Revert "Merge pull request #10450 from creative-commoners/pulls/5/res…

…cue-master-generators" (#10483)

This reverts commit 9edf3a5, reversing
changes made to 934fafd.

src/Forms/GridField/GridFieldExportButton.php

@@ -223,6 +223,10 @@ public function generateExportFileData($gridField)
 
         // Remove limit as the list may be paginated, we want the full list for the export
         $items = $items->limit(null);
+        // Use Generator in applicable cases to reduce memory consumption
+        $items = $items instanceof DataList
+            ? $items->getGenerator()
+            : $items;
 
         /** @var DataObject $item */
         foreach ($items as $item) {

src/ORM/ArrayList.php

@@ -2,8 +2,8 @@
 
 namespace SilverStripe\ORM;
 
+use ArrayIterator;
 use InvalidArgumentException;
-use Iterator;
 use LogicException;
 use SilverStripe\Dev\Debug;
 use SilverStripe\Dev\Deprecation;
@@ -103,16 +103,19 @@ public function exists()
     /**
      * Returns an Iterator for this ArrayList.
      * This function allows you to use ArrayList in foreach loops
+     *
+     * @return ArrayIterator
      */
-    public function getIterator(): Iterator
-    {
-        foreach ($this->items as $i => $item) {
-            if (is_array($item)) {
-                yield new ArrayData($item);
-            } else {
-                yield $item;
-            }
-        }
+    #[\ReturnTypeWillChange]
+    public function getIterator()
+    {
+        $items = array_map(
+            function ($item) {
+                return is_array($item) ? new ArrayData($item) : $item;
+            },
+            $this->items ?? []
+        );
+        return new ArrayIterator($items);
     }
 
     /**

src/ORM/Connect/DBSchemaManager.php

@@ -378,7 +378,7 @@ public function requireTable(
             if ($dbID && isset($options[$dbID])) {
                 if (preg_match('/ENGINE=([^\s]*)/', $options[$dbID] ?? '', $alteredEngineMatches)) {
                     $alteredEngine = $alteredEngineMatches[1];
-                    $tableStatus = $this->query(sprintf('SHOW TABLE STATUS LIKE \'%s\'', $table))->record();
+                    $tableStatus = $this->query(sprintf('SHOW TABLE STATUS LIKE \'%s\'', $table))->first();
                     $tableOptionsChanged = ($tableStatus['Engine'] != $alteredEngine);
                 }
             }

src/ORM/Connect/MySQLQuery.php

@@ -2,8 +2,6 @@
 
 namespace SilverStripe\ORM\Connect;
 
-use Iterator;
-
 /**
  * A result-set from a MySQL database (using MySQLiConnector)
  * Note that this class is only used for the results of non-prepared statements
@@ -47,21 +45,44 @@ public function __destruct()
         }
     }
 
-    public function getIterator(): Iterator
+    public function seek($row)
     {
         if (is_object($this->handle)) {
-            while ($data = $this->handle->fetch_assoc()) {
-                yield $data;
-            }
+            // Fix for https://github.com/silverstripe/silverstripe-framework/issues/9097 without breaking the seek() API
+            $this->handle->data_seek($row);
+            $result = $this->nextRecord();
+            $this->handle->data_seek($row);
+            return $result;
         }
+        return null;
     }
 
     public function numRecords()
     {
         if (is_object($this->handle)) {
             return $this->handle->num_rows;
         }
-
         return null;
     }
+
+    public function nextRecord()
+    {
+        $floatTypes = [MYSQLI_TYPE_FLOAT, MYSQLI_TYPE_DOUBLE, MYSQLI_TYPE_DECIMAL, MYSQLI_TYPE_NEWDECIMAL];
+
+        if (is_object($this->handle) && ($row = $this->handle->fetch_array(MYSQLI_NUM))) {
+            $data = [];
+            foreach ($row as $i => $value) {
+                if (!isset($this->columns[$i])) {
+                    throw new DatabaseException("Can't get metadata for column $i");
+                }
+                if (in_array($this->columns[$i]->type, $floatTypes ?? [])) {
+                    $value = (float)$value;
+                }
+                $data[$this->columns[$i]->name] = $value;
+            }
+            return $data;
+        } else {
+            return false;
+        }
+    }
 }

src/ORM/Connect/MySQLStatement.php

@@ -2,7 +2,6 @@
 
 namespace SilverStripe\ORM\Connect;
 
-use Iterator;
 use mysqli_result;
 use mysqli_stmt;
 
@@ -57,26 +56,6 @@ class MySQLStatement extends Query
      */
     protected $boundValues = [];
 
-    /**
-     * Hook the result-set given into a Query class, suitable for use by SilverStripe.
-     * @param mysqli_stmt $statement The related statement, if present
-     * @param mysqli_result $metadata The metadata for this statement
-     */
-    public function __construct($statement, $metadata)
-    {
-        $this->statement = $statement;
-        $this->metadata = $metadata;
-
-        // Immediately bind and buffer
-        $this->bind();
-    }
-
-    public function __destruct()
-    {
-        $this->statement->close();
-        $this->currentRecord = false;
-    }
-
     /**
      * Binds this statement to the variables
      */
@@ -103,20 +82,58 @@ protected function bind()
         call_user_func_array([$this->statement, 'bind_result'], $variables ?? []);
     }
 
-    public function getIterator(): Iterator
+    /**
+     * Hook the result-set given into a Query class, suitable for use by SilverStripe.
+     * @param mysqli_stmt $statement The related statement, if present
+     * @param mysqli_result $metadata The metadata for this statement
+     */
+    public function __construct($statement, $metadata)
+    {
+        $this->statement = $statement;
+        $this->metadata = $metadata;
+
+        // Immediately bind and buffer
+        $this->bind();
+    }
+
+    public function __destruct()
     {
-        while ($this->statement->fetch()) {
-            // Dereferenced row
-            $row = [];
-            foreach ($this->boundValues as $key => $value) {
-                $row[$key] = $value;
-            }
-            yield $row;
-        }
+        $this->statement->close();
+        $this->currentRecord = false;
+    }
+
+    public function seek($row)
+    {
+        $this->rowNum = $row - 1;
+
+        // Fix for https://github.com/silverstripe/silverstripe-framework/issues/9097 without breaking the seek() API
+        $this->statement->data_seek($row);
+        $result = $this->next();
+        $this->statement->data_seek($row);
+        return $result;
     }
 
     public function numRecords()
     {
         return $this->statement->num_rows();
     }
+
+    public function nextRecord()
+    {
+        // Skip data if out of data
+        if (!$this->statement->fetch()) {
+            return false;
+        }
+
+        // Dereferenced row
+        $row = [];
+        foreach ($this->boundValues as $key => $value) {
+            $floatTypes = [MYSQLI_TYPE_FLOAT, MYSQLI_TYPE_DOUBLE, MYSQLI_TYPE_DECIMAL, MYSQLI_TYPE_NEWDECIMAL];
+            if (in_array($this->types[$key], $floatTypes ?? [])) {
+                $value = (float)$value;
+            }
+            $row[$key] = $value;
+        }
+        return $row;
+    }
 }

src/ORM/Connect/PDOQuery.php

@@ -2,9 +2,6 @@
 
 namespace SilverStripe\ORM\Connect;
 
-use ArrayIterator;
-use Iterator;
-
 /**
  * A result-set from a PDO database.
  */
@@ -17,7 +14,7 @@ class PDOQuery extends Query
 
     /**
      * Hook the result-set given into a Query class, suitable for use by SilverStripe.
-     * @param PDOStatementHandle $statement The internal PDOStatement containing the results
+     * @param PDOStatement $statement The internal PDOStatement containing the results
      */
     public function __construct(PDOStatementHandle $statement)
     {
@@ -29,13 +26,25 @@ public function __construct(PDOStatementHandle $statement)
         $statement->closeCursor();
     }
 
-    public function getIterator(): Iterator
+    public function seek($row)
     {
-        return new ArrayIterator($this->results);
+        $this->rowNum = $row - 1;
+        return $this->nextRecord();
     }
 
     public function numRecords()
     {
-        return count($this->results);
+        return count($this->results ?? []);
+    }
+
+    public function nextRecord()
+    {
+        $index = $this->rowNum + 1;
+
+        if (isset($this->results[$index])) {
+            return $this->results[$index];
+        } else {
+            return false;
+        }
     }
 }