QDirIterator: port to QDirListing internally

De-duplicates the code between the two classes.

[ChangeLog][Core][QDirIterator] This class has been deprecated and may
be removed in a future Qt release. Use QDirListing instead.

Change-Id: Iceba5091e72ea462dc9c5145a474bf312ee78043
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/io/qdiriterator.cpp

@@ -34,6 +34,9 @@
     you cannot iterate directories in reverse order) and does not allow random
     access.
 
+    \note This class is deprecated and may be removed in a Qt release. Use
+    QDirListing instead.
+
     \sa QDir, QDir::entryList()
 */
 
@@ -56,6 +59,8 @@
 #include "qdiriterator.h"
 #include "qdir_p.h"
 #include "qabstractfileengine_p.h"
+#include "qdirlisting.h"
+#include "qdirentryinfo_p.h"
 
 #include <QtCore/qset.h>
 #include <QtCore/qstack.h>
@@ -81,292 +86,66 @@ using namespace Qt::StringLiterals;
 
 class QDirIteratorPrivate
 {
+    static QDirListing::IteratorFlags toDirListingFlags(QDirIterator::IteratorFlags flags)
+    {
+        using F = QDirListing::IteratorFlag;
+        QDirListing::IteratorFlags listerFlags;
+
+        if (flags & QDirIterator::NoIteratorFlags)
+            listerFlags.setFlag(F::NoFlag);
+        if (flags & QDirIterator::FollowSymlinks)
+            listerFlags.setFlag(F::FollowSymlinks);
+        if (flags & QDirIterator::Subdirectories)
+            listerFlags.setFlag(F::Recursive);
+
+        return listerFlags;
+    }
+
 public:
-    void init(bool resolveEngine);
+    QDirIteratorPrivate(const QDir &dir, QDirIterator::IteratorFlags flags)
-    void advance();
+        : lister(dir, toDirListingFlags(flags))
+    {
+        init();
+    }
+    QDirIteratorPrivate(const QString &path, QDirIterator::IteratorFlags flags)
+        : lister(path, toDirListingFlags(flags))
+    {
+        init();
+    }
+    QDirIteratorPrivate(const QString &path, QDir::Filters filters,
+                        QDirIterator::IteratorFlags flags)
+        : lister(path, filters, toDirListingFlags(flags))
+    {
+        init();
+    }
+    QDirIteratorPrivate(const QString &path, const QStringList &nameFilters, QDir::Filters filters,
+                        QDirIterator::IteratorFlags flags)
+        : lister(path, nameFilters, filters, toDirListingFlags(flags))
+    {
+        init();
+    }
 
-    bool entryMatches(const QString & fileName, const QFileInfo &fileInfo);
+    void init()
-    void pushDirectory(const QFileInfo &fileInfo);
+    {
-    void checkAndPushDirectory(const QFileInfo &);
+        it = lister.begin();
-    bool matchesFilters(const QString &fileName, const QFileInfo &fi) const;
+        if (it != lister.end())
+            nextFileInfo = it->fileInfo();
+    }
 
-    std::unique_ptr<QAbstractFileEngine> engine;
+    void advance()
-
+    {
-    QFileSystemEntry dirEntry;
+        currentFileInfo = nextFileInfo;
-    QStringList nameFilters;
+        if (++it != lister.end()) {
-    QDir::Filters filters;
+            nextFileInfo = it->fileInfo();
-    QDirIterator::IteratorFlags iteratorFlags;
+        }
-
+    }
-#if QT_CONFIG(regularexpression)
-    QList<QRegularExpression> nameRegExps;
-#endif
-
-    using FEngineIteratorPtr = std::unique_ptr<QAbstractFileEngineIterator>;
-    std::stack<FEngineIteratorPtr, std::vector<FEngineIteratorPtr>> fileEngineIterators;
-#ifndef QT_NO_FILESYSTEMITERATOR
-    using FsIteratorPtr = std::unique_ptr<QFileSystemIterator>;
-    std::stack<FsIteratorPtr, std::vector<FsIteratorPtr>> nativeIterators;
-#endif
 
+    QDirListing lister;
+    QDirListing::const_iterator it = {};
     QFileInfo currentFileInfo;
     QFileInfo nextFileInfo;
-
-    // Loop protection
-    QDuplicateTracker<QString> visitedLinks;
 };
 
-void QDirIteratorPrivate::init(bool resolveEngine = true)
-{
-    if (nameFilters.contains("*"_L1))
-        nameFilters.clear();
-
-    if (filters == QDir::NoFilter)
-        filters = QDir::AllEntries;
-
-#if QT_CONFIG(regularexpression)
-    nameRegExps.reserve(nameFilters.size());
-    for (const auto &filter : nameFilters) {
-        auto re = QRegularExpression::fromWildcard(filter, (filters & QDir::CaseSensitive ?
-                                                            Qt::CaseSensitive : Qt::CaseInsensitive));
-        nameRegExps.append(re);
-    }
-#endif
-    QFileSystemMetaData metaData;
-    if (resolveEngine)
-        engine.reset(QFileSystemEngine::resolveEntryAndCreateLegacyEngine(dirEntry, metaData));
-    QFileInfo fileInfo(new QFileInfoPrivate(dirEntry, metaData));
-
-    // Populate fields for hasNext() and next()
-    pushDirectory(fileInfo);
-    advance();
-}
-
-/*!
-    \internal
-*/
-void QDirIteratorPrivate::pushDirectory(const QFileInfo &fileInfo)
-{
-    QString path = fileInfo.filePath();
-
-#ifdef Q_OS_WIN
-    if (fileInfo.isSymLink())
-        path = fileInfo.canonicalFilePath();
-#endif
-
-    if ((iteratorFlags & QDirIterator::FollowSymlinks)) {
-        // Stop link loops
-        if (visitedLinks.hasSeen(fileInfo.canonicalFilePath()))
-            return;
-    }
-
-    if (engine) {
-        engine->setFileName(path);
-        QAbstractFileEngineIterator *it = engine->beginEntryList(filters, nameFilters);
-        if (it) {
-            it->setPath(path);
-            fileEngineIterators.emplace(FEngineIteratorPtr(it));
-        } else {
-            // No iterator; no entry list.
-        }
-    } else {
-#ifndef QT_NO_FILESYSTEMITERATOR
-        nativeIterators.emplace(std::make_unique<QFileSystemIterator>(
-            fileInfo.d_ptr->fileEntry, filters));
-#else
-        qWarning("Qt was built with -no-feature-filesystemiterator: no files/plugins will be found!");
-#endif
-    }
-}
-
-inline bool QDirIteratorPrivate::entryMatches(const QString & fileName, const QFileInfo &fileInfo)
-{
-    checkAndPushDirectory(fileInfo);
-
-    if (matchesFilters(fileName, fileInfo)) {
-        currentFileInfo = nextFileInfo;
-        nextFileInfo = fileInfo;
-
-        //We found a matching entry.
-        return true;
-    }
-
-    return false;
-}
-
-/*!
-    \internal
-
-    Advances the internal iterator, either a QAbstractFileEngineIterator (e.g.
-    QResourceFileEngineIterator) or a QFileSystemIterator (which uses low-level
-    system methods, e.g. readdir() on Unix).
-
-    An iterator stack is used for holding the iterators.
-
-    A typical example of doing recursive iteration:
-    - while iterating directory A we find a sub-dir B
-    - an iterator for B is added to the iterator stack
-    - B's iterator is processed (the top() of the stack) first; then loop
-      goes back to processing A's iterator
-*/
-void QDirIteratorPrivate::advance()
-{
-    // Use get() in both code paths below because the iterator returned by top()
-    // may be invalidated due to reallocation when appending new iterators in
-    // pushDirectory().
-
-    if (engine) {
-        while (!fileEngineIterators.empty()) {
-            // Find the next valid iterator that matches the filters.
-            QAbstractFileEngineIterator *it;
-            while (it = fileEngineIterators.top().get(), it->hasNext()) {
-                it->next();
-                if (entryMatches(it->currentFileName(), it->currentFileInfo()))
-                    return;
-            }
-
-            fileEngineIterators.pop();
-        }
-    } else {
-#ifndef QT_NO_FILESYSTEMITERATOR
-        QFileSystemEntry nextEntry;
-        QFileSystemMetaData nextMetaData;
-
-        while (!nativeIterators.empty()) {
-            // Find the next valid iterator that matches the filters.
-            QFileSystemIterator *it;
-            while (it = nativeIterators.top().get(), it->advance(nextEntry, nextMetaData)) {
-                QFileInfo info(new QFileInfoPrivate(nextEntry, nextMetaData));
-
-                if (entryMatches(nextEntry.fileName(), info))
-                    return;
-                nextMetaData = QFileSystemMetaData();
-            }
-
-            nativeIterators.pop();
-        }
-#endif
-    }
-
-    currentFileInfo = nextFileInfo;
-    nextFileInfo = QFileInfo();
-}
-
-/*!
-    \internal
- */
-void QDirIteratorPrivate::checkAndPushDirectory(const QFileInfo &fileInfo)
-{
-    // If we're doing flat iteration, we're done.
-    if (!(iteratorFlags & QDirIterator::Subdirectories))
-        return;
-
-    // Never follow non-directory entries
-    if (!fileInfo.isDir())
-        return;
-
-    // Follow symlinks only when asked
-    if (!(iteratorFlags & QDirIterator::FollowSymlinks) && fileInfo.isSymLink())
-        return;
-
-    // Never follow . and ..
-    QString fileName = fileInfo.fileName();
-    if ("."_L1 == fileName || ".."_L1 == fileName)
-        return;
-
-    // No hidden directories unless requested
-    if (!(filters & QDir::AllDirs) && !(filters & QDir::Hidden) && fileInfo.isHidden())
-        return;
-
-    pushDirectory(fileInfo);
-}
-
-/*!
-    \internal
-
-    This convenience function implements the iterator's filtering logics and
-    applies then to the current directory entry.
-
-    It returns \c true if the current entry matches the filters (i.e., the
-    current entry will be returned as part of the directory iteration);
-    otherwise, false is returned.
-*/
-
-bool QDirIteratorPrivate::matchesFilters(const QString &fileName, const QFileInfo &fi) const
-{
-    if (fileName.isEmpty())
-        return false;
-
-    // filter . and ..?
-    const qsizetype fileNameSize = fileName.size();
-    const bool dotOrDotDot = fileName[0] == u'.'
-                             && ((fileNameSize == 1)
-                                 ||(fileNameSize == 2 && fileName[1] == u'.'));
-    if ((filters & QDir::NoDot) && dotOrDotDot && fileNameSize == 1)
-        return false;
-    if ((filters & QDir::NoDotDot) && dotOrDotDot && fileNameSize == 2)
-        return false;
-
-    // name filter
-#if QT_CONFIG(regularexpression)
-    // Pass all entries through name filters, except dirs if the AllDirs
-    if (!nameFilters.isEmpty() && !((filters & QDir::AllDirs) && fi.isDir())) {
-        bool matched = false;
-        for (const auto &re : nameRegExps) {
-            if (re.match(fileName).hasMatch()) {
-                matched = true;
-                break;
-            }
-        }
-        if (!matched)
-            return false;
-    }
-#endif
-    // skip symlinks
-    const bool skipSymlinks = filters.testAnyFlag(QDir::NoSymLinks);
-    const bool includeSystem = filters.testAnyFlag(QDir::System);
-    if (skipSymlinks && fi.isSymLink()) {
-        // The only reason to save this file is if it is a broken link and we are requesting system files.
-        if (!includeSystem || fi.exists())
-            return false;
-    }
-
-    // filter hidden
-    const bool includeHidden = filters.testAnyFlag(QDir::Hidden);
-    if (!includeHidden && !dotOrDotDot && fi.isHidden())
-        return false;
-
-    // filter system files
-    if (!includeSystem && (!(fi.isFile() || fi.isDir() || fi.isSymLink())
-                    || (!fi.exists() && fi.isSymLink())))
-        return false;
-
-    // skip directories
-    const bool skipDirs = !(filters & (QDir::Dirs | QDir::AllDirs));
-    if (skipDirs && fi.isDir())
-        return false;
-
-    // skip files
-    const bool skipFiles    = !(filters & QDir::Files);
-    if (skipFiles && fi.isFile())
-        // Basically we need a reason not to exclude this file otherwise we just eliminate it.
-        return false;
-
-    // filter permissions
-    const bool filterPermissions = ((filters & QDir::PermissionMask)
-                                    && (filters & QDir::PermissionMask) != QDir::PermissionMask);
-    const bool doWritable = !filterPermissions || (filters & QDir::Writable);
-    const bool doExecutable = !filterPermissions || (filters & QDir::Executable);
-    const bool doReadable = !filterPermissions || (filters & QDir::Readable);
-    if (filterPermissions
-        && ((doReadable && !fi.isReadable())
-            || (doWritable && !fi.isWritable())
-            || (doExecutable && !fi.isExecutable()))) {
-        return false;
-    }
-
-    return true;
-}
-
 /*!
     Constructs a QDirIterator that can iterate over \a dir's entrylist, using
     \a dir's name filters and regular filters. You can pass options via \a
@@ -383,15 +162,8 @@ bool QDirIteratorPrivate::matchesFilters(const QString &fileName, const QFileInf
     \sa hasNext(), next(), IteratorFlags
 */
 QDirIterator::QDirIterator(const QDir &dir, IteratorFlags flags)
-    : d(new QDirIteratorPrivate)
+    : d(new QDirIteratorPrivate(dir, flags))
 {
-    const QDirPrivate *other = dir.d_ptr.constData();
-    d->dirEntry = other->dirEntry;
-    d->nameFilters = other->nameFilters;
-    d->filters = other->filters;
-    d->iteratorFlags = flags;
-    const bool resolveEngine = other->fileEngine ? true : false;
-    d->init(resolveEngine);
 }
 
 /*!
@@ -408,12 +180,8 @@ QDirIterator::QDirIterator(const QDir &dir, IteratorFlags flags)
     \sa hasNext(), next(), IteratorFlags
 */
 QDirIterator::QDirIterator(const QString &path, QDir::Filters filters, IteratorFlags flags)
-    : d(new QDirIteratorPrivate)
+    : d(new QDirIteratorPrivate(path, filters, flags))
 {
-    d->dirEntry = QFileSystemEntry(path);
-    d->filters = filters;
-    d->iteratorFlags = flags;
-    d->init();
 }
 
 /*!
@@ -429,12 +197,8 @@ QDirIterator::QDirIterator(const QString &path, QDir::Filters filters, IteratorF
     \sa hasNext(), next(), IteratorFlags
 */
 QDirIterator::QDirIterator(const QString &path, IteratorFlags flags)
-    : d(new QDirIteratorPrivate)
+    : d(new QDirIteratorPrivate(path, flags))
 {
-    d->dirEntry = QFileSystemEntry(path);
-    d->filters = QDir::NoFilter;
-    d->iteratorFlags = flags;
-    d->init();
 }
 
 /*!
@@ -457,13 +221,8 @@ QDirIterator::QDirIterator(const QString &path, IteratorFlags flags)
 */
 QDirIterator::QDirIterator(const QString &path, const QStringList &nameFilters,
                            QDir::Filters filters, IteratorFlags flags)
-    : d(new QDirIteratorPrivate)
+    : d(new QDirIteratorPrivate(path, nameFilters, filters, flags))
 {
-    d->dirEntry = QFileSystemEntry(path);
-    d->nameFilters = nameFilters;
-    d->filters = filters;
-    d->iteratorFlags = flags;
-    d->init();
 }
 
 /*!
@@ -488,7 +247,7 @@ QDirIterator::~QDirIterator()
 QString QDirIterator::next()
 {
     d->advance();
-    return filePath();
+    return d->currentFileInfo.filePath();
 }
 
 /*!
@@ -508,7 +267,7 @@ QString QDirIterator::next()
 QFileInfo QDirIterator::nextFileInfo()
 {
     d->advance();
-    return fileInfo();
+    return d->currentFileInfo;
 }
 
 /*!
@@ -519,14 +278,7 @@ QFileInfo QDirIterator::nextFileInfo()
 */
 bool QDirIterator::hasNext() const
 {
-    if (d->engine)
+    return d->it != d->lister.end();
-        return !d->fileEngineIterators.empty();
-    else
-#ifndef QT_NO_FILESYSTEMITERATOR
-        return !d->nativeIterators.empty();
-#else
-        return false;
-#endif
 }
 
 /*!
@@ -569,7 +321,7 @@ QFileInfo QDirIterator::fileInfo() const
 */
 QString QDirIterator::path() const
 {
-    return d->dirEntry.filePath();
+    return d->lister.iteratorPath();
 }
 
 QT_END_NAMESPACE