MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / libs / objectcache / RESTBagOStuff.php

diff --git a/includes/libs/objectcache/RESTBagOStuff.php b/includes/libs/objectcache/RESTBagOStuff.php
new file mode 100644 (file)
index 0000000..d3aa9f5
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+++ b/includes/libs/objectcache/RESTBagOStuff.php
@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * Interface to key-value storage behind an HTTP server.
+ *
+ * Uses URL of the form "baseURL/{KEY}" to store, fetch, and delete values.
+ *
+ * E.g., when base URL is `/v1/sessions/`, then the store would do:
+ *
+ * `PUT /v1/sessions/12345758`
+ *
+ * and fetch would do:
+ *
+ * `GET /v1/sessions/12345758`
+ *
+ * delete would do:
+ *
+ * `DELETE /v1/sessions/12345758`
+ *
+ * Configure with:
+ *
+ * @code
+ * $wgObjectCaches['sessions'] = array(
+ *     'class' => 'RESTBagOStuff',
+ *     'url' => 'http://localhost:7231/wikimedia.org/v1/sessions/'
+ * );
+ * @endcode
+ */
+class RESTBagOStuff extends BagOStuff {
+
+       /**
+        * @var MultiHttpClient
+        */
+       private $client;
+
+       /**
+        * REST URL to use for storage.
+        * @var string
+        */
+       private $url;
+
+       public function __construct( $params ) {
+               if ( empty( $params['url'] ) ) {
+                       throw new InvalidArgumentException( 'URL parameter is required' );
+               }
+               parent::__construct( $params );
+               if ( empty( $params['client'] ) ) {
+                       $this->client = new MultiHttpClient( [] );
+               } else {
+                       $this->client = $params['client'];
+               }
+               // Make sure URL ends with /
+               $this->url = rtrim( $params['url'], '/' ) . '/';
+               // Default config, R+W > N; no locks on reads though; writes go straight to state-machine
+               $this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_QC;
+       }
+
+       /**
+        * @param string $key
+        * @param int $flags Bitfield of BagOStuff::READ_* constants [optional]
+        * @return mixed Returns false on failure and if the item does not exist
+        */
+       protected function doGet( $key, $flags = 0 ) {
+               $req = [
+                       'method' => 'GET',
+                       'url' => $this->url . rawurlencode( $key ),
+               ];
+
+               list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
+               if ( $rcode === 200 ) {
+                       if ( is_string( $rbody ) ) {
+                               return unserialize( $rbody );
+                       }
+                       return false;
+               }
+               if ( $rcode === 0 || ( $rcode >= 400 && $rcode != 404 ) ) {
+                       return $this->handleError( "Failed to fetch $key", $rcode, $rerr );
+               }
+               return false;
+       }
+
+       /**
+        * Handle storage error
+        * @param string $msg Error message
+        * @param int $rcode Error code from client
+        * @param string $rerr Error message from client
+        * @return false
+        */
+       protected function handleError( $msg, $rcode, $rerr ) {
+               $this->logger->error( "$msg : ({code}) {error}", [
+                       'code' => $rcode,
+                       'error' => $rerr
+               ] );
+               $this->setLastError( $rcode === 0 ? self::ERR_UNREACHABLE : self::ERR_UNEXPECTED );
+               return false;
+       }
+
+       /**
+        * Set an item
+        *
+        * @param string $key
+        * @param mixed $value
+        * @param int $exptime Either an interval in seconds or a unix timestamp for expiry
+        * @param int $flags Bitfield of BagOStuff::WRITE_* constants
+        * @return bool Success
+        */
+       public function set( $key, $value, $exptime = 0, $flags = 0 ) {
+               $req = [
+                       'method' => 'PUT',
+                       'url' => $this->url . rawurlencode( $key ),
+                       'body' => serialize( $value )
+               ];
+               list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
+               if ( $rcode === 200 || $rcode === 201 ) {
+                       return true;
+               }
+               return $this->handleError( "Failed to store $key", $rcode, $rerr );
+       }
+
+       /**
+        * Delete an item.
+        *
+        * @param string $key
+        * @return bool True if the item was deleted or not found, false on failure
+        */
+       public function delete( $key ) {
+               $req = [
+                       'method' => 'DELETE',
+                       'url' => $this->url . rawurlencode( $key ),
+               ];
+               list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
+               if ( $rcode === 200 || $rcode === 204 || $rcode === 205 ) {
+                       return true;
+               }
+               return $this->handleError( "Failed to delete $key", $rcode, $rerr );
+       }
+}