CachePeekMode.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.ignite.cache;

import org.apache.ignite.IgniteCache;
import org.jetbrains.annotations.Nullable;

/**
 * Enumeration of all supported cache peek modes. Peek modes can be passed
 * into {@link IgniteCache#localPeek(Object, CachePeekMode...)},
 * {@link IgniteCache#localEntries(CachePeekMode...)},
 * {@link IgniteCache#localSize(CachePeekMode...)} and
 * {@link IgniteCache#size(CachePeekMode...)} methods.
 * <p>
 * The following modes are supported:
 * <ul>
 * <li>{@link #ALL}</li>
 * <li>{@link #NEAR}</li>
 * <li>{@link #PRIMARY}</li>
 * <li>{@link #BACKUP}</li>
 * <li>{@link #ONHEAP}</li>
 * <li>{@link #OFFHEAP}</li>
 * </ul>
 */
public enum CachePeekMode {
    /** Peeks into all available cache storages. */
    ALL,

    /**
     * Peek into near cache only (don't peek into partitioned cache).
     * In case of {@link CacheMode#LOCAL} cache, behaves as {@link #ALL} mode.
     */
    NEAR,

    /**
     * Peek value from primary copy of partitioned cache only (skip near cache).
     * In case of {@link CacheMode#LOCAL} cache, behaves as {@link #ALL} mode.
     */
    PRIMARY,

    /**
     * Peek value from backup copies of partitioned cache only (skip near cache).
     * In case of {@link CacheMode#LOCAL} cache, behaves as {@link #ALL} mode.
     */
    BACKUP,

    /** Peeks value from the on-heap storage only. */
    ONHEAP,

    /** Peeks value from the off-heap storage only, without loading off-heap value into cache. */
    OFFHEAP;

    /** Enumerated values. */
    private static final CachePeekMode[] VALS = values();

    /**
     * Efficiently gets enumerated value from its ordinal.
     *
     * @param ord Ordinal value.
     * @return Enumerated value or {@code null} if ordinal out of range.
     */
    @Nullable public static CachePeekMode fromOrdinal(byte ord) {
        return ord >= 0 && ord < VALS.length ? VALS[ord] : null;
    }
}