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

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