bit
			} catch (IOException e) {
				throw e;
			}
			bsBuff <<= 8;
			bsLive -= 8;
			bytesOut++;
		}
	}

	private void bsW(int n, int v) throws IOException {
		while (bsLive >= 8) {
			int ch = (bsBuff >> 24);
			try {
				bsStream.write(ch); // write 8-bit
			} catch (IOException e) {
				throw e;
			}
			bsBuff <<= 8;
			bsLive -= 8;
			bytesOut++;
		}
		bsBuff |= (v << (32 - bsLive - n));
		bsLive += n;
	}

	private void bsPutUChar(int c) throws IOException {
		bsW(8, c);
	}

	private void bsPutint(int u) throws IOException {
		bsW(8, (u >> 24) & 0xff);
		bsW(8, (u >> 16) & 0xff);
		bsW(8, (u >> 8) & 0xff);
		bsW(8, u & 0xff);
	}

	private void bsPutIntVS(int numBits, int c) throws IOException {
		bsW(numBits, c);
	}

	private void sendMTFValues() throws IOException {
		char len[][] = new char[N_GROUPS][MAX_ALPHA_SIZE];

		@SuppressWarnings("unused")
		int v, t, i, j, gs, ge, totc, bt, bc, iter;
		int nSelectors = 0, alphaSize, minLen, maxLen, selCtr;
		@SuppressWarnings("unused")
		int nGroups, nBytes;

		alphaSize = nInUse + 2;
		for (t = 0; t < N_GROUPS; t++) {
			for (v = 0; v < alphaSize; v++) {
				len[t][v] = (char) GREATER_ICOST;
			}
		}

		/* Decide how many coding tables to use */
		if (nMTF <= 0) {
			panic();
		}

		if (nMTF < 200) {
			nGroups = 2;
		} else if (nMTF < 600) {
			nGroups = 3;
		} else if (nMTF < 1200) {
			nGroups = 4;
		} else if (nMTF < 2400) {
			nGroups = 5;
		} else {
			nGroups = 6;
		}

		/* Generate an initial set of coding tables */ {
			int nPart, remF, tFreq, aFreq;

			nPart = nGroups;
			remF = nMTF;
			gs = 0;
			while (nPart > 0) {
				tFreq = remF / nPart;
				ge = gs - 1;
				aFreq = 0;
				while (aFreq < tFreq && ge < alphaSize - 1) {
					ge++;
					aFreq += mtfFreq[ge];
				}

				if (ge > gs && nPart != nGroups && nPart != 1 && ((nGroups - nPart) % 2 == 1)) {
					aFreq -= mtfFreq[ge];
					ge--;
				}

				for (v = 0; v < alphaSize; v++) {
					if (v >= gs && v <= ge) {
						len[nPart - 1][v] = (char) LESSER_ICOST;
					} else {
						len[nPart - 1][v] = (char) GREATER_ICOST;
					}
				}

				nPart--;
				gs = ge + 1;
				remF -= aFreq;
			}
		}

		int[][] rfreq = new int[N_GROUPS][MAX_ALPHA_SIZE];
		int[] fave = new int[N_GROUPS];
		short[] cost = new short[N_GROUPS];
		/*
		 * Iterate up to N_ITERS times to improve the tables.
		 */
		for (iter = 0; iter < N_ITERS; iter++) {
			for (t = 0; t < nGroups; t++) {
				fave[t] = 0;
			}

			for (t = 0; t < nGroups; t++) {
				for (v = 0; v < alphaSize; v++) {
					rfreq[t][v] = 0;
				}
			}

			nSelectors = 0;
			totc = 0;
			gs = 0;
			while (true) {

				/* Set group start & end marks. */
				if (gs >= nMTF) {
					break;
				}
				ge = gs + G_SIZE - 1;
				if (ge >= nMTF) {
					ge = nMTF - 1;
				}

				/*
				 * Calculate the cost of this group as coded by each of the coding tables.
				 */
				for (t = 0; t < nGroups; t++) {
					cost[t] = 0;
				}

				if (nGroups == 6) {
					short cost0, cost1, cost2, cost3, cost4, cost5;
					cost0 = cost1 = cost2 = cost3 = cost4 = cost5 = 0;
					for (i = gs; i <= ge; i++) {
						short icv = szptr[i];
						cost0 += len[0][icv];
						cost1 += len[1][icv];
						cost2 += len[2][icv];
						cost3 += len[3][icv];
						cost4 += len[4][icv];
						cost5 += len[5][icv];
					}
					cost[0] = cost0;
					cost[1] = cost1;
					cost[2] = cost2;
					cost[3] = cost3;
					cost[4] = cost4;
					cost[5] = cost5;
				} else {
					for (i = gs; i <= ge; i++) {
						short icv = szptr[i];
						for (t = 0; t < nGroups; t++) {
							cost[t] += len[t][icv];
						}
					}
				}

				/*
				 * Find the coding table which is best for this group, and record its identity in the selector table.
				 */
				bc = 999999999;
				bt = -1;
				for (t = 0; t < nGroups; t++) {
					if (cost[t] < bc) {
						bc = cost[t];
						bt = t;
					}
				}
				;
				totc += bc;
				fave[bt]++;
				selector[nSelectors] = (char) bt;
				nSelectors++;

				/*
				 * Increment the symbol frequencies for the selected table.
				 */
				for (i = gs; i <= ge; i++) {
					rfreq[bt][szptr[i]]++;
				}

				gs = ge + 1;
			}

			/*
			 * Recompute the tables based on the accumulated frequencies.
			 */
			for (t = 0; t < nGroups; t++) {
				hbMakeCodeLengths(len[t], rfreq[t], alphaSize, 20);
			}
		}

		rfreq = null;
		fave = null;
		cost = null;

		if (!(nGroups < 8)) {
			panic();
		}
		if (!(nSelectors < 32768 && nSelectors <= (2 + (900000 / G_SIZE)))) {
			panic();
		}

		/* Compute MTF values for the selectors. */
		{
			char[] pos = new char[N_GROUPS];
			char ll_i, tmp2, tmp;
			for (i = 0; i < nGroups; i++) {
				pos[i] = (char) i;
			}
			for (i = 0; i < nSelectors; i++) {
				ll_i = selector[i];
				j = 0;
				tmp = pos[j];
				while (ll_i != tmp) {
					j++;
					tmp2 = tmp;
					tmp = pos[j];
					pos[j] = tmp2;
				}
				pos[0] = tmp;
				selectorMtf[i] = (char) j;
			}
		}

		int[][] code = new int[N_GROUPS][MAX_ALPHA_SIZE];

		/* Assign actual codes for the tables. */
		for (t = 0; t < nGroups; t++) {
			minLen = 32;
			maxLen = 0;
			for (i = 0; i < alphaSize; i++) {
				if (len[t][i] > maxLen) {
					maxLen = len[t][i];
				}
				if (len[t][i] < minLen) {
					minLen = len[t][i];
				}
			}
			if (maxLen > 20) {
				panic();
			}
			if (minLen < 1) {
				panic();
			}
			hbAssignCodes(code[t], len[t], minLen, maxLen, alphaSize);
		}

		/* Transmit the mapping table. */
		{
			boolean[] inUse16 = new boolean[16];
			for (i = 0; i < 16; i++) {
				inUse16[i] = false;
				for (j = 0; j < 16; j++) {
					if (inUse[i * 16 + j]) {
						inUse16[i] = true;
					}
				}
			}

			nBytes = bytesOut;
			for (i = 0; i < 16; i++) {
				if (inUse16[i]) {
					bsW(1, 1);
				} else {
					bsW(1, 0);
				}
			}

			for (i = 0; i < 16; i++) {
				if (inUse16[i]) {
					for (j = 0; j < 16; j++) {
						if (inUse[i * 16 + j]) {
							bsW(1, 1);
						} else {
							bsW(1, 0);
						}
					}
				}
			}

		}

		/* Now the selectors. */
		nBytes = bytesOut;
		bsW(3, nGroups);
		bsW(15, nSelectors);
		for (i = 0; i < nSelectors; i++) {
			for (j = 0; j < selectorMtf[i]; j++) {
				bsW(1, 1);
			}
			bsW(1, 0);
		}

		/* Now the coding tables. */
		nBytes = bytesOut;

		for (t = 0; t < nGroups; t++) {
			int curr = len[t][0];
			bsW(5, curr);
			for (i = 0; i < alphaSize; i++) {
				while (curr < len[t][i]) {
					bsW(2, 2);
					curr++; /* 10 */
				}
				while (curr > len[t][i]) {
					bsW(2, 3);
					curr--; /* 11 */
				}
				bsW(1, 0);
			}
		}

		/* And finally, the block data proper */
		nBytes = bytesOut;
		selCtr = 0;
		gs = 0;
		while (true) {
			if (gs >= nMTF) {
				break;
			}
			ge = gs + G_SIZE - 1;
			if (ge >= nMTF) {
				ge = nMTF - 1;
			}
			for (i = gs; i <= ge; i++) {
				bsW(len[selector[selCtr]][szptr[i]], code[selector[selCtr]][szptr[i]]);
			}

			gs = ge + 1;
			selCtr++;
		}
		if (!(selCtr == nSelectors)) {
			panic();
		}
	}

	private void moveToFrontCodeAndSend() throws IOException {
		bsPutIntVS(24, origPtr);
		generateMTFValues();
		sendMTFValues();
	}

	private OutputStream bsStream;

	private void simpleSort(int lo, int hi, int d) {
		int i, j, h, bigN, hp;
		int v;

		bigN = hi - lo + 1;
		if (bigN < 2) {
			return;
		}

		hp = 0;
		while (incs[hp] < bigN) {
			hp++;
		}
		hp--;

		for (; hp >= 0; hp--) {
			h = incs[hp];

			i = lo + h;
			while (true) {
				/* copy 1 */
				if (i > hi) {
					break;
				}
				v = zptr[i];
				j = i;
				while (fullGtU(zptr[j - h] + d, v + d)) {
					zptr[j] = zptr[j - h];
					j = j - h;
					if (j <= (lo + h - 1)) {
						break;
					}
				}
				zptr[j] = v;
				i++;

				/* copy 2 */
				if (i > hi) {
					break;
				}
				v = zptr[i];
				j = i;
				while (fullGtU(zptr[j - h] + d, v + d)) {
					zptr[j] = zptr[j - h];
					j = j - h;
					if (j <= (lo + h - 1)) {
						break;
					}
				}
				zptr[j] = v;
				i++;

				/* copy 3 */
				if (i > hi) {
					break;
				}
				v = zptr[i];
				j = i;
				while (fullGtU(zptr[j - h] + d, v + d)) {
					zptr[j] = zptr[j - h];
					j = j - h;
					if (j <= (lo + h - 1)) {
						break;
					}
				}
				zptr[j] = v;
				i++;

				if (workDone > workLimit && firstAttempt) {
					return;
				}
			}
		}
	}

	private void vswap(int p1, int p2, int n) {
		int temp = 0;
		while (n > 0) {
			temp = zptr[p1];
			zptr[p1] = zptr[p2];
			zptr[p2] = temp;
			p1++;
			p2++;
			n--;
		}
	}

	private char med3(char a, char b, char c) {
		char t;
		if (a > b) {
			t = a;
			a = b;
			b = t;
		}
		if (b > c) {
			t = b;
			b = c;
			c = t;
		}
		if (a > b) {
			b = a;
		}
		return b;
	}

	private static class StackElem {
		int ll;
		int hh;
		int dd;
	}

	private void qSort3(int loSt, int hiSt, int dSt) {
		int unLo, unHi, ltLo, gtHi, med, n, m;
		int sp, lo, hi, d;
		StackElem[] stack = new StackElem[QSORT_STACK_SIZE];
		for (int count = 0; count < QSORT_STACK_SIZE; count++) {
			stack[count] = new StackElem();
		}

		sp = 0;

		stack[sp].ll = loSt;
		stack[sp].hh = hiSt;
		stack[sp].dd = dSt;
		sp++;

		while (sp > 0) {
			if (sp >= QSORT_STACK_SIZE) {
				panic();
			}

			sp--;
			lo = stack[sp].ll;
			hi = stack[sp].hh;
			d = stack[sp].dd;

			if (hi - lo < SMALL_THRESH || d > DEPTH_THRESH) {
				simpleSort(lo, hi, d);
				if (workDone > workLimit && firstAttempt) {
					return;
				}
				continue;
			}

			med = med3(block[zptr[lo] + d + 1], block[zptr[hi] + d + 1], block[zptr[(lo + hi) >> 1] + d + 1]);

			unLo = ltLo = lo;
			unHi = gtHi = hi;

			while (true) {
				while (true) {
					if (unLo > unHi) {
						break;
					}
					n = (block[zptr[unLo] + d + 1]) - med;
					if (n == 0) {
						int temp = 0;
						temp = zptr[unLo];
						zptr[unLo] = zptr[ltLo];
						zptr[ltLo] = temp;
						ltLo++;
						unLo++;
						continue;
					}
					;
					if (n > 0) {
						break;
					}
					unLo++;
				}
				while (true) {
					if (unLo > unHi) {
						break;
					}
					n = (block[zptr[unHi] + d + 1]) - med;
					if (n == 0) {
						int temp = 0;
						temp = zptr[unHi];
						zptr[unHi] = zptr[gtHi];
						zptr[gtHi] = temp;
						gtHi--;
						unHi--;
						continue;
					}
					;
					if (n < 0) {
						break;
					}
					unHi--;
				}
				if (unLo > unHi) {
					break;
				}
				int temp = 0;
				temp = zptr[unLo];
				zptr[unLo] = zptr[unHi];
				zptr[unHi] = temp;
				unLo++;
				unHi--;
			}

			if (gtHi < ltLo) {
				stack[sp].ll = lo;
				stack[sp].hh = hi;
				stack[sp].dd = d + 1;
				sp++;
				continue;
			}

			n = ((ltLo - lo) < (unLo - ltLo)) ? (ltLo - lo) : (unLo - ltLo);
			vswap(lo, unLo - n, n);
			m = ((hi - gtHi) < (gtHi - unHi)) ? (hi - gtHi) : (gtHi - unHi);
			vswap(unLo, hi - m + 1, m);

			n = lo + unLo - ltLo - 1;
			m = hi - (gtHi - unHi) + 1;

			stack[sp].ll = lo;
			stack[sp].hh = n;
			stack[sp].dd = d;
			sp++;

			stack[sp].ll = n + 1;
			stack[sp].hh = m - 1;
			stack[sp].dd = d + 1;
			sp++;

			stack[sp].ll = m;
			stack[sp].hh = hi;
			stack[sp].dd = d;
			sp++;
		}
	}

	private void mainSort() {
		int i, j, ss, sb;
		int[] runningOrder = new int[256];
		int[] copy = new int[256];
		boolean[] bigDone = new boolean[256];
		int c1, c2;
		@SuppressWarnings("unused")
		int numQSorted;

		/*
		 * In the various block-sized structures, live data runs from 0 to last+NUM_OVERSHOOT_BYTES inclusive. First, set up the
		 * overshoot area for block.
		 */

		// if (verbosity >= 4) fprintf ( stderr, " sort initialise ...\n" );
		for (i = 0; i < NUM_OVERSHOOT_BYTES; i++) {
			block[last + i + 2] = block[(i % (last + 1)) + 1];
		}
		for (i = 0; i <= last + NUM_OVERSHOOT_BYTES; i++) {
			quadrant[i] = 0;
		}

		block[0] = (block[last + 1]);

		if (last < 4000) {
			/*
			 * Use simpleSort(), since the full sorting mechanism has quite a large constant overhead.
			 */
			for (i = 0; i <= last; i++) {
				zptr[i] = i;
			}
			firstAttempt = false;
			workDone = workLimit = 0;
			simpleSort(0, last, 0);
		} else {
			numQSorted = 0;
			for (i = 0; i <= 255; i++) {
				bigDone[i] = false;
			}

			for (i = 0; i <= 65536; i++) {
				ftab[i] = 0;
			}

			c1 = block[0];
			for (i = 0; i <= last; i++) {
				c2 = block[i + 1];
				ftab[(c1 << 8) + c2]++;
				c1 = c2;
			}

			for (i = 1; i <= 65536; i++) {
				ftab[i] += ftab[i - 1];
			}

			c1 = block[1];
			for (i = 0; i < last; i++) {
				c2 = block[i + 2];
				j = (c1 << 8) + c2;
				c1 = c2;
				ftab[j]--;
				zptr[ftab[j]] = i;
			}

			j = ((block[last + 1]) << 8) + (block[1]);
			ftab[j]--;
			zptr[ftab[j]] = last;

			/*
			 * Now ftab contains the first loc of every small bucket. Calculate the running order, from smallest to largest big bucket.
			 */

			for (i = 0; i <= 255; i++) {
				runningOrder[i] = i;
			}

			{
				int vv;
				int h = 1;
				do {
					h = 3 * h + 1;
				} while (h <= 256);
				do {
					h = h / 3;
					for (i = h; i <= 255; i++) {
						vv = runningOrder[i];
						j = i;
						while ((ftab[((runningOrder[j - h]) + 1) << 8] - ftab[(runningOrder[j - h]) << 8]) > (ftab[((vv) + 1) << 8] - ftab[(vv) << 8])) {
							runningOrder[j] = runningOrder[j - h];
							j = j - h;
							if (j <= (h - 1)) {
								break;
							}
						}
						runningOrder[j] = vv;
					}
				} while (h != 1);
			}

			/*
			 * The main sorting loop.
			 */
			for (i = 0; i <= 255; i++) {

				/*
				 * Process big buckets, starting with the least full.
				 */
				ss = runningOrder[i];

				/*
				 * Complete the big bucket [ss] by quicksorting any unsorted small buckets [ss, j]. Hopefully previous pointer-scanning
				 * phases have already completed many of the small buckets [ss, j], so we don't have to sort them at all.
				 */
				for (j = 0; j <= 255; j++) {
					sb = (ss << 8) + j;
					if (!((ftab[sb] & SETMASK) == SETMASK)) {
						int lo = ftab[sb] & CLEARMASK;
						int hi = (ftab[sb + 1] & CLEARMASK) - 1;
						if (hi > lo) {
							qSort3(lo, hi, 2);
							numQSorted += (hi - lo + 1);
							if (workDone > workLimit && firstAttempt) {
								return;
							}
						}
						ftab[sb] |= SETMASK;
					}
				}

				/*
				 * The ss big bucket is now done. Record this fact, and update the quadrant descriptors. Remember to update quadrants in the
				 * overshoot area too, if necessary. The "if (i < 255)" test merely skips this updating for the last bucket processed, since
				 * updating for the last bucket is pointless.
				 */
				bigDone[ss] = true;

				if (i < 255) {
					int bbStart = ftab[ss << 8] & CLEARMASK;
					int bbSize = (ftab[(ss + 1) << 8] & CLEARMASK) - bbStart;
					int shifts = 0;

					while ((bbSize >> shifts) > 65534) {
						shifts++;
					}

					for (j = 0; j < bbSize; j++) {
						int a2update = zptr[bbStart + j];
						int qVal = (j >> shifts);
						quadrant[a2update] = qVal;
						if (a2update < NUM_OVERSHOOT_BYTES) {
							quadrant[a2update + last + 1] = qVal;
						}
					}

					if (!(((bbSize - 1) >> shifts) <= 65535)) {
						panic();
					}
				}

				/*
				 * Now scan this big bucket so as to synthesise the sorted order for small buckets [t, ss] for all t != ss.
				 */
				for (j = 0; j <= 255; j++) {
					copy[j] = ftab[(j << 8) + ss] & CLEARMASK;
				}

				for (j = ftab[ss << 8] & CLEARMASK; j < (ftab[(ss + 1) << 8] & CLEARMASK); j++) {
					c1 = block[zptr[j]];
					if (!bigDone[c1]) {
						zptr[copy[c1]] = zptr[j] == 0 ? last : zptr[j] - 1;
						copy[c1]++;
					}
				}

				for (j = 0; j <= 255; j++) {
					ftab[(j << 8) + ss] |= SETMASK;
				}
			}
		}
	}

	private void randomiseBlock() {
		int i;
		int rNToGo = 0;
		int rTPos = 0;
		for (i = 0; i < 256; i++) {
			inUse[i] = false;
		}

		for (i = 0; i <= last; i++) {
			if (rNToGo == 0) {
				rNToGo = (char) rNums[rTPos];
				rTPos++;
				if (rTPos == 512) {
					rTPos = 0;
				}
			}
			rNToGo--;
			block[i + 1] ^= ((rNToGo == 1) ? 1 : 0);
			// handle 16 bit signed numbers
			block[i + 1] &= 0xFF;

			inUse[block[i + 1]] = true;
		}
	}

	private void doReversibleTransformation() {
		int i;

		workLimit = workFactor * last;
		workDone = 0;
		blockRandomised = false;
		firstAttempt = true;

		mainSort();

		if (workDone > workLimit && firstAttempt) {
			randomiseBlock();
			workLimit = workDone = 0;
			blockRandomised = true;
			firstAttempt = false;
			mainSort();
		}

		origPtr = -1;
		for (i = 0; i <= last; i++) {
			if (zptr[i] == 0) {
				origPtr = i;
				break;
			}
		}
		;

		if (origPtr == -1) {
			panic();
		}
	}

	private boolean fullGtU(int i1, int i2) {
		int k;
		char c1, c2;
		int s1, s2;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		c1 = block[i1 + 1];
		c2 = block[i2 + 1];
		if (c1 != c2) {
			return (c1 > c2);
		}
		i1++;
		i2++;

		k = last + 1;

		do {
			c1 = block[i1 + 1];
			c2 = block[i2 + 1];
			if (c1 != c2) {
				return (c1 > c2);
			}
			s1 = quadrant[i1];
			s2 = quadrant[i2];
			if (s1 != s2) {
				return (s1 > s2);
			}
			i1++;
			i2++;

			c1 = block[i1 + 1];
			c2 = block[i2 + 1];
			if (c1 != c2) {
				return (c1 > c2);
			}
			s1 = quadrant[i1];
			s2 = quadrant[i2];
			if (s1 != s2) {
				return (s1 > s2);
			}
			i1++;
			i2++;

			c1 = block[i1 + 1];
			c2 = block[i2 + 1];
			if (c1 != c2) {
				return (c1 > c2);
			}
			s1 = quadrant[i1];
			s2 = quadrant[i2];
			if (s1 != s2) {
				return (s1 > s2);
			}
			i1++;
			i2++;

			c1 = block[i1 + 1];
			c2 = block[i2 + 1];
			if (c1 != c2) {
				return (c1 > c2);
			}
			s1 = quadrant[i1];
			s2 = quadrant[i2];
			if (s1 != s2) {
				return (s1 > s2);
			}
			i1++;
			i2++;

			if (i1 > last) {
				i1 -= last;
				i1--;
			}
			;
			if (i2 > last) {
				i2 -= last;
				i2--;
			}
			;

			k -= 4;
			workDone++;
		} while (k >= 0);

		return false;
	}

	/*
	 * Knuth's increments seem to work better than Incerpi-Sedgewick here. Possibly because the number of elems to sort is
	 * usually small, typically <= 20.
	 */
	private int[] incs = { 1, 4, 13, 40, 121, 364, 1093, 3280, 9841, 29524, 88573, 265720, 797161, 2391484 };

	private void allocateCompressStructures() {
		int n = baseBlockSize * blockSize100k;
		block = new char[(n + 1 + NUM_OVERSHOOT_BYTES)];
		quadrant = new int[(n + NUM_OVERSHOOT_BYTES)];
		zptr = new int[n];
		ftab = new int[65537];

		if (block == null || quadrant == null || zptr == null || ftab == null) {
			// int totalDraw = (n + 1 + NUM_OVERSHOOT_BYTES) + (n + NUM_OVERSHOOT_BYTES) + n + 65537;
			// compressOutOfMemory ( totalDraw, n );
		}

		/*
		 * The back end needs a place to store the MTF values whilst it calculates the coding tables. We could put them in the zptr
		 * array. However, these values will fit in a short, so we overlay szptr at the start of zptr, in the hope of reducing the
		 * number of cache misses induced by the multiple traversals of the MTF values when calculating coding tables. Seems to
		 * improve compression speed by about 1%.
		 */
		// szptr = zptr;

		szptr = new short[2 * n];
	}

	private void generateMTFValues() {
		char[] yy = new char[256];
		int i, j;
		char tmp;
		char tmp2;
		int zPend;
		int wr;
		int EOB;

		makeMaps();
		EOB = nInUse + 1;

		for (i = 0; i <= EOB; i++) {
			mtfFreq[i] = 0;
		}

		wr = 0;
		zPend = 0;
		for (i = 0; i < nInUse; i++) {
			yy[i] = (char) i;
		}

		for (i = 0; i <= last; i++) {
			char ll_i;

			ll_i = unseqToSeq[block[zptr[i]]];

			j = 0;
			tmp = yy[j];
			while (ll_i != tmp) {
				j++;
				tmp2 = tmp;
				tmp = yy[j];
				yy[j] = tmp2;
			}
			;
			yy[0] = tmp;

			if (j == 0) {
				zPend++;
			} else {
				if (zPend > 0) {
					zPend--;
					while (true) {
						switch (zPend % 2) {
						case 0:
							szptr[wr] = (short) RUNA;
							wr++;
							mtfFreq[RUNA]++;
							break;
						case 1:
							szptr[wr] = (short) RUNB;
							wr++;
							mtfFreq[RUNB]++;
							break;
						}
						;
						if (zPend < 2) {
							break;
						}
						zPend = (zPend - 2) / 2;
					}
					;
					zPend = 0;
				}
				szptr[wr] = (short) (j + 1);
				wr++;
				mtfFreq[j + 1]++;
			}
		}

		if (zPend > 0) {
			zPend--;
			while (true) {
				switch (zPend % 2) {
				case 0:
					szptr[wr] = (short) RUNA;
					wr++;
					mtfFreq[RUNA]++;
					break;
				case 1:
					szptr[wr] = (short) RUNB;
					wr++;
					mtfFreq[RUNB]++;
					break;
				}
				if (zPend < 2) {
					break;
				}
				zPend = (zPend - 2) / 2;
			}
		}

		szptr[wr] = (short) EOB;
		wr++;
		mtfFreq[EOB]++;

		nMTF = wr;
	}
}
