rd5 diff progress

This commit is contained in:
Arndt Brenschede 2020-01-18 19:05:35 +01:00
parent 19a7555483
commit db4757abbb
2 changed files with 133 additions and 6 deletions

View file

@ -0,0 +1,119 @@
/**
* Proof of concept for delta rd5's
*
* @author ab
*/
package btools.mapaccess;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
final public class Rd5DiffManager
{
public static void main( String[] args ) throws Exception
{
calcDiffs( new File( args[0] ),new File( args[1] ) );
}
/**
* Compute diffs for all RD5 files
*/
public static void calcDiffs( File oldDir, File newDir ) throws Exception
{
File oldDiffDir = new File( oldDir, "diff" );
File newDiffDir = new File( newDir, "diff" );
File[] filesNew = newDir.listFiles();
for( File fn : filesNew )
{
String name = fn.getName();
if ( !name.endsWith( ".rd5" ) )
{
continue;
}
if ( fn.length() < 1024*1024 )
{
continue; // exclude very small files from diffing
}
String basename = name.substring( 0, name.length() - 4 );
File fo = new File( oldDir, name );
if ( !fo.isFile() )
{
continue;
}
// calculate MD5 of old file
String md5 = getMD5( fo );
System.out.println( "name=" + name + " md5=" + md5 );
File specificNewDiffs = new File( newDiffDir, basename );
specificNewDiffs.mkdirs();
String diffFileName = md5 + ".rd5diff";
File diffFile = new File( specificNewDiffs, diffFileName );
// calc the new diff
Rd5DiffTool.diff2files( fo, fn, diffFile );
// ... and add that to old diff files
File specificOldDiffs = new File( oldDiffDir, basename );
if ( specificOldDiffs.isDirectory() )
{
File[] oldDiffs = specificOldDiffs.listFiles();
for( File od : oldDiffs )
{
if ( !od.getName().endsWith( ".rd5diff" ) )
{
continue;
}
if ( System.currentTimeMillis() - od.lastModified() > 31*86400000L )
{
continue; // limit diff history to 31 days
}
File updatedDiff = new File( specificNewDiffs, od.getName() );
Rd5DiffTool.addDeltas( od, diffFile, updatedDiff );
updatedDiff.setLastModified( od.lastModified() );
}
}
}
}
public static String getMD5( File f ) throws Exception
{
MessageDigest md = MessageDigest.getInstance("MD5");
BufferedInputStream bis = new BufferedInputStream( new FileInputStream( f ) );
DigestInputStream dis = new DigestInputStream(bis, md);
byte[] buf = new byte[8192];
for(;;)
{
int len = dis.read( buf );
if ( len <= 0 )
{
break;
}
}
dis.close();
byte[] bytes = md.digest();
StringBuilder sb = new StringBuilder();
for (int j = 0; j < bytes.length; j++)
{
int v = bytes[j] & 0xff;
sb.append( hexChar( v >>> 4 ) ).append( hexChar( v & 0xf ) );
}
return sb.toString();
}
private static char hexChar( int v )
{
return (char) ( v > 9 ? 'a' + (v-10) : '0' + v );
}
}

View file

@ -138,6 +138,8 @@ final public class Rd5DiffTool
long[] fileIndex1 = readFileIndex( dis1, null ); long[] fileIndex1 = readFileIndex( dis1, null );
long[] fileIndex2 = readFileIndex( dis2, dos ); long[] fileIndex2 = readFileIndex( dis2, dos );
long t0 = System.currentTimeMillis();
try try
{ {
DataBuffers dataBuffers = new DataBuffers(); DataBuffers dataBuffers = new DataBuffers();
@ -181,15 +183,15 @@ final public class Rd5DiffTool
dos.writeInt( len ); dos.writeInt( len );
dos.write( abBuf1, 0, len ); dos.write( abBuf1, 0, len );
// do some consistemcy checks on the encoding bytesDiff += len;
nodesDiff += mc.getSize();
diffedTiles++;
/* // do some consistemcy checks on the encoding
byte[] bytes = new byte[len]; byte[] bytes = new byte[len];
System.arraycopy( abBuf1, 0, bytes, 0, len ); System.arraycopy( abBuf1, 0, bytes, 0, len );
bytesDiff += len;
nodesDiff += mc.getSize();
diffedTiles++;
// cross-check the encoding: decode again // cross-check the encoding: decode again
MicroCache mcCheck = new MicroCache2( new StatCoderContext( bytes ), new DataBuffers( null ), 0, 0, 32, null, null ); MicroCache mcCheck = new MicroCache2( new StatCoderContext( bytes ), new DataBuffers( null ), 0, 0, 32, null, null );
@ -220,6 +222,7 @@ final public class Rd5DiffTool
throw new IllegalArgumentException( "decoded data mismatch at i=" + i ); throw new IllegalArgumentException( "decoded data mismatch at i=" + i );
} }
} }
*/
} }
} }
} }
@ -233,7 +236,8 @@ final public class Rd5DiffTool
} }
dos.write( abBuf1, 0, len ); dos.write( abBuf1, 0, len );
} }
System.out.println( "nodesDiff=" + nodesDiff + " bytesDiff=" + bytesDiff + " diffedTiles=" + diffedTiles ); long t1 = System.currentTimeMillis();
System.out.println( "nodesDiff=" + nodesDiff + " bytesDiff=" + bytesDiff + " diffedTiles=" + diffedTiles + " took " + (t1-t0) + "ms" );
} }
finally finally
{ {
@ -416,6 +420,8 @@ final public class Rd5DiffTool
long[] fileIndex1 = readFileIndex( dis1, null ); long[] fileIndex1 = readFileIndex( dis1, null );
long[] fileIndex2 = readFileIndex( dis2, dos ); long[] fileIndex2 = readFileIndex( dis2, dos );
long t0 = System.currentTimeMillis();
try try
{ {
DataBuffers dataBuffers = new DataBuffers(); DataBuffers dataBuffers = new DataBuffers();
@ -475,6 +481,8 @@ final public class Rd5DiffTool
} }
dos.write( abBuf1, 0, len ); dos.write( abBuf1, 0, len );
} }
long t1 = System.currentTimeMillis();
System.out.println( "adding diffs took " + (t1-t0) + "ms" );
} }
finally finally
{ {