* fix --cuda-device arg for AMD/HIP devices

CUDA_VISIBLE_DEVICES is ignored for HIP devices/backend. Instead it uses HIP_VISIBLE_DEVICES. Setting this environment variable has no side effect for CUDA/NVIDIA so it can safely be set in any case and vice versa.

* deleted accidental if

* Override user directory.

* Use overridden user directory.

* Remove prints.

* Remove references to global user_files.

* Remove unused replace_folder function.

* Remove newline.

* Remove global during get_user_directory.

* Add validation.

* Expand user path.

* Add test.

* Add unit test for expanding base path.

* Simplify unit test.

* Remove comment.

* Remove comment.

* Checkpoints.

* Refactor.

The model_diff input should be connected to the output of a
ModelMergeSubtract node.

* Add route for getting output logs

* Include ComfyUI version

* Move to own function

* Changed to memory logger

* Unify logger setup logic

* Fix get version git fallback

---------

Co-authored-by: pythongosssss <125205205+pythongosssss@users.noreply.github.com>

* Execution Model Inversion

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,
    so those features are *not* a part of this PR. (There are some
    front-end changes that should occur before that functionality is
    made widely available, particularly around variant sockets.)

The custom nodes associated with this PR can be found at:
https://github.com/BadCafeCode/execution-inversion-demo-comfyui

Note that some of them require that variant socket types ("*") be
enabled.

* Allow `input_info` to be of type `None`

* Handle errors (like OOM) more gracefully

* Add a command-line argument to enable variants

This allows the use of nodes that have sockets of type '*' without
applying a patch to the code.

* Fix an overly aggressive assertion.

This could happen when attempting to evaluate `IS_CHANGED` for a node
during the creation of the cache (in order to create the cache key).

* Fix Pyright warnings

* Add execution model unit tests

* Fix issue with unused literals

Behavior should now match the master branch with regard to undeclared
inputs. Undeclared inputs that are socket connections will be used while
undeclared inputs that are literals will be ignored.

* Make custom VALIDATE_INPUTS skip normal validation

Additionally, if `VALIDATE_INPUTS` takes an argument named `input_types`,
that variable will be a dictionary of the socket type of all incoming
connections. If that argument exists, normal socket type validation will
not occur. This removes the last hurdle for enabling variant types
entirely from custom nodes, so I've removed that command-line option.

I've added appropriate unit tests for these changes.

* Fix example in unit test

This wouldn't have caused any issues in the unit test, but it would have
bugged the UI if someone copy+pasted it into their own node pack.

* Use fstrings instead of '%' formatting syntax

* Use custom exception types.

* Display an error for dependency cycles

Previously, dependency cycles that were created during node expansion
would cause the application to quit (due to an uncaught exception). Now,
we'll throw a proper error to the UI. We also make an attempt to 'blame'
the most relevant node in the UI.

* Add docs on when ExecutionBlocker should be used

* Remove unused functionality

* Rename ExecutionResult.SLEEPING to PENDING

* Remove superfluous function parameter

* Pass None for uneval inputs instead of default

This applies to `VALIDATE_INPUTS`, `check_lazy_status`, and lazy values
in evaluation functions.

* Add a test for mixed node expansion

This test ensures that a node that returns a combination of expanded
subgraphs and literal values functions correctly.

* Raise exception for bad get_node calls.

* Minor refactor of IsChangedCache.get

* Refactor `map_node_over_list` function

* Fix ui output for duplicated nodes

* Add documentation on `check_lazy_status`

* Add file for execution model unit tests

* Clean up Javascript code as per review

* Improve documentation

Converted some comments to docstrings as per review

* Add a new unit test for mixed lazy results

This test validates that when an output list is fed to a lazy node, the
node will properly evaluate previous nodes that are needed by any inputs
to the lazy node.

No code in the execution model has been changed. The test already
passes.

* Allow kwargs in VALIDATE_INPUTS functions

When kwargs are used, validation is skipped for all inputs as if they
had been mentioned explicitly.

* List cached nodes in `execution_cached` message

This was previously just bugged in this PR.

* Add model downloading endpoint.

* Move client session init to async function.

* Break up large function.

* Send "download_progress" as websocket event.

* Fixed

* Fixed.

* Use async mock.

* Move server set up to right before run call.

* Validate that model subdirectory cannot contain relative paths.

* Add download_model test checking for invalid paths.

* Remove DS_Store.

* Consolidate DownloadStatus and DownloadModelResult

* Add progress_interval as an optional parameter.

* Use tuple type from annotations.

* Use pydantic.

* Update comment.

* Revert "Use pydantic."

This reverts commit 7461e8eb.

* Add new line.

* Add newline EOF.

* Validate model filename as well.

* Add comment to not reply on internal.

* Restrict downloading to safetensor files only.

Remove code.

* Add --no-custom-node cmd flag

* nit

* Add TLS Support

* Add to readme

* Add guidance for windows users on generating certificates

* Add guidance for windows users on generating certificates

* Fix typo

I think message describes them better.

A POST request to /free with: {"unload_models":true}
will unload models from vram.

A POST request to /free with: {"free_memory":true}
will unload models and free all cached data from the last run workflow.

Add --disable-cuda-malloc to disable it.

feat/startup-script: Feature to avoid package installation errors when installing custom nodes. (#856)

* support startup script for installation without locking on windows

* modified: Instead of executing scripts from the startup-scripts directory, I will change it to execute the prestartup_script.py for each custom node.