consistent cache key for Stitch objects

2 files changed, 40 insertions, 15 deletions

diff --git a/lib/elements/element.py b/lib/elements/element.py
index 7164c17c..84a9199b 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -396,7 +396,15 @@ class EmbroideryElement(object):
             # we don't care about the previous stitch
             previous_stitch = None
 
-        return get_stitch_plan_cache().get(self._get_cache_key(previous_stitch))
+        cache_key = self._get_cache_key(previous_stitch)
+        stitch_groups = get_stitch_plan_cache().get(cache_key)
+
+        if stitch_groups:
+            debug.log(f"used cache for {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}")
+        else:
+            debug.log(f"did not use cache for {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}, key={cache_key}")
+
+        return stitch_groups
 
     def uses_previous_stitch(self):
         """Returns True if the previous stitch can affect this Element's stitches.
@@ -408,12 +416,16 @@ class EmbroideryElement(object):
     @debug.time
     def _save_cached_stitch_groups(self, stitch_groups, previous_stitch):
         stitch_plan_cache = get_stitch_plan_cache()
-        stitch_plan_cache[self._get_cache_key(previous_stitch)] = stitch_groups
+        cache_key = self._get_cache_key(previous_stitch)
+        if cache_key not in stitch_plan_cache:
+            stitch_plan_cache[cache_key] = stitch_groups
 
         if previous_stitch is not None:
             # Also store it with None as the previous stitch, so that it can be used next time
             # if we don't care about the previous stitch
-            stitch_plan_cache[self._get_cache_key(None)] = stitch_groups
+            cache_key = self._get_cache_key(None)
+            if cache_key not in stitch_plan_cache:
+                stitch_plan_cache[cache_key] = stitch_groups
 
     def get_params_and_values(self):
         params = {}
@@ -436,11 +448,13 @@ class EmbroideryElement(object):
         cache_key_generator.update([(c.command, c.target_point) for c in self.commands])
         cache_key_generator.update(self._get_patterns_cache_key_data())
 
-        # TODO: include commands and patterns that apply to this element
+        cache_key = cache_key_generator.get_cache_key()
+        debug.log(f"cache key for {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)} {previous_stitch}: {cache_key}")
 
-        return cache_key_generator.get_cache_key()
+        return cache_key
 
     def embroider(self, last_stitch_group):
+        debug.log(f"starting {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}")
         if last_stitch_group:
             previous_stitch = last_stitch_group.stitches[-1]
         else:
@@ -463,6 +477,7 @@ class EmbroideryElement(object):
 
             self._save_cached_stitch_groups(stitch_groups, previous_stitch)
 
+        debug.log(f"ending {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}")
         return stitch_groups
 
     def fatal(self, message, point_to_troubleshoot=False):
diff --git a/lib/stitch_plan/stitch.py b/lib/stitch_plan/stitch.py
index 67a0fd64..c1553ce5 100644
--- a/lib/stitch_plan/stitch.py
+++ b/lib/stitch_plan/stitch.py
@@ -55,16 +55,17 @@ class Stitch(Point):
         return instance
 
     def __repr__(self):
-        return "Stitch(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)" % (self.x,
-                                                                   self.y,
-                                                                   self.color,
-                                                                   "JUMP" if self.jump else " ",
-                                                                   "TRIM" if self.trim else " ",
-                                                                   "STOP" if self.stop else " ",
-                                                                   "TIE MODUS" if self.tie_modus else " ",
-                                                                   "FORCE LOCK STITCHES" if self.force_lock_stitches else " ",
-                                                                   "NO TIES" if self.no_ties else " ",
-                                                                   "COLOR CHANGE" if self.color_change else " ")
+        return "Stitch(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)" % (self.x,
+                                                                       self.y,
+                                                                       self.color,
+                                                                       self.tags,
+                                                                       "JUMP" if self.jump else " ",
+                                                                       "TRIM" if self.trim else " ",
+                                                                       "STOP" if self.stop else " ",
+                                                                       self.tie_modus,
+                                                                       "FORCE LOCK STITCHES" if self.force_lock_stitches else " ",
+                                                                       "NO TIES" if self.no_ties else " ",
+                                                                       "COLOR CHANGE" if self.color_change else " ")
 
     def _set(self, attribute, value, base_stitch):
         # Set an attribute.  If the caller passed a Stitch object, use its value, unless
@@ -104,3 +105,12 @@ class Stitch(Point):
         attributes = dict(vars(self))
         attributes['tags'] = list(attributes['tags'])
         return attributes
+
+    def __getstate__(self):
+        # This is used by pickle.  We want to sort the tag list so that the
+        # pickled representation is stable, since it's used to generate cache
+        # keys.
+        state = self.__json__()
+        state['tags'].sort()
+
+        return state