ComfyUI/comfy/graph_utils.py
Jacob Segal b234baee2c Add lazy evaluation and dynamic node expansion
This PR inverts the execution model -- from recursively calling nodes to
using a topological sort of the nodes. This change allows for
modification of the node graph during execution. This allows for two
major advantages:
1. The implementation of lazy evaluation in nodes. For example, if a
   "Mix Images" node has a mix factor of exactly 0.0, the second image
   input doesn't even need to be evaluated (and visa-versa if the mix
   factor is 1.0).
2. Dynamic expansion of nodes. This allows for the creation of dynamic
   "node groups". Specifically, custom nodes can return subgraphs that
   replace the original node in the graph. This is an *incredibly*
   powerful concept. Using this functionality, it was easy to
   implement:
   a. Components (a.k.a. node groups)
   b. Flow control (i.e. while loops) via tail recursion
   c. All-in-one nodes that replicate the WebUI functionality
   d. and more
All of those were able to be implemented entirely via custom nodes
without hooking or replacing any core functionality. Within this PR,
I've included all of these proof-of-concepts within a custom node pack.
In reality, I would expect some number of them to be merged into the
core node set (with the rest left to be implemented by custom nodes).

I made very few changes to the front-end, so there are probably some
easy UX wins for someone who is more willing to wade into .js land. The
user experience is a lot better than I expected though -- progress shows
correctly in the UI over the nodes that are being expanded.
2023-07-18 20:08:12 -07:00

105 lines
3.2 KiB
Python

import json
import random
# The GraphBuilder is just a utility class that outputs graphs in the form expected by the ComfyUI back-end
class GraphBuilder:
def __init__(self, prefix = True):
if isinstance(prefix, str):
self.prefix = prefix
elif prefix:
self.prefix = "%d.%d." % (random.randint(0, 0xffffffffffffffff), random.randint(0, 0xffffffffffffffff))
else:
self.prefix = ""
self.nodes = {}
self.id_gen = 1
def node(self, class_type, id=None, **kwargs):
if id is None:
id = str(self.id_gen)
self.id_gen += 1
id = self.prefix + id
if id in self.nodes:
return self.nodes[id]
node = Node(id, class_type, kwargs)
self.nodes[id] = node
return node
def lookup_node(self, id):
id = self.prefix + id
return self.nodes.get(id)
def finalize(self):
output = {}
for node_id, node in self.nodes.items():
output[node_id] = node.serialize()
return output
def replace_node_output(self, node_id, index, new_value):
node_id = self.prefix + node_id
to_remove = []
for node in self.nodes.values():
for key, value in node.inputs.items():
if isinstance(value, list) and value[0] == node_id and value[1] == index:
if new_value is None:
to_remove.append((node, key))
else:
node.inputs[key] = new_value
for node, key in to_remove:
del node.inputs[key]
def remove_node(self, id):
id = self.prefix + id
del self.nodes[id]
class Node:
def __init__(self, id, class_type, inputs):
self.id = id
self.class_type = class_type
self.inputs = inputs
def out(self, index):
return [self.id, index]
def set_input(self, key, value):
if value is None:
if key in self.inputs:
del self.inputs[key]
else:
self.inputs[key] = value
def get_input(self, key):
return self.inputs.get(key)
def serialize(self):
return {
"class_type": self.class_type,
"inputs": self.inputs
}
def add_graph_prefix(graph, outputs, prefix):
# Change the node IDs and any internal links
new_graph = {}
for node_id, node_info in graph.items():
# Make sure the added nodes have unique IDs
new_node_id = prefix + node_id
new_node = { "class_type": node_info["class_type"], "inputs": {} }
for input_name, input_value in node_info.get("inputs", {}).items():
if isinstance(input_value, list):
new_node["inputs"][input_name] = [prefix + input_value[0], input_value[1]]
else:
new_node["inputs"][input_name] = input_value
new_graph[new_node_id] = new_node
# Change the node IDs in the outputs
new_outputs = []
for n in range(len(outputs)):
output = outputs[n]
if isinstance(output, list): # This is a node link
new_outputs.append([prefix + output[0], output[1]])
else:
new_outputs.append(output)
return new_graph, tuple(new_outputs)