[KPhotoAlbum] Patch to improve performance of new image scan

[Robert L Krawitz]

This is a patch I posted a while back to improve performance of the
new image scan.  It improves performance by not attempting to stat()
files unless we have reason to be interested in them in the first
place (the QDir class winds up stat'ing every file in the directory,
which is quite expensive since it requires a lot of disk accesses).

Index: DB/NewImageFinder.cpp
===================================================================
--- DB/NewImageFinder.cpp       (revision 642901)
+++ DB/NewImageFinder.cpp       (working copy)
@@ -20,7 +20,9 @@
 #include <qfileinfo.h>
 #include "Settings/SettingsData.h"
 #include "Browser/BrowserWidget.h"
-#include <qdir.h>
+#include "ImageManager/RawImageDecoder.h"
+#include <sys/types.h>
+#include <dirent.h>
 #include "Utilities/Util.h"
 #include <qprogressdialog.h>
 #include <klocale.h>
@@ -56,6 +58,54 @@
     return (!_pendingLoad.isEmpty()); // returns if new images was found.
 }
 
+class MyDir
+{
+public:
+    MyDir();
+    MyDir(const QString &path);
+    virtual QStringList entryList(void) const;
+    virtual ~MyDir();
+private:
+    QString path_;
+};
+
+MyDir::MyDir()
+  : path_(QString::fromLatin1("."))
+{
+}
+
+MyDir::MyDir(const QString &path)
+  : path_(path)
+{
+}
+
+MyDir::~MyDir()
+{
+}
+
+QStringList MyDir::entryList(void) const
+{
+    QStringList answer;
+    DIR *dir;
+    dirent *file;
+    dir = opendir( QFile::encodeName(path_) );
+    if ( !dir )
+       return answer; // cannot read the directory
+
+#if defined(QT_THREAD_SUPPORT) && defined(_POSIX_THREAD_SAFE_FUNCTIONS) && !defined(Q_OS_CYGWIN)
+    union {
+       struct dirent mt_file;
+       char b[sizeof(struct dirent) + MAXNAMLEN + 1];
+    } u;
+    while ( readdir_r(dir, &u.mt_file, &file ) == 0 && file )
+#else
+    while ( (file = readdir(dir)) )
+#endif // QT_THREAD_SUPPORT && _POSIX_THREAD_SAFE_FUNCTIONS
+       answer.append(QFile::decodeName(file->d_name));
+    (void) closedir(dir);
+    return answer;
+}
+
 void NewImageFinder::searchForNewFiles( const QDict<void>& loadedFiles, QString directory )
 {
     if ( directory.endsWith( QString::fromLatin1("/") ) )
@@ -65,18 +115,24 @@
     if ( imageDir.endsWith( QString::fromLatin1("/") ) )
         imageDir = imageDir.mid( 0, imageDir.length()-1 );
 
-    QDir dir( directory );
-    QStringList dirList = dir.entryList( QDir::All );
+    MyDir dir( directory );
+    QStringList dirList = dir.entryList( );
+    ImageManager::RAWImageDecoder dec;
     for( QStringList::Iterator it = dirList.begin(); it != dirList.end(); ++it ) {
         QString file = directory + QString::fromLatin1("/") + *it;
-        QFileInfo fi( file );
         if ( (*it) == QString::fromLatin1(".") || (*it) == QString::fromLatin1("..") ||
              (*it) == QString::fromLatin1("ThumbNails") ||
              (*it) == QString::fromLatin1("CategoryImages") ||
-             !fi.isReadable() )
+            loadedFiles.find( file ) ||
+            dec._skipThisFile(loadedFiles, file) )
             continue;
 
-        if ( fi.isFile() && loadedFiles.find( file ) == 0) {
+        QFileInfo fi( file );
+
+       if ( !fi.isReadable() )
+           continue;
+
+        if ( fi.isFile() ) {
             QString baseName = file.mid( imageDir.length()+1 );
             if ( ! DB::ImageDB::instance()->isBlocking( baseName ) ) {
                 if ( Utilities::canReadImage(file) )
Index: ImageManager/RawImageDecoder.cpp
===================================================================
--- ImageManager/RawImageDecoder.cpp    (revision 642901)
+++ ImageManager/RawImageDecoder.cpp    (working copy)
@@ -109,4 +109,52 @@
        return false;
 }
 
+bool RAWImageDecoder::_skipThisFile( const QDict<void>& loadedFiles, const QString& imageFile )
+{
+       /* Known RAW file extensions. TODO: Complete */
+       static const QString extensions[] = { QString::fromLatin1("crw"),
+                                                                                QString::fromLatin1("cr2"),
+                                                                                QString::fromLatin1("nef"),
+                                                                                QString::fromLatin1("bay"),
+                                                                                QString::fromLatin1("mos"),
+                                                                                QString::fromLatin1("mrw"),
+                                                                                QString::fromLatin1("orf"),
+                                                                                QString::fromLatin1("cs1"),
+                                                                                QString::fromLatin1("dc2"),
+                                                                                QString::fromLatin1("kdc"),
+                                                                                QString::fromLatin1("raf"),
+                                                                                QString::fromLatin1("rdc"),
+                                                                                QString::fromLatin1("x3f"),
+                                                                                QString::null };
+       if (imageFile.endsWith(QString::fromLatin1(".thm")) ||
+           imageFile.endsWith(QString::fromLatin1(".THM")))
+         return true;
+       if (! (Settings::SettingsData::instance()->dontReadRawFilesWithOtherMatchingFile()))
+         return false;
+       bool isRaw = false;
+       for( int i = 0; !extensions[i].isNull(); ++i ) {
+         if( imageFile.endsWith( extensions[i], false ) ) {
+           isRaw = true;
+           break;
+         }
+       }
+       if (!isRaw)
+         return false;
+       static const QString standardExtensions[] = {
+         QString::fromLatin1("jpg"),
+         QString::fromLatin1("JPG"),
+         QString::fromLatin1("tif"),
+         QString::fromLatin1("TIF"),
+         QString::fromLatin1("png"),
+         QString::fromLatin1("PNG"),
+         QString::null };
+       QString baseFileName = imageFile;
+       baseFileName.remove(baseFileName.length() - 3, 3);
+       for (int i = 0; !standardExtensions[i].isNull(); ++i) {
+         if (loadedFiles.find(baseFileName + standardExtensions[i]))
+           return true;
+       }
+       return false;
 }
+
+}
Index: ImageManager/RawImageDecoder.h
===================================================================
--- ImageManager/RawImageDecoder.h      (revision 642901)
+++ ImageManager/RawImageDecoder.h      (working copy)
@@ -19,6 +19,7 @@
 #define RAWIMAGEDECODER_H
 
 #include "ImageDecoder.h"
+#include <qdict.h>
 
 namespace ImageManager
 {
@@ -29,6 +30,7 @@
 
        virtual bool _decode(QImage *img, const QString& imageFile, QSize* fullSize, int dim=-1);
        virtual bool _mightDecode( const QString& imageFile );
+       virtual bool _skipThisFile( const QDict<void>& loadedFiles, const QString& imageFile );
 };
 
 }