ONOS-6464 interfaces for protocol-independence (PI)

And also ONOS-6553, implementation of table entry classes

Change-Id: Ia7146b1bb0aac794e19b3fd8150c042e7ec70535
diff --git a/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
new file mode 100644
index 0000000..ab05f26
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2017-present 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.flow.criteria;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Objects;
+import org.onosproject.net.pi.runtime.PiFieldMatch;
+
+import java.util.Collection;
+import java.util.StringJoiner;
+
+/**
+ * Protocol-indepedent criterion.
+ */
+@Beta
+public final class PiCriterion implements Criterion {
+
+    private final Collection<PiFieldMatch> fieldMatches;
+
+    /**
+     * Creates a new protocol-independent criterion for the given match fields.
+     *
+     * @param fieldMatches fields to match
+     */
+    PiCriterion(Collection<PiFieldMatch> fieldMatches) {
+        this.fieldMatches = fieldMatches;
+    }
+
+    /**
+     * Returns the match parameters map of this selector.
+     *
+     * @return a match parameter map
+     */
+    public Collection<PiFieldMatch> fieldMatches() {
+        return fieldMatches;
+    }
+
+    @Override
+    public Type type() {
+        return Type.PROTOCOL_INDEPENDENT;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        PiCriterion that = (PiCriterion) o;
+        return Objects.equal(fieldMatches, that.fieldMatches);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(fieldMatches);
+    }
+
+    @Override
+    public String toString() {
+        StringJoiner stringParams = new StringJoiner(", ", "{", "}");
+        fieldMatches.forEach(f -> stringParams.add(f.toString()));
+        return stringParams.toString();
+    }
+}