From 828227f59de3c5f442631d03158f3feddb8da64f Mon Sep 17 00:00:00 2001
From: Arndt Brenschede <Arndt.Brenschede@web.de>
Date: Sat, 29 Jun 2019 10:11:59 +0200
Subject: [PATCH] decoding performance

---
 .../main/java/btools/codec/MicroCache2.java   |  2 +-
 .../java/btools/codec/StatCoderContext.java   | 16 +++----
 .../btools/codec/StatCoderContextTest.java    |  6 +--
 .../java/btools/mapaccess/DirectWeaver.java   | 45 ++++++++++---------
 .../main/java/btools/mapaccess/OsmNode.java   |  9 +---
 .../java/btools/util/BitCoderContext.java     | 33 ++++++++++++--
 6 files changed, 65 insertions(+), 46 deletions(-)

diff --git a/brouter-codec/src/main/java/btools/codec/MicroCache2.java b/brouter-codec/src/main/java/btools/codec/MicroCache2.java
index ca3c1b3..7829384 100644
--- a/brouter-codec/src/main/java/btools/codec/MicroCache2.java
+++ b/brouter-codec/src/main/java/btools/codec/MicroCache2.java
@@ -62,7 +62,7 @@ public final class MicroCache2 extends MicroCache
 
     if ( debug ) System.out.println( "*** decoding cache of size=" + size + " for lonIdx=" + lonIdx + " latIdx=" + latIdx );
 
-    bc.decodeSortedArray( faid, 0, size, 0x20000000, 0 );
+    bc.decodeSortedArray( faid, 0, size, 29, 0 );
     
     for( int n = 0; n<size; n++ )
     {
diff --git a/brouter-codec/src/main/java/btools/codec/StatCoderContext.java b/brouter-codec/src/main/java/btools/codec/StatCoderContext.java
index 515efa4..4b67a54 100644
--- a/brouter-codec/src/main/java/btools/codec/StatCoderContext.java
+++ b/brouter-codec/src/main/java/btools/codec/StatCoderContext.java
@@ -269,22 +269,18 @@ public final class StatCoderContext extends BitCoderContext
    * @param value
    *          should be 0
    */
-  public void decodeSortedArray( int[] values, int offset, int subsize, int nextbit, int value )
+  public void decodeSortedArray( int[] values, int offset, int subsize, int nextbitpos, int value )
   {
     if ( subsize == 1 ) // last-choice shortcut
     {
-      while (nextbit != 0)
+      if ( nextbitpos >= 0 )
       {
-        if ( decodeBit() )
-        {
-          value |= nextbit;
-        }
-        nextbit >>= 1;
+        value |= decodeBitsReverse( nextbitpos+1 );
       }
       values[offset] = value;
       return;
     }
-    if ( nextbit == 0 )
+    if ( nextbitpos < 0 )
     {
       while (subsize-- > 0)
       {
@@ -298,11 +294,11 @@ public final class StatCoderContext extends BitCoderContext
 
     if ( size1 > 0 )
     {
-      decodeSortedArray( values, offset, size1, nextbit >> 1, value );
+      decodeSortedArray( values, offset, size1, nextbitpos-1, value );
     }
     if ( size2 > 0 )
     {
-      decodeSortedArray( values, offset + size1, size2, nextbit >> 1, value | nextbit );
+      decodeSortedArray( values, offset + size1, size2, nextbitpos-1, value | (1 << nextbitpos) );
     }
   }
 
diff --git a/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java b/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java
index 2ee1af6..616e421 100644
--- a/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java
+++ b/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java
@@ -13,7 +13,7 @@ public class StatCoderContextTest
   {
     byte[] ab = new byte[40000];
     StatCoderContext ctx = new StatCoderContext( ab );
-    for ( int noisybits = 0; noisybits < 12; noisybits++ )
+    for ( int noisybits = 1; noisybits < 12; noisybits++ )
     {
       for ( int i = 0; i < 1000; i++ )
       {
@@ -22,7 +22,7 @@ public class StatCoderContextTest
     }
     ctx = new StatCoderContext( ab );
 
-    for ( int noisybits = 0; noisybits < 12; noisybits++ )
+    for ( int noisybits = 1; noisybits < 12; noisybits++ )
     {
       for ( int i = 0; i < 1000; i++ )
       {
@@ -114,7 +114,7 @@ public class StatCoderContextTest
     ctx = new StatCoderContext( ab );
 
     int[] decodedValues = new int[size];
-    ctx.decodeSortedArray( decodedValues, 0, size, 0x08000000, 0 );
+    ctx.decodeSortedArray( decodedValues, 0, size, 27, 0 );
 
     for ( int i = 0; i < size; i++ )
     {
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/DirectWeaver.java b/brouter-mapaccess/src/main/java/btools/mapaccess/DirectWeaver.java
index aa25238..7331af3 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/DirectWeaver.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/DirectWeaver.java
@@ -16,20 +16,15 @@ import btools.util.IByteArrayUnifier;
  */
 public final class DirectWeaver extends ByteDataWriter
 {
-  private int lonBase;
-  private int latBase;
-  private int cellsize;
+  private long id64Base;
 
   private int size = 0;
 
-  private static boolean debug = false;
-  
   public DirectWeaver( DataBuffers dataBuffers, int lonIdx, int latIdx, int divisor, TagValueValidator wayValidator, WaypointMatcher waypointMatcher, OsmNodesMap hollowNodes ) throws Exception
   {
     super( null );
-    cellsize = 1000000 / divisor;
-    lonBase = lonIdx*cellsize;
-    latBase = latIdx*cellsize;
+    int cellsize = 1000000 / divisor;
+    id64Base = ((long)(lonIdx*cellsize))<<32 | (latIdx*cellsize);
 
     StatCoderContext bc = new StatCoderContext( dataBuffers.iobuffer );
 
@@ -45,9 +40,7 @@ public final class DirectWeaver extends ByteDataWriter
 
     int[] faid = size > dataBuffers.ibuf2.length ? new int[size] : dataBuffers.ibuf2;
 
-    if ( debug ) System.out.println( "*** decoding cache of size=" + size + " for lonIdx=" + lonIdx + " latIdx=" + latIdx );
-
-    bc.decodeSortedArray( faid, 0, size, 0x20000000, 0 );
+    bc.decodeSortedArray( faid, 0, size, 29, 0 );
     
     OsmNode[] nodes = new OsmNode[size];
     for( int n = 0; n<size; n++ )
@@ -59,7 +52,6 @@ public final class DirectWeaver extends ByteDataWriter
       if ( node == null )
       {
         node = new OsmNode( ilon, ilat );
-        node.visitID = 0;
       }
       else
       {
@@ -116,7 +108,6 @@ public final class DirectWeaver extends ByteDataWriter
       node.nodeDescription = nodeTags == null ? null : nodeTags.data; // TODO: unified?
 
       int links = bc.decodeNoisyNumber( 1 );
-      if ( debug ) System.out.println( "***   decoding node " + ilon + "/" + ilat + " with links=" + links );
       for( int li=0; li<links; li++ )
       {
         int nodeIdx = n + nodeIdxDiff.decodeSignedValue();
@@ -136,7 +127,6 @@ public final class DirectWeaver extends ByteDataWriter
           dlon_remaining = extLonDiff.decodeSignedValue();
           dlat_remaining = extLatDiff.decodeSignedValue();
         }
-        if ( debug ) System.out.println( "***     decoding link to " + (ilon+dlon_remaining) + "/" + (ilat+dlat_remaining) + " extern=" + (nodeIdx == n) );
 
         TagValueWrapper wayTags = wayTagCoder.decodeTagValueSet();
 
@@ -157,7 +147,6 @@ public final class DirectWeaver extends ByteDataWriter
           }
           
           int transcount = bc.decodeVarBits();
-          if ( debug ) System.out.println( "***       decoding geometry with count=" + transcount );
           int count = transcount+1;
           for( int i=0; i<transcount; i++ )
           {
@@ -212,7 +201,21 @@ public final class DirectWeaver extends ByteDataWriter
     hollowNodes.cleanupAndCount( nodes );
   }
 
-  public long expandId( int id32 )
+  private static final long[] id32_00 = new long[1024];
+  private static final long[] id32_10 = new long[1024];
+  private static final long[] id32_20 = new long[1024];
+
+  static
+  {
+    for( int i=0; i<1024; i++ )
+    {
+      id32_00[i] = _expandId( i       );
+      id32_10[i] = _expandId( i << 10 );
+      id32_20[i] = _expandId( i << 20 );
+    }
+  }
+
+  private static long _expandId( int id32 )
   {
     int dlon = 0;
     int dlat = 0;
@@ -223,11 +226,11 @@ public final class DirectWeaver extends ByteDataWriter
       if ( (id32 & 2) != 0 ) dlat |= bm;
       id32 >>= 2;
     }
-
-    int lon32 = lonBase + dlon;
-    int lat32 = latBase + dlat;
-
-    return ((long)lon32)<<32 | lat32;
+    return ((long)dlon)<<32 | dlat;
   }
 
+  public long expandId( int id32 )
+  {
+    return id64Base + id32_00[ id32 & 1023 ] + id32_10[ (id32>>10) & 1023 ] + id32_20[ (id32>>20) & 1023 ];
+  }
 }
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmNode.java b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmNode.java
index 3cf9ddb..0bcc2b3 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmNode.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmNode.java
@@ -46,7 +46,7 @@ public class OsmNode extends OsmLink implements OsmPos
   /**
    * The links to other nodes
    */
-  public OsmLink firstlink = null;
+  public OsmLink firstlink;
 
   public OsmNode()
   {
@@ -303,12 +303,7 @@ public class OsmNode extends OsmLink implements OsmPos
   @Override
   public final boolean equals( Object o )
   {
-    if ( o instanceof OsmNode )
-    {
-      OsmNode n = (OsmNode) o;
-      return n.ilon == ilon && n.ilat == ilat;
-    }
-    return false;
+    return ((OsmNode)o).ilon == ilon && ((OsmNode)o).ilat == ilat;
   }
 
   @Override
diff --git a/brouter-util/src/main/java/btools/util/BitCoderContext.java b/brouter-util/src/main/java/btools/util/BitCoderContext.java
index 1b88f29..4d80db2 100644
--- a/brouter-util/src/main/java/btools/util/BitCoderContext.java
+++ b/brouter-util/src/main/java/btools/util/BitCoderContext.java
@@ -13,6 +13,8 @@ public class BitCoderContext
   private static final int[] vl_values = new int[4096];
   private static final int[] vl_length = new int[4096];
 
+  private static final int[] reverse_byte = new int[256];
+
   static
   {
     // fill varbits lookup table
@@ -28,6 +30,15 @@ public class BitCoderContext
       vl_values[i] = bc.decodeVarBits2();
       vl_length[i] = bc.getReadingBitPosition() - b0;
     }
+    for( int b=0; b<256; b++ )
+    {
+      int r = 0;
+      for( int i=0; i<8; i++ )
+      {
+        if ( (b & (1<<i) ) != 0 ) r |= 1 << (7-i);
+      }
+      reverse_byte[b] = r;
+    }
   }
 
 
@@ -190,10 +201,6 @@ public class BitCoderContext
 
   public final int decodeBits( int count )
   {
-    if ( count == 0 )
-    {
-      return 0;
-    }
     fillBuffer();
     int mask = 0xffffffff >>> ( 32 - count );
     int value = b & mask;
@@ -202,6 +209,24 @@ public class BitCoderContext
     return value;
   }
 
+  public final int decodeBitsReverse( int count )
+  {
+    fillBuffer();
+    int value = 0;
+    while( count > 8 )
+    {
+      value = (value << 8) | reverse_byte[ b & 0xff ];
+      b >>=8;
+      count -=8;
+      bits -=8;
+      fillBuffer();
+    }
+    value = (value << count) | reverse_byte[ b & 0xff ] >> (8-count);
+    bits -= count;
+    b >>= count;
+    return value;
+  }
+
   private void fillBuffer()
   {
     while (bits < 24)