Define sub-types of Bandwidth to reduce round-off error
Two sub-types are defined
- LongBandwidth
- DoubleBandwidth
LongBandwidth can reduce round-off error cause by floating point arithmetics.
These classes are not exposed outside the package and only instantiated
through static factory methods.
Change-Id: Ice5d8ff1397c9dd9c8c1fff46af256fff08fa616
diff --git a/utils/misc/src/main/java/org/onlab/util/LongBandwidth.java b/utils/misc/src/main/java/org/onlab/util/LongBandwidth.java
new file mode 100644
index 0000000..d45f715
--- /dev/null
+++ b/utils/misc/src/main/java/org/onlab/util/LongBandwidth.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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 org.onlab.util;
+
+import com.google.common.collect.ComparisonChain;
+
+/**
+ * Representation of bandwidth.
+ * Use the static factory method corresponding to the unit (like Kbps) you desire on instantiation.
+ */
+final class LongBandwidth implements Bandwidth {
+
+ private final long bps;
+
+ /**
+ * Creates a new instance with given bandwidth.
+ *
+ * @param bps bandwidth value to be assigned
+ */
+ LongBandwidth(long bps) {
+ this.bps = bps;
+ }
+
+ // Constructor for serialization
+ private LongBandwidth() {
+ this.bps = 0;
+ }
+ /**
+ * Returns bandwidth in bps.
+ *
+ * @return bandwidth in bps.
+ */
+ public double bps() {
+ return bps;
+ }
+
+ /**
+ * Returns a Bandwidth whose value is (this + value).
+ *
+ * @param value value to be added to this Frequency
+ * @return this + value
+ */
+ public Bandwidth add(Bandwidth value) {
+ if (value instanceof LongBandwidth) {
+ return Bandwidth.bps(this.bps + ((LongBandwidth) value).bps);
+ }
+ return Bandwidth.bps(this.bps + value.bps());
+ }
+
+ /**
+ * Returns a Bandwidth whose value is (this - value).
+ *
+ * @param value value to be added to this Frequency
+ * @return this - value
+ */
+ public Bandwidth subtract(Bandwidth value) {
+ if (value instanceof LongBandwidth) {
+ return Bandwidth.bps(this.bps - ((LongBandwidth) value).bps);
+ }
+ return Bandwidth.bps(this.bps - value.bps());
+ }
+
+ @Override
+ public int compareTo(Bandwidth other) {
+ if (other instanceof LongBandwidth) {
+ return ComparisonChain.start()
+ .compare(this.bps, ((LongBandwidth) other).bps)
+ .result();
+ }
+ return ComparisonChain.start()
+ .compare(this.bps, other.bps())
+ .result();
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (obj == this) {
+ return true;
+ }
+
+ if (obj instanceof Bandwidth) {
+ return this.compareTo((Bandwidth) obj) == 0;
+ }
+
+ return false;
+ }
+
+ @Override
+ public int hashCode() {
+ return Long.hashCode(bps);
+ }
+
+ @Override
+ public String toString() {
+ return String.valueOf(this.bps);
+ }
+}