/*
 * 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.internal.processors.cache;

import java.util.Set;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.ignite.internal.processors.affinity.AffinityTopologyVersion;
import org.apache.ignite.internal.util.typedef.internal.S;
import org.jetbrains.annotations.Nullable;

/**
 * Concurrent cache map.
 */
public interface GridCacheConcurrentMap {
    /**
     * Returns the entry associated with the specified key in the
     * HashMap. Returns null if the HashMap contains no mapping
     * for this key.
     *
     * @param ctx Cache context.
     * @param key Key.
     * @return Entry.
     */
    @Nullable public GridCacheMapEntry getEntry(GridCacheContext ctx, KeyCacheObject key);

    /**
     * @param ctx Cache context.
     * @param topVer Topology version.
     * @param key Key.
     * @param create Create flag.
     * @return Existing or new GridCacheMapEntry. Will return {@code null} if entry is obsolete or absent and create
     * flag is set to {@code false}. Will also return {@code null} if create flag is set to {@code true}, but entry
     * couldn't be created.
     */
    @Nullable public GridCacheMapEntry putEntryIfObsoleteOrAbsent(
        GridCacheContext ctx,
        AffinityTopologyVersion topVer,
        KeyCacheObject key,
        boolean create,
        boolean touch);

    /**
     * Removes passed in entry if it presents in the map.
     *
     * @param entry Entry to remove.
     * @return {@code True} if remove happened.
     */
    public boolean removeEntry(GridCacheEntryEx entry);

    /**
     * Returns the number of key-value mappings in this map.
     * It does not include entries from underlying data store.
     *
     * @return the number of key-value mappings in this map.
     */
    public int internalSize();

    /**
     * Returns the number of publicly available key-value mappings in this map.
     * It excludes entries that are marked as deleted.
     * It also does not include entries from underlying data store.
     *
     * @param cacheId Cache ID.
     * @return the number of publicly available key-value mappings in this map.
     */
    public int publicSize(int cacheId);

    /**
     * Increments public size.
     *
     * @param e Entry that caused public size change.
     * @param hld Cache map (passed as optimization to avoid cache map lookup for shared groups).
     */
    public void incrementPublicSize(@Nullable CacheMapHolder hld, GridCacheEntryEx e);

    /**
     * Decrements public size.
     *
     * @param e Entry that caused public size change.
     * @param hld Cache map (passed as optimization to avoid cache map lookup for shared groups).
     */
    public void decrementPublicSize(@Nullable CacheMapHolder hld, GridCacheEntryEx e);

    /**
     * @param cacheId Cache ID.
     * @param filter Filter.
     * @return Iterable of the mappings contained in this map, excluding entries in unvisitable state.
     */
    public Iterable<GridCacheMapEntry> entries(int cacheId, CacheEntryPredicate... filter);

    /**
     * @param cacheId Cache ID.
     * @param filter Filter.
     * @return Set of the mappings contained in this map.
     */
    public Set<GridCacheMapEntry> entrySet(int cacheId, CacheEntryPredicate... filter);

    /**
     *
     */
    static class CacheMapHolder {
        /** */
        public final GridCacheContext cctx;

        /** */
        public final AtomicInteger size = new AtomicInteger();

        /** */
        public final ConcurrentMap<KeyCacheObject, GridCacheMapEntry> map;

        /**
         * @param cctx Cache context.
         * @param map Map.
         */
        public CacheMapHolder(GridCacheContext cctx, ConcurrentMap<KeyCacheObject, GridCacheMapEntry> map) {
            this.cctx = cctx;
            this.map = map;
        }

        /** {@inheritDoc} */
        @Override public String toString() {
            return S.toString(CacheMapHolder.class, this);
        }
    }
}