Fixed timeout issue for now.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

py_tools_ds/geo/raster/conversion.py

@@ -74,34 +74,33 @@ def raster2polygon(array, gt, prj, DN2extract=1, exact=True, maxfeatCount=None,
     fd = ogr.FieldDefn('DN', ogr.OFTInteger)
     mem_layer.CreateField(fd)
 
-    try:
-        timeout = 0.01
-        # set callback
-        callback = \
-            ProgressBar(prefix='Polygonize progress    ',
-                        suffix='Complete',
-                        barLength=50,
-                        timeout=timeout,
-                        use_as_callback=True) \
-            if progress and not q else Timer(timeout, use_as_callback=True) if timeout else None
-
-        # run the algorithm
-        status = gdal.Polygonize(src_band,
-                                 src_band.GetMaskBand(),
-                                 mem_layer,
-                                 0,
-                                 ["8CONNECTED=8"] if exact else [],
-                                 callback=callback)
-
-        # handle exit status other than 0 (fail)
-        if status != 0:
-            errMsg = gdal.GetLastErrorMsg()
-            if errMsg == 'User terminated':
-                raise TimeoutError('raster2polygon timed out!')
-            raise Exception(errMsg)
-
-    except KeyboardInterrupt:
-        raise TimeoutError('raster2polygon timed out!')
+    # set callback
+    callback = \
+        ProgressBar(prefix='Polygonize progress    ',
+                    suffix='Complete',
+                    barLength=50,
+                    timeout=timeout,
+                    use_as_callback=True) \
+        if progress and not q else Timer(timeout, use_as_callback=True) if timeout else None
+
+    # run the algorithm
+    status = gdal.Polygonize(src_band,
+                             src_band.GetMaskBand(),
+                             mem_layer,
+                             0,
+                             ["8CONNECTED=8"] if exact else [],
+                             callback=callback)
+
+    # handle exit status other than 0 (fail)
+    if status != 0:
+        errMsg = gdal.GetLastErrorMsg()
+
+        # Catch the KeyboardInterrupt raised in case of a timeout within the callback. It seems like there is no other
+        # way to catch exceptions within callbacks.
+        if errMsg == 'User terminated':
+            raise TimeoutError('raster2polygon timed out!')
+
+        raise Exception(errMsg)
 
     # extract polygon
     mem_layer.SetAttributeFilter('DN = %s' % DN2extract)

py_tools_ds/processing/progress_mon.py

@@ -32,6 +32,7 @@ class Timer(object):
     def __init__(self, timeout=None, use_as_callback=False):
         self.starttime = time()
         self.endtime = self.starttime + timeout if timeout else None
+        self.timeout = timeout
         self.use_as_cb = use_as_callback
 
     @property
@@ -39,7 +40,9 @@ class Timer(object):
         if self.endtime:
             if time() > self.endtime:
                 if self.use_as_cb:
-                    raise KeyboardInterrupt
+                    # raise a KeyBoardInterrupt instead of a TimeOutError
+                    # as this is catchable by gdal.GetLastException()
+                    raise KeyboardInterrupt()
                 else:
                     return True
             else:
@@ -88,6 +91,7 @@ class ProgressBar(object):
         self.decimals = decimals
         self.barLength = barLength
         self.show_elapsed = show_elapsed
+        self.timeout = timeout
         self.Timer = Timer(timeout=timeout)
         self.use_as_cb = use_as_callback
         self.out = out
@@ -103,7 +107,9 @@ class ProgressBar(object):
         if self.Timer.timed_out:
             self.out.flush()
             if self.use_as_cb:
-                raise KeyboardInterrupt
+                # raise a KeyBoardInterrupt instead of a TimeOutError
+                # as this is catchable by gdal.GetLastException()
+                raise KeyboardInterrupt()
 
         formatStr = "{0:." + str(self.decimals) + "f}"
         percents = formatStr.format(percent)
@@ -124,7 +130,7 @@ class ProgressBar(object):
         self.out.flush()
 
     def __call__(self, percent01, message, user_data):
-        """Allow ProgressBar instances ato be callable and thus to be used as callback function, e.g., for GDAL.
+        """Allow ProgressBar instances to be callable and thus to be used as callback function, e.g., for GDAL.
 
         :param percent01:   a float number between 0 and 1
         :param message:     this is not used but expected when used as GDAL callback