PHPLIB-286: Support hint option for Find and FindOne

docs/includes/apiargs-MongoDBCollection-method-find-option.yaml

@@ -80,6 +80,19 @@ interface: phpmethod
 operation: ~
 optional: true
 ---
+arg_name: option
+name: hint
+type: string|array|object
+description: |
+  The index to use. Specify either the index name as a string or the index key
+  pattern as a document. If specified, then the query system will only consider
+  plans using the hinted index.
+
+  .. versionadded:: 1.2
+interface: phpmethod
+operation: ~
+optional: true
+---
 source:
   file: apiargs-common-option.yaml
   ref: maxTimeMS

docs/includes/apiargs-MongoDBCollection-method-findOne-option.yaml

@@ -18,6 +18,10 @@ source:
   file: apiargs-MongoDBCollection-method-find-option.yaml
   ref: comment
 ---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: hint
+---
 source:
   file: apiargs-common-option.yaml
   ref: maxTimeMS

src/Operation/Find.php

@@ -70,6 +70,10 @@ class Find implements Executable
      *    NON_TAILABLE, TAILABLE, or TAILABLE_AWAIT. The default is
      *    NON_TAILABLE.
      *
+     *  * hint (string|document): The index to use. Specify either the index
+     *    name as a string or the index key pattern as a document. If specified,
+     *    then the query system will only consider plans using the hinted index.
+     *
      *  * limit (integer): The maximum number of documents to return.
      *
      *  * maxTimeMS (integer): The maximum amount of time to allow the query to
@@ -146,6 +150,10 @@ class Find implements Executable
             }
         }
 
+        if (isset($options['hint']) && ! is_string($options['hint']) && ! is_array($options['hint']) && ! is_object($options['hint'])) {
+            throw InvalidArgumentException::invalidType('"hint" option', $options['hint'], 'string or array or object');
+        }
+
         if (isset($options['limit']) && ! is_integer($options['limit'])) {
             throw InvalidArgumentException::invalidType('"limit" option', $options['limit'], 'integer');
         }
@@ -249,7 +257,7 @@ class Find implements Executable
             }
         }
 
-        foreach (['allowPartialResults', 'batchSize', 'comment', 'limit', 'maxTimeMS', 'noCursorTimeout', 'oplogReplay', 'projection', 'readConcern', 'skip', 'sort'] as $option) {
+        foreach (['allowPartialResults', 'batchSize', 'comment', 'hint', 'limit', 'maxTimeMS', 'noCursorTimeout', 'oplogReplay', 'projection', 'readConcern', 'skip', 'sort'] as $option) {
             if (isset($this->options[$option])) {
                 $options[$option] = $this->options[$option];
             }

src/Operation/FindOne.php

@@ -48,6 +48,10 @@ class FindOne implements Executable
      *  * comment (string): Attaches a comment to the query. If "$comment" also
      *    exists in the modifiers document, this option will take precedence.
      *
+     *  * hint (string|document): The index to use. Specify either the index
+     *    name as a string or the index key pattern as a document. If specified,
+     *    then the query system will only consider plans using the hinted index.
+     *
      *  * maxTimeMS (integer): The maximum amount of time to allow the query to
      *    run. If "$maxTimeMS" also exists in the modifiers document, this
      *    option will take precedence.

tests/Operation/FindFunctionalTest.php

@@ -3,6 +3,7 @@
 namespace MongoDB\Tests\Operation;
 
 use MongoDB\Driver\BulkWrite;
+use MongoDB\Operation\CreateIndexes;
 use MongoDB\Operation\Find;
 use MongoDB\Tests\CommandObserver;
 use stdClass;
@@ -28,6 +29,57 @@ class FindFunctionalTest extends FunctionalTestCase
         );
     }
 
+    public function testHintOption()
+    {
+        $bulkWrite = new BulkWrite;
+        $bulkWrite->insert(['_id' => 1, 'x' => 1]);
+        $bulkWrite->insert(['_id' => 2, 'x' => 2]);
+        $bulkWrite->insert(['_id' => 3, 'y' => 3]);
+        $this->manager->executeBulkWrite($this->getNamespace(), $bulkWrite);
+
+        $createIndexes = new CreateIndexes($this->getDatabaseName(), $this->getCollectionName(), [
+            ['key' => ['x' => 1], 'sparse' => true, 'name' => 'sparse_x'],
+            ['key' => ['y' => 1]],
+        ]);
+        $createIndexes->execute($this->getPrimaryServer());
+
+        $hintsUsingSparseIndex = [
+            ['x' => 1],
+            'sparse_x',
+        ];
+
+        foreach ($hintsUsingSparseIndex as $hint) {
+            $operation = new Find($this->getDatabaseName(), $this->getCollectionName(), [], ['hint' => $hint]);
+            $cursor = $operation->execute($this->getPrimaryServer());
+
+            $expectedDocuments = [
+                (object) ['_id' => 1, 'x' => 1],
+                (object) ['_id' => 2, 'x' => 2],
+            ];
+
+            $this->assertEquals($expectedDocuments, $cursor->toArray());
+        }
+
+        $hintsNotUsingSparseIndex = [
+            ['_id' => 1],
+            ['y' => 1],
+            'y_1',
+        ];
+
+        foreach ($hintsNotUsingSparseIndex as $hint) {
+            $operation = new Find($this->getDatabaseName(), $this->getCollectionName(), [], ['hint' => $hint]);
+            $cursor = $operation->execute($this->getPrimaryServer());
+
+            $expectedDocuments = [
+                (object) ['_id' => 1, 'x' => 1],
+                (object) ['_id' => 2, 'x' => 2],
+                (object) ['_id' => 3, 'y' => 3],
+            ];
+
+            $this->assertEquals($expectedDocuments, $cursor->toArray());
+        }
+    }
+
     /**
      * @dataProvider provideTypeMapOptionsAndExpectedDocuments
      */

tests/Operation/FindTest.php

@@ -48,6 +48,10 @@ class FindTest extends TestCase
             $options[][] = ['cursorType' => $value];
         }
 
+        foreach ($this->getInvalidHintValues() as $value) {
+            $options[][] = ['hint' => $value];
+        }
+
         foreach ($this->getInvalidIntegerValues() as $value) {
             $options[][] = ['limit' => $value];
         }
@@ -91,6 +95,11 @@ class FindTest extends TestCase
         return $options;
     }
 
+    private function getInvalidHintValues()
+    {
+        return [123, 3.14, true];
+    }
+
     /**
      * @expectedException MongoDB\Exception\InvalidArgumentException
      * @dataProvider provideInvalidConstructorCursorTypeOptions