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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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 io.undertow.server.handlers;

import static org.wildfly.common.Assert.checkNotNullParam;

import java.util.Collections;
import java.util.Map;
import java.util.Set;

import io.undertow.server.HandlerWrapper;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.builder.HandlerBuilder;

/**
 * A handler which limits the maximum number of concurrent requests.  Requests beyond the limit will
 * block until the previous request is complete.
 *
 * @author David M. Lloyd
 */
public final class RequestLimitingHandler implements HttpHandler {

    private final HttpHandler nextHandler;

    private final RequestLimit requestLimit;

    /**
     * Construct a new instance. The maximum number of concurrent requests must be at least one.  The next handler
     * must not be {@code null}.
     *
     * @param maximumConcurrentRequests the maximum concurrent requests
     * @param nextHandler the next handler
     */
    public RequestLimitingHandler(int maximumConcurrentRequests, HttpHandler nextHandler) {
        this(maximumConcurrentRequests, -1, nextHandler);
    }

    /**
     * Construct a new instance. The maximum number of concurrent requests must be at least one.  The next handler
     * must not be {@code null}.
     *
     * @param maximumConcurrentRequests the maximum concurrent requests
     * @param queueSize the maximum number of requests to queue
     * @param nextHandler the next handler
     */
    public RequestLimitingHandler(int maximumConcurrentRequests, int queueSize, HttpHandler nextHandler) {
        checkNotNullParam("nextHandler", nextHandler);
        if (maximumConcurrentRequests < 1) {
            throw new IllegalArgumentException("Maximum concurrent requests must be at least 1");
        }
        this.requestLimit = new RequestLimit(maximumConcurrentRequests, queueSize);
        this.nextHandler = nextHandler;
    }

    /**
     * Construct a new instance. This version takes a {@link RequestLimit} directly which may be shared with other
     * handlers.
     *
     * @param requestLimit the request limit information.
     * @param nextHandler the next handler
     */
    public RequestLimitingHandler(RequestLimit requestLimit, HttpHandler nextHandler) {
        checkNotNullParam("nextHandler", nextHandler);
        this.requestLimit = requestLimit;
        this.nextHandler = nextHandler;
    }

    public void handleRequest(final HttpServerExchange exchange) throws Exception {
        requestLimit.handleRequest(exchange, nextHandler);
    }

    public RequestLimit getRequestLimit() {
        return requestLimit;
    }

    @Override
    public String toString() {
        return "request-limit( " + requestLimit.getMaximumConcurrentRequests() + " )";
    }

    public static class Builder implements HandlerBuilder {

        @Override
        public String name() {
            return "request-limit";
        }

        @Override
        public Map> parameters() {
            return Collections.>singletonMap("requests", int.class);
        }

        @Override
        public Set requiredParameters() {
            return Collections.singleton("requests");
        }

        @Override
        public String defaultParameter() {
            return "requests";
        }

        @Override
        public HandlerWrapper build(Map config) {
            return new Wrapper((Integer) config.get("requests"));
        }

    }

    private static class Wrapper implements HandlerWrapper {

        private final int requests;

        private Wrapper(int requests) {
            this.requests = requests;
        }

        @Override
        public HttpHandler wrap(HttpHandler handler) {
            return new RequestLimitingHandler(requests, handler);
        }
    }
}