class ClassLoader
{
// ... /**
* composer 类加载器，对 <PSR-4的风格>、<PSR-0的风格>、<PEAR的风格> 风格的类的加载
*/
private function findFileWithExtension($class, $ext)
{
// PSR-4 lookup <PSR-4的风格>： Dir1\Dir2\ClassName1 ---> Dir1/Dir2/ClassName1
$logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext; $first = $class[0];
if (isset($this->prefixLengthsPsr4[$first])) {
foreach ($this->prefixLengthsPsr4[$first] as $prefix => $length) {
if (0 === strpos($class, $prefix)) {
foreach ($this->prefixDirsPsr4[$prefix] as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $length))) {
return $file;
}
}
}
}
} // PSR-4 fallback dirs 匹配失败
foreach ($this->fallbackDirsPsr4 as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
return $file;
}
} // PSR-0 lookup <PSR-0的风格>： Dir1\Dir2\Dir3_ClassName1 ---> Dir1\Dir2/ClassName1
if (false !== $pos = strrpos($class, '\\')) {
// namespaced class name
$logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
. strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
} else {
// PEAR-like class name <PEAR的风格>： Dir1_Dir2_ClassName1 --->Dir1/Dir2/ClassName1
$logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
} if (isset($this->prefixesPsr0[$first])) {
foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
if (0 === strpos($class, $prefix)) {
foreach ($dirs as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
return $file;
}
}
}
}
} // PSR-0 fallback dirs
foreach ($this->fallbackDirsPsr0 as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
return $file;
}
} // PSR-0 include paths.
if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
return $file;
}
} // ...
}