avoid mutating existing progress objects

api/onnx_web/worker/command.py

@@ -51,13 +51,16 @@ class Progress:
             "total": self.total,
         }
 
-    def complete(self) -> bool:
+    def is_complete(self) -> bool:
         return self.current >= self.total
 
-    def empty(self) -> bool:
+    def is_empty(self) -> bool:
         # TODO: what if total is also 0?
         return self.current == 0
 
+    def update(self, current: int) -> "Progress":
+        return Progress(current, self.total)
+
 
 class ProgressCommand:
     device: str

api/onnx_web/worker/context.py

@@ -140,13 +140,13 @@ class WorkerContext:
             raise CancelledException("job has been cancelled")
 
         # update current progress counters
-        self.steps.current = steps
+        self.steps = self.steps.update(steps)
 
         if stages is not None:
-            self.stages.current = stages
+            self.stages = self.stages.update(stages)
 
         if tiles is not None:
-            self.tiles.current = tiles
+            self.tiles = self.tiles.update(tiles)
 
         # TODO: result should really be part of context at this point
         result = None
@@ -174,19 +174,19 @@ class WorkerContext:
         if total > 0:
             self.steps = Progress(current, total)
         else:
-            self.steps.current = current
+            self.steps = self.steps.update(current)
 
     def set_stages(self, current: int, total: int = 0) -> None:
         if total > 0:
             self.stages = Progress(current, total)
         else:
-            self.stages.current = current
+            self.stages = self.stages.update(current)
 
     def set_tiles(self, current: int, total: int = 0) -> None:
         if total > 0:
             self.tiles = Progress(current, total)
         else:
-            self.tiles.current = current
+            self.tiles = self.tiles.update(current)
 
     def set_totals(self, steps: int, stages: int = 0, tiles: int = 0) -> None:
         self.steps.total = steps