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package org.openslx.filetransfer.util;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.apache.log4j.Logger;
public class ChunkList
{
private static final Logger LOGGER = Logger.getLogger( ChunkList.class );
/**
* Here we keep a list of all chunks in the proper order, in case we quickly need to access one
*/
private final List<FileChunk> allChunks;
/**
* Chunks that are missing from the file
*/
private final List<FileChunk> missingChunks = new LinkedList<>();
/**
* Chunks that are currently being uploaded or hash-checked
*/
private final List<FileChunk> pendingChunks = new LinkedList<>();
private final List<FileChunk> completeChunks = new ArrayList<>( 100 );
// 0 = complete, 1 = missing, 2 = uploading, 3 = queued for copying, 4 = copying
private final ByteBuffer statusArray;
// Do we need to keep valid chunks, or chunks that failed too many times?
public ChunkList( long fileSize, List<byte[]> sha1Sums )
{
FileChunk.createChunkList( missingChunks, fileSize, sha1Sums );
statusArray = ByteBuffer.allocate( missingChunks.size() );
allChunks = Collections.unmodifiableList( new ArrayList<>( missingChunks ) );
}
/**
* Update the sha1sums of all chunks. This is meant to be used if you passed an incomplete list
* before (with null elements), so you don't have to has hthe whole file before starting the
* upload, but periodically update it while thie upload is running.
*
* @param sha1Sums list of sums
*/
public synchronized void updateSha1Sums( List<byte[]> sha1Sums )
{
int index = 0;
for ( byte[] sum : sha1Sums ) {
if ( index >= allChunks.size() )
break;
if ( sum == null )
continue;
allChunks.get( index ).setSha1Sum( sum );
index++;
}
}
/**
* Get a missing chunk, marking it pending.
*
* @return chunk marked as missing
* @throws InterruptedException
*/
public synchronized FileChunk getMissing() throws InterruptedException
{
if ( missingChunks.isEmpty() && pendingChunks.isEmpty() )
return null;
if ( missingChunks.isEmpty() ) {
this.wait( 6000 );
if ( missingChunks.isEmpty() )
return null;
}
FileChunk c = missingChunks.remove( 0 );
c.setStatus( ChunkStatus.UPLOADING );
pendingChunks.add( c );
return c;
}
/**
* Get the block status as byte representation.
*/
public synchronized ByteBuffer getStatusArray()
{
byte[] array = statusArray.array();
for ( int i = 0; i < array.length; ++i ) {
array[i] = allChunks.get( i ).getStatus().val;
}
return statusArray;
}
/**
* Get completed chunks as list
*
* @return List containing all successfully transfered chunks
*/
public synchronized List<FileChunk> getCompleted()
{
return new ArrayList<>( completeChunks );
}
/**
* Get a chunk that is marked complete, has a sha1 hash, but has not been hash-checked yet.
*
* @return chunk
*/
public synchronized FileChunk getUnhashedComplete()
{
for ( Iterator<FileChunk> it = completeChunks.iterator(); it.hasNext(); ) {
FileChunk chunk = it.next();
if ( chunk.sha1sum != null && chunk.status == ChunkStatus.HASHING ) {
it.remove();
pendingChunks.add( chunk );
return chunk;
}
}
return null;
}
/**
* Mark a chunk currently transferring as successfully transfered.
*
* @param c The chunk in question
*/
public synchronized void markSuccessful( FileChunk c )
{
if ( !pendingChunks.remove( c ) ) {
LOGGER.warn( "Inconsistent state: markSuccessful called for Chunk " + c.toString()
+ ", but chunk is not marked as currently transferring!" );
return;
}
c.setStatus( ChunkStatus.COMPETE );
completeChunks.add( c );
this.notifyAll();
}
/**
* Mark a chunk currently transferring or being hash checked as failed
* transfer. This increases its fail count and re-adds it to the list of
* missing chunks.
*
* @param c The chunk in question
* @return Number of times transfer of this chunk failed
*/
public synchronized int markFailed( FileChunk c )
{
if ( !pendingChunks.remove( c ) ) {
LOGGER.warn( "Inconsistent state: markTransferred called for Chunk " + c.toString()
+ ", but chunk is not marked as currently transferring!" );
return -1;
}
// Add as first element so it will be re-transmitted immediately
c.setStatus( ChunkStatus.MISSING );
missingChunks.add( 0, c );
this.notifyAll();
return c.incFailed();
}
/**
* Check if all blocks in this list are marked as successfully transfered. If a complete chunk is
* marked as "hashing", or if there are some complete chunks without a sha1sum and some with a
* sha1sum, the transfer is considered incomplete.
*
* @return true iff transfer is complete
*/
public synchronized boolean isComplete()
{
if ( !missingChunks.isEmpty() || !pendingChunks.isEmpty() )
return false;
boolean sawWithHash = false;
for ( FileChunk chunk : completeChunks ) {
if ( chunk.status == ChunkStatus.HASHING )
return false;
if ( chunk.sha1sum != null ) {
sawWithHash = true;
} else if ( chunk.sha1sum == null && sawWithHash ) {
return false;
}
}
return true;
}
@Override
public synchronized String toString()
{
StringBuilder sb = new StringBuilder();
sb.append( '{' );
for ( FileChunk chunk : allChunks ) {
sb.append( '[' );
sb.append( chunk.getChunkIndex() );
if ( chunk.getSha1Sum() != null )
sb.append( '+' );
////
switch ( chunk.status ) {
case COMPETE:
sb.append( 'C' );
break;
case COPYING:
sb.append( '>' );
break;
case HASHING:
sb.append( 'H' );
break;
case MISSING:
sb.append( 'M' );
break;
case QUEUED_FOR_COPY:
sb.append( 'Q' );
break;
case UPLOADING:
sb.append( 'P' );
break;
default:
sb.append( '?' );
break;
}
sb.append( '|' ); ////////////
if ( missingChunks.contains( chunk ) )
sb.append( 'M' );
if ( pendingChunks.contains( chunk ) )
sb.append( 'P' );
if ( completeChunks.contains( chunk ) )
sb.append( 'C' );
sb.append( ']' );
}
sb.append( '}' );
return sb.toString();
}
public synchronized boolean isEmpty()
{
return allChunks.isEmpty();
}
public List<FileChunk> getAll()
{
return allChunks;
}
}
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