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itflow/libs/vendor/guzzlehttp/psr7/src/UriResolver.php

310 lines
13 KiB
PHP

<?php
declare(strict_types=1);
namespace GuzzleHttp\Psr7;
use Psr\Http\Message\UriInterface;
/**
* Resolves a URI reference in the context of a base URI and the opposite way.
*
* @author Tobias Schultze
*
* @see https://datatracker.ietf.org/doc/html/rfc3986#section-5
*/
final class UriResolver
{
/**
* Removes dot segments from a path and returns the new path according to
* RFC 3986 Section 5.2.4.
*
* Excess `..` segments above the root of an absolute path are dropped
* without consuming the root, so the result can begin with `//` (e.g.
* `/..//a` becomes `//a`). Such a path is not valid for a URI without an
* authority (RFC 3986 Section 3.3); `resolve()` and
* `UriNormalizer::normalize()` serialize it with a `/.` prefix in that
* case, like the WHATWG URL Standard.
*
* @see https://datatracker.ietf.org/doc/html/rfc3986#section-5.2.4
*/
public static function removeDotSegments(string $path): string
{
if ($path === '' || $path === '/') {
return $path;
}
$results = [];
$segments = explode('/', $path);
// The first segment of an absolute path is the empty root marker producing the
// leading slash. RFC 3986 Section 5.2.4 (2C) drops ".." segments in excess of
// the path hierarchy without consuming the root, so it must never be popped.
$floor = $segments[0] === '' ? 1 : 0;
foreach ($segments as $segment) {
if ($segment === '..') {
if (count($results) > $floor) {
array_pop($results);
}
} elseif ($segment !== '.') {
$results[] = $segment;
}
}
$newPath = implode('/', $results);
if (str_starts_with($path, '/') && !str_starts_with($newPath, '/')) {
// Re-add the leading slash if necessary for cases like "/.."
$newPath = '/'.$newPath;
} elseif ($newPath !== '' && ($segment === '.' || $segment === '..')) {
// Add the trailing slash if necessary
// If newPath is not empty, then $segment must be set and is the last segment from the foreach
$newPath .= '/';
}
return $newPath;
}
/**
* Returns the path, prefixed with "/." or "./" when the URI could not
* otherwise hold it.
*
* A URI without an authority cannot hold a path beginning with "//" (RFC
* 3986 Section 3.3), but removeDotSegments() can produce one. The "/."
* prefix serializes such a path unambiguously, the same way the WHATWG URL
* Standard does, and resolves back to the same path. Hostless http and
* https Uri instances gain the default localhost host when the path is
* written, so the path cannot be mistaken for an authority and the prefix
* is not added.
*
* A relative-path reference cannot begin with a segment containing a colon
* (RFC 3986 Section 4.2), as it would be mistaken for a scheme name, but
* reference resolution and percent-encoding normalization can produce one.
* The "./" prefix the RFC prescribes resolves back to the same path.
*
* @see https://url.spec.whatwg.org/#url-serializing
* @see https://datatracker.ietf.org/doc/html/rfc3986#section-4.2
*
* @internal
*/
public static function guardedPath(UriInterface $uri, string $path): string
{
if ($uri->getAuthority() !== '') {
return $path;
}
if (str_starts_with($path, '//')) {
if ($uri instanceof Uri && ($uri->getScheme() === 'http' || $uri->getScheme() === 'https')) {
return $path;
}
return '/.'.$path;
}
if ($uri->getScheme() === '' && str_contains(explode('/', $path, 2)[0], ':')) {
return './'.$path;
}
return $path;
}
/**
* Converts the relative URI into a new URI that is resolved against the
* base URI.
*
* When the resolved path is a relative-path reference whose first segment
* contains a colon, which would be mistaken for a scheme name (RFC 3986
* Section 4.2), it is prefixed with `./`, e.g. `./a:b`.
*
* @see https://datatracker.ietf.org/doc/html/rfc3986#section-5.2
* @see https://datatracker.ietf.org/doc/html/rfc3986#section-4.2
*/
public static function resolve(UriInterface $base, UriInterface $rel): UriInterface
{
if ((string) $rel === '') {
// we can simply return the same base URI instance for this same-document reference
return $base;
}
if ($rel->getScheme() != '') {
return $rel->withPath(self::guardedPath($rel, self::removeDotSegments(Uri::rawPath($rel))));
}
if ($rel->getAuthority() != '') {
return $rel
->withScheme($base->getScheme())
->withPath(self::removeDotSegments(Uri::rawPath($rel)));
}
$relPath = Uri::rawPath($rel);
if ($relPath === '') {
// the base path is used as-is per RFC 3986 Section 5.2.2, so it must not be
// rewritten through a getPath()/withPath() round-trip
return $base
->withQuery($rel->getQuery() != '' ? $rel->getQuery() : $base->getQuery())
->withFragment($rel->getFragment());
}
if (str_starts_with($relPath, '/')) {
$targetPath = $relPath;
} else {
$basePath = Uri::rawPath($base);
if ($base->getAuthority() != '' && $basePath === '') {
$targetPath = '/'.$relPath;
} else {
$lastSlashPos = strrpos($basePath, '/');
if ($lastSlashPos === false) {
$targetPath = $relPath;
} else {
$targetPath = substr($basePath, 0, $lastSlashPos + 1).$relPath;
}
}
}
$targetPath = self::removeDotSegments($targetPath);
return $base
->withPath(self::guardedPath($base, $targetPath))
->withQuery($rel->getQuery())
->withFragment($rel->getFragment());
}
/**
* Returns the target URI as a relative reference from the base URI.
*
* This method is the counterpart to `resolve()`:
*
* (string) $target === (string) UriResolver::resolve($base, UriResolver::relativize($base, $target))
*
* One use case is to use the current request URI as the base URI and then
* generate relative links in your documents to reduce the document size or
* offer self-contained downloadable document archives.
*
* $base = new Uri('http://example.com/a/b/');
* echo UriResolver::relativize($base, new Uri('http://example.com/a/b/c')); // prints 'c'.
* echo UriResolver::relativize($base, new Uri('http://example.com/a/x/y')); // prints '../x/y'.
* echo UriResolver::relativize($base, new Uri('http://example.com/a/b/?q')); // prints '?q'.
* echo UriResolver::relativize($base, new Uri('http://example.org/a/b/')); // prints '//example.org/a/b/'.
* echo UriResolver::relativize($base, new Uri('http://example.com')); // prints '//example.com'.
*
* This method also accepts a target that is already relative and will try
* to relativize it further. Only a relative-path reference will be returned
* as-is.
*
* echo UriResolver::relativize($base, new Uri('/a/b/c')); // prints 'c' as well
*/
public static function relativize(UriInterface $base, UriInterface $target): UriInterface
{
if ($target->getScheme() !== ''
&& ($base->getScheme() !== $target->getScheme() || $target->getAuthority() === '' && $base->getAuthority() !== '')
) {
return $target;
}
if (Uri::isRelativePathReference($target)) {
// As the target is already highly relative we return it as-is. It would be possible to resolve
// the target with `$target = self::resolve($base, $target);` and then try make it more relative
// by removing a duplicate query. But let's not do that automatically.
return $target;
}
if ($target->getAuthority() !== '' && $base->getAuthority() !== $target->getAuthority()) {
return $target->withScheme('');
}
// A same-authority target with an empty path can only be expressed by a
// network-path reference (RFC 3986 Section 5.2.2).
if (self::needsNetworkPathReference($base, $target)) {
return $target->withScheme('');
}
// We must remove the path before removing the authority because if the path starts with two slashes, the URI
// would turn invalid. And we also cannot set a relative path before removing the authority, as that is also
// invalid.
$emptyPathUri = $target->withScheme('')->withPath('')->withUserInfo('')->withPort(null)->withHost('');
if (Uri::rawPath($base) !== Uri::rawPath($target)) {
return $emptyPathUri->withPath(self::getRelativePath($base, $target));
}
if ($base->getQuery() === $target->getQuery() && ($target->getFragment() !== '' || $base->getFragment() === '')) {
// Only the target fragment is left. And it must be returned even if base and target fragment are the same.
return $emptyPathUri->withQuery('');
}
// If the base URI has a query or fragment that the target lacks, we cannot return an empty path
// reference as it would inherit that base component when resolving.
if ($target->getQuery() === '') {
$segments = explode('/', Uri::rawPath($target));
/** @var string $lastSegment */
$lastSegment = end($segments);
// A reference to an empty last segment must be prefixed with "./". The same applies
// to a segment with a colon character, which would be mistaken for a scheme name.
if ($lastSegment === '' || str_contains($lastSegment, ':')) {
$lastSegment = "./$lastSegment";
}
return $emptyPathUri->withPath($lastSegment);
}
return $emptyPathUri;
}
/**
* Whether relativizing to $target requires a network-path reference.
*
* A same-authority target with an empty path is expressible by a shorter
* relative reference unless resolving one would inherit a base component
* the target lacks: the base path (kept by any empty-path reference), or
* the base query or fragment (inherited by the empty reference).
*/
private static function needsNetworkPathReference(UriInterface $base, UriInterface $target): bool
{
if ($target->getAuthority() === '' || Uri::rawPath($target) !== '') {
return false;
}
return Uri::rawPath($base) !== ''
|| ($base->getQuery() !== '' && $target->getQuery() === '')
|| ($base->getFragment() !== '' && $target->getFragment() === '' && $base->getQuery() === $target->getQuery());
}
private static function getRelativePath(UriInterface $base, UriInterface $target): string
{
$sourceSegments = explode('/', Uri::rawPath($base));
$targetSegments = explode('/', Uri::rawPath($target));
array_pop($sourceSegments);
$targetLastSegment = array_pop($targetSegments);
foreach ($sourceSegments as $i => $segment) {
if (isset($targetSegments[$i]) && $segment === $targetSegments[$i]) {
unset($sourceSegments[$i], $targetSegments[$i]);
} else {
break;
}
}
$targetSegments[] = $targetLastSegment;
$relativePath = str_repeat('../', count($sourceSegments)).implode('/', $targetSegments);
// A reference to am empty last segment or an empty first sub-segment must be prefixed with "./".
// This also applies to a segment with a colon character (e.g., "file:colon") that cannot be used
// as the first segment of a relative-path reference, as it would be mistaken for a scheme name.
if ($relativePath === '' || str_contains(explode('/', $relativePath, 2)[0], ':')) {
$relativePath = "./$relativePath";
} elseif (str_starts_with($relativePath, '/')) {
if ($base->getAuthority() != '' && Uri::rawPath($base) === '') {
// In this case an extra slash is added by resolve() automatically. So we must not add one here.
$relativePath = ".$relativePath";
} else {
$relativePath = "./$relativePath";
}
}
return $relativePath;
}
private function __construct()
{
// cannot be instantiated
}
}