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 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
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 */
package org.apache.http.pool;

import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.annotation.Contract;

import java.io.Serializable;

Pool statistics.
 The total number of connections in the pool is equal to available plus leased. 
Since:
4.2/**
 * Pool statistics.
 * <p>
 * The total number of connections in the pool is equal to {@code available} plus {@code leased}.
 * </p>
 *
 * @since 4.2
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class PoolStats implements Serializable {

    private static final long serialVersionUID = -2807686144795228544L;

    private final int leased;
    private final int pending;
    private final int available;
    private final int max;

    public PoolStats(final int leased, final int pending, final int free, final int max) {
        super();
        this.leased = leased;
        this.pending = pending;
        this.available = free;
        this.max = max;
    }

    
Gets the number of persistent connections tracked by the connection manager currently being used to execute
requests.
 The total number of connections in the pool is equal to available plus leased. 
Returns:
the number of persistent connections./**
     * Gets the number of persistent connections tracked by the connection manager currently being used to execute
     * requests.
     * <p>
     * The total number of connections in the pool is equal to {@code available} plus {@code leased}.
     * </p>
     *
     * @return the number of persistent connections.
     */
    public int getLeased() {
        return this.leased;
    }

    
Gets the number of connection requests being blocked awaiting a free connection. This can happen only if there
are more worker threads contending for fewer connections.
Returns:
the number of connection requests being blocked awaiting a free connection./**
     * Gets the number of connection requests being blocked awaiting a free connection. This can happen only if there
     * are more worker threads contending for fewer connections.
     *
     * @return the number of connection requests being blocked awaiting a free connection.
     */
    public int getPending() {
        return this.pending;
    }

    
Gets the number idle persistent connections.
 The total number of connections in the pool is equal to available plus leased. 
Returns:
number idle persistent connections./**
     * Gets the number idle persistent connections.
     * <p>
     * The total number of connections in the pool is equal to {@code available} plus {@code leased}.
     * </p>
     *
     * @return number idle persistent connections.
     */
    public int getAvailable() {
        return this.available;
    }

    
Gets the maximum number of allowed persistent connections.
Returns:
the maximum number of allowed persistent connections./**
     * Gets the maximum number of allowed persistent connections.
     *
     * @return the maximum number of allowed persistent connections.
     */
    public int getMax() {
        return this.max;
    }

    @Override
    public String toString() {
        final StringBuilder buffer = new StringBuilder();
        buffer.append("[leased: ");
        buffer.append(this.leased);
        buffer.append("; pending: ");
        buffer.append(this.pending);
        buffer.append("; available: ");
        buffer.append(this.available);
        buffer.append("; max: ");
        buffer.append(this.max);
        buffer.append("]");
        return buffer.toString();
    }

}