1 files changed, 70 insertions, 0 deletions
diff --git a/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollection2.java b/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollection2.java
new file mode 100644
index 0000000..8d8eb14
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollection2.java
@@ -0,0 +1,70 @@
+package com.keuin.kbackupfabric.backup.incremental;
+
+import java.io.Serializable;
+import java.util.*;
+
+/**
+ * This class must be in package `com.keuin.kbackupfabric.util.backup.incremental.ObjectCollection`,
+ * or it will not be compatible with old backups.
+ */
+public class ObjectCollection2 implements Serializable {
+
+    private final String name;
+    private final Map<String, ObjectElement> elements;
+    private final Map<String, ObjectCollection2> subCollections;
+
+    ObjectCollection2(String name, Set<ObjectElement> elements, Map<String, ObjectCollection2> subCollections) {
+        this.name = Objects.requireNonNull(name);
+        this.elements = new HashMap<>();
+        for (ObjectElement e : elements) {
+            Objects.requireNonNull(e);
+            if (this.elements.put(e.getName(), e) != null) {
+                throw new IllegalStateException("elements conflict with the same name");
+            }
+        }
+        this.subCollections = new HashMap<>(Objects.requireNonNull(subCollections));
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Set<ObjectElement> getElementSet() {
+        return new HashSet<>(elements.values());
+    }
+
+    public Map<String, ObjectElement> getElementMap() {
+        return Collections.unmodifiableMap(elements);
+    }
+
+    public ObjectElement getElement(String name) {
+        return elements.get(name);
+    }
+
+    public Set<ObjectCollection2> getSubCollectionSet() {
+        return new HashSet<>(subCollections.values());
+    }
+
+    public Map<String, ObjectCollection2> getSubCollectionMap() {
+        return Collections.unmodifiableMap(subCollections);
+    }
+
+    public ObjectCollection2 getSubCollection(String name) {
+        return subCollections.get(name);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ObjectCollection2 that = (ObjectCollection2) o;
+        return name.equals(that.name) &&
+                elements.equals(that.elements) &&
+                subCollections.equals(that.subCollections);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, elements, subCollections);
+    }
+}