org.springframework.integration.util.Pool.java Source code

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Here is the source code for org.springframework.integration.util.Pool.java

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/*
 * Copyright 2002-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.integration.util;

/**
 * Represents a pool of items.
 * @author Gary Russell
 * @since 2.2
 *
 */
public interface Pool<T> {

    /**
     * Obtains an item from the pool.
     * @return the item.
     */
    T getItem();

    /**
     * Releases an item back into the pool. This must be an item that
     * was previously retrieved using {@link #getItem()}.
     * @param t the item.
     * @throws IllegalArgumentException when a "foreign" object
     * is released.
     */
    void releaseItem(T t);

    /**
     * Removes all idle items from the pool.
     */
    void removeAllIdleItems();

    /**
     * Returns the current size (limit) of the pool.
     * @return the size.
     */
    int getPoolSize();

    /**
     * Returns the number of items that have been allocated
     * but are not currently in use.
     * @return The number of items.
     */
    int getIdleCount();

    /**
     * Returns the number of allocated items that are currently
     * checked out of the pool.
     * @return The number of items.
     */
    int getActiveCount();

    /**
     * Returns the current count of allocated items (in use and
     * idle). May be less than the pool size, and reflects the
     * high water mark of pool usage.
     * @return the number of items.
     */
    int getAllocatedCount();

}