corrected lazy crc logic

brouter-codec/src/main/java/btools/codec/MicroCache2.java

@@ -34,15 +34,13 @@ public final class MicroCache2 extends MicroCache
   	return b;
   }
 
-  public MicroCache2( DataBuffers dataBuffers, int lonIdx, int latIdx, int divisor, TagValueValidator wayValidator, WaypointMatcher waypointMatcher ) throws Exception
+  public MicroCache2( StatCoderContext bc, DataBuffers dataBuffers, int lonIdx, int latIdx, int divisor, TagValueValidator wayValidator, WaypointMatcher waypointMatcher ) throws Exception
   {
     super( null );
     cellsize = 1000000 / divisor;
     lonBase = lonIdx*cellsize;
     latBase = latIdx*cellsize;
 
-    StatCoderContext bc = new StatCoderContext( dataBuffers.iobuffer );
-
     TagValueCoder wayTagCoder = new TagValueCoder( bc, dataBuffers, wayValidator );
     TagValueCoder nodeTagCoder = new TagValueCoder( bc, dataBuffers, null );
     NoisyDiffCoder nodeIdxDiff = new NoisyDiffCoder( bc );

brouter-map-creator/src/main/java/btools/mapcreator/WayLinker.java

@@ -433,7 +433,7 @@ public class WayLinker extends MapCreatorBase
                     System.arraycopy( abBuf1, 0, subBytes, 0, len );
 
                     // cross-check the encoding: re-instantiate the cache
-                    MicroCache mc2 = new MicroCache2( new DataBuffers( subBytes ), lonIdxDiv, latIdxDiv, divisor, null, null );
+                    MicroCache mc2 = new MicroCache2( new StatCoderContext( subBytes ), new DataBuffers( null ), lonIdxDiv, latIdxDiv, divisor, null, null );
                     // ..and check if still the same
                     String diffMessage = mc.compareWith( mc2 );
                     if ( diffMessage != null )

brouter-mapaccess/src/main/java/btools/mapaccess/DirectWeaver.java

@@ -20,14 +20,12 @@ public final class DirectWeaver extends ByteDataWriter
 
   private int size = 0;
 
-  public DirectWeaver( DataBuffers dataBuffers, int lonIdx, int latIdx, int divisor, TagValueValidator wayValidator, WaypointMatcher waypointMatcher, OsmNodesMap hollowNodes ) throws Exception
+  public DirectWeaver( StatCoderContext bc, DataBuffers dataBuffers, int lonIdx, int latIdx, int divisor, TagValueValidator wayValidator, WaypointMatcher waypointMatcher, OsmNodesMap hollowNodes ) throws Exception
   {
     super( null );
     int cellsize = 1000000 / divisor;
     id64Base = ((long)(lonIdx*cellsize))<<32 | (latIdx*cellsize);
 
-    StatCoderContext bc = new StatCoderContext( dataBuffers.iobuffer );
-
     TagValueCoder wayTagCoder = new TagValueCoder( bc, dataBuffers, wayValidator );
     TagValueCoder nodeTagCoder = new TagValueCoder( bc, dataBuffers, null );
     NoisyDiffCoder nodeIdxDiff = new NoisyDiffCoder( bc );

brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java

@@ -11,6 +11,7 @@ import java.io.RandomAccessFile;
 import btools.codec.DataBuffers;
 import btools.codec.MicroCache;
 import btools.codec.MicroCache2;
+import btools.codec.StatCoderContext;
 import btools.codec.TagValueValidator;
 import btools.codec.WaypointMatcher;
 import btools.util.ByteDataReader;
@@ -142,9 +143,10 @@ final class OsmFile
     {
       ab = new byte[asize];
       asize = getDataInputForSubIdx( subIdx, ab );
-      dataBuffers = new DataBuffers( ab );
     }
 
+    StatCoderContext bc = new StatCoderContext( ab );
+
     try
     {
       if ( !reallyDecode )
@@ -153,25 +155,28 @@ final class OsmFile
       }
       if ( hollowNodes == null )
       {
-        return new MicroCache2( dataBuffers, lonIdx, latIdx, divisor, wayValidator, waypointMatcher );
+        return new MicroCache2( bc, dataBuffers, lonIdx, latIdx, divisor, wayValidator, waypointMatcher );
       }
-      new DirectWeaver( dataBuffers, lonIdx, latIdx, divisor, wayValidator, waypointMatcher, hollowNodes );
+      new DirectWeaver( bc, dataBuffers, lonIdx, latIdx, divisor, wayValidator, waypointMatcher, hollowNodes );
       return MicroCache.emptyNonVirgin;
     }
-    catch( Throwable t )
+    finally
+    {
+      // crc check only if the buffer has not been fully read 
+      int readBytes = (bc.getReadingBitPosition()+7)>>3;
+      if ( readBytes != asize-4 )
       {
-      // checksum test now only in case of trouble
         int crcData = Crc32.crc( ab, 0, asize - 4 );
         int crcFooter = new ByteDataReader( ab, asize - 4 ).readInt();
         if ( crcData == crcFooter )
         {
           throw new IOException( "old, unsupported data-format" );
         }
-      else if ( ( crcData ^ 2 ) == crcFooter )
+        else if ( ( crcData ^ 2 ) != crcFooter )
         {
           throw new IOException( "checkum error" );
         }
-      throw t instanceof Exception ? (Exception)t : new Exception( t.toString(), t );
+      }
     }
   }
 

brouter-util/src/main/java/btools/util/BitCoderContext.java

@@ -287,9 +287,9 @@ public class BitCoderContext
   {
     while (bits < 24)
     {
-      if ( idx < idxMax )
+      if ( idx++ < idxMax )
       {
-        b |= (ab[++idx] & 0xff) << bits;
+        b |= (ab[idx] & 0xff) << bits;
       }
       bits += 8;
     }