Merge pull request #9 from Philreact/master-kenny3

fix in digest, was putting whole file in memory.

src/main/java/org/qortal/arbitrary/ArbitraryDataDigest.java

@@ -4,6 +4,7 @@ import org.qortal.repository.DataException;
 import org.qortal.utils.Base58;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.FileSystem;
 import java.nio.file.Files;
@@ -25,47 +26,53 @@ public class ArbitraryDataDigest {
     }
 
     public void compute() throws IOException, DataException {
-        List<Path> allPaths = Files.walk(path).filter(Files::isRegularFile).sorted().collect(Collectors.toList());
+        List<Path> allPaths = Files.walk(path)
+            .filter(Files::isRegularFile)
+            .sorted()
+            .collect(Collectors.toList());
+    
         Path basePathAbsolute = this.path.toAbsolutePath();
-
+    
         MessageDigest sha256;
         try {
             sha256 = MessageDigest.getInstance("SHA-256");
         } catch (NoSuchAlgorithmException e) {
             throw new DataException("SHA-256 hashing algorithm unavailable");
         }
-
+    
         for (Path path : allPaths) {
             // We need to work with paths relative to the base path, to ensure the same hash
             // is generated on different systems
             Path relativePath = basePathAbsolute.relativize(path.toAbsolutePath());
-
+    
             // Exclude Qortal folder since it can be different each time
             // We only care about hashing the actual user data
             if (relativePath.startsWith(".qortal/")) {
                 continue;
             }
-
+    
             // Account for \ VS / : Linux VS Windows
             String pathString = relativePath.toString();
-
+            if (relativePath.getFileSystem().toString().contains("Windows")) {
-            if(relativePath.getFileSystem().toString().contains("Windows")) {
+                pathString = pathString.replace("\\", "/");
-                pathString = pathString.replace("\\","/");
             }
-
+    
             // Hash path
             byte[] filePathBytes = pathString.getBytes(StandardCharsets.UTF_8);
-            System.out.printf("Path: %s \n", pathString);
-            System.out.printf("Path Byte Array: %s \n", Arrays.toString(filePathBytes));
             sha256.update(filePathBytes);
-
+    
-            // Hash contents
+            try (InputStream in = Files.newInputStream(path)) {
-            byte[] fileContent = Files.readAllBytes(path);
+                byte[] buffer = new byte[65536]; // 64 KB
-            System.out.printf("File Content: %s \n", Arrays.toString(fileContent));
+                int bytesRead;
-            sha256.update(fileContent);
+                while ((bytesRead = in.read(buffer)) != -1) {
+                    sha256.update(buffer, 0, bytesRead);
+                }
+            }
         }
+    
         this.hash = sha256.digest();
     }
+    
 
     public boolean isHashValid(byte[] hash) {
         return Arrays.equals(hash, this.hash);