Refactored code to consolidate functionality in Database* classes.
Renamed few methods and variables to align with local convention and also to match the description of functionality.
Change-Id: Ib17e73079534c76f76bcb01f14b6496e62275dbd
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/Match.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/Match.java
new file mode 100644
index 0000000..093e02c
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/Match.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2015 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.store.consistent.impl;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+import java.util.Arrays;
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * Utility class for checking matching values.
+ *
+ * @param <T> type of value
+ */
+public final class Match<T> {
+
+ private final boolean matchAny;
+ private final T value;
+
+ /**
+ * Returns a Match that matches any value.
+ * @param <T> match type
+ * @return new instance
+ */
+ public static <T> Match<T> any() {
+ return new Match<>();
+ }
+
+ /**
+ * Returns a Match that matches null values.
+ * @param <T> match type
+ * @return new instance
+ */
+ public static <T> Match<T> ifNull() {
+ return ifValue(null);
+ }
+
+ /**
+ * Returns a Match that matches only specified value.
+ * @param value value to match
+ * @param <T> match type
+ * @return new instance
+ */
+ public static <T> Match<T> ifValue(T value) {
+ return new Match<>(value);
+ }
+
+ private Match() {
+ matchAny = true;
+ value = null;
+ }
+
+ private Match(T value) {
+ matchAny = false;
+ this.value = value;
+ }
+
+ /**
+ * Maps this instance to a Match of another type.
+ * @param mapper transformation function
+ * @param <V> new match type
+ * @return new instance
+ */
+ public <V> Match<V> map(Function<T, V> mapper) {
+ if (matchAny) {
+ return any();
+ } else if (value == null) {
+ return ifNull();
+ } else {
+ return ifValue(mapper.apply(value));
+ }
+ }
+
+ /**
+ * Checks if this instance matches specified value.
+ * @param other other value
+ * @return true if matches; false otherwise
+ */
+ public boolean matches(T other) {
+ if (matchAny) {
+ return true;
+ } else if (other == null) {
+ return value == null;
+ } else {
+ if (value instanceof byte[]) {
+ return Arrays.equals((byte[]) value, (byte[]) other);
+ }
+ return Objects.equals(value, other);
+ }
+ }
+
+ @Override
+ public String toString() {
+ return toStringHelper(this)
+ .add("matchAny", matchAny)
+ .add("value", value)
+ .toString();
+ }
+}