1 files changed, 83 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/net/packet/PacketProcessor.java b/framework/src/onos/core/api/src/main/java/org/onosproject/net/packet/PacketProcessor.java
new file mode 100644
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--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/net/packet/PacketProcessor.java
@@ -0,0 +1,83 @@
+/*
+ * 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.packet;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Abstraction of an inbound packet processor.
+ */
+public interface PacketProcessor {
+
+    static final int ADVISOR_MAX = Integer.MAX_VALUE / 3;
+    static final int DIRECTOR_MAX = (Integer.MAX_VALUE / 3) * 2;
+    static final int OBSERVER_MAX = Integer.MAX_VALUE;
+
+    /**
+     * Returns a priority in the ADVISOR range, where processors can take early action and
+     * influence the packet context. However, they cannot handle the packet (i.e. call send() or block()).
+     * The valid range is from 1 to ADVISOR_MAX.
+     * Processors in this range get to see the packet first.
+     *
+     * @param priority priority within ADVISOR range
+     * @return overall priority
+     */
+    static int advisor(int priority) {
+        int overallPriority = priority + 1;
+        checkArgument(overallPriority > 0 && overallPriority <= ADVISOR_MAX,
+                "Priority not within ADVISOR range");
+        return overallPriority;
+    }
+
+    /**
+     * Returns a priority in the DIRECTOR range, where processors can handle the packet.
+     * The valid range is from ADVISOR_MAX+1 to DIRECTOR_MAX.
+     * Processors in this range get to see the packet second, after ADVISORS.
+     *
+     * @param priority priority within the DIRECTOR range
+     * @return overall priority
+     */
+    static int director(int priority) {
+        int overallPriority = ADVISOR_MAX + priority + 1;
+        checkArgument(overallPriority > ADVISOR_MAX && overallPriority <= DIRECTOR_MAX,
+                "Priority not within DIRECTOR range");
+        return overallPriority;
+    }
+
+    /**
+     * Returns a priority in the OBSERVER range, where processors cannot take any action,
+     * but can observe what action has been taken until then.
+     * The valid range is from DIRECTOR_MAX+1 to OBSERVER_MAX.
+     * Processors in this range get to see the packet last, after ADVISORS and DIRECTORS.
+     *
+     * @param priority priority within the OBSERVER range
+     * @return overall priority
+     */
+    static int observer(int priority) {
+        int overallPriority = DIRECTOR_MAX + priority + 1;
+        checkArgument(overallPriority > DIRECTOR_MAX && overallPriority <= OBSERVER_MAX,
+                "Priority not within OBSERVER range");
+        return overallPriority;
+    }
+
+    /**
+     * Processes the inbound packet as specified in the given context.
+     *
+     * @param context packet processing context
+     */
+    void process(PacketContext context);
+
+}