prevent division by zero errors

these can happen on MS Windows because the timestamps lack granularity

xpra/client/gui/window_backing_base.py

@@ -225,7 +225,7 @@ def calculate_fps(self) -> int:
         e0 = pe[0]
         now = monotonic()
         elapsed = now - e0
-        if elapsed <= 1 and len(pe) >= 5:
+        if 0 < elapsed <= 1 and len(pe) >= 5:
             return round(len(pe) / elapsed)
         cutoff = now - 1
         count = 0

xpra/codecs/nvidia/cuda/image.py

@@ -48,9 +48,13 @@ def may_download(self):
         self.wait_for_stream()
         self.pixels = host_buffer.tobytes()
         elapsed = monotonic() - start
+        if elapsed > 0:
+            mbs = self.buffer_size / elapsed / 1024 / 1024
+        else:
+            mbs = 9999
         log("may_download() from %#x to %s, size=%s, elapsed=%ims - %iMB/s",
             int(self.cuda_device_buffer), host_buffer, self.buffer_size,
-            int(1000 * elapsed), self.buffer_size / elapsed / 1024 / 1024)
+            int(1000 * elapsed), mbs)
         self.free_cuda()
         ctx.pop()
 

xpra/net/file_transfer.py

@@ -1056,8 +1056,12 @@ def _process_ack_file_chunk(self, packet: PacketType) -> None:
         if not chunk_state.data:
             # all sent!
             elapsed = monotonic() - chunk_state.start
+            if elapsed > 0:
+                bs = chunk * chunk_size / elapsed
+            else:
+                bs = 9999 * 1000 * 1000
             filelog("%i chunks of %i bytes sent in %ims (%sB/s)",
-                    chunk, chunk_size, elapsed * 1000, std_unit(chunk * chunk_size / elapsed))
+                    chunk, chunk_size, elapsed * 1000, std_unit(bs))
             self.cancel_sending(chunk_id)
             return
         assert chunk_size > 0

xpra/opengl/check.py

@@ -389,11 +389,12 @@ def recs(rname) -> list[str]:
             else:
                 log.info(msg)
         if missing_accelerators:
-            if len(missing_accelerators) == 1 and missing_accelerators[0] == "numpy_formathandler":
+            missing_str = csv(missing_accelerators)
+            if missing_str == "numpy_formathandler":
                 log_fn = log.debug
             else:
                 log_fn = log.info
-            log_fn("OpenGL accelerate missing: %s", csv(missing_accelerators))
+            log_fn(f"OpenGL accelerate missing: {missing_str}")
 
         for msg in recs("plugins"):
             log(f"plugins msg={msg}")

xpra/server/source/source_stats.py

@@ -285,10 +285,11 @@ def get_info(self) -> dict[str, Any]:
             einfo["pixels_decoded_per_second"] = pixels_decoded_per_second
         if start_time:
             elapsed = now - start_time
-            pixels_per_second = int(total_pixels / elapsed)
-            einfo.update({
-                "pixels_per_second": pixels_per_second,
-                "regions_per_second": int(len(region_sizes) / elapsed),
-                "average_region_size": int(total_pixels / len(region_sizes)),
-            })
+            if elapsed > 0:
+                einfo.update({
+                    "pixels_per_second": int(total_pixels / elapsed),
+                    "regions_per_second": int(len(region_sizes) / elapsed),
+                })
+            if region_sizes:
+                einfo["average_region_size"] = int(total_pixels / len(region_sizes))
         return info

xpra/server/window/perfstats.py

@@ -109,7 +109,9 @@ def update_averages(self) -> None:
         if cdt:
             # the elapsed time recorded is in microseconds:
             decode_speed = tuple(
-                (event_time, size, int(size * 1000 * 1000 / elapsed)) for event_time, size, elapsed in cdt)
+                (event_time, size, int(size * 1000 * 1000 / elapsed))
+                for event_time, size, elapsed in cdt if elapsed > 0
+            )
             r = calculate_size_weighted_average(decode_speed)
             self.avg_decode_speed = int(r[0])
             self.recent_decode_speed = int(r[1])