1 files changed, 53 insertions, 0 deletions
diff --git a/src/main/java/com/keuin/kbackupfabric/backup/incremental/identifier/SingleHashIdentifier.java b/src/main/java/com/keuin/kbackupfabric/backup/incremental/identifier/SingleHashIdentifier.java
new file mode 100644
index 0000000..9fd61c8
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/backup/incremental/identifier/SingleHashIdentifier.java
@@ -0,0 +1,53 @@
+package com.keuin.kbackupfabric.backup.incremental.identifier;
+
+import com.keuin.kbackupfabric.util.BytesUtil;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * A simple identifier based on a single hash function.
+ * Immutable.
+ */
+public abstract class SingleHashIdentifier implements ObjectIdentifier {
+
+    private final byte[] hash;
+    private final String type;
+
+    protected SingleHashIdentifier(byte[] hash, String type) {
+        Objects.requireNonNull(hash);
+        Objects.requireNonNull(type);
+        this.hash = Arrays.copyOf(hash, hash.length);
+        this.type = type;
+    }
+
+    /**
+     * The hash function.
+     *
+     * @param file the file to be hashed.
+     * @return the hash bytes.
+     */
+    protected abstract byte[] hash(File file) throws IOException;
+
+    @Override
+    public String getIdentification() {
+        return type + "-" + BytesUtil.bytesToHex(hash);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (!(obj instanceof SingleHashIdentifier)) {
+            return false;
+        }
+        return Arrays.equals(hash, ((SingleHashIdentifier) obj).hash);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hash(type);
+        result = 31 * result + Arrays.hashCode(hash);
+        return result;
+    }
+}