[WIP] Refactoring InnerResultArray to CachingIterator

src/Iterators/CachingIterator.php

@@ -0,0 +1,235 @@
+<?php
+
+
+namespace TheCodingMachine\TDBM\Iterators;
+
+
+use Countable;
+use Iterator;
+use TheCodingMachine\TDBM\AbstractTDBMObject;
+use TheCodingMachine\TDBM\InnerResultIteratorInterface;
+use TheCodingMachine\TDBM\TDBMInvalidOffsetException;
+use TheCodingMachine\TDBM\TDBMInvalidOperationException;
+use Traversable;
+use function current;
+use function filter_var;
+use function get_class;
+use function key;
+use function next;
+use const FILTER_VALIDATE_INT;
+
+/**
+ * An iterator that caches results (just like \CachingIterator), but that also accepts seeking a value even if
+ * iteration did not started yet.
+ */
+class CachingIterator implements Iterator, InnerResultIteratorInterface
+{
+    /**
+     * The list of results already fetched.
+     *
+     * @var AbstractTDBMObject[]
+     */
+    private $results = [];
+    /**
+     * @var Traversable
+     */
+    private $iterator;
+    /**
+     * @var bool
+     */
+    private $fetchStarted = false;
+    /**
+     * @var mixed
+     */
+    private $current;
+    /**
+     * @var int
+     */
+    private $key;
+
+    public function __construct(Traversable $iterator)
+    {
+        $this->iterator = $iterator;
+    }
+
+    /**
+     * Whether a offset exists.
+     *
+     * @link http://php.net/manual/en/arrayaccess.offsetexists.php
+     *
+     * @param mixed $offset <p>
+     *                      An offset to check for.
+     *                      </p>
+     *
+     * @return bool true on success or false on failure.
+     *              </p>
+     *              <p>
+     *              The return value will be casted to boolean if non-boolean was returned
+     *
+     * @since 5.0.0
+     */
+    public function offsetExists($offset)
+    {
+        try {
+            $this->toIndex($offset);
+        } catch (TDBMInvalidOffsetException $e) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Offset to retrieve.
+     *
+     * @link http://php.net/manual/en/arrayaccess.offsetget.php
+     *
+     * @param mixed $offset <p>
+     *                      The offset to retrieve.
+     *                      </p>
+     *
+     * @return mixed Can return all value types
+     *
+     * @since 5.0.0
+     */
+    public function offsetGet($offset)
+    {
+        $this->toIndex($offset);
+
+        return $this->results[$offset];
+    }
+
+    /**
+     * @param mixed $offset
+     * @throws TDBMInvalidOffsetException
+     */
+    private function toIndex($offset): void
+    {
+        if ($offset < 0 || filter_var($offset, FILTER_VALIDATE_INT) === false) {
+            throw new TDBMInvalidOffsetException('Trying to access result set using offset "'.$offset.'". An offset must be a positive integer.');
+        }
+        if (!$this->fetchStarted) {
+            $this->rewind();
+        }
+        while (!isset($this->results[$offset])) {
+            $this->next();
+            if ($this->current === null) {
+                throw new TDBMInvalidOffsetException('Offset "'.$offset.'" does not exist in result set.');
+            }
+        }
+    }
+
+    public function next()
+    {
+        // Let's overload the next() method to store the result.
+        if (isset($this->results[$this->key + 1])) {
+            ++$this->key;
+            $this->current = $this->results[$this->key];
+        } else {
+            $this->current = next($this->iterator);
+            $this->key = key($this->iterator);
+            if ($this->key !== null) {
+                $this->results[$this->key] = $this->current;
+            }
+        }
+    }
+
+    /**
+     * Do not reexecute the query.
+     */
+    public function rewind()
+    {
+        if (!$this->fetchStarted) {
+            reset($this->iterator);
+            $this->fetchStarted = true;
+            $this->key = key($this->iterator);
+            $this->current = current($this->iterator);
+            $this->results[$this->key] = $this->current;
+        } else {
+            $this->key = 0;
+            $this->current = $this->results[0];
+        }
+    }
+
+    /**
+     * Return the current element
+     * @link https://php.net/manual/en/iterator.current.php
+     * @return mixed Can return any type.
+     * @since 5.0.0
+     */
+    public function current()
+    {
+        return $this->current;
+    }
+
+    /**
+     * Return the key of the current element
+     * @link https://php.net/manual/en/iterator.key.php
+     * @return mixed scalar on success, or null on failure.
+     * @since 5.0.0
+     */
+    public function key()
+    {
+        return $this->key;
+    }
+
+    /**
+     * Checks if current position is valid
+     * @link https://php.net/manual/en/iterator.valid.php
+     * @return boolean The return value will be casted to boolean and then evaluated.
+     * Returns true on success or false on failure.
+     * @since 5.0.0
+     */
+    public function valid()
+    {
+        return $this->key !== null;
+    }
+
+    /**
+     * Offset to set
+     * @link https://php.net/manual/en/arrayaccess.offsetset.php
+     * @param mixed $offset <p>
+     * The offset to assign the value to.
+     * </p>
+     * @param mixed $value <p>
+     * The value to set.
+     * </p>
+     * @return void
+     * @since 5.0.0
+     */
+    public function offsetSet($offset, $value)
+    {
+        throw new TDBMInvalidOperationException('You cannot set values in a TDBM result set.');
+    }
+
+    /**
+     * Offset to unset
+     * @link https://php.net/manual/en/arrayaccess.offsetunset.php
+     * @param mixed $offset <p>
+     * The offset to unset.
+     * </p>
+     * @return void
+     * @since 5.0.0
+     */
+    public function offsetUnset($offset)
+    {
+        throw new TDBMInvalidOperationException('You cannot unset values in a TDBM result set.');
+    }
+
+    /**
+     * Count elements of an object
+     * @link https://php.net/manual/en/countable.count.php
+     * @return int The custom count as an integer.
+     * </p>
+     * <p>
+     * The return value is cast to an integer.
+     * @since 5.1.0
+     */
+    public function count()
+    {
+        if ($this->iterator instanceof Countable) {
+            return $this->iterator->count();
+        }
+        throw new TDBMInvalidOperationException('Cannot count items of iterator '.get_class($this->iterator));
+    }
+}

src/ResultIterator.php

@@ -5,6 +5,7 @@
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
 use Psr\Log\NullLogger;
+use TheCodingMachine\TDBM\Iterators\CachingIterator;
 use function array_map;
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Statement;
@@ -167,10 +168,11 @@ public function getIterator()
         if ($this->innerResultIterator === null) {
             if ($this->totalCount === 0) {
                 $this->innerResultIterator = new EmptyInnerResultIterator();
-            } elseif ($this->mode === TDBMService::MODE_CURSOR) {
-                $this->innerResultIterator = InnerResultIterator::createInnerResultIterator($this->queryFactory->getMagicSql(), $this->parameters, null, null, $this->queryFactory->getColumnDescriptors(), $this->objectStorage, $this->className, $this->tdbmService, $this->magicQuery, $this->logger);
             } else {
-                $this->innerResultIterator = InnerResultArray::createInnerResultIterator($this->queryFactory->getMagicSql(), $this->parameters, null, null, $this->queryFactory->getColumnDescriptors(), $this->objectStorage, $this->className, $this->tdbmService, $this->magicQuery, $this->logger);
+                $this->innerResultIterator = InnerResultIterator::createInnerResultIterator($this->queryFactory->getMagicSql(), $this->parameters, null, null, $this->queryFactory->getColumnDescriptors(), $this->objectStorage, $this->className, $this->tdbmService, $this->magicQuery, $this->logger);
+                if ($this->mode === TDBMService::MODE_ARRAY) {
+                    $this->innerResultIterator = new CachingIterator($this->innerResultIterator);
+                }
             }
         }
 

tests/Iterators/CachingIteratorTest.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace TheCodingMachine\TDBM\Iterators;
+
+use ArrayIterator;
+use PHPUnit\Framework\TestCase;
+use function iterator_to_array;
+use function range;
+
+class CachingIteratorTest extends TestCase
+{
+    public function testCachingIterator()
+    {
+        $it = new CachingIterator(new ArrayIterator(range(1,5)));
+
+        $it[3];
+        $this->assertArrayHasKey(3, $it);
+        $this->assertCount(5, $it);
+        $arr = iterator_to_array($it);
+        $this->assertSame([1, 2, 3, 4, 5], $arr);
+    }
+
+    public function testCachingIterator2()
+    {
+        $it = new CachingIterator(new ArrayIterator(range(1,5)));
+
+        $arr = iterator_to_array($it);
+        $this->assertSame([1, 2, 3, 4, 5], $arr);
+    }
+}