MediaWiki  REL1_31
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 }
VirtualRESTServiceClient\run
run(array $req)
Execute a virtual HTTP(S) request.
Definition: VirtualRESTServiceClient.php:144
MultiHttpClient
Class to handle concurrent HTTP requests.
Definition: MultiHttpClient.php:48
use
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
Definition: APACHE-LICENSE-2.0.txt:10
array
the array() calling protocol came about after MediaWiki 1.4rc1.
VirtualRESTServiceClient\$instances
array $instances
Map of (prefix => VirtualRESTService|array)
Definition: VirtualRESTServiceClient.php:49
VirtualRESTServiceClient\$http
MultiHttpClient $http
Definition: VirtualRESTServiceClient.php:47
http
Apache License January http
Definition: APACHE-LICENSE-2.0.txt:6
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:37
VirtualRESTServiceClient\runMulti
runMulti(array $reqs)
Execute a set of virtual HTTP(S) requests concurrently.
Definition: VirtualRESTServiceClient.php:166
VirtualRESTServiceClient\VALID_MOUNT_REGEX
const VALID_MOUNT_REGEX
Definition: VirtualRESTServiceClient.php:51
$matches
$matches
Definition: NoLocalSettings.php:24
VirtualRESTServiceClient
Virtual HTTP service client loosely styled after a Virtual File System.
Definition: VirtualRESTServiceClient.php:45
VirtualRESTServiceClient\mount
mount( $prefix, $instance)
Map a prefix to service handler.
Definition: VirtualRESTServiceClient.php:70
list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
VirtualRESTServiceClient\getMountAndService
getMountAndService( $path)
Get the prefix and service that a virtual path is serviced by.
Definition: VirtualRESTServiceClient.php:104
VirtualRESTServiceClient\getInstance
getInstance( $prefix)
Definition: VirtualRESTServiceClient.php:304
VirtualRESTServiceClient\__construct
__construct(MultiHttpClient $http)
Definition: VirtualRESTServiceClient.php:56
$req
this hook is for auditing only $req
Definition: hooks.txt:990
VirtualRESTServiceClient\unmount
unmount( $prefix)
Unmap a prefix to service handler.
Definition: VirtualRESTServiceClient.php:89
$path
$path
Definition: NoLocalSettings.php:25
as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:22
VirtualRESTService
Virtual HTTP service instance that can be mounted on to a VirtualRESTService.
Definition: VirtualRESTService.php:36