1 files changed, 125 insertions, 0 deletions
diff --git a/qpid/java/common/src/main/java/org/apache/qpid/transport/Range.java b/qpid/java/common/src/main/java/org/apache/qpid/transport/Range.java
new file mode 100644
index 0000000000..f4335dc8a6
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+++ b/qpid/java/common/src/main/java/org/apache/qpid/transport/Range.java
@@ -0,0 +1,125 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.qpid.transport;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.apache.qpid.util.Serial.*;
+
+
+/**
+ * Range
+ *
+ * @author Rafael H. Schloming
+ */
+
+public final class Range
+{
+    private final int lower;
+    private final int upper;
+
+    public Range(int lower, int upper)
+    {
+        this.lower = lower;
+        this.upper = upper;
+    }
+
+    public int getLower()
+    {
+        return lower;
+    }
+
+    public int getUpper()
+    {
+        return upper;
+    }
+
+    public boolean includes(int value)
+    {
+        return le(lower, value) && le(value, upper);
+    }
+
+    public boolean includes(Range range)
+    {
+        return includes(range.lower) && includes(range.upper);
+    }
+
+    public boolean intersects(Range range)
+    {
+        return (includes(range.lower) || includes(range.upper) ||
+                range.includes(lower) || range.includes(upper));
+    }
+
+    public boolean touches(Range range)
+    {
+        return (intersects(range) ||
+                includes(range.upper + 1) || includes(range.lower - 1) ||
+                range.includes(upper + 1) || range.includes(lower - 1));
+    }
+
+    public Range span(Range range)
+    {
+        return new Range(min(lower, range.lower), max(upper, range.upper));
+    }
+
+    public List<Range> subtract(Range range)
+    {
+        List<Range> result = new ArrayList<Range>();
+
+        if (includes(range.lower) && le(lower, range.lower - 1))
+        {
+            result.add(new Range(lower, range.lower - 1));
+        }
+
+        if (includes(range.upper) && le(range.upper + 1, upper))
+        {
+            result.add(new Range(range.upper + 1, upper));
+        }
+
+        if (result.isEmpty() && !range.includes(this))
+        {
+            result.add(this);
+        }
+
+        return result;
+    }
+
+    public Range intersect(Range range)
+    {
+        int l = max(lower, range.lower);
+        int r = min(upper, range.upper);
+        if (gt(l, r))
+        {
+            return null;
+        }
+        else
+        {
+            return new Range(l, r);
+        }
+    }
+
+    public String toString()
+    {
+        return "[" + lower + ", " + upper + "]";
+    }
+
+}