Add lazy array and document models with codecs

Author: alcaeus

src/Codec/LazyBSONArrayCodec.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace MongoDB\Codec;
+
+use MongoDB\BSON\PackedArray;
+use MongoDB\Exception\UnexpectedValueException;
+use MongoDB\Model\LazyBSONArray;
+
+use function array_values;
+use function sprintf;
+
+/**
+ * Codec for lazy decoding of BSON PackedArray instances
+ *
+ * @template-implements Codec<PackedArray, LazyBSONArray>
+ */
+class LazyBSONArrayCodec implements Codec, KnowsCodecLibrary
+{
+    /** @var CodecLibrary|null */
+    private $library = null;
+
+    public function attachLibrary(CodecLibrary $library): void
+    {
+        $this->library = $library;
+    }
+
+    /** @inheritDoc */
+    public function canDecode($value): bool
+    {
+        return $value instanceof PackedArray;
+    }
+
+    /** @inheritDoc */
+    public function canEncode($value): bool
+    {
+        return $value instanceof LazyBSONArray;
+    }
+
+    /** @inheritDoc */
+    public function decode($value): LazyBSONArray
+    {
+        if (! $value instanceof PackedArray) {
+            throw new UnexpectedValueException(sprintf('"%s" can only decode from "%s" instances', self::class, PackedArray::class));
+        }
+
+        return new LazyBSONArray($value, $this->getLibrary());
+    }
+
+    /** @inheritDoc */
+    public function encode($value): PackedArray
+    {
+        if (! $value instanceof LazyBSONArray) {
+            throw new UnexpectedValueException(sprintf('"%s" can only encode "%s" instances', self::class, LazyBSONArray::class));
+        }
+
+        $return = [];
+        foreach ($value as $offset => $offsetValue) {
+            $return[$offset] = $this->getLibrary()->canEncode($offsetValue) ? $this->getLibrary()->encode($offsetValue) : $offsetValue;
+        }
+
+        return PackedArray::fromPHP(array_values($return));
+    }
+
+    private function getLibrary(): CodecLibrary
+    {
+        return $this->library ?? $this->library = new CodecLibrary(new LazyBSONDocumentCodec(), $this);
+    }
+}

src/Codec/LazyBSONDocumentCodec.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace MongoDB\Codec;
+
+use MongoDB\BSON\Document;
+use MongoDB\Exception\UnexpectedValueException;
+use MongoDB\Model\LazyBSONDocument;
+
+use function sprintf;
+
+/**
+ * Codec for lazy decoding of BSON Document instances
+ *
+ * @template-implements Codec<Document, LazyBSONDocument>
+ */
+class LazyBSONDocumentCodec implements Codec, KnowsCodecLibrary
+{
+    /** @var CodecLibrary|null */
+    private $library = null;
+
+    public function attachLibrary(CodecLibrary $library): void
+    {
+        $this->library = $library;
+    }
+
+    /** @inheritDoc */
+    public function canDecode($value): bool
+    {
+        return $value instanceof Document;
+    }
+
+    /** @inheritDoc */
+    public function canEncode($value): bool
+    {
+        return $value instanceof LazyBSONDocument;
+    }
+
+    /** @inheritDoc */
+    public function decode($value): LazyBSONDocument
+    {
+        if (! $value instanceof Document) {
+            throw new UnexpectedValueException(sprintf('"%s" can only decode from "%s" instances', self::class, Document::class));
+        }
+
+        return new LazyBSONDocument($value, $this->getLibrary());
+    }
+
+    /** @inheritDoc */
+    public function encode($value): Document
+    {
+        if (! $value instanceof LazyBSONDocument) {
+            throw new UnexpectedValueException(sprintf('"%s" can only encode "%s" instances', self::class, LazyBSONDocument::class));
+        }
+
+        $return = [];
+        foreach ($value as $field => $fieldValue) {
+            $return[$field] = $this->getLibrary()->canEncode($fieldValue) ? $this->getLibrary()->encode($fieldValue) : $fieldValue;
+        }
+
+        return Document::fromPHP($return);
+    }
+
+    private function getLibrary(): CodecLibrary
+    {
+        return $this->library ?? $this->library = new CodecLibrary($this, new LazyBSONArrayCodec());
+    }
+}

src/Model/AsListIterator.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace MongoDB\Model;
+
+use IteratorIterator;
+use Traversable;
+
+/**
+ * @internal
+ * @template TKey as int
+ * @template TValue
+ * @template TIterator as Traversable<TKey, TValue>
+ *
+ * @template-extends IteratorIterator<int, TValue, TIterator>
+ */
+final class AsListIterator extends IteratorIterator
+{
+    /** @var int */
+    private $index = 0;
+
+    public function key(): ?int
+    {
+        return $this->valid() ? $this->index : null;
+    }
+
+    public function next(): void
+    {
+        $this->index++;
+
+        parent::next();
+    }
+
+    public function rewind(): void
+    {
+        $this->index = 0;
+
+        parent::rewind();
+    }
+}

src/Model/CallbackIterator.php

@@ -49,7 +49,7 @@ public function __construct(Traversable $traversable, Closure $callback)
     #[ReturnTypeWillChange]
     public function current()
     {
-        return ($this->callback)($this->iterator->current());
+        return ($this->callback)($this->iterator->current(), $this->iterator->key());
     }
 
     /**