bundles/org.simantics.db.procore/src/org/simantics/db/procore/cluster/FastLZ.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.db.procore.cluster;
  13
  14 import java.nio.ByteBuffer;
  15 import java.nio.ByteOrder;
  16
  17 import org.simantics.db.exception.InternalException;
  18
  19 public class FastLZ {
  20     static private final int InLength = 1<<20;
  21
  22         public static class DecompressStruct {
  23                 public long[] longs;
  24                 public int[] ints;
  25                 public byte[] bytes;
  26         }
  27         static class SourceData {
  28                 SourceData(byte[] data) {
  29                         this.data = data;
  30                         this.offset = 0;
  31                 }
  32                 int left() {
  33                         return data.length - offset;
  34                 }
  35                 int readInt() {
  36                     int inLength = 4; // sizeof(int)
  37                     assert(left() >= inLength); // must have data for input
  38                         ByteBuffer buffer = ByteBuffer.wrap(data, offset, inLength);
  39                         buffer.order(ByteOrder.LITTLE_ENDIAN); // argh!
  40                         int t = buffer.getInt();
  41                         offset += inLength;
  42                         return t;
  43                 }
  44                 void readBytes(byte[] bytes, int aOffset, int inLength) {
  45                     assert(left() >= inLength); // must have data for input
  46                         System.arraycopy(data, offset, bytes, aOffset, inLength);
  47                         offset += inLength;
  48                 }
  49                 byte[] data;
  50                 int offset;
  51         }
  52         public static DecompressStruct decompress(byte[] data) throws InternalException {
  53                 assert(data.length > 12); // 3*(table size)
  54                 SourceData sourceData = new SourceData(data);
  55                 DecompressStruct struct = new DecompressStruct();
  56                 int longSize = sourceData.readInt();
  57                 int intSize = sourceData.readInt();
  58                 int byteSize = sourceData.readInt();
  59                 struct.longs = new long[longSize];
  60                 try {
  61                         decompress(sourceData, struct.longs);
  62                         struct.ints = new int[intSize];
  63                         decompress(sourceData, struct.ints);
  64                         struct.bytes = new byte[byteSize];
  65                         decompress(sourceData, struct.bytes);
  66                 } catch (CompressionException e) {
  67                         throw new InternalException("Failed to decompress.", e);
  68                 }
  69                 return struct;
  70         }
  71         private static void decompress(SourceData sourceData, long[] longs) throws CompressionException {
  72                 int length = longs.length * 8;
  73                 ByteBuffer bytes = ByteBuffer.allocate(length);
  74                 int size = decompressRaw(sourceData, bytes.array());
  75                 assert(size == length);
  76                 bytes.order(ByteOrder.LITTLE_ENDIAN); // argh
  77                 for (int i=0; i<longs.length; ++i)
  78                         longs[i] = bytes.getLong();
  79         }
  80         private static void decompress(SourceData sourceData, int[] ints) throws CompressionException {
  81                 int length = ints.length * 4;
  82                 ByteBuffer bytes = ByteBuffer.allocate(length);
  83                 int size = decompressRaw(sourceData, bytes.array());
  84                 assert(size == length);
  85                 bytes.order(ByteOrder.LITTLE_ENDIAN); // argh
  86                 for (int i=0; i<ints.length; ++i)
  87                         ints[i] = bytes.getInt();
  88         }
  89         private static void decompress(SourceData sourceData, byte[] bytes) throws CompressionException {
  90                 int size = decompressRaw(sourceData, bytes);
  91                 assert(size == bytes.length);
  92         }
  93         private static int decompressRaw(SourceData sourceData, byte[] bytes) throws CompressionException {
  94                 int aDstSize = bytes.length;
  95                 if (aDstSize < 1)
  96                         return aDstSize;
  97                 int dstOffset = 0;
  98                 for (int dstSize = 0;;) {
  99                         int dataLength = sourceData.readInt();
 100                         assert(dataLength <= InLength); // data is written in blocks
 101                         if (0 == dataLength) // EOF
 102                                 return dstSize;
 103                         dstSize += dataLength;
 104                 int inLength = sourceData.readInt();
 105
 106                         assert(aDstSize >= dstSize); // must have space for data
 107                         assert(sourceData.left() >= inLength); // must have data for input
 108                         assert(inLength > 0); // no data no block
 109                         assert(inLength <= InLength); // input size is block size or less
 110                         assert(inLength <= dataLength); // input size is never bigger than data size
 111
 112                         if (inLength < dataLength) {// block was actually compressed
 113                                 decompress(sourceData.data, sourceData.offset, inLength, bytes, dstOffset, dataLength);
 114                                 sourceData.offset += inLength;
 115                                 dstOffset += dataLength;
 116                 } else {
 117                         sourceData.readBytes(bytes, dstOffset, inLength);
 118                         dstOffset += inLength;
 119                 }
 120             }
 121         }
 122         private static void decompress(byte[] in, int inOffset, int inLength, byte[] out, int outOffset, int outLength) throws CompressionException {
 123             ByteBuffer inBuffer = ByteBuffer.allocateDirect(inLength);
 124                 inBuffer.put(in, inOffset, inLength);
 125                 inBuffer.flip();
 126                 ByteBuffer outBuffer = ByteBuffer.allocateDirect(outLength);
 127                 int inflateSize = org.simantics.fastlz.FastLZ.decompressBuffer(inBuffer, 0, inLength, outBuffer, 0, outLength);
 128                 if (inflateSize != outLength)
 129                         throw new RuntimeException("Decompression error.");
 130                 //outBuffer.flip();
 131                 outBuffer.get(out, outOffset, outLength);
 132         }
 133 }