From 773a6df46243831dee7559f90e33d7eff3c5c71e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jo=C3=A3o=20Abecasis?= Date: Fri, 5 Aug 2011 10:40:46 +0200 Subject: Avoid spurious detaching in QDir::to/fromNativeSeparators The new code avoids non-const detaching operations until needed and uses a pointer into the "raw" QChar data from then on, thus skipping unneeded checks on the reference count for further detaching. These functions are used all the time by the file system classes so this small optimization won't hurt. In particular, it will help users who already use '/' when passing paths into Qt. Reviewed-by: Peter Hartmann --- src/corelib/io/qdir.cpp | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp index b31cf69..f9196e0 100644 --- a/src/corelib/io/qdir.cpp +++ b/src/corelib/io/qdir.cpp @@ -802,14 +802,23 @@ QString QDir::convertSeparators(const QString &pathName) */ QString QDir::toNativeSeparators(const QString &pathName) { - QString n(pathName); #if defined(Q_FS_FAT) || defined(Q_OS_OS2EMX) || defined(Q_OS_SYMBIAN) - for (int i = 0; i < (int)n.length(); ++i) { - if (n[i] == QLatin1Char('/')) - n[i] = QLatin1Char('\\'); + int i = pathName.indexOf(QLatin1Char('/')); + if (i != -1) { + QString n(pathName); + + QChar * const data = n.data(); + data[i++] = QLatin1Char('\\'); + + for (; i < n.length(); ++i) { + if (data[i] == QLatin1Char('/')) + data[i] = QLatin1Char('\\'); + } + + return n; } #endif - return n; + return pathName; } /*! @@ -826,14 +835,23 @@ QString QDir::toNativeSeparators(const QString &pathName) */ QString QDir::fromNativeSeparators(const QString &pathName) { - QString n(pathName); #if defined(Q_FS_FAT) || defined(Q_OS_OS2EMX) || defined(Q_OS_SYMBIAN) - for (int i = 0; i < (int)n.length(); ++i) { - if (n[i] == QLatin1Char('\\')) - n[i] = QLatin1Char('/'); + int i = pathName.indexOf(QLatin1Char('\\')); + if (i != -1) { + QString n(pathName); + + QChar * const data = n.data(); + data[i++] = QLatin1Char('/'); + + for (; i < n.length(); ++i) { + if (data[i] == QLatin1Char('\\')) + data[i] = QLatin1Char('/'); + } + + return n; } #endif - return n; + return pathName; } /*! -- cgit v0.12