comparison vendor/guzzlehttp/guzzle/src/HandlerStack.php @ 0:4c8ae668cc8c

Initial import (non-working)
author Chris Cannam
date Wed, 29 Nov 2017 16:09:58 +0000
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children 5fb285c0d0e3
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-1:000000000000 0:4c8ae668cc8c
1 <?php
2 namespace GuzzleHttp;
3
4 use Psr\Http\Message\RequestInterface;
5
6 /**
7 * Creates a composed Guzzle handler function by stacking middlewares on top of
8 * an HTTP handler function.
9 */
10 class HandlerStack
11 {
12 /** @var callable */
13 private $handler;
14
15 /** @var array */
16 private $stack = [];
17
18 /** @var callable|null */
19 private $cached;
20
21 /**
22 * Creates a default handler stack that can be used by clients.
23 *
24 * The returned handler will wrap the provided handler or use the most
25 * appropriate default handler for you system. The returned HandlerStack has
26 * support for cookies, redirects, HTTP error exceptions, and preparing a body
27 * before sending.
28 *
29 * The returned handler stack can be passed to a client in the "handler"
30 * option.
31 *
32 * @param callable $handler HTTP handler function to use with the stack. If no
33 * handler is provided, the best handler for your
34 * system will be utilized.
35 *
36 * @return HandlerStack
37 */
38 public static function create(callable $handler = null)
39 {
40 $stack = new self($handler ?: choose_handler());
41 $stack->push(Middleware::httpErrors(), 'http_errors');
42 $stack->push(Middleware::redirect(), 'allow_redirects');
43 $stack->push(Middleware::cookies(), 'cookies');
44 $stack->push(Middleware::prepareBody(), 'prepare_body');
45
46 return $stack;
47 }
48
49 /**
50 * @param callable $handler Underlying HTTP handler.
51 */
52 public function __construct(callable $handler = null)
53 {
54 $this->handler = $handler;
55 }
56
57 /**
58 * Invokes the handler stack as a composed handler
59 *
60 * @param RequestInterface $request
61 * @param array $options
62 */
63 public function __invoke(RequestInterface $request, array $options)
64 {
65 $handler = $this->resolve();
66
67 return $handler($request, $options);
68 }
69
70 /**
71 * Dumps a string representation of the stack.
72 *
73 * @return string
74 */
75 public function __toString()
76 {
77 $depth = 0;
78 $stack = [];
79 if ($this->handler) {
80 $stack[] = "0) Handler: " . $this->debugCallable($this->handler);
81 }
82
83 $result = '';
84 foreach (array_reverse($this->stack) as $tuple) {
85 $depth++;
86 $str = "{$depth}) Name: '{$tuple[1]}', ";
87 $str .= "Function: " . $this->debugCallable($tuple[0]);
88 $result = "> {$str}\n{$result}";
89 $stack[] = $str;
90 }
91
92 foreach (array_keys($stack) as $k) {
93 $result .= "< {$stack[$k]}\n";
94 }
95
96 return $result;
97 }
98
99 /**
100 * Set the HTTP handler that actually returns a promise.
101 *
102 * @param callable $handler Accepts a request and array of options and
103 * returns a Promise.
104 */
105 public function setHandler(callable $handler)
106 {
107 $this->handler = $handler;
108 $this->cached = null;
109 }
110
111 /**
112 * Returns true if the builder has a handler.
113 *
114 * @return bool
115 */
116 public function hasHandler()
117 {
118 return (bool) $this->handler;
119 }
120
121 /**
122 * Unshift a middleware to the bottom of the stack.
123 *
124 * @param callable $middleware Middleware function
125 * @param string $name Name to register for this middleware.
126 */
127 public function unshift(callable $middleware, $name = null)
128 {
129 array_unshift($this->stack, [$middleware, $name]);
130 $this->cached = null;
131 }
132
133 /**
134 * Push a middleware to the top of the stack.
135 *
136 * @param callable $middleware Middleware function
137 * @param string $name Name to register for this middleware.
138 */
139 public function push(callable $middleware, $name = '')
140 {
141 $this->stack[] = [$middleware, $name];
142 $this->cached = null;
143 }
144
145 /**
146 * Add a middleware before another middleware by name.
147 *
148 * @param string $findName Middleware to find
149 * @param callable $middleware Middleware function
150 * @param string $withName Name to register for this middleware.
151 */
152 public function before($findName, callable $middleware, $withName = '')
153 {
154 $this->splice($findName, $withName, $middleware, true);
155 }
156
157 /**
158 * Add a middleware after another middleware by name.
159 *
160 * @param string $findName Middleware to find
161 * @param callable $middleware Middleware function
162 * @param string $withName Name to register for this middleware.
163 */
164 public function after($findName, callable $middleware, $withName = '')
165 {
166 $this->splice($findName, $withName, $middleware, false);
167 }
168
169 /**
170 * Remove a middleware by instance or name from the stack.
171 *
172 * @param callable|string $remove Middleware to remove by instance or name.
173 */
174 public function remove($remove)
175 {
176 $this->cached = null;
177 $idx = is_callable($remove) ? 0 : 1;
178 $this->stack = array_values(array_filter(
179 $this->stack,
180 function ($tuple) use ($idx, $remove) {
181 return $tuple[$idx] !== $remove;
182 }
183 ));
184 }
185
186 /**
187 * Compose the middleware and handler into a single callable function.
188 *
189 * @return callable
190 */
191 public function resolve()
192 {
193 if (!$this->cached) {
194 if (!($prev = $this->handler)) {
195 throw new \LogicException('No handler has been specified');
196 }
197
198 foreach (array_reverse($this->stack) as $fn) {
199 $prev = $fn[0]($prev);
200 }
201
202 $this->cached = $prev;
203 }
204
205 return $this->cached;
206 }
207
208 /**
209 * @param $name
210 * @return int
211 */
212 private function findByName($name)
213 {
214 foreach ($this->stack as $k => $v) {
215 if ($v[1] === $name) {
216 return $k;
217 }
218 }
219
220 throw new \InvalidArgumentException("Middleware not found: $name");
221 }
222
223 /**
224 * Splices a function into the middleware list at a specific position.
225 *
226 * @param $findName
227 * @param $withName
228 * @param callable $middleware
229 * @param $before
230 */
231 private function splice($findName, $withName, callable $middleware, $before)
232 {
233 $this->cached = null;
234 $idx = $this->findByName($findName);
235 $tuple = [$middleware, $withName];
236
237 if ($before) {
238 if ($idx === 0) {
239 array_unshift($this->stack, $tuple);
240 } else {
241 $replacement = [$tuple, $this->stack[$idx]];
242 array_splice($this->stack, $idx, 1, $replacement);
243 }
244 } elseif ($idx === count($this->stack) - 1) {
245 $this->stack[] = $tuple;
246 } else {
247 $replacement = [$this->stack[$idx], $tuple];
248 array_splice($this->stack, $idx, 1, $replacement);
249 }
250 }
251
252 /**
253 * Provides a debug string for a given callable.
254 *
255 * @param array|callable $fn Function to write as a string.
256 *
257 * @return string
258 */
259 private function debugCallable($fn)
260 {
261 if (is_string($fn)) {
262 return "callable({$fn})";
263 }
264
265 if (is_array($fn)) {
266 return is_string($fn[0])
267 ? "callable({$fn[0]}::{$fn[1]})"
268 : "callable(['" . get_class($fn[0]) . "', '{$fn[1]}'])";
269 }
270
271 return 'callable(' . spl_object_hash($fn) . ')';
272 }
273 }