From d86c9f376fc8e08e472a78d6ec580b51c6fba6c6 Mon Sep 17 00:00:00 2001
From: Bogdan <matolq@gmail.com>
Date: Mon, 29 Jun 2026 23:10:50 +0200
Subject: [PATCH] perf: optimize _processForeignKeys()

Refactors _processForeignKeys() to:
- calculate invariant SQL fragments outside the loop
- cache escaped table identifier
- build SQL string locally before concatenating to the array, saving intermediate string allocations
---
 system/Database/Forge.php | 55 +++++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index f6eb617fd389..a329bf123351 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -1072,7 +1072,8 @@ protected function _attributeUnique(array &$attributes, array &$field)
      */
     protected function _attributeAutoIncrement(array &$attributes, array &$field)
     {
-        if (! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true
+        if (
+            ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true
             && str_contains(strtolower($field['type']), 'int')
         ) {
             $field['auto_increment'] = ' AUTO_INCREMENT';
@@ -1105,7 +1106,7 @@ protected function _processPrimaryKeys(string $table, bool $asQuery = false): st
             $sql .= 'CONSTRAINT ' . $this->db->escapeIdentifiers(($this->primaryKeys['keyName'] === '' ?
                 'pk_' . $table :
                 $this->primaryKeys['keyName']))
-                    . ' PRIMARY KEY(' . implode(', ', $this->db->escapeIdentifiers($this->primaryKeys['fields'])) . ')';
+                . ' PRIMARY KEY(' . implode(', ', $this->db->escapeIdentifiers($this->primaryKeys['fields'])) . ')';
         }
 
         return $sql;
@@ -1225,40 +1226,44 @@ protected function _processForeignKeys(string $table, bool $asQuery = false): ar
             throw new DatabaseException(lang('Database.fieldNotExists', $errorNames));
         }
 
-        $sqls = [''];
+        $sqls     = [''];
+        $isOci8   = $this->db->DBDriver === 'OCI8';
+        $dbPrefix = $this->db->DBPrefix;
+        $fkSuffix = $isOci8 ? '_fk' : '_foreign';
 
-        foreach ($this->foreignKeys as $index => $fkey) {
-            if ($asQuery === false) {
-                $index = 0;
-            } else {
-                $sqls[$index] = '';
-            }
+        // Niezmienne fragmenty SQL przygotowane przed pętlą
+        $prefixSql = $asQuery
+            ? 'ALTER TABLE ' . $this->db->escapeIdentifiers($dbPrefix . $table) . ' ADD '
+            : ",\n\t";
 
-            $nameIndex = $fkey['fkName'] !== '' ?
-            $fkey['fkName'] :
-            $table . '_' . implode('_', $fkey['field']) . ($this->db->DBDriver === 'OCI8' ? '_fk' : '_foreign');
-
-            $nameIndexFilled      = $this->db->escapeIdentifiers($nameIndex);
-            $foreignKeyFilled     = implode(', ', $this->db->escapeIdentifiers($fkey['field']));
-            $referenceTableFilled = $this->db->escapeIdentifiers($this->db->DBPrefix . $fkey['referenceTable']);
-            $referenceFieldFilled = implode(', ', $this->db->escapeIdentifiers($fkey['referenceField']));
+        foreach ($this->foreignKeys as $index => $fkey) {
+            $idx = $asQuery ? $index : 0;
 
             if ($asQuery) {
-                $sqls[$index] .= 'ALTER TABLE ' . $this->db->escapeIdentifiers($this->db->DBPrefix . $table) . ' ADD ';
-            } else {
-                $sqls[$index] .= ",\n\t";
+                $sqls[$idx] = '';
             }
 
-            $formatSql = 'CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s(%s)';
-            $sqls[$index] .= sprintf($formatSql, $nameIndexFilled, $foreignKeyFilled, $referenceTableFilled, $referenceFieldFilled);
+            $nameIndex = $fkey['fkName'] !== ''
+                ? $fkey['fkName']
+                : $table . '_' . implode('_', $fkey['field']) . $fkSuffix;
+
+            $sql = $prefixSql . sprintf(
+                'CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s(%s)',
+                $this->db->escapeIdentifiers($nameIndex),
+                implode(', ', $this->db->escapeIdentifiers($fkey['field'])),
+                $this->db->escapeIdentifiers($dbPrefix . $fkey['referenceTable']),
+                implode(', ', $this->db->escapeIdentifiers($fkey['referenceField'])),
+            );
 
             if ($fkey['onDelete'] !== false && in_array($fkey['onDelete'], $this->fkAllowActions, true)) {
-                $sqls[$index] .= ' ON DELETE ' . $fkey['onDelete'];
+                $sql .= ' ON DELETE ' . $fkey['onDelete'];
             }
 
-            if ($this->db->DBDriver !== 'OCI8' && $fkey['onUpdate'] !== false && in_array($fkey['onUpdate'], $this->fkAllowActions, true)) {
-                $sqls[$index] .= ' ON UPDATE ' . $fkey['onUpdate'];
+            if (! $isOci8 && $fkey['onUpdate'] !== false && in_array($fkey['onUpdate'], $this->fkAllowActions, true)) {
+                $sql .= ' ON UPDATE ' . $fkey['onUpdate'];
             }
+
+            $sqls[$idx] .= $sql;
         }
 
         return $sqls;