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1 /* |
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2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 package jdk.incubator.http; |
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27 |
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28 import java.util.Iterator; |
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29 import java.util.concurrent.Flow; |
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30 |
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31 /** |
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32 * A Publisher that is expected to run in same thread as subscriber. |
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33 * Items are obtained from Iterable. Each new subscription gets a new Iterator. |
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34 */ |
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35 class PullPublisher<T> implements Flow.Publisher<T> { |
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36 |
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37 private final Iterable<T> iterable; |
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38 |
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39 PullPublisher(Iterable<T> iterable) { |
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40 this.iterable = iterable; |
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41 } |
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42 |
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43 @Override |
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44 public void subscribe(Flow.Subscriber<? super T> subscriber) { |
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45 subscriber.onSubscribe(new Subscription(subscriber, iterable.iterator())); |
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46 } |
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47 |
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48 private class Subscription implements Flow.Subscription { |
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49 |
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50 private final Flow.Subscriber<? super T> subscriber; |
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51 private final Iterator<T> iter; |
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52 private boolean done = false; |
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53 private long demand = 0; |
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54 private int recursion = 0; |
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55 |
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56 Subscription(Flow.Subscriber<? super T> subscriber, Iterator<T> iter) { |
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57 this.subscriber = subscriber; |
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58 this.iter = iter; |
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59 } |
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60 |
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61 @Override |
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62 public void request(long n) { |
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63 if (done) { |
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64 subscriber.onError(new IllegalArgumentException("request(" + n + ")")); |
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65 } |
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66 demand += n; |
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67 recursion ++; |
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68 if (recursion > 1) { |
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69 return; |
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70 } |
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71 while (demand > 0) { |
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72 done = !iter.hasNext(); |
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73 if (done) { |
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74 subscriber.onComplete(); |
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75 recursion --; |
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76 return; |
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77 } |
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78 subscriber.onNext(iter.next()); |
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79 demand --; |
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80 } |
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81 } |
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82 |
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83 @Override |
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84 public void cancel() { |
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85 done = true; |
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86 } |
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87 |
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88 } |
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89 } |