Moved file chunk helper classes from dozmod-server to shared lib

1 files changed, 77 insertions, 0 deletions

diff --git a/src/main/java/org/openslx/filetransfer/util/FileChunk.java b/src/main/java/org/openslx/filetransfer/util/FileChunk.java
new file mode 100644
index 0000000..3e89b84
--- /dev/null
+++ b/src/main/java/org/openslx/filetransfer/util/FileChunk.java
@@ -0,0 +1,77 @@
+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;
+		}
+	}
+}