Merge 2db3ca609d into f5030e26fd

comfy_execution/caching.py

@@ -23,7 +23,7 @@ def include_unique_id_in_input(class_type: str) -> bool:
     return NODE_CLASS_CONTAINS_UNIQUE_ID[class_type]
 
 class CacheKeySet(ABC):
-    def __init__(self, dynprompt, node_ids, is_changed_cache):
+    def __init__(self, dynprompt, node_ids, is_changed):
         self.keys = {}
         self.subcache_keys = {}
 
@@ -45,6 +45,12 @@ class CacheKeySet(ABC):
 
     def get_subcache_key(self, node_id):
         return self.subcache_keys.get(node_id, None)
+    
+    async def update_cache_key(self, node_id) -> None:
+        pass
+
+    def is_key_updated(self, node_id) -> bool:
+        return True
 
 class Unhashable:
     def __init__(self):
@@ -62,10 +68,21 @@ def to_hashable(obj):
     else:
         # TODO - Support other objects like tensors?
         return Unhashable()
+    
+def throw_on_unhashable(obj):
+    # Same as to_hashable except throwing for unhashables instead.
+    if isinstance(obj, (int, float, str, bool, bytes, type(None))):
+        return obj
+    elif isinstance(obj, Mapping):
+        return frozenset([(throw_on_unhashable(k), throw_on_unhashable(v)) for k, v in sorted(obj.items())])
+    elif isinstance(obj, Sequence):
+        return frozenset(zip(itertools.count(), [throw_on_unhashable(i) for i in obj]))
+    else:
+        raise Exception("Object unhashable.")
 
 class CacheKeySetID(CacheKeySet):
-    def __init__(self, dynprompt, node_ids, is_changed_cache):
+    def __init__(self, dynprompt, node_ids, is_changed):
-        super().__init__(dynprompt, node_ids, is_changed_cache)
+        super().__init__(dynprompt, node_ids, is_changed)
         self.dynprompt = dynprompt
 
     async def add_keys(self, node_ids):
@@ -79,13 +96,25 @@ class CacheKeySetID(CacheKeySet):
             self.subcache_keys[node_id] = (node_id, node["class_type"])
 
 class CacheKeySetInputSignature(CacheKeySet):
-    def __init__(self, dynprompt, node_ids, is_changed_cache):
+    def __init__(self, dynprompt, node_ids, is_changed):
-        super().__init__(dynprompt, node_ids, is_changed_cache)
+        super().__init__(dynprompt, node_ids, is_changed)
         self.dynprompt = dynprompt
-        self.is_changed_cache = is_changed_cache
+        self.is_changed = is_changed
+        self.updated_node_ids = set()
 
     def include_node_id_in_input(self) -> bool:
         return False
+    
+    async def update_cache_key(self, node_id):
+        if node_id in self.updated_node_ids:
+            return
+        if node_id not in self.keys:
+            return
+        self.updated_node_ids.add(node_id)
+        self.keys[node_id] = await self.get_node_signature(node_id)
+
+    def is_key_updated(self, node_id):
+        return node_id in self.updated_node_ids
 
     async def add_keys(self, node_ids):
         for node_id in node_ids:
@@ -94,28 +123,30 @@ class CacheKeySetInputSignature(CacheKeySet):
             if not self.dynprompt.has_node(node_id):
                 continue
             node = self.dynprompt.get_node(node_id)
-            self.keys[node_id] = await self.get_node_signature(self.dynprompt, node_id)
+            self.keys[node_id] = None
             self.subcache_keys[node_id] = (node_id, node["class_type"])
 
-    async def get_node_signature(self, dynprompt, node_id):
+    async def get_node_signature(self, node_id):
-        signature = []
+        signatures = []
-        ancestors, order_mapping = self.get_ordered_ancestry(dynprompt, node_id)
+        ancestors, order_mapping, node_inputs = self.get_ordered_ancestry(node_id)
-        signature.append(await self.get_immediate_node_signature(dynprompt, node_id, order_mapping))
+        node = self.dynprompt.get_node(node_id)
+        node["signature"] = to_hashable(await self.get_immediate_node_signature(node_id, order_mapping, node_inputs))
+        signatures.append(node["signature"])
         for ancestor_id in ancestors:
-            signature.append(await self.get_immediate_node_signature(dynprompt, ancestor_id, order_mapping))
+            ancestor_node = self.dynprompt.get_node(ancestor_id)
-        return to_hashable(signature)
+            assert "signature" in ancestor_node
+            signatures.append(ancestor_node["signature"])
+        signatures = frozenset(zip(itertools.count(), signatures))
+        return signatures
 
-    async def get_immediate_node_signature(self, dynprompt, node_id, ancestor_order_mapping):
+    async def get_immediate_node_signature(self, node_id, ancestor_order_mapping, inputs):
-        if not dynprompt.has_node(node_id):
+        if not self.dynprompt.has_node(node_id):
             # This node doesn't exist -- we can't cache it.
             return [float("NaN")]
-        node = dynprompt.get_node(node_id)
+        node = self.dynprompt.get_node(node_id)
         class_type = node["class_type"]
         class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
-        signature = [class_type, await self.is_changed_cache.get(node_id)]
+        signature = [class_type, await self.is_changed.get(node_id)]
-        if self.include_node_id_in_input() or (hasattr(class_def, "NOT_IDEMPOTENT") and class_def.NOT_IDEMPOTENT) or include_unique_id_in_input(class_type):
-            signature.append(node_id)
-        inputs = node["inputs"]
         for key in sorted(inputs.keys()):
             if is_link(inputs[key]):
                 (ancestor_id, ancestor_socket) = inputs[key]
@@ -123,28 +154,69 @@ class CacheKeySetInputSignature(CacheKeySet):
                 signature.append((key,("ANCESTOR", ancestor_index, ancestor_socket)))
             else:
                 signature.append((key, inputs[key]))
+        if self.include_node_id_in_input() or (hasattr(class_def, "NOT_IDEMPOTENT") and class_def.NOT_IDEMPOTENT) or include_unique_id_in_input(class_type):
+            signature.append(node_id)
         return signature
+    
+    def get_ordered_ancestry(self, node_id):
+        def get_ancestors(ancestors, ret: list=[]):
+            for ancestor_id in ancestors:
+                if ancestor_id not in ret:
+                    ret.append(ancestor_id)
+                ancestor_node = self.dynprompt.get_node(ancestor_id)
+                get_ancestors(ancestor_node["ancestors"], ret)
+            return ret
+        
+        ancestors, node_inputs = self.get_ordered_ancestry_internal(node_id)
+        ancestors = get_ancestors(ancestors)
 
-    # This function returns a list of all ancestors of the given node. The order of the list is
-    # deterministic based on which specific inputs the ancestor is connected by.
-    def get_ordered_ancestry(self, dynprompt, node_id):
-        ancestors = []
         order_mapping = {}
-        self.get_ordered_ancestry_internal(dynprompt, node_id, ancestors, order_mapping)
+        for i, ancestor_id in enumerate(ancestors):
-        return ancestors, order_mapping
+            order_mapping[ancestor_id] = i
+        
+        return ancestors, order_mapping, node_inputs
 
-    def get_ordered_ancestry_internal(self, dynprompt, node_id, ancestors, order_mapping):
+    def get_ordered_ancestry_internal(self, node_id):
-        if not dynprompt.has_node(node_id):
+        def get_hashable(obj):
-            return
+            try:
-        inputs = dynprompt.get_node(node_id)["inputs"]
+                return throw_on_unhashable(obj)
-        input_keys = sorted(inputs.keys())
+            except:
-        for key in input_keys:
+                return Unhashable
-            if is_link(inputs[key]):
+        
-                ancestor_id = inputs[key][0]
+        ancestors = []
-                if ancestor_id not in order_mapping:
+        node_inputs = {}
-                    ancestors.append(ancestor_id)
+
-                    order_mapping[ancestor_id] = len(ancestors) - 1
+        if not self.dynprompt.has_node(node_id):
-                    self.get_ordered_ancestry_internal(dynprompt, ancestor_id, ancestors, order_mapping)
+            return ancestors, node_inputs
+        
+        node = self.dynprompt.get_node(node_id)
+        if "ancestors" in node:
+            return node["ancestors"], node_inputs
+        
+        input_data_all, _, _ = self.is_changed.get_input_data(node_id)
+        inputs = self.dynprompt.get_node(node_id)["inputs"]
+        for key in sorted(inputs.keys()):
+            if key in input_data_all:
+                if is_link(inputs[key]):
+                    ancestor_id = inputs[key][0]
+                    hashable = get_hashable(input_data_all[key])
+                    if hashable is Unhashable or is_link(input_data_all[key][0]):
+                        # Link still needed
+                        node_inputs[key] = inputs[key]
+                        if ancestor_id not in ancestors:
+                            ancestors.append(ancestor_id)
+                    else:
+                        # Replace link
+                        node_inputs[key] = input_data_all[key]
+                else:
+                    hashable = get_hashable(inputs[key])
+                    if hashable is Unhashable:
+                        node_inputs[key] = Unhashable()
+                    else:
+                        node_inputs[key] = [inputs[key]]
+        
+        node["ancestors"] = ancestors
+        return node["ancestors"], node_inputs
 
 class BasicCache:
     def __init__(self, key_class):
@@ -155,11 +227,11 @@ class BasicCache:
         self.cache = {}
         self.subcaches = {}
 
-    async def set_prompt(self, dynprompt, node_ids, is_changed_cache):
+    async def set_prompt(self, dynprompt, node_ids, is_changed):
         self.dynprompt = dynprompt
-        self.cache_key_set = self.key_class(dynprompt, node_ids, is_changed_cache)
+        self.cache_key_set = self.key_class(dynprompt, node_ids, is_changed)
         await self.cache_key_set.add_keys(node_ids)
-        self.is_changed_cache = is_changed_cache
+        self.is_changed = is_changed
         self.initialized = True
 
     def all_node_ids(self):
@@ -185,6 +257,8 @@ class BasicCache:
         for key in self.subcaches:
             if key not in preserve_subcaches:
                 to_remove.append(key)
+            else:
+                self.subcaches[key].clean_unused()
         for key in to_remove:
             del self.subcaches[key]
 
@@ -196,16 +270,23 @@ class BasicCache:
     def poll(self, **kwargs):
         pass
 
+    async def _update_cache_key_immediate(self, node_id):
+        await self.cache_key_set.update_cache_key(node_id)
+    
+    def _is_key_updated_immediate(self, node_id):
+        return self.cache_key_set.is_key_updated(node_id)
+
     def _set_immediate(self, node_id, value):
         assert self.initialized
         cache_key = self.cache_key_set.get_data_key(node_id)
-        self.cache[cache_key] = value
+        if cache_key is not None:
+            self.cache[cache_key] = value
 
     def _get_immediate(self, node_id):
         if not self.initialized:
             return None
         cache_key = self.cache_key_set.get_data_key(node_id)
-        if cache_key in self.cache:
+        if cache_key is not None and cache_key in self.cache:
             return self.cache[cache_key]
         else:
             return None
@@ -216,7 +297,7 @@ class BasicCache:
         if subcache is None:
             subcache = BasicCache(self.key_class)
             self.subcaches[subcache_key] = subcache
-        await subcache.set_prompt(self.dynprompt, children_ids, self.is_changed_cache)
+        await subcache.set_prompt(self.dynprompt, children_ids, self.is_changed)
         return subcache
 
     def _get_subcache(self, node_id):
@@ -272,10 +353,20 @@ class HierarchicalCache(BasicCache):
         cache = self._get_cache_for(node_id)
         assert cache is not None
         return await cache._ensure_subcache(node_id, children_ids)
+    
+    async def update_cache_key(self, node_id):
+        cache = self._get_cache_for(node_id)
+        assert cache is not None
+        await cache._update_cache_key_immediate(node_id)
+        
+    def is_key_updated(self, node_id):
+        cache = self._get_cache_for(node_id)
+        assert cache is not None
+        return cache._is_key_updated_immediate(node_id)
 
 class NullCache:
 
-    async def set_prompt(self, dynprompt, node_ids, is_changed_cache):
+    async def set_prompt(self, dynprompt, node_ids, is_changed):
         pass
 
     def all_node_ids(self):
@@ -295,6 +386,12 @@ class NullCache:
 
     async def ensure_subcache_for(self, node_id, children_ids):
         return self
+    
+    async def update_cache_key(self, node_id):
+        pass
+        
+    def is_key_updated(self, node_id):
+        return True
 
 class LRUCache(BasicCache):
     def __init__(self, key_class, max_size=100):
@@ -305,8 +402,8 @@ class LRUCache(BasicCache):
         self.used_generation = {}
         self.children = {}
 
-    async def set_prompt(self, dynprompt, node_ids, is_changed_cache):
+    async def set_prompt(self, dynprompt, node_ids, is_changed):
-        await super().set_prompt(dynprompt, node_ids, is_changed_cache)
+        await super().set_prompt(dynprompt, node_ids, is_changed)
         self.generation += 1
         for node_id in node_ids:
             self._mark_used(node_id)
@@ -314,7 +411,7 @@ class LRUCache(BasicCache):
     def clean_unused(self):
         while len(self.cache) > self.max_size and self.min_generation < self.generation:
             self.min_generation += 1
-            to_remove = [key for key in self.cache if self.used_generation[key] < self.min_generation]
+            to_remove = [key for key in self.cache if key not in self.used_generation or self.used_generation[key] < self.min_generation]
             for key in to_remove:
                 del self.cache[key]
                 del self.used_generation[key]
@@ -347,6 +444,14 @@ class LRUCache(BasicCache):
             self._mark_used(child_id)
             self.children[cache_key].append(self.cache_key_set.get_data_key(child_id))
         return self
+    
+    async def update_cache_key(self, node_id):
+        await self._update_cache_key_immediate(node_id)
+        self._mark_used(node_id)
+        
+    def is_key_updated(self, node_id):
+        self._mark_used(node_id)
+        return self._is_key_updated_immediate(node_id)
 
 
 #Iterating the cache for usage analysis might be expensive, so if we trigger make sure

execution.py

@@ -48,49 +48,40 @@ class ExecutionResult(Enum):
 class DuplicateNodeError(Exception):
     pass
 
-class IsChangedCache:
+class IsChanged:
-    def __init__(self, prompt_id: str, dynprompt: DynamicPrompt, outputs_cache: BasicCache):
+    def __init__(self, prompt_id: str, dynprompt: DynamicPrompt, execution_list: ExecutionList|None=None, extra_data: dict={}):
         self.prompt_id = prompt_id
         self.dynprompt = dynprompt
-        self.outputs_cache = outputs_cache
+        self.execution_list = execution_list
-        self.is_changed = {}
+        self.extra_data = extra_data
-
-    async def get(self, node_id):
-        if node_id in self.is_changed:
-            return self.is_changed[node_id]
 
+    def get_input_data(self, node_id):
+        node = self.dynprompt.get_node(node_id)
+        class_type = node["class_type"]
+        class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
+        return get_input_data(node["inputs"], class_def, node_id, self.execution_list, self.dynprompt, self.extra_data)
+
+    async def get(self, node_id):
         node = self.dynprompt.get_node(node_id)
         class_type = node["class_type"]
         class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
-        has_is_changed = False
         is_changed_name = None
         if issubclass(class_def, _ComfyNodeInternal) and first_real_override(class_def, "fingerprint_inputs") is not None:
-            has_is_changed = True
             is_changed_name = "fingerprint_inputs"
         elif hasattr(class_def, "IS_CHANGED"):
-            has_is_changed = True
             is_changed_name = "IS_CHANGED"
-        if not has_is_changed:
+        if is_changed_name is None:
-            self.is_changed[node_id] = False
+            return False
-            return self.is_changed[node_id]
 
-        if "is_changed" in node:
+        input_data_all, _, v3_data = self.get_input_data(node_id)
-            self.is_changed[node_id] = node["is_changed"]
-            return self.is_changed[node_id]
-
-        # Intentionally do not use cached outputs here. We only want constants in IS_CHANGED
-        input_data_all, _, v3_data = get_input_data(node["inputs"], class_def, node_id, None)
         try:
             is_changed = await _async_map_node_over_list(self.prompt_id, node_id, class_def, input_data_all, is_changed_name, v3_data=v3_data)
             is_changed = await resolve_map_node_over_list_results(is_changed)
-            node["is_changed"] = [None if isinstance(x, ExecutionBlocker) else x for x in is_changed]
+            is_changed = [None if isinstance(x, ExecutionBlocker) else x for x in is_changed]
         except Exception as e:
             logging.warning("WARNING: {}".format(e))
-            node["is_changed"] = float("NaN")
+            is_changed = float("NaN")
-        finally:
+        return is_changed
-            self.is_changed[node_id] = node["is_changed"]
-        return self.is_changed[node_id]
-
 
 class CacheEntry(NamedTuple):
     ui: dict
@@ -416,16 +407,19 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
     inputs = dynprompt.get_node(unique_id)['inputs']
     class_type = dynprompt.get_node(unique_id)['class_type']
     class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
-    cached = caches.outputs.get(unique_id)
+    if caches.outputs.is_key_updated(unique_id):
-    if cached is not None:
+        # Key is updated, the cache can be checked.
-        if server.client_id is not None:
+        cached = caches.outputs.get(unique_id)
-            cached_ui = cached.ui or {}
+        if cached is not None:
-            server.send_sync("executed", { "node": unique_id, "display_node": display_node_id, "output": cached_ui.get("output",None), "prompt_id": prompt_id }, server.client_id)
+            if server.client_id is not None:
-            if cached.ui is not None:
+                cached_ui = cached.ui or {}
-                ui_outputs[unique_id] = cached.ui
+                server.send_sync("execution_cached", { "nodes": [unique_id], "prompt_id": prompt_id}, server.client_id)
-        get_progress_state().finish_progress(unique_id)
+                server.send_sync("executed", { "node": unique_id, "display_node": display_node_id, "output": cached_ui.get("output",None), "prompt_id": prompt_id }, server.client_id)
-        execution_list.cache_update(unique_id, cached)
+                if cached.ui is not None:
-        return (ExecutionResult.SUCCESS, None, None)
+                    ui_outputs[unique_id] = cached.ui
+            get_progress_state().finish_progress(unique_id)
+            execution_list.cache_update(unique_id, cached)
+            return (ExecutionResult.SUCCESS, None, None)
 
     input_data_all = None
     try:
@@ -466,11 +460,14 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
             del pending_subgraph_results[unique_id]
             has_subgraph = False
         else:
-            get_progress_state().start_progress(unique_id)
+            if caches.outputs.is_key_updated(unique_id):
+                # The key is updated, the node is executing.
+                get_progress_state().start_progress(unique_id)
+                if server.client_id is not None:
+                    server.last_node_id = display_node_id
+                    server.send_sync("executing", { "node": unique_id, "display_node": display_node_id, "prompt_id": prompt_id }, server.client_id)
+
             input_data_all, missing_keys, v3_data = get_input_data(inputs, class_def, unique_id, execution_list, dynprompt, extra_data)
-            if server.client_id is not None:
-                server.last_node_id = display_node_id
-                server.send_sync("executing", { "node": unique_id, "display_node": display_node_id, "prompt_id": prompt_id }, server.client_id)
 
             obj = caches.objects.get(unique_id)
             if obj is None:
@@ -496,6 +493,14 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                         execution_list.make_input_strong_link(unique_id, i)
                     return (ExecutionResult.PENDING, None, None)
 
+            if not caches.outputs.is_key_updated(unique_id):
+                # Update the cache key after any lazy inputs are evaluated.
+                async def update_cache_key(node_id, unblock):
+                    await caches.outputs.update_cache_key(node_id)
+                    unblock()
+                asyncio.create_task(update_cache_key(unique_id, execution_list.add_external_block(unique_id)))
+                return (ExecutionResult.PENDING, None, None)
+
             def execution_block_cb(block):
                 if block.message is not None:
                     mes = {
@@ -577,8 +582,7 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                     cached_outputs.append((True, node_outputs))
             new_node_ids = set(new_node_ids)
             for cache in caches.all:
-                subcache = await cache.ensure_subcache_for(unique_id, new_node_ids)
+                await cache.ensure_subcache_for(unique_id, new_node_ids)
-                subcache.clean_unused()
             for node_id in new_output_ids:
                 execution_list.add_node(node_id)
                 execution_list.cache_link(node_id, unique_id)
@@ -703,25 +707,16 @@ class PromptExecutor:
             dynamic_prompt = DynamicPrompt(prompt)
             reset_progress_state(prompt_id, dynamic_prompt)
             add_progress_handler(WebUIProgressHandler(self.server))
-            is_changed_cache = IsChangedCache(prompt_id, dynamic_prompt, self.caches.outputs)
+            execution_list = ExecutionList(dynamic_prompt, self.caches.outputs)
+            is_changed = IsChanged(prompt_id, dynamic_prompt, execution_list, extra_data)
             for cache in self.caches.all:
-                await cache.set_prompt(dynamic_prompt, prompt.keys(), is_changed_cache)
+                await cache.set_prompt(dynamic_prompt, prompt.keys(), is_changed)
-                cache.clean_unused()
-
-            cached_nodes = []
-            for node_id in prompt:
-                if self.caches.outputs.get(node_id) is not None:
-                    cached_nodes.append(node_id)
 
             comfy.model_management.cleanup_models_gc()
-            self.add_message("execution_cached",
-                          { "nodes": cached_nodes, "prompt_id": prompt_id},
-                          broadcast=False)
             pending_subgraph_results = {}
             pending_async_nodes = {} # TODO - Unify this with pending_subgraph_results
             ui_node_outputs = {}
             executed = set()
-            execution_list = ExecutionList(dynamic_prompt, self.caches.outputs)
             current_outputs = self.caches.outputs.all_node_ids()
             for node_id in list(execute_outputs):
                 execution_list.add_node(node_id)
@@ -759,7 +754,9 @@ class PromptExecutor:
             self.server.last_node_id = None
             if comfy.model_management.DISABLE_SMART_MEMORY:
                 comfy.model_management.unload_all_models()
-
+            
+            for cache in self.caches.all:
+                cache.clean_unused()
 
 async def validate_inputs(prompt_id, prompt, item, validated):
     unique_id = item

tests/execution/test_execution.py

@@ -552,27 +552,50 @@ class TestExecution:
         assert len(images1) == 1, "Should have 1 image"
         assert len(images2) == 1, "Should have 1 image"
 
-    # This tests that only constant outputs are used in the call to `IS_CHANGED`
+    def test_is_changed_passed_cached_outputs(self, client: ComfyClient, builder: GraphBuilder, server):
-    def test_is_changed_with_outputs(self, client: ComfyClient, builder: GraphBuilder, server):
         g = builder
         input1 = g.node("StubConstantImage", value=0.5, height=512, width=512, batch_size=1)
-        test_node = g.node("TestIsChangedWithConstants", image=input1.out(0), value=0.5)
+        test_node = g.node("TestIsChangedWithAllInputs", image=input1.out(0), value=0.5)
-
         output = g.node("PreviewImage", images=test_node.out(0))
 
-        result = client.run(g)
+        result1 = client.run(g)
-        images = result.get_images(output)
+        images = result1.get_images(output)
         assert len(images) == 1, "Should have 1 image"
         assert numpy.array(images[0]).min() == 63 and numpy.array(images[0]).max() == 63, "Image should have value 0.25"
 
-        result = client.run(g)
+        result2 = client.run(g)
-        images = result.get_images(output)
+        images = result2.get_images(output)
         assert len(images) == 1, "Should have 1 image"
         assert numpy.array(images[0]).min() == 63 and numpy.array(images[0]).max() == 63, "Image should have value 0.25"
+        
         if server["should_cache_results"]:
-            assert not result.did_run(test_node), "The execution should have been cached"
+            assert not result2.did_run(test_node), "Test node should not have run again"
         else:
-            assert result.did_run(test_node), "The execution should have been re-run"
+            assert result2.did_run(test_node), "Test node should always run here"
+
+    def test_dont_always_run_downstream(self, client: ComfyClient, builder: GraphBuilder, server):
+        g = builder
+        float1 = g.node("TestDontAlwaysRunDownstream", float=0.5) # IS_CHANGED returns float("NaN")
+        image1 = g.node("StubConstantImage", value=float1.out(0), height=512, width=512, batch_size=1)
+        output = g.node("PreviewImage", images=image1.out(0))
+
+        result1 = client.run(g)
+        images = result1.get_images(output)
+        assert len(images) == 1, "Should have 1 image"
+        assert numpy.array(images[0]).min() == 127 and numpy.array(images[0]).max() == 127, "Image should have value 0.50"
+
+        result2 = client.run(g)
+        images = result2.get_images(output)
+        assert len(images) == 1, "Should have 1 image"
+        assert numpy.array(images[0]).min() == 127 and numpy.array(images[0]).max() == 127, "Image should have value 0.50"
+
+        assert result2.did_run(float1), "Float node should always run"
+        if server["should_cache_results"]:
+            assert not result2.did_run(image1), "Image node should not have run again"
+            assert not result2.did_run(output), "Output node should not have run again"
+        else:
+            assert result2.did_run(image1), "Image node should have run again"
+            assert result2.did_run(output), "Output node should have run again"
 
 
     def test_parallel_sleep_nodes(self, client: ComfyClient, builder: GraphBuilder, skip_timing_checks):

tests/execution/testing_nodes/testing-pack/specific_tests.py

@@ -100,7 +100,7 @@ class TestCustomIsChanged:
         else:
             return False
 
-class TestIsChangedWithConstants:
+class TestIsChangedWithAllInputs:
     @classmethod
     def INPUT_TYPES(cls):
         return {
@@ -120,10 +120,29 @@ class TestIsChangedWithConstants:
 
     @classmethod
     def IS_CHANGED(cls, image, value):
-        if image is None:
+        # if image is None then an exception is thrown and is_changed becomes float("NaN")
-            return value
+        return image.mean().item() * value
-        else:
+    
-            return image.mean().item() * value
+class TestDontAlwaysRunDownstream:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "float": ("FLOAT",),
+            },
+        }
+    
+    RETURN_TYPES = ("FLOAT",)
+    FUNCTION = "always_run"
+
+    CATEGORY = "Testing/Nodes"
+
+    def always_run(self, float):
+        return (float,)
+    
+    @classmethod
+    def IS_CHANGED(cls, *args, **kwargs):
+        return float("NaN")
 
 class TestCustomValidation1:
     @classmethod
@@ -486,7 +505,8 @@ TEST_NODE_CLASS_MAPPINGS = {
     "TestLazyMixImages": TestLazyMixImages,
     "TestVariadicAverage": TestVariadicAverage,
     "TestCustomIsChanged": TestCustomIsChanged,
-    "TestIsChangedWithConstants": TestIsChangedWithConstants,
+    "TestIsChangedWithAllInputs": TestIsChangedWithAllInputs,
+    "TestDontAlwaysRunDownstream": TestDontAlwaysRunDownstream,
     "TestCustomValidation1": TestCustomValidation1,
     "TestCustomValidation2": TestCustomValidation2,
     "TestCustomValidation3": TestCustomValidation3,
@@ -504,7 +524,8 @@ TEST_NODE_DISPLAY_NAME_MAPPINGS = {
     "TestLazyMixImages": "Lazy Mix Images",
     "TestVariadicAverage": "Variadic Average",
     "TestCustomIsChanged": "Custom IsChanged",
-    "TestIsChangedWithConstants": "IsChanged With Constants",
+    "TestIsChangedWithAllInputs": "IsChanged With All Inputs",
+    "TestDontAlwaysRunDownstream": "Dont Always Run Downstream",
     "TestCustomValidation1": "Custom Validation 1",
     "TestCustomValidation2": "Custom Validation 2",
     "TestCustomValidation3": "Custom Validation 3",