I did the test and appearantly it's the painting which is very expensive... with no slot connected, the program takes 1,5 seconds to complete the task. There is a very similar issue reported at https://bugreports.qt.io/browse/QTBUG-49655.
But generally ProgressBars are consuming especially when we update it that often (>365000 times) while there is no significant change at each iteration. So I simply update the QProgressBar less often and the results are good (~1s) and the progression still smooth. PSB :
class ParseFileAsync(QtCore.QThread):
match = QtCore.pyqtSignal(str)
PBupdate = QtCore.pyqtSignal(int)
PBMax = QtCore.pyqtSignal(int)
def run(self):
with open("test_long.log", "r") as fichier:
fileLines = fichier.readlines()
self.lineNumber = len(fileLines)
self.PBMax.emit(self.lineNumber)
if (self.lineNumber < 30):
self.parseFile(fileLines, False)
else:
self.parseFile(fileLines, True)
def parseFile(self, fileLines, isBig):
cpt = 0
if(isBig):
for line in fileLines:
cpt+=1
if(cpt % (int(self.lineNumber/30)) == 0):
self.PBupdate.emit(cpt)
for element in liste:
if element in line:
self.match.emit(line)
self.PBupdate.emit(self.lineNumber) #To avoid QProgressBar stopping at 99%
else:
for line in fileLines:
cpt+=1
self.PBupdate.emit(cpt)
for element in liste:
if element in line:
self.match.emit(line)
