path: root/src/corelib/io/qfilesystemengine.cpp

// Copyright (C) 2016 The Qt Company Ltd.// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only#include"qfilesystemengine_p.h"#include <QtCore/qdir.h>#include <QtCore/qset.h>#include <QtCore/qstringbuilder.h>#include <QtCore/private/qabstractfileengine_p.h>#ifdef QT_BUILD_CORE_LIB#include <QtCore/private/qresource_p.h>#endif#include <QtCore/private/qduplicatetracker_p.h> QT_BEGIN_NAMESPACE /*! \class QFileSystemEngine \internal QFileSystemEngine offers OS-independent API for native system library methods, which work with files on physical disk drives; using such methods directly is faster than using a custom file engine (see QAbstractFileEngine and its sub-classes). Typically, you need a custom file engine when working with virtual file systems (for example QResource). Various Qt classes, for example QDir, QFile, and QFileInfo, can handle both types of files by detecting the file path scheme, for example, \c file:///, \c :/someresource (QResource). \sa QAbstractFileEngine, QAbstractFileEngineHandler, QFSFileEngine, QResourceFileEngine*//*! \internal Returns the canonicalized form of \a path (i.e., with all symlinks resolved, and all redundant path elements removed.*/ QString QFileSystemEngine::slowCanonicalized(const QString &path){if(path.isEmpty())return path; QFileInfo fi;const QChar slash(u'/'); QString tmpPath = path; qsizetype separatorPos =0; QSet<QString> nonSymlinks; QDuplicateTracker<QString> known;(void)known.hasSeen(path);do{#ifdef Q_OS_WINif(separatorPos ==0) {if(tmpPath.size() >=2&& tmpPath.at(0) == slash && tmpPath.at(1) == slash) {// UNC, skip past the first two elements separatorPos = tmpPath.indexOf(slash,2);}else if(tmpPath.size() >=3&& tmpPath.at(1) == u':'&& tmpPath.at(2) == slash) {// volume root, skip since it can not be a symlink separatorPos =2;}}if(separatorPos != -1)#endif separatorPos = tmpPath.indexOf(slash, separatorPos +1); QString prefix = separatorPos == -1? tmpPath : tmpPath.left(separatorPos);if(!nonSymlinks.contains(prefix)) { fi.setFile(prefix);if(fi.isSymLink()) { QString target = fi.symLinkTarget();if(separatorPos != -1) {if(fi.isDir() && !target.endsWith(slash)) target.append(slash); target.append(QStringView{tmpPath}.mid(separatorPos));} tmpPath =QDir::cleanPath(target); separatorPos =0;if(known.hasSeen(tmpPath))returnQString();}else{ nonSymlinks.insert(prefix);}}}while(separatorPos != -1);returnQDir::cleanPath(tmpPath);}staticinlinebool_q_checkEntry(QFileSystemEntry &entry, QFileSystemMetaData &data,bool resolvingEntry){if(resolvingEntry) {if(!QFileSystemEngine::fillMetaData(entry, data,QFileSystemMetaData::ExistsAttribute)|| !data.exists()) { data.clear();return false;}}return true;}staticinlinebool_q_checkEntry(std::unique_ptr<QAbstractFileEngine> &engine,bool resolvingEntry){if(resolvingEntry) {if(!(engine->fileFlags(QAbstractFileEngine::FlagsMask) &QAbstractFileEngine::ExistsFlag)) { engine.reset();return false;}}return true;}static bool_q_createLegacyEngine_recursive(QFileSystemEntry &entry, QFileSystemMetaData &data,std::unique_ptr<QAbstractFileEngine> &engine,bool resolvingEntry =false){ QString const&filePath = entry.filePath();if((engine =qt_custom_file_engine_handler_create(filePath)))return_q_checkEntry(engine, resolvingEntry);#if defined(QT_BUILD_CORE_LIB)for(qsizetype prefixSeparator =0; prefixSeparator < filePath.size(); ++prefixSeparator) { QChar const ch = filePath[prefixSeparator];if(ch == u'/')break;if(ch == u':') {if(prefixSeparator ==0) { engine =std::make_unique<QResourceFileEngine>(filePath);return_q_checkEntry(engine, resolvingEntry);}if(prefixSeparator ==1)break;const QStringList &paths =QDir::searchPaths(filePath.left(prefixSeparator));for(int i =0; i < paths.size(); i++) { entry =QFileSystemEntry(QDir::cleanPath( paths.at(i) % u'/'% QStringView{filePath}.mid(prefixSeparator +1)));// Recurse!if(_q_createLegacyEngine_recursive(entry, data, engine,true))return true;}// entry may have been clobbered at this point.return false;}// There's no need to fully validate the prefix here. Consulting the// unicode tables could be expensive and validation is already// performed in QDir::setSearchPaths.//// if (!ch.isLetterOrNumber())// break;}#endif// defined(QT_BUILD_CORE_LIB)return_q_checkEntry(entry, data, resolvingEntry);} Q_CORE_EXPORT boolqt_isCaseSensitive(const QFileSystemEntry &entry, QFileSystemMetaData &data){// called from QtGui (QFileSystemModel, QFileInfoGatherer)returnQFileSystemEngine::isCaseSensitive(entry, data);}/*! \internal Resolves the \a entry (see QDir::searchPaths) and returns an engine for it, but never a QFSFileEngine. Returns a file engine that can be used to access the entry. Returns 0 if QFileSystemEngine API should be used to query and interact with the file system object.*/std::unique_ptr<QAbstractFileEngine>QFileSystemEngine::createLegacyEngine(QFileSystemEntry &entry, QFileSystemMetaData &data){ QFileSystemEntry copy = entry;std::unique_ptr<QAbstractFileEngine> engine;if(_q_createLegacyEngine_recursive(copy, data, engine))// Reset entry to resolved copy. entry = copy;else data.clear();return engine;}//static QString QFileSystemEngine::resolveUserName(const QFileSystemEntry &entry, QFileSystemMetaData &metaData){#if defined(Q_OS_WIN)Q_UNUSED(metaData);returnQFileSystemEngine::owner(entry,QAbstractFileEngine::OwnerUser);#else//(Q_OS_UNIX)if(!metaData.hasFlags(QFileSystemMetaData::UserId))QFileSystemEngine::fillMetaData(entry, metaData,QFileSystemMetaData::UserId);if(!metaData.exists())returnQString();returnresolveUserName(metaData.userId());#endif}//static QString QFileSystemEngine::resolveGroupName(const QFileSystemEntry &entry, QFileSystemMetaData &metaData){#if defined(Q_OS_WIN)Q_UNUSED(metaData);returnQFileSystemEngine::owner(entry,QAbstractFileEngine::OwnerGroup);#else//(Q_OS_UNIX)if(!metaData.hasFlags(QFileSystemMetaData::GroupId))QFileSystemEngine::fillMetaData(entry, metaData,QFileSystemMetaData::GroupId);if(!metaData.exists())returnQString();returnresolveGroupName(metaData.groupId());#endif}//static QFileSystemEntry QFileSystemEngine::getJunctionTarget(const QFileSystemEntry &link, QFileSystemMetaData &data){#if defined(Q_OS_WIN)returnjunctionTarget(link, data);#elseQ_UNUSED(link);Q_UNUSED(data);return{};#endif} QT_END_NAMESPACE