| /* |
| * Copyright (C) 2013 Square, Inc. |
| * |
| * 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 com.squareup.okhttp; |
| |
| import com.squareup.okhttp.Call.AsyncCall; |
| import com.squareup.okhttp.internal.Util; |
| import com.squareup.okhttp.internal.http.HttpEngine; |
| import java.util.ArrayDeque; |
| import java.util.Deque; |
| import java.util.Iterator; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.SynchronousQueue; |
| import java.util.concurrent.ThreadPoolExecutor; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * Policy on when async requests are executed. |
| * |
| * <p>Each dispatcher uses an {@link ExecutorService} to run calls internally. If you |
| * supply your own executor, it should be able to run {@linkplain #getMaxRequests the |
| * configured maximum} number of calls concurrently. |
| */ |
| public final class Dispatcher { |
| private int maxRequests = 64; |
| private int maxRequestsPerHost = 5; |
| |
| /** Executes calls. Created lazily. */ |
| private ExecutorService executorService; |
| |
| /** Ready calls in the order they'll be run. */ |
| private final Deque<AsyncCall> readyCalls = new ArrayDeque<>(); |
| |
| /** Running calls. Includes canceled calls that haven't finished yet. */ |
| private final Deque<AsyncCall> runningCalls = new ArrayDeque<>(); |
| |
| /** In-flight synchronous calls. Includes canceled calls that haven't finished yet. */ |
| private final Deque<Call> executedCalls = new ArrayDeque<>(); |
| |
| public Dispatcher(ExecutorService executorService) { |
| this.executorService = executorService; |
| } |
| |
| public Dispatcher() { |
| } |
| |
| public synchronized ExecutorService getExecutorService() { |
| if (executorService == null) { |
| executorService = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60, TimeUnit.SECONDS, |
| new SynchronousQueue<Runnable>(), Util.threadFactory("OkHttp Dispatcher", false)); |
| } |
| return executorService; |
| } |
| |
| /** |
| * Set the maximum number of requests to execute concurrently. Above this |
| * requests queue in memory, waiting for the running calls to complete. |
| * |
| * <p>If more than {@code maxRequests} requests are in flight when this is |
| * invoked, those requests will remain in flight. |
| */ |
| public synchronized void setMaxRequests(int maxRequests) { |
| if (maxRequests < 1) { |
| throw new IllegalArgumentException("max < 1: " + maxRequests); |
| } |
| this.maxRequests = maxRequests; |
| promoteCalls(); |
| } |
| |
| public synchronized int getMaxRequests() { |
| return maxRequests; |
| } |
| |
| /** |
| * Set the maximum number of requests for each host to execute concurrently. |
| * This limits requests by the URL's host name. Note that concurrent requests |
| * to a single IP address may still exceed this limit: multiple hostnames may |
| * share an IP address or be routed through the same HTTP proxy. |
| * |
| * <p>If more than {@code maxRequestsPerHost} requests are in flight when this |
| * is invoked, those requests will remain in flight. |
| */ |
| public synchronized void setMaxRequestsPerHost(int maxRequestsPerHost) { |
| if (maxRequestsPerHost < 1) { |
| throw new IllegalArgumentException("max < 1: " + maxRequestsPerHost); |
| } |
| this.maxRequestsPerHost = maxRequestsPerHost; |
| promoteCalls(); |
| } |
| |
| public synchronized int getMaxRequestsPerHost() { |
| return maxRequestsPerHost; |
| } |
| |
| synchronized void enqueue(AsyncCall call) { |
| if (runningCalls.size() < maxRequests && runningCallsForHost(call) < maxRequestsPerHost) { |
| runningCalls.add(call); |
| getExecutorService().execute(call); |
| } else { |
| readyCalls.add(call); |
| } |
| } |
| |
| /** Cancel all calls with the tag {@code tag}. */ |
| public synchronized void cancel(Object tag) { |
| for (AsyncCall call : readyCalls) { |
| if (Util.equal(tag, call.tag())) { |
| call.cancel(); |
| } |
| } |
| |
| for (AsyncCall call : runningCalls) { |
| if (Util.equal(tag, call.tag())) { |
| call.get().canceled = true; |
| HttpEngine engine = call.get().engine; |
| if (engine != null) engine.cancel(); |
| } |
| } |
| |
| for (Call call : executedCalls) { |
| if (Util.equal(tag, call.tag())) { |
| call.cancel(); |
| } |
| } |
| } |
| |
| /** Used by {@code AsyncCall#run} to signal completion. */ |
| synchronized void finished(AsyncCall call) { |
| if (!runningCalls.remove(call)) throw new AssertionError("AsyncCall wasn't running!"); |
| promoteCalls(); |
| } |
| |
| private void promoteCalls() { |
| if (runningCalls.size() >= maxRequests) return; // Already running max capacity. |
| if (readyCalls.isEmpty()) return; // No ready calls to promote. |
| |
| for (Iterator<AsyncCall> i = readyCalls.iterator(); i.hasNext(); ) { |
| AsyncCall call = i.next(); |
| |
| if (runningCallsForHost(call) < maxRequestsPerHost) { |
| i.remove(); |
| runningCalls.add(call); |
| getExecutorService().execute(call); |
| } |
| |
| if (runningCalls.size() >= maxRequests) return; // Reached max capacity. |
| } |
| } |
| |
| /** Returns the number of running calls that share a host with {@code call}. */ |
| private int runningCallsForHost(AsyncCall call) { |
| int result = 0; |
| for (AsyncCall c : runningCalls) { |
| if (c.host().equals(call.host())) result++; |
| } |
| return result; |
| } |
| |
| /** Used by {@code Call#execute} to signal it is in-flight. */ |
| synchronized void executed(Call call) { |
| executedCalls.add(call); |
| } |
| |
| /** Used by {@code Call#execute} to signal completion. */ |
| synchronized void finished(Call call) { |
| if (!executedCalls.remove(call)) throw new AssertionError("Call wasn't in-flight!"); |
| } |
| |
| public synchronized int getRunningCallCount() { |
| return runningCalls.size(); |
| } |
| |
| public synchronized int getQueuedCallCount() { |
| return readyCalls.size(); |
| } |
| } |