1 files changed, 111 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/net/statistic/DefaultLoad.java b/framework/src/onos/core/api/src/main/java/org/onosproject/net/statistic/DefaultLoad.java
new file mode 100644
index 00000000..45e85372
--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/net/statistic/DefaultLoad.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2014 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.onosproject.net.statistic;
+
+import com.google.common.base.MoreObjects;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Implementation of a load.
+ */
+public class DefaultLoad implements Load {
+
+    private final boolean isValid;
+    private final long current;
+    private final long previous;
+    private final long time;
+    private final long interval;
+
+    /**
+     * Indicates the flow statistics poll interval in seconds.
+     */
+    private static long pollInterval = 10;
+
+    /**
+     * Creates an invalid load.
+     */
+    public DefaultLoad() {
+        this.isValid = false;
+        this.time = System.currentTimeMillis();
+        this.current = -1;
+        this.previous = -1;
+        this.interval = pollInterval;
+    }
+
+    /**
+     * Creates a load value from the parameters.
+     *
+     * @param current  the current value
+     * @param previous the previous value
+     */
+    public DefaultLoad(long current, long previous) {
+        this(current, previous, pollInterval);
+    }
+
+    /**
+     * Creates a load value from the parameters.
+     *
+     * @param current  the current value
+     * @param previous the previous value
+     * @param interval poll interval for this load
+     */
+    public DefaultLoad(long current, long previous, long interval) {
+        checkArgument(interval > 0, "Interval must be greater than 0");
+        this.current = current;
+        this.previous = previous;
+        this.time = System.currentTimeMillis();
+        this.isValid = true;
+        this.interval = interval;
+    }
+
+    /**
+     * Sets the poll interval in seconds. Used solely for the purpose of
+     * computing the load.
+     *
+     * @param newPollInterval poll interval duration in seconds
+     */
+    public static void setPollInterval(long newPollInterval) {
+        pollInterval = newPollInterval;
+    }
+
+    @Override
+    public long rate() {
+        return (current - previous) / interval;
+    }
+
+    @Override
+    public long latest() {
+        return current;
+    }
+
+    @Override
+    public boolean isValid() {
+        return isValid;
+    }
+
+    @Override
+    public long time() {
+        return time;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper("Load").add("rate", rate())
+                .add("latest", latest()).toString();
+
+    }
+}