More refactoring

src/main/java/org/qortal/api/resource/WebsiteResource.java

@@ -295,7 +295,7 @@ public class WebsiteResource {
                 byte[] chunkHashes = transactionData.getChunkHashes();
 
                 // Load data file(s)
-                DataFile dataFile = DataFile.fromDigest(digest);
+                DataFile dataFile = DataFile.fromHash(digest);
                 if (!dataFile.exists()) {
                     if (!dataFile.allChunksExist(chunkHashes)) {
                         // TODO: fetch them?

src/main/java/org/qortal/network/message/GetDataFileMessage.java

@@ -1,5 +1,7 @@
 package org.qortal.network.message;
 
+import org.qortal.transform.transaction.TransactionTransformer;
+
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
@@ -7,33 +9,33 @@ import java.nio.ByteBuffer;
 
 public class GetDataFileMessage extends Message {
 
-	private static final int DIGEST_LENGTH = 32;
+	private static final int HASH_LENGTH = TransactionTransformer.SHA256_LENGTH;
 
-	private final byte[] digest;
+	private final byte[] hash;
 
-	public GetDataFileMessage(byte[] digest) {
-		this(-1, digest);
+	public GetDataFileMessage(byte[] hash) {
+		this(-1, hash);
 	}
 
-	private GetDataFileMessage(int id, byte[] digest) {
+	private GetDataFileMessage(int id, byte[] hash) {
 		super(id, MessageType.GET_DATA_FILE);
 
-		this.digest = digest;
+		this.hash = hash;
 	}
 
-	public byte[] getDigest() {
-		return this.digest;
+	public byte[] getHash() {
+		return this.hash;
 	}
 
 	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != DIGEST_LENGTH)
+		if (bytes.remaining() != HASH_LENGTH)
 			return null;
 
-		byte[] digest = new byte[DIGEST_LENGTH];
+		byte[] hash = new byte[HASH_LENGTH];
 
-		bytes.get(digest);
+		bytes.get(hash);
 
-		return new GetDataFileMessage(id, digest);
+		return new GetDataFileMessage(id, hash);
 	}
 
 	@Override
@@ -41,7 +43,7 @@ public class GetDataFileMessage extends Message {
 		try {
 			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
 
-			bytes.write(this.digest);
+			bytes.write(this.hash);
 
 			return bytes.toByteArray();
 		} catch (IOException e) {

src/main/java/org/qortal/repository/hsqldb/HSQLDBArbitraryRepository.java

@@ -47,7 +47,7 @@ public class HSQLDBArbitraryRepository implements ArbitraryRepository {
 		byte[] chunkHashes = transactionData.getChunkHashes();
 
 		// Load data file(s)
-		DataFile dataFile = DataFile.fromDigest(digest);
+		DataFile dataFile = DataFile.fromHash(digest);
 		if (chunkHashes.length > 0) {
 			dataFile.addChunkHashes(chunkHashes);
 		}
@@ -82,7 +82,7 @@ public class HSQLDBArbitraryRepository implements ArbitraryRepository {
 		byte[] chunkHashes = transactionData.getChunkHashes();
 
 		// Load data file(s)
-		DataFile dataFile = DataFile.fromDigest(digest);
+		DataFile dataFile = DataFile.fromHash(digest);
 		if (chunkHashes.length > 0) {
 			dataFile.addChunkHashes(chunkHashes);
 		}
@@ -167,7 +167,7 @@ public class HSQLDBArbitraryRepository implements ArbitraryRepository {
 		byte[] chunkHashes = arbitraryTransactionData.getChunkHashes();
 
 		// Load data file(s)
-		DataFile dataFile = DataFile.fromDigest(digest);
+		DataFile dataFile = DataFile.fromHash(digest);
 		if (chunkHashes.length > 0) {
 			dataFile.addChunkHashes(chunkHashes);
 		}

src/main/java/org/qortal/storage/DataFile.java

@@ -90,8 +90,8 @@ public class DataFile {
         return new DataFile(hash58);
     }
 
-    public static DataFile fromDigest(byte[] digest) {
-        return DataFile.fromHash58(Base58.encode(digest));
+    public static DataFile fromHash(byte[] hash) {
+        return DataFile.fromHash58(Base58.encode(hash));
     }
 
     public static DataFile fromPath(String path) {
@@ -100,7 +100,7 @@ public class DataFile {
             try {
                 byte[] fileContent = Files.readAllBytes(file.toPath());
                 byte[] digest = Crypto.digest(fileContent);
-                DataFile dataFile = DataFile.fromDigest(digest);
+                DataFile dataFile = DataFile.fromHash(digest);
 
                 // Copy file to base directory if needed
                 Path filePath = Paths.get(path);
@@ -194,6 +194,9 @@ public class DataFile {
     }
 
     public void addChunkHashes(byte[] chunks) {
+        if (chunks == null || chunks.length == 0) {
+            return;
+        }
         ByteBuffer byteBuffer = ByteBuffer.wrap(chunks);
         while (byteBuffer.remaining() >= TransactionTransformer.SHA256_LENGTH) {
             byte[] chunkDigest = new byte[TransactionTransformer.SHA256_LENGTH];