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package org.openslx.filetransfer.util;
import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.List;
import org.openslx.filetransfer.FileRange;
public class FileChunk {
public static final int CHUNK_SIZE_MIB = 16;
public static final int CHUNK_SIZE = CHUNK_SIZE_MIB * (1024 * 1024);
public final FileRange range;
public final byte[] sha1sum;
private int failCount = 0;
public FileChunk(long startOffset, long endOffset, byte[] sha1sum) {
this.range = new FileRange(startOffset, endOffset);
this.sha1sum = sha1sum;
}
/**
* Signal that transferring this chunk seems to have failed (checksum
* mismatch).
*
* @return Number of times the transfer failed now
*/
public synchronized int incFailed() {
return ++failCount;
}
public int getChunkIndex() {
return (int)(range.startOffset / CHUNK_SIZE);
}
@Override
public String toString() {
return "[Chunk " + getChunkIndex() + " (" + range.startOffset + "-" + range.endOffset + "), fails: " + failCount + "]";
}
//
public static int fileSizeToChunkCount(long fileSize) {
return (int) ((fileSize + CHUNK_SIZE - 1) / CHUNK_SIZE);
}
public static void createChunkList(Collection<FileChunk> list, long fileSize, List<ByteBuffer> sha1Sums) {
if (fileSize < 0)
throw new IllegalArgumentException("fileSize cannot be negative");
if (!list.isEmpty())
throw new IllegalArgumentException("Passed list is not empty");
long chunkCount = fileSizeToChunkCount(fileSize);
if (sha1Sums != null) {
if (sha1Sums.size() != chunkCount)
throw new IllegalArgumentException(
"Passed a sha1sum list, but hash count in list doesn't match expected chunk count");
long offset = 0;
for (ByteBuffer sha1sum : sha1Sums) { // Do this as we don't know how efficient List.get(index) is...
long end = offset + CHUNK_SIZE;
if (end > fileSize)
end = fileSize;
list.add(new FileChunk(offset, end, sha1sum.array()));
offset = end;
}
return;
}
long offset = 0;
while (offset < fileSize) { // ...otherwise we could share this code
long end = offset + CHUNK_SIZE;
if (end > fileSize)
end = fileSize;
list.add(new FileChunk(offset, end, null));
offset = end;
}
}
}
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