REFACTOR: Move code extraction into ReflectionClosure

The todos are also refered to in issue frodeborli#12

src/ReflectionClosure.php

@@ -4,13 +4,137 @@
 
 namespace Serializor;
 
+use Closure;
+use PhpToken;
 use ReflectionFunction;
-use Serializor\Transformers\ClosureTransformer;
+use RuntimeException;
+
+use function file_get_contents;
+use function implode;
+use function str_contains;
+
+use const T_FN;
+use const T_FUNCTION;
+use const T_STATIC;
 
 final class ReflectionClosure extends ReflectionFunction
 {
+ /** @var array<string, FunctionDescription> $functionCache */
+ private static array $functionCache = [];
+
+ /** @var array<string, array<int, PhpToken>> $tokenCache */
+ private static array $tokenCache = [];
+
+ private FunctionDescription $functionDescription;
+
+ /** @param callable-string|Closure $function */
+ public function __construct(string|Closure $function)
+ {
+ parent::__construct($function);
+
+ $this->functionDescription = static::$functionCache[Reflect::getHash($this)]
+ ??= $this->generateFunctionDescription();
+ }
+
+ private function generateFunctionDescription(): FunctionDescription
+ {
+ $usedThis = false;
+ $usedStatic = false;
+ $sourceFile = $this->getFileName();
+
+ if ($sourceFile === false) {
+ return new FunctionDescription(
+ code: '/* native code */',
+ usedThis: false,
+ usedStatic: false,
+ );
+ }
+
+ if (str_contains($sourceFile, 'eval()\'d')) {
+ throw new RuntimeException("Can't serialize a closure that was generated with eval()");
+ }
+ $tokens = self::$tokenCache[$sourceFile]
+ ??= PhpToken::tokenize(file_get_contents($sourceFile));
+
+ $capture = false;
+ $capturedTokens = [];
+ $stackDepth = 0;
+ $stack = [];
+
+ foreach ($tokens as $idx => $token) {
+ if (!$capture) {
+ if ($token->line === $this->getStartLine()) {
+ if ($token->is(T_STATIC) && $tokens[$idx + 2]?->is([T_FUNCTION, T_FN])) {
+ $capture = true;
+ } elseif ($token->is([T_FUNCTION, T_FN])) {
+ $capture = true;
+ } else {
+ continue;
+ }
+ } else {
+ continue;
+ }
+ }
+ if (!$token->isIgnorable()) {
+ if ($stackDepth === 0 && $token->is([',', ')', '}', ']', ';'])) {
+ break;
+ }
+ if (!$usedStatic && $token->is(['self', 'static', 'parent'])) {
+ $usedStatic = true;
+ }
+ if (!$usedThis && $token->is('$this')) {
+ $usedThis = true;
+ }
+ }
+ $capturedTokens[] = $token;
+ if ($token->text === '{') {
+ $stack[$stackDepth++] = '}';
+ } elseif ($token->text === '(') {
+ $stack[$stackDepth++] = ')';
+ } elseif ($token->text === '[') {
+ $stack[$stackDepth++] = ']';
+ } elseif ($stackDepth > 0 && $stack[$stackDepth - 1] === $token->text) {
+ --$stackDepth;
+ if ($stackDepth === 0 && $token->text === '}') {
+ if ($token->line !== $this->getEndLine() && $token->line === $this->getStartLine()) {
+ $capture = false;
+ $capturedTokens = [];
+ } else {
+ break;
+ }
+ }
+ }
+ }
+
+ return new FunctionDescription(
+ code: implode($capturedTokens),
+ usedThis: $usedThis,
+ usedStatic: $usedStatic,
+ );
+ }
+
  public function getCode(): string
  {
- return ClosureTransformer::getCode($this, $usedThis, $usedStatic);
+ return $this->functionDescription->code;
+ }
+
+ public function usedThis(): bool
+ {
+ return $this->functionDescription->usedThis;
  }
+
+ public function usedStatic(): bool
+ {
+ return $this->functionDescription->usedStatic;
+ }
+}
+
+/** @internal */
+final readonly class FunctionDescription
+{
+ public function __construct(
+ public string $code,
+ public bool $usedThis,
+ public bool $usedStatic,
+ ) {}
 }