Matthias Andreas Benkard | 12a5735 | 2021-12-28 18:02:04 +0100 | [diff] [blame^] | 1 | <?php |
| 2 | |
| 3 | /* |
| 4 | * This file is part of Twig. |
| 5 | * |
| 6 | * (c) Fabien Potencier |
| 7 | * |
| 8 | * For the full copyright and license information, please view the LICENSE |
| 9 | * file that was distributed with this source code. |
| 10 | */ |
| 11 | |
| 12 | namespace Twig\NodeVisitor; |
| 13 | |
| 14 | use Twig\Environment; |
| 15 | use Twig\Node\BlockReferenceNode; |
| 16 | use Twig\Node\Expression\BlockReferenceExpression; |
| 17 | use Twig\Node\Expression\ConstantExpression; |
| 18 | use Twig\Node\Expression\FilterExpression; |
| 19 | use Twig\Node\Expression\FunctionExpression; |
| 20 | use Twig\Node\Expression\GetAttrExpression; |
| 21 | use Twig\Node\Expression\NameExpression; |
| 22 | use Twig\Node\Expression\ParentExpression; |
| 23 | use Twig\Node\ForNode; |
| 24 | use Twig\Node\IncludeNode; |
| 25 | use Twig\Node\Node; |
| 26 | use Twig\Node\PrintNode; |
| 27 | |
| 28 | /** |
| 29 | * Tries to optimize the AST. |
| 30 | * |
| 31 | * This visitor is always the last registered one. |
| 32 | * |
| 33 | * You can configure which optimizations you want to activate via the |
| 34 | * optimizer mode. |
| 35 | * |
| 36 | * @author Fabien Potencier <fabien@symfony.com> |
| 37 | * |
| 38 | * @internal |
| 39 | */ |
| 40 | final class OptimizerNodeVisitor implements NodeVisitorInterface |
| 41 | { |
| 42 | public const OPTIMIZE_ALL = -1; |
| 43 | public const OPTIMIZE_NONE = 0; |
| 44 | public const OPTIMIZE_FOR = 2; |
| 45 | public const OPTIMIZE_RAW_FILTER = 4; |
| 46 | |
| 47 | private $loops = []; |
| 48 | private $loopsTargets = []; |
| 49 | private $optimizers; |
| 50 | |
| 51 | /** |
| 52 | * @param int $optimizers The optimizer mode |
| 53 | */ |
| 54 | public function __construct(int $optimizers = -1) |
| 55 | { |
| 56 | if ($optimizers > (self::OPTIMIZE_FOR | self::OPTIMIZE_RAW_FILTER)) { |
| 57 | throw new \InvalidArgumentException(sprintf('Optimizer mode "%s" is not valid.', $optimizers)); |
| 58 | } |
| 59 | |
| 60 | $this->optimizers = $optimizers; |
| 61 | } |
| 62 | |
| 63 | public function enterNode(Node $node, Environment $env): Node |
| 64 | { |
| 65 | if (self::OPTIMIZE_FOR === (self::OPTIMIZE_FOR & $this->optimizers)) { |
| 66 | $this->enterOptimizeFor($node, $env); |
| 67 | } |
| 68 | |
| 69 | return $node; |
| 70 | } |
| 71 | |
| 72 | public function leaveNode(Node $node, Environment $env): ?Node |
| 73 | { |
| 74 | if (self::OPTIMIZE_FOR === (self::OPTIMIZE_FOR & $this->optimizers)) { |
| 75 | $this->leaveOptimizeFor($node, $env); |
| 76 | } |
| 77 | |
| 78 | if (self::OPTIMIZE_RAW_FILTER === (self::OPTIMIZE_RAW_FILTER & $this->optimizers)) { |
| 79 | $node = $this->optimizeRawFilter($node, $env); |
| 80 | } |
| 81 | |
| 82 | $node = $this->optimizePrintNode($node, $env); |
| 83 | |
| 84 | return $node; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Optimizes print nodes. |
| 89 | * |
| 90 | * It replaces: |
| 91 | * |
| 92 | * * "echo $this->render(Parent)Block()" with "$this->display(Parent)Block()" |
| 93 | */ |
| 94 | private function optimizePrintNode(Node $node, Environment $env): Node |
| 95 | { |
| 96 | if (!$node instanceof PrintNode) { |
| 97 | return $node; |
| 98 | } |
| 99 | |
| 100 | $exprNode = $node->getNode('expr'); |
| 101 | if ( |
| 102 | $exprNode instanceof BlockReferenceExpression || |
| 103 | $exprNode instanceof ParentExpression |
| 104 | ) { |
| 105 | $exprNode->setAttribute('output', true); |
| 106 | |
| 107 | return $exprNode; |
| 108 | } |
| 109 | |
| 110 | return $node; |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Removes "raw" filters. |
| 115 | */ |
| 116 | private function optimizeRawFilter(Node $node, Environment $env): Node |
| 117 | { |
| 118 | if ($node instanceof FilterExpression && 'raw' == $node->getNode('filter')->getAttribute('value')) { |
| 119 | return $node->getNode('node'); |
| 120 | } |
| 121 | |
| 122 | return $node; |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Optimizes "for" tag by removing the "loop" variable creation whenever possible. |
| 127 | */ |
| 128 | private function enterOptimizeFor(Node $node, Environment $env): void |
| 129 | { |
| 130 | if ($node instanceof ForNode) { |
| 131 | // disable the loop variable by default |
| 132 | $node->setAttribute('with_loop', false); |
| 133 | array_unshift($this->loops, $node); |
| 134 | array_unshift($this->loopsTargets, $node->getNode('value_target')->getAttribute('name')); |
| 135 | array_unshift($this->loopsTargets, $node->getNode('key_target')->getAttribute('name')); |
| 136 | } elseif (!$this->loops) { |
| 137 | // we are outside a loop |
| 138 | return; |
| 139 | } |
| 140 | |
| 141 | // when do we need to add the loop variable back? |
| 142 | |
| 143 | // the loop variable is referenced for the current loop |
| 144 | elseif ($node instanceof NameExpression && 'loop' === $node->getAttribute('name')) { |
| 145 | $node->setAttribute('always_defined', true); |
| 146 | $this->addLoopToCurrent(); |
| 147 | } |
| 148 | |
| 149 | // optimize access to loop targets |
| 150 | elseif ($node instanceof NameExpression && \in_array($node->getAttribute('name'), $this->loopsTargets)) { |
| 151 | $node->setAttribute('always_defined', true); |
| 152 | } |
| 153 | |
| 154 | // block reference |
| 155 | elseif ($node instanceof BlockReferenceNode || $node instanceof BlockReferenceExpression) { |
| 156 | $this->addLoopToCurrent(); |
| 157 | } |
| 158 | |
| 159 | // include without the only attribute |
| 160 | elseif ($node instanceof IncludeNode && !$node->getAttribute('only')) { |
| 161 | $this->addLoopToAll(); |
| 162 | } |
| 163 | |
| 164 | // include function without the with_context=false parameter |
| 165 | elseif ($node instanceof FunctionExpression |
| 166 | && 'include' === $node->getAttribute('name') |
| 167 | && (!$node->getNode('arguments')->hasNode('with_context') |
| 168 | || false !== $node->getNode('arguments')->getNode('with_context')->getAttribute('value') |
| 169 | ) |
| 170 | ) { |
| 171 | $this->addLoopToAll(); |
| 172 | } |
| 173 | |
| 174 | // the loop variable is referenced via an attribute |
| 175 | elseif ($node instanceof GetAttrExpression |
| 176 | && (!$node->getNode('attribute') instanceof ConstantExpression |
| 177 | || 'parent' === $node->getNode('attribute')->getAttribute('value') |
| 178 | ) |
| 179 | && (true === $this->loops[0]->getAttribute('with_loop') |
| 180 | || ($node->getNode('node') instanceof NameExpression |
| 181 | && 'loop' === $node->getNode('node')->getAttribute('name') |
| 182 | ) |
| 183 | ) |
| 184 | ) { |
| 185 | $this->addLoopToAll(); |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Optimizes "for" tag by removing the "loop" variable creation whenever possible. |
| 191 | */ |
| 192 | private function leaveOptimizeFor(Node $node, Environment $env): void |
| 193 | { |
| 194 | if ($node instanceof ForNode) { |
| 195 | array_shift($this->loops); |
| 196 | array_shift($this->loopsTargets); |
| 197 | array_shift($this->loopsTargets); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | private function addLoopToCurrent(): void |
| 202 | { |
| 203 | $this->loops[0]->setAttribute('with_loop', true); |
| 204 | } |
| 205 | |
| 206 | private function addLoopToAll(): void |
| 207 | { |
| 208 | foreach ($this->loops as $loop) { |
| 209 | $loop->setAttribute('with_loop', true); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | public function getPriority(): int |
| 214 | { |
| 215 | return 255; |
| 216 | } |
| 217 | } |