MediaWiki REL1_30
VirtualRESTServiceClient.php
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1<?php
47 private $http;
49 private $instances = [];
50
51 const VALID_MOUNT_REGEX = '#^/[0-9a-z]+/([0-9a-z]+/)*$#';
52
56 public function __construct( MultiHttpClient $http ) {
57 $this->http = $http;
58 }
59
70 public function mount( $prefix, $instance ) {
71 if ( !preg_match( self::VALID_MOUNT_REGEX, $prefix ) ) {
72 throw new UnexpectedValueException( "Invalid service mount point '$prefix'." );
73 } elseif ( isset( $this->instances[$prefix] ) ) {
74 throw new UnexpectedValueException( "A service is already mounted on '$prefix'." );
75 }
76 if ( !( $instance instanceof VirtualRESTService ) ) {
77 if ( !isset( $instance['class'] ) || !isset( $instance['config'] ) ) {
78 throw new UnexpectedValueException( "Missing 'class' or 'config' ('$prefix')." );
79 }
80 }
81 $this->instances[$prefix] = $instance;
82 }
83
89 public function unmount( $prefix ) {
90 if ( !preg_match( self::VALID_MOUNT_REGEX, $prefix ) ) {
91 throw new UnexpectedValueException( "Invalid service mount point '$prefix'." );
92 } elseif ( !isset( $this->instances[$prefix] ) ) {
93 throw new UnexpectedValueException( "No service is mounted on '$prefix'." );
94 }
95 unset( $this->instances[$prefix] );
96 }
97
104 public function getMountAndService( $path ) {
105 $cmpFunc = function ( $a, $b ) {
106 $al = substr_count( $a, '/' );
107 $bl = substr_count( $b, '/' );
108 if ( $al === $bl ) {
109 return 0; // should not actually happen
110 }
111 return ( $al < $bl ) ? 1 : -1; // largest prefix first
112 };
113
114 $matches = []; // matching prefixes (mount points)
115 foreach ( $this->instances as $prefix => $unused ) {
116 if ( strpos( $path, $prefix ) === 0 ) {
117 $matches[] = $prefix;
118 }
119 }
120 usort( $matches, $cmpFunc );
121
122 // Return the most specific prefix and corresponding service
123 return $matches
124 ? [ $matches[0], $this->getInstance( $matches[0] ) ]
125 : [ null, null ];
126 }
127
144 public function run( array $req ) {
145 return $this->runMulti( [ $req ] )[0];
146 }
147
166 public function runMulti( array $reqs ) {
167 foreach ( $reqs as $index => &$req ) {
168 if ( isset( $req[0] ) ) {
169 $req['method'] = $req[0]; // short-form
170 unset( $req[0] );
171 }
172 if ( isset( $req[1] ) ) {
173 $req['url'] = $req[1]; // short-form
174 unset( $req[1] );
175 }
176 $req['chain'] = []; // chain or list of replaced requests
177 }
178 unset( $req ); // don't assign over this by accident
179
180 $curUniqueId = 0;
181 $armoredIndexMap = []; // (original index => new index)
182
183 $doneReqs = []; // (index => request)
184 $executeReqs = []; // (index => request)
185 $replaceReqsByService = []; // (prefix => index => request)
186 $origPending = []; // (index => 1) for original requests
187
188 foreach ( $reqs as $origIndex => $req ) {
189 // Re-index keys to consecutive integers (they will be swapped back later)
190 $index = $curUniqueId++;
191 $armoredIndexMap[$origIndex] = $index;
192 $origPending[$index] = 1;
193 if ( preg_match( '#^(http|ftp)s?://#', $req['url'] ) ) {
194 // Absolute FTP/HTTP(S) URL, run it as normal
195 $executeReqs[$index] = $req;
196 } else {
197 // Must be a virtual HTTP URL; resolve it
198 list( $prefix, $service ) = $this->getMountAndService( $req['url'] );
199 if ( !$service ) {
200 throw new UnexpectedValueException( "Path '{$req['url']}' has no service." );
201 }
202 // Set the URL to the mount-relative portion
203 $req['url'] = substr( $req['url'], strlen( $prefix ) );
204 $replaceReqsByService[$prefix][$index] = $req;
205 }
206 }
207
208 // Function to get IDs that won't collide with keys in $armoredIndexMap
209 $idFunc = function () use ( &$curUniqueId ) {
210 return $curUniqueId++;
211 };
212
213 $rounds = 0;
214 do {
215 if ( ++$rounds > 5 ) { // sanity
216 throw new Exception( "Too many replacement rounds detected. Aborting." );
217 }
218 // Track requests executed this round that have a prefix/service.
219 // Note that this also includes requests where 'response' was forced.
220 $checkReqIndexesByPrefix = [];
221 // Resolve the virtual URLs valid and qualified HTTP(S) URLs
222 // and add any required authentication headers for the backend.
223 // Services can also replace requests with new ones, either to
224 // defer the original or to set a proxy response to the original.
225 $newReplaceReqsByService = [];
226 foreach ( $replaceReqsByService as $prefix => $servReqs ) {
227 $service = $this->getInstance( $prefix );
228 foreach ( $service->onRequests( $servReqs, $idFunc ) as $index => $req ) {
229 // Services use unique IDs for replacement requests
230 if ( isset( $servReqs[$index] ) || isset( $origPending[$index] ) ) {
231 // A current or original request which was not modified
232 } else {
233 // Replacement request that will convert to original requests
234 $newReplaceReqsByService[$prefix][$index] = $req;
235 }
236 if ( isset( $req['response'] ) ) {
237 // Replacement requests with pre-set responses should not execute
238 unset( $executeReqs[$index] );
239 unset( $origPending[$index] );
240 $doneReqs[$index] = $req;
241 } else {
242 // Original or mangled request included
243 $executeReqs[$index] = $req;
244 }
245 $checkReqIndexesByPrefix[$prefix][$index] = 1;
246 }
247 }
248 // Run the actual work HTTP requests
249 foreach ( $this->http->runMulti( $executeReqs ) as $index => $ranReq ) {
250 $doneReqs[$index] = $ranReq;
251 unset( $origPending[$index] );
252 }
253 $executeReqs = [];
254 // Services can also replace requests with new ones, either to
255 // defer the original or to set a proxy response to the original.
256 // Any replacement requests executed above will need to be replaced
257 // with new requests (eventually the original). The responses can be
258 // forced by setting 'response' rather than actually be sent over the wire.
259 $newReplaceReqsByService = [];
260 foreach ( $checkReqIndexesByPrefix as $prefix => $servReqIndexes ) {
261 $service = $this->getInstance( $prefix );
262 // $doneReqs actually has the requests (with 'response' set)
263 $servReqs = array_intersect_key( $doneReqs, $servReqIndexes );
264 foreach ( $service->onResponses( $servReqs, $idFunc ) as $index => $req ) {
265 // Services use unique IDs for replacement requests
266 if ( isset( $servReqs[$index] ) || isset( $origPending[$index] ) ) {
267 // A current or original request which was not modified
268 } else {
269 // Replacement requests with pre-set responses should not execute
270 $newReplaceReqsByService[$prefix][$index] = $req;
271 }
272 if ( isset( $req['response'] ) ) {
273 // Replacement requests with pre-set responses should not execute
274 unset( $origPending[$index] );
275 $doneReqs[$index] = $req;
276 } else {
277 // Update the request in case it was mangled
278 $executeReqs[$index] = $req;
279 }
280 }
281 }
282 // Update index of requests to inspect for replacement
283 $replaceReqsByService = $newReplaceReqsByService;
284 } while ( count( $origPending ) );
285
286 $responses = [];
287 // Update $reqs to include 'response' and normalized request 'headers'.
288 // This maintains the original order of $reqs.
289 foreach ( $reqs as $origIndex => $req ) {
290 $index = $armoredIndexMap[$origIndex];
291 if ( !isset( $doneReqs[$index] ) ) {
292 throw new UnexpectedValueException( "Response for request '$index' is NULL." );
293 }
294 $responses[$origIndex] = $doneReqs[$index]['response'];
295 }
296
297 return $responses;
298 }
299
304 private function getInstance( $prefix ) {
305 if ( !isset( $this->instances[$prefix] ) ) {
306 throw new RuntimeException( "No service registered at prefix '{$prefix}'." );
307 }
308
309 if ( !( $this->instances[$prefix] instanceof VirtualRESTService ) ) {
310 $config = $this->instances[$prefix]['config'];
311 $class = $this->instances[$prefix]['class'];
312 $service = new $class( $config );
313 if ( !( $service instanceof VirtualRESTService ) ) {
314 throw new UnexpectedValueException( "Registered service has the wrong class." );
315 }
316 $this->instances[$prefix] = $service;
317 }
318
319 return $this->instances[$prefix];
320 }
321}
Apache License January http
Class to handle concurrent HTTP requests.
Virtual HTTP service client loosely styled after a Virtual File System.
mount( $prefix, $instance)
Map a prefix to service handler.
array $instances
Map of (prefix => VirtualRESTService|array)
unmount( $prefix)
Unmap a prefix to service handler.
run(array $req)
Execute a virtual HTTP(S) request.
runMulti(array $reqs)
Execute a set of virtual HTTP(S) requests concurrently.
__construct(MultiHttpClient $http)
getMountAndService( $path)
Get the prefix and service that a virtual path is serviced by.
Virtual HTTP service instance that can be mounted on to a VirtualRESTService.
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Definition deferred.txt:11
this hook is for auditing only $req
Definition hooks.txt:988