1 files changed, 61 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/skyframe/IntVersion.java b/src/main/java/com/google/devtools/build/skyframe/IntVersion.java
new file mode 100644
index 0000000000..3d2a31d9b9
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/skyframe/IntVersion.java
@@ -0,0 +1,61 @@
+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.skyframe;
+
+/**
+ * Versioning scheme based on integers.
+ */
+public final class IntVersion implements Version {
+
+  private final long val;
+
+  public IntVersion(long val) {
+    this.val = val;
+  }
+
+  public long getVal() {
+    return val;
+  }
+
+  public IntVersion next() {
+    return new IntVersion(val + 1);
+  }
+
+  @Override
+  public boolean atMost(Version other) {
+    if (!(other instanceof IntVersion)) {
+      return false;
+    }
+    return val <= ((IntVersion) other).val;
+  }
+
+  @Override
+  public int hashCode() {
+    return Long.valueOf(val).hashCode();
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj instanceof IntVersion) {
+      IntVersion other = (IntVersion) obj;
+      return other.val == val;
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return "IntVersion: " + val;
+  }
+}