Merge pull request #295

docs/includes/apiargs-MongoDBCollection-common-option.yaml

@@ -36,6 +36,9 @@ type: :php:`MongoDB\\Driver\\ReadConcern <class.mongodb-driver-readconcern>`
 description: |
    :manual:`Read concern </reference/read-concern>` to use for the operation.
    Defaults to the collection's read concern.
+
+   This is not supported for server versions prior to 3.2 and will result in an
+   exception at execution time if used.
 interface: phpmethod
 operation: ~
 optional: true

docs/includes/extracts-error.yaml

@@ -29,5 +29,6 @@ content: |
 ref: error-unsupportedexception
 content: |
   :phpclass:`MongoDB\\Exception\\UnsupportedException` if options are used and
-  not supported by the selected server (e.g. ``collation``, ``writeConcern``).
+  not supported by the selected server (e.g. ``collation``, ``readConcern``,
+  ``writeConcern``).
 ...

src/Exception/UnsupportedException.php

@@ -14,6 +14,16 @@ class UnsupportedException extends RuntimeException implements Exception
         return new static('Collations are not supported by the server executing this operation');
     }
 
+    /**
+     * Thrown when a command's readConcern option is not supported by a server.
+     *
+     * @return self
+     */
+    public static function readConcernNotSupported()
+    {
+        return new static('Read concern is not supported by the server executing this command');
+    }
+
     /**
      * Thrown when a command's writeConcern option is not supported by a server.
      *

src/Operation/Aggregate.php

@@ -64,8 +64,8 @@ class Aggregate implements Executable
      *  * readConcern (MongoDB\Driver\ReadConcern): Read concern. Note that a
      *    "majority" read concern is not compatible with the $out stage.
      *
-     *    For servers < 3.2, this option is ignored as read concern is not
-     *    available.
+     *    This is not supported for server versions < 3.2 and will result in an
+     *    exception at execution time if used.
      *
      *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
      *
@@ -182,7 +182,7 @@ class Aggregate implements Executable
      * @param Server $server
      * @return Traversable
      * @throws UnexpectedValueException if the command response was malformed
-     * @throws UnsupportedException if collation or write concern is used and unsupported
+     * @throws UnsupportedException if collation, read concern, or write concern is used and unsupported
      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
      */
     public function execute(Server $server)
@@ -191,6 +191,10 @@ class Aggregate implements Executable
             throw UnsupportedException::collationNotSupported();
         }
 
+        if (isset($this->options['readConcern']) && ! \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+            throw UnsupportedException::readConcernNotSupported();
+        }
+
         if (isset($this->options['writeConcern']) && ! \MongoDB\server_supports_feature($server, self::$wireVersionForWriteConcern)) {
             throw UnsupportedException::writeConcernNotSupported();
         }
@@ -254,7 +258,7 @@ class Aggregate implements Executable
             $cmd['maxTimeMS'] = $this->options['maxTimeMS'];
         }
 
-        if (isset($this->options['readConcern']) && \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+        if (isset($this->options['readConcern'])) {
             $cmd['readConcern'] = \MongoDB\read_concern_as_document($this->options['readConcern']);
         }
 

src/Operation/Count.php

@@ -48,8 +48,8 @@ class Count implements Executable
      *
      *  * readConcern (MongoDB\Driver\ReadConcern): Read concern.
      *
-     *    For servers < 3.2, this option is ignored as read concern is not
-     *    available.
+     *    This is not supported for server versions < 3.2 and will result in an
+     *    exception at execution time if used.
      *
      *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
      *
@@ -115,7 +115,7 @@ class Count implements Executable
      * @param Server $server
      * @return integer
      * @throws UnexpectedValueException if the command response was malformed
-     * @throws UnsupportedException if collation is used and unsupported
+     * @throws UnsupportedException if collation or read concern is used and unsupported
      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
      */
     public function execute(Server $server)
@@ -124,6 +124,10 @@ class Count implements Executable
             throw UnsupportedException::collationNotSupported();
         }
 
+        if (isset($this->options['readConcern']) && ! \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+            throw UnsupportedException::readConcernNotSupported();
+        }
+
         $readPreference = isset($this->options['readPreference']) ? $this->options['readPreference'] : null;
 
         $cursor = $server->executeCommand($this->databaseName, $this->createCommand($server), $readPreference);
@@ -161,7 +165,7 @@ class Count implements Executable
             }
         }
 
-        if (isset($this->options['readConcern']) && \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+        if (isset($this->options['readConcern'])) {
             $cmd['readConcern'] = \MongoDB\read_concern_as_document($this->options['readConcern']);
         }
 

src/Operation/Distinct.php

@@ -44,8 +44,8 @@ class Distinct implements Executable
      *
      *  * readConcern (MongoDB\Driver\ReadConcern): Read concern.
      *
-     *    For servers < 3.2, this option is ignored as read concern is not
-     *    available.
+     *    This is not supported for server versions < 3.2 and will result in an
+     *    exception at execution time if used.
      *
      *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
      *
@@ -92,7 +92,7 @@ class Distinct implements Executable
      * @param Server $server
      * @return mixed[]
      * @throws UnexpectedValueException if the command response was malformed
-     * @throws UnsupportedException if collation is used and unsupported
+     * @throws UnsupportedException if collation or read concern is used and unsupported
      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
      */
     public function execute(Server $server)
@@ -101,6 +101,10 @@ class Distinct implements Executable
             throw UnsupportedException::collationNotSupported();
         }
 
+        if (isset($this->options['readConcern']) && ! \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+            throw UnsupportedException::readConcernNotSupported();
+        }
+
         $readPreference = isset($this->options['readPreference']) ? $this->options['readPreference'] : null;
 
         $cursor = $server->executeCommand($this->databaseName, $this->createCommand($server), $readPreference);

src/Operation/Find.php

@@ -75,8 +75,8 @@ class Find implements Executable
      *
      *  * readConcern (MongoDB\Driver\ReadConcern): Read concern.
      *
-     *    For servers < 3.2, this option is ignored as read concern is not
-     *    available.
+     *    This is not supported for server versions < 3.2 and will result in an
+     *    exception at execution time if used.
      *
      *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
      *
@@ -185,7 +185,7 @@ class Find implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return Cursor
-     * @throws UnsupportedException if collation is used and unsupported
+     * @throws UnsupportedException if collation or read concern is used and unsupported
      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
      */
     public function execute(Server $server)
@@ -194,6 +194,10 @@ class Find implements Executable
             throw UnsupportedException::collationNotSupported();
         }
 
+        if (isset($this->options['readConcern']) && ! \MongoDB\server_supports_feature($server, self::$wireVersionForReadConcern)) {
+            throw UnsupportedException::readConcernNotSupported();
+        }
+
         $readPreference = isset($this->options['readPreference']) ? $this->options['readPreference'] : null;
 
         $cursor = $server->executeQuery($this->databaseName . '.' . $this->collectionName, $this->createQuery(), $readPreference);

src/Operation/FindOne.php

@@ -45,8 +45,8 @@ class FindOne implements Executable
      *
      *  * readConcern (MongoDB\Driver\ReadConcern): Read concern.
      *
-     *    For servers < 3.2, this option is ignored as read concern is not
-     *    available.
+     *    This is not supported for server versions < 3.2 and will result in an
+     *    exception at execution time if used.
      *
      *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
      *
@@ -82,7 +82,7 @@ class FindOne implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return array|object|null
-     * @throws UnsupportedException if collation is used and unsupported
+     * @throws UnsupportedException if collation or read concern is used and unsupported
      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
      */
     public function execute(Server $server)