Remove unnecessary cursor wrapping for iterators

Author: alcaeus

src/GridFS/ReadableStream.php

@@ -17,7 +17,7 @@
 
 namespace MongoDB\GridFS;
 
-use IteratorIterator;
+use MongoDB\Driver\CursorInterface;
 use MongoDB\Exception\InvalidArgumentException;
 use MongoDB\GridFS\Exception\CorruptFileException;
 use stdClass;
@@ -48,7 +48,7 @@ class ReadableStream
     /** @var integer */
     private $chunkOffset = 0;
 
-    /** @var IteratorIterator|null */
+    /** @var CursorInterface|null */
     private $chunksIterator;
 
     /** @var CollectionWrapper */
@@ -315,9 +315,7 @@ private function initBufferFromNextChunk()
      */
     private function initChunksIterator()
     {
-        $cursor = $this->collectionWrapper->findChunksByFileId($this->file->_id, $this->chunkOffset);
-
-        $this->chunksIterator = new IteratorIterator($cursor);
+        $this->chunksIterator = $this->collectionWrapper->findChunksByFileId($this->file->_id, $this->chunkOffset);
         $this->chunksIterator->rewind();
     }
 }

src/Model/CachingIterator.php

@@ -41,7 +41,7 @@ class CachingIterator implements Countable, Iterator
     /** @var array */
     private $items = [];
 
-    /** @var IteratorIterator */
+    /** @var Iterator */
     private $iterator;
 
     /** @var boolean */
@@ -53,14 +53,14 @@ class CachingIterator implements Countable, Iterator
     /**
      * Initialize the iterator and stores the first item in the cache. This
      * effectively rewinds the Traversable and the wrapping IteratorIterator.
-     *  Additionally, this mimics behavior of the SPL iterators and allows users
-     * to omit an explicit call * to rewind() before using the other methods.
+     * Additionally, this mimics behavior of the SPL iterators and allows users
+     * to omit an explicit call to rewind() before using the other methods.
      *
      * @param Traversable $traversable
      */
     public function __construct(Traversable $traversable)
     {
-        $this->iterator = new IteratorIterator($traversable);
+        $this->iterator = $traversable instanceof Iterator ? $traversable : new IteratorIterator($traversable);
 
         $this->iterator->rewind();
         $this->storeCurrentItem();

src/Model/CallbackIterator.php

@@ -32,12 +32,12 @@ class CallbackIterator implements Iterator
     /** @var Closure */
     private $callback;
 
-    /** @var IteratorIterator */
+    /** @var Iterator */
     private $iterator;
 
     public function __construct(Traversable $traversable, Closure $callback)
     {
-        $this->iterator = new IteratorIterator($traversable);
+        $this->iterator = $traversable instanceof Iterator ? $traversable : new IteratorIterator($traversable);
         $this->callback = $callback;
     }
 

tests/Collection/CrudSpecFunctionalTest.php

@@ -2,7 +2,6 @@
 
 namespace MongoDB\Tests\Collection;
 
-use IteratorIterator;
 use LogicException;
 use MongoDB\BulkWriteResult;
 use MongoDB\Collection;
@@ -105,8 +104,8 @@ public function provideSpecificationTests()
     private function assertEquivalentCollections($expectedCollection, $actualCollection)
     {
         $mi = new MultipleIterator(MultipleIterator::MIT_NEED_ANY);
-        $mi->attachIterator(new IteratorIterator($expectedCollection->find()));
-        $mi->attachIterator(new IteratorIterator($actualCollection->find()));
+        $mi->attachIterator($expectedCollection->find());
+        $mi->attachIterator($actualCollection->find());
 
         foreach ($mi as $documents) {
             list($expectedDocument, $actualDocument) = $documents;

tests/GridFS/SpecFunctionalTest.php

@@ -3,7 +3,6 @@
 namespace MongoDB\Tests\GridFS;
 
 use DateTime;
-use IteratorIterator;
 use LogicException;
 use MongoDB\BSON\Binary;
 use MongoDB\BSON\ObjectId;
@@ -121,8 +120,8 @@ public function provideSpecificationTests()
     private function assertEquivalentCollections($expectedCollection, $actualCollection, $actualResult)
     {
         $mi = new MultipleIterator(MultipleIterator::MIT_NEED_ANY);
-        $mi->attachIterator(new IteratorIterator($expectedCollection->find()));
-        $mi->attachIterator(new IteratorIterator($actualCollection->find()));
+        $mi->attachIterator($expectedCollection->find());
+        $mi->attachIterator($actualCollection->find());
 
         foreach ($mi as $documents) {
             list($expectedDocument, $actualDocument) = $documents;

tests/Operation/FindFunctionalTest.php

@@ -2,7 +2,6 @@
 
 namespace MongoDB\Tests\Operation;
 
-use IteratorIterator;
 use MongoDB\Driver\BulkWrite;
 use MongoDB\Driver\ReadPreference;
 use MongoDB\Operation\CreateCollection;
@@ -183,40 +182,39 @@ public function testMaxAwaitTimeMS()
 
         $operation = new Find($databaseName, $cappedCollectionName, [], ['cursorType' => Find::TAILABLE_AWAIT, 'maxAwaitTimeMS' => $maxAwaitTimeMS]);
         $cursor = $operation->execute($this->getPrimaryServer());
-        $it = new IteratorIterator($cursor);
 
         /* The initial query includes the one and only document in its result
          * batch, so we should not expect a delay. */
         $startTime = microtime(true);
-        $it->rewind();
+        $cursor->rewind();
         $duration = microtime(true) - $startTime;
         $this->assertLessThan($pivot, $duration);
 
-        $this->assertTrue($it->valid());
-        $this->assertSameDocument(['_id' => 1], $it->current());
+        $this->assertTrue($cursor->valid());
+        $this->assertSameDocument(['_id' => 1], $cursor->current());
 
         /* Advancing again takes us to the last document of the result batch,
          * but still should not issue a getMore */
         $startTime = microtime(true);
-        $it->next();
+        $cursor->next();
         $duration = microtime(true) - $startTime;
         $this->assertLessThan($pivot, $duration);
 
-        $this->assertTrue($it->valid());
-        $this->assertSameDocument(['_id' => 2], $it->current());
+        $this->assertTrue($cursor->valid());
+        $this->assertSameDocument(['_id' => 2], $cursor->current());
 
         /* Now that we've reached the end of the initial result batch, advancing
          * again will issue a getMore. Expect to wait at least maxAwaitTimeMS,
          * since no new documents should be inserted to wake up the server's
          * query thread. Also ensure we don't wait too long (server default is
          * one second). */
         $startTime = microtime(true);
-        $it->next();
+        $cursor->next();
         $duration = microtime(true) - $startTime;
         $this->assertGreaterThan($pivot, $duration);
         $this->assertLessThan(0.5, $duration);
 
-        $this->assertFalse($it->valid());
+        $this->assertFalse($cursor->valid());
     }
 
     public function testReadPreferenceWithinTransaction()

tests/SpecTests/FunctionalTestCase.php

@@ -3,7 +3,6 @@
 namespace MongoDB\Tests\SpecTests;
 
 use ArrayIterator;
-use IteratorIterator;
 use LogicException;
 use MongoDB\Collection;
 use MongoDB\Driver\Server;
@@ -106,7 +105,7 @@ protected function assertOutcomeCollectionData(array $expectedDocuments, $result
 
         $mi = new MultipleIterator(MultipleIterator::MIT_NEED_ANY);
         $mi->attachIterator(new ArrayIterator($expectedDocuments));
-        $mi->attachIterator(new IteratorIterator($outcomeCollection->find([], ['sort' => ['_id' => 1]])));
+        $mi->attachIterator($outcomeCollection->find([], ['sort' => ['_id' => 1]]));
 
         foreach ($mi as $documents) {
             list($expectedDocument, $actualDocument) = $documents;

tests/SpecTests/PrimaryStepDownSpecTest.php

@@ -2,7 +2,6 @@
 
 namespace MongoDB\Tests\SpecTests;
 
-use IteratorIterator;
 use MongoDB\Client;
 use MongoDB\Collection;
 use MongoDB\Driver\Command;
@@ -205,12 +204,11 @@ public function testGetMoreIteration()
         // Start a find operation on the collection with a batch size of 2, and retrieve the first batch of results.
         $cursor = $this->collection->find([], ['batchSize' => 2]);
 
-        $iterator = new IteratorIterator($cursor);
-        $iterator->rewind();
-        $this->assertTrue($iterator->valid());
+        $cursor->rewind();
+        $this->assertTrue($cursor->valid());
 
-        $iterator->next();
-        $this->assertTrue($iterator->valid());
+        $cursor->next();
+        $this->assertTrue($cursor->valid());
 
         $totalConnectionsCreated = $this->getTotalConnectionsCreated();
 
@@ -235,14 +233,14 @@ public function testGetMoreIteration()
         $events = [];
         $observer = new CommandObserver();
         $observer->observe(
-            function () use ($iterator) {
-                $iterator->next();
+            function () use ($cursor) {
+                $cursor->next();
             },
             function ($event) use (&$events) {
                 $events[] = $event;
             }
         );
-        $this->assertTrue($iterator->valid());
+        $this->assertTrue($cursor->valid());
         $this->assertCount(1, $events);
         $this->assertSame('getMore', $events[0]['started']->getCommandName());
 

tests/UnifiedSpecTests/CollectionData.php

@@ -3,7 +3,6 @@
 namespace MongoDB\Tests\UnifiedSpecTests;
 
 use ArrayIterator;
-use IteratorIterator;
 use MongoDB\Client;
 use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
@@ -75,7 +74,7 @@ public function assertOutcome(Client $client)
 
         $mi = new MultipleIterator(MultipleIterator::MIT_NEED_ANY);
         $mi->attachIterator(new ArrayIterator($this->documents));
-        $mi->attachIterator(new IteratorIterator($cursor));
+        $mi->attachIterator($cursor);
 
         foreach ($mi as $i => $documents) {
             list($expectedDocument, $actualDocument) = $documents;