git.m6w6.name Git - m6w6/seekat/blob - lib/API/Consumer.php

   1 <?php
   2
   3 namespace seekat\API;
   4
   5 use Generator;
   6 use http\Client;
   7 use seekat\API;
   8 use seekat\Exception\{
   9         InvalidArgumentException, UnexpectedValueException, function exception
  10 };
  11
  12 final class Consumer
  13 {
  14         /**
  15          * Loop
  16          * @var callable
  17          */
  18         private $loop;
  19
  20         /**
  21          * The return value of the generator
  22          * @var mixed
  23          */
  24         private $result;
  25
  26         /**
  27          * Cancellation flag
  28          * @var bool
  29          */
  30         private $cancelled = false;
  31
  32         /**
  33          * @var Future
  34          */
  35         private $future;
  36
  37         /**
  38          * @var mixed
  39          */
  40         private $context;
  41
  42         /**
  43          * @var \Closure
  44          */
  45         private $resolve;
  46
  47         /**
  48          * @var \Closure
  49          */
  50         private $reject;
  51
  52         /**
  53          * @var \Closure
  54          */
  55         private $reduce;
  56
  57         /**
  58          * Create a new generator consumer
  59          * @param Future $future
  60          * @param callable $loop
  61          */
  62         function __construct(Future $future, callable $loop) {
  63                 $this->loop = $loop;
  64
  65                 $this->future = $future;
  66                 $this->context = $future->createContext(function() {
  67                         $this->cancelled = true;
  68                 });
  69                 $this->resolve = API\Future\resolver($future, $this->context);
  70                 $this->reject = API\Future\rejecter($future, $this->context);
  71                 $this->reduce = API\Future\reducer($future, $this->context);
  72         }
  73
  74         /**
  75          * Iterate over $gen, a \Generator yielding promises
  76          *
  77          * @param Generator $gen
  78          * @return mixed promise
  79          */
  80         function __invoke(Generator $gen) {
  81                 $this->cancelled = false;
  82
  83                 foreach ($gen as $promise) {
  84                         if ($this->cancelled) {
  85                                 break;
  86                         }
  87                         $this->give($promise, $gen);
  88                 }
  89
  90                 #($this->loop)();
  91
  92                 if (!$this->cancelled) {
  93                         $this->result = $gen->getReturn();
  94                 }
  95                 if (isset($this->result)) {
  96                         ($this->resolve)($this->result);
  97                 } else {
  98                         ($this->reject)("Cancelled");
  99                 }
 100
 101                 return $this->context->promise();
 102         }
 103
 104         /**
 105          * Promise handler
 106          *
 107          * @param mixed $promise
 108          * @param Generator $gen
 109          */
 110         private function give($promise, Generator $gen) {
 111                 if ($promise instanceof \Traversable) {
 112                         $promise = iterator_to_array($promise);
 113                 }
 114                 if (is_array($promise)) {
 115                         $promise = ($this->reduce)($promise);
 116                 }
 117
 118                 $this->future->handlePromise($promise, function($result) use($gen) {
 119                         if (($promise = $gen->send($result))) {
 120                                 $this->give($promise, $gen);
 121                         }
 122                 }, function($error) use($gen) {
 123                         $gen->throw(exception($error));
 124                 });
 125
 126                 /* FIXME: external loop */
 127                 ($this->loop)();
 128         }
 129 }