70 KiB
Introduction to the Model Manager V2
The Model Manager is responsible for organizing the various machine learning models used by InvokeAI. It consists of a series of interdependent services that together handle the full lifecycle of a model. These are the:
-
ModelRecordServiceBase Responsible for managing model metadata and configuration information. Among other things, the record service tracks the type of the model, its provenance, and where it can be found on disk.
-
ModelInstallServiceBase A service for installing models to disk. It uses
DownloadQueueServiceBase
to download models and their metadata, andModelRecordServiceBase
to store that information. It is also responsible for managing the InvokeAImodels
directory and its contents. -
ModelMetadataStore and ModelMetaDataFetch Backend modules that are able to retrieve metadata from online model repositories, transform them into Pydantic models, and cache them to the InvokeAI SQL database.
-
DownloadQueueServiceBase A multithreaded downloader responsible for downloading models from a remote source to disk. The download queue has special methods for downloading repo_id folders from Hugging Face, as well as discriminating among model versions in Civitai, but can be used for arbitrary content.
- ModelLoadServiceBase Responsible for loading a model from disk into RAM and VRAM and getting it ready for inference.
Location of the Code
The four main services can be found in
invokeai/app/services
in the following directories:
invokeai/app/services/model_records/
invokeai/app/services/model_install/
invokeai/app/services/downloads/
invokeai/app/services/model_load/
Code related to the FastAPI web API can be found in
invokeai/app/api/routers/model_manager_v2.py
.
What's in a Model? The ModelRecordService
The ModelRecordService
manages the model's metadata. It supports a
hierarchy of pydantic metadata "config" objects, which become
increasingly specialized to support particular model types.
ModelConfigBase
All model metadata classes inherit from this pydantic class. it provides the following fields:
Field Name | Type | Description |
---|---|---|
key |
str | Unique identifier for the model |
name |
str | Name of the model (not unique) |
model_type |
ModelType | The type of the model |
model_format |
ModelFormat | The format of the model (e.g. "diffusers"); also used as a Union discriminator |
base_model |
BaseModelType | The base model that the model is compatible with |
path |
str | Location of model on disk |
hash |
str | Hash of the model |
description |
str | Human-readable description of the model (optional) |
source |
str | Model's source URL or repo id (optional) |
The key
is a unique 32-character random ID which was generated at
install time. The hash
field stores a hash of the model's
contents at install time obtained by sampling several parts of the
model's files using the imohash
library. Over the course of the
model's lifetime it may be transformed in various ways, such as
changing its precision or converting it from a .safetensors to a
diffusers model.
ModelType
, ModelFormat
and BaseModelType
are string enums that
are defined in invokeai.backend.model_manager.config
. They are also
imported by, and can be reexported from,
invokeai.app.services.model_manager.model_records
:
from invokeai.app.services.model_records import ModelType, ModelFormat, BaseModelType
The path
field can be absolute or relative. If relative, it is taken
to be relative to the models_dir
setting in the user's
invokeai.yaml
file.
CheckpointConfig
This adds support for checkpoint configurations, and adds the following field:
Field Name | Type | Description |
---|---|---|
config |
str | Path to the checkpoint's config file |
config
is the path to the checkpoint's config file. If relative, it
is taken to be relative to the InvokeAI root directory
(e.g. configs/stable-diffusion/v1-inference.yaml
)
MainConfig
This adds support for "main" Stable Diffusion models, and adds these fields:
Field Name | Type | Description |
---|---|---|
vae |
str | Path to a VAE to use instead of the burnt-in one |
variant |
ModelVariantType | Model variant type, such as "inpainting" |
vae
can be an absolute or relative path. If relative, its base is
taken to be the models_dir
directory.
variant
is an enumerated string class with values normal
,
inpaint
and depth
. If needed, it can be imported if needed from
either invokeai.app.services.model_records
or
invokeai.backend.model_manager.config
.
ONNXSD2Config
Field Name | Type | Description |
---|---|---|
prediction_type |
SchedulerPredictionType | Scheduler prediction type to use, e.g. "epsilon" |
upcast_attention |
bool | Model requires its attention module to be upcast |
The SchedulerPredictionType
enum can be imported from either
invokeai.app.services.model_records
or
invokeai.backend.model_manager.config
.
Other config classes
There are a series of such classes each discriminated by their
ModelFormat
, including LoRAConfig
, IPAdapterConfig
, and so
forth. These are rarely needed outside the model manager's internal
code, but available in invokeai.backend.model_manager.config
if
needed. There is also a Union of all ModelConfig classes, called
AnyModelConfig
that can be imported from the same file.
Limitations of the Data Model
The config hierarchy has a major limitation in its handling of the
base model type. Each model can only be compatible with one base
model, which breaks down in the event of models that are compatible
with two or more base models. For example, SD-1 VAEs also work with
SD-2 models. A partial workaround is to use BaseModelType.Any
, which
indicates that the model is compatible with any of the base
models. This works OK for some models, such as the IP Adapter image
encoders, but is an all-or-nothing proposition.
Reading and Writing Model Configuration Records
The ModelRecordService
provides the ability to retrieve model
configuration records from SQL or YAML databases, update them, and
write them back.
A application-wide ModelRecordService
is created during API
initialization and can be retrieved within an invocation from the
InvocationContext
object:
store = context.services.model_manager.store
or from elsewhere in the code by accessing
ApiDependencies.invoker.services.model_manager.store
.
Creating a ModelRecordService
To create a new ModelRecordService
database or open an existing one,
you can directly create either a ModelRecordServiceSQL
or a
ModelRecordServiceFile
object:
from invokeai.app.services.model_records import ModelRecordServiceSQL, ModelRecordServiceFile
store = ModelRecordServiceSQL.from_connection(connection, lock)
store = ModelRecordServiceSQL.from_db_file('/path/to/sqlite_database.db')
store = ModelRecordServiceFile.from_db_file('/path/to/database.yaml')
The from_connection()
form is only available from the
ModelRecordServiceSQL
class, and is used to manage records in a
previously-opened SQLITE3 database using a sqlite3.connection
object
and a threading.lock
object. It is intended for the specific use
case of storing the record information in the main InvokeAI database,
usually databases/invokeai.db
.
The from_db_file()
methods can be used to open new connections to
the named database files. If the file doesn't exist, it will be
created and initialized.
As a convenience, ModelRecordServiceBase
offers two methods,
from_db_file
and open
, which will return either a SQL or File
implementation depending on the context. The former looks at the file
extension to determine whether to open the file as a SQL database
(".db") or as a file database (".yaml"). If the file exists, but is
either the wrong type or does not contain the expected schema
metainformation, then an appropriate AssertionError
will be raised:
store = ModelRecordServiceBase.from_db_file('/path/to/a/file.{yaml,db}')
The ModelRecordServiceBase.open()
method is specifically designed
for use in the InvokeAI web server. Its signature is:
def open(
cls,
config: InvokeAIAppConfig,
conn: Optional[sqlite3.Connection] = None,
lock: Optional[threading.Lock] = None
) -> Union[ModelRecordServiceSQL, ModelRecordServiceFile]:
The way it works is as follows:
- Retrieve the value of the
model_config_db
option from the user'sinvokeai.yaml
config file. - If
model_config_db
isauto
(the default), then:- Use the values of
conn
andlock
to return aModelRecordServiceSQL
object opened on the passed connection and lock. - Open up a new connection to
databases/invokeai.db
ifconn
and/orlock
are missing (see note below).
- Use the values of
- If
model_config_db
is a Path, then usefrom_db_file
to return the appropriate type of ModelRecordService. - If
model_config_db
is None, then retrieve the legacyconf_path
option frominvokeai.yaml
and use the Path indicated there. This will default toconfigs/models.yaml
.
So a typical startup pattern would be:
import sqlite3
from invokeai.app.services.thread import lock
from invokeai.app.services.model_records import ModelRecordServiceBase
from invokeai.app.services.config import InvokeAIAppConfig
config = InvokeAIAppConfig.get_config()
db_conn = sqlite3.connect(config.db_path.as_posix(), check_same_thread=False)
store = ModelRecordServiceBase.open(config, db_conn, lock)
Fetching a Model's Configuration from ModelRecordServiceBase
Configurations can be retrieved in several ways.
get_model(key) -> AnyModelConfig
The basic functionality is to call the record store object's
get_model()
method with the desired model's unique key. It returns
the appropriate subclass of ModelConfigBase:
model_conf = store.get_model('f13dd932c0c35c22dcb8d6cda4203764')
print(model_conf.path)
>> '/tmp/models/ckpts/v1-5-pruned-emaonly.safetensors'
If the key is unrecognized, this call raises an
UnknownModelException
.
exists(key) -> AnyModelConfig
Returns True if a model with the given key exists in the databsae.
search_by_path(path) -> AnyModelConfig
Returns the configuration of the model whose path is path
. The path
is matched using a simple string comparison and won't correctly match
models referred to by different paths (e.g. using symbolic links).
search_by_name(name, base, type) -> List[AnyModelConfig]
This method searches for models that match some combination of name
,
BaseType
and ModelType
. Calling without any arguments will return
all the models in the database.
all_models() -> List[AnyModelConfig]
Return all the model configs in the database. Exactly equivalent to
calling search_by_name()
with no arguments.
search_by_tag(tags) -> List[AnyModelConfig]
tags
is a list of strings. This method returns a list of model
configs that contain all of the given tags. Examples:
# find all models that are marked as both SFW and as generating
# background scenery
configs = store.search_by_tag(['sfw', 'scenery'])
Note that only tags are not searchable in this way. Other fields can be searched using a filter:
commercializable_models = [x for x in store.all_models() \
if x.license.contains('allowCommercialUse=Sell')]
version() -> str
Returns the version of the database, currently at 3.2
model_info_by_name(name, base_model, model_type) -> ModelConfigBase
This method exists to ease the transition from the previous version of
the model manager, in which get_model()
took the three arguments
shown above. This looks for a unique model identified by name, base
model and model type and returns it.
The method will generate a DuplicateModelException
if there are more
than one models that share the same type, base and name. While
unlikely, it is certainly possible to have a situation in which the
user had added two models with the same name, base and type, one
located at path /foo/my_model
and the other at /bar/my_model
. It
is strongly recommended to search for models using search_by_name()
,
which can return multiple results, and then to select the desired
model and pass its key to get_model()
.
Writing model configs to the database
Several methods allow you to create and update stored model config records.
add_model(key, config) -> AnyModelConfig
Given a key and a configuration, this will add the model's
configuration record to the database. config
can either be a subclass of
ModelConfigBase
(i.e. any class listed in AnyModelConfig
), or a
dict
of key/value pairs. In the latter case, the correct
configuration class will be picked by Pydantic's discriminated union
mechanism.
If successful, the method will return the appropriate subclass of
ModelConfigBase
. It will raise a DuplicateModelException
if a
model with the same key is already in the database, or an
InvalidModelConfigException
if a dict was passed and Pydantic
experienced a parse or validation error.
update_model(key, config) -> AnyModelConfig
Given a key and a configuration, this will update the model
configuration record in the database. config
can be either a
instance of ModelConfigBase
, or a sparse dict
containing the
fields to be updated. This will return an AnyModelConfig
on success,
or raise InvalidModelConfigException
or UnknownModelException
exceptions on failure.
Model installation
The ModelInstallService
class implements the
ModelInstallServiceBase
abstract base class, and provides a one-stop
shop for all your model install needs. It provides the following
functionality:
-
Registering a model config record for a model already located on the local filesystem, without moving it or changing its path.
-
Installing a model alreadiy located on the local filesystem, by moving it into the InvokeAI root directory under the
models
folder (or wherever config parametermodels_dir
specifies). -
Probing of models to determine their type, base type and other key information.
-
Interface with the InvokeAI event bus to provide status updates on the download, installation and registration process.
-
Downloading a model from an arbitrary URL and installing it in
models_dir
. -
Special handling for Civitai model URLs which allow the user to paste in a model page's URL or download link
-
Special handling for HuggingFace repo_ids to recursively download the contents of the repository, paying attention to alternative variants such as fp16.
-
Saving tags and other metadata about the model into the invokeai database when fetching from a repo that provides that type of information, (currently only Civitai and HuggingFace).
Initializing the installer
A default installer is created at InvokeAI api startup time and stored
in ApiDependencies.invoker.services.model_install
and can
also be retrieved from an invocation's context
argument with
context.services.model_install
.
In the event you wish to create a new installer, you may use the following initialization pattern:
from invokeai.app.services.config import InvokeAIAppConfig
from invokeai.app.services.model_records import ModelRecordServiceSQL
from invokeai.app.services.model_install import ModelInstallService
from invokeai.app.services.download import DownloadQueueService
from invokeai.app.services.shared.sqlite import SqliteDatabase
from invokeai.backend.util.logging import InvokeAILogger
config = InvokeAIAppConfig.get_config()
config.parse_args()
logger = InvokeAILogger.get_logger(config=config)
db = SqliteDatabase(config, logger)
record_store = ModelRecordServiceSQL(db)
queue = DownloadQueueService()
queue.start()
installer = ModelInstallService(app_config=config,
record_store=record_store,
download_queue=queue
)
installer.start()
The full form of ModelInstallService()
takes the following
required parameters:
Argument | Type | Description |
---|---|---|
app_config |
InvokeAIAppConfig | InvokeAI app configuration object |
record_store |
ModelRecordServiceBase | Config record storage database |
download_queue |
DownloadQueueServiceBase | Download queue object |
metadata_store |
Optional[ModelMetadataStore] | Metadata storage object |
session |
Optional[requests.Session] | Swap in a different Session object (usually for debugging) |
Once initialized, the installer will provide the following methods:
install_job = installer.heuristic_import(source, [config], [access_token])
This is a simplified interface to the installer which takes a source string, an optional model configuration dictionary and an optional access token.
The source
is a string that can be any of these forms
- A path on the local filesystem (
C:\\users\\fred\\model.safetensors
) - A Url pointing to a single downloadable model file (
https://civitai.com/models/58390/detail-tweaker-lora-lora
) - A HuggingFace repo_id with any of the following formats:
model/name
-- entire modelmodel/name:fp32
-- entire model, using the fp32 variantmodel/name:fp16:vae
-- vae submodel, using the fp16 variantmodel/name::vae
-- vae submodel, using default precisionmodel/name:fp16:path/to/model.safetensors
-- an individual model file, fp16 variantmodel/name::path/to/model.safetensors
-- an individual model file, default variant
Note that by specifying a relative path to the top of the HuggingFace repo, you can download and install arbitrary models files.
The variant, if not provided, will be automatically filled in with
fp32
if the user has requested full precision, and fp16
otherwise. If a variant that does not exist is requested, then the
method will install whatever HuggingFace returns as its default
revision.
config
is an optional dict of values that will override the
autoprobed values for model type, base, scheduler prediction type, and
so forth. See Model configuration and
probing for details.
access_token
is an optional access token for accessing resources
that need authentication.
The method will return a ModelInstallJob
. This object is discussed
at length in the following section.
install_job = installer.import_model()
The import_model()
method is the core of the installer. The
following illustrates basic usage:
from invokeai.app.services.model_install import (
LocalModelSource,
HFModelSource,
URLModelSource,
)
source1 = LocalModelSource(path='/opt/models/sushi.safetensors') # a local safetensors file
source2 = LocalModelSource(path='/opt/models/sushi_diffusers') # a local diffusers folder
source3 = HFModelSource(repo_id='runwayml/stable-diffusion-v1-5') # a repo_id
source4 = HFModelSource(repo_id='runwayml/stable-diffusion-v1-5', subfolder='vae') # a subfolder within a repo_id
source5 = HFModelSource(repo_id='runwayml/stable-diffusion-v1-5', variant='fp16') # a named variant of a HF model
source6 = HFModelSource(repo_id='runwayml/stable-diffusion-v1-5', subfolder='OrangeMix/OrangeMix1.ckpt') # path to an individual model file
source7 = URLModelSource(url='https://civitai.com/api/download/models/63006') # model located at a URL
source8 = URLModelSource(url='https://civitai.com/api/download/models/63006', access_token='letmein') # with an access token
for source in [source1, source2, source3, source4, source5, source6, source7]:
install_job = installer.install_model(source)
source2job = installer.wait_for_installs(timeout=120)
for source in sources:
job = source2job[source]
if job.complete:
model_config = job.config_out
model_key = model_config.key
print(f"{source} installed as {model_key}")
elif job.errored:
print(f"{source}: {job.error_type}.\nStack trace:\n{job.error}")
As shown here, the import_model()
method accepts a variety of
sources, including local safetensors files, local diffusers folders,
HuggingFace repo_ids with and without a subfolder designation,
Civitai model URLs and arbitrary URLs that point to checkpoint files
(but not to folders).
Each call to import_model()
return a ModelInstallJob
job,
an object which tracks the progress of the install.
If a remote model is requested, the model's files are downloaded in
parallel across a multiple set of threads using the download
queue. During the download process, the ModelInstallJob
is updated
to provide status and progress information. After the files (if any)
are downloaded, the remainder of the installation runs in a single
serialized background thread. These are the model probing, file
copying, and config record database update steps.
Multiple install jobs can be queued up. You may block until all
install jobs are completed (or errored) by calling the
wait_for_installs()
method as shown in the code
example. wait_for_installs()
will return a dict
that maps the
requested source to its job. This object can be interrogated
to determine its status. If the job errored out, then the error type
and details can be recovered from job.error_type
and job.error
.
The full list of arguments to import_model()
is as follows:
Argument | Type | Default | Description |
---|---|---|---|
source |
ModelSource | None | The source of the model, Path, URL or repo_id |
config |
Dict[str, Any] | None | Override all or a portion of model's probed attributes |
The next few sections describe the various types of ModelSource that
can be passed to import_model()
.
config
can be used to override all or a portion of the configuration
attributes returned by the model prober. See the section below for
details.
LocalModelSource
This is used for a model that is located on a locally-accessible Posix filesystem, such as a local disk or networked fileshare.
Argument | Type | Default | Description |
---|---|---|---|
path |
str | Path | None |
inplace |
bool | False | If set, the model file(s) will be left in their location; otherwise they will be copied into the InvokeAI root's models directory |
URLModelSource
This is used for a single-file model that is accessible via a URL. The fields are:
Argument | Type | Default | Description |
---|---|---|---|
url |
AnyHttpUrl | None | The URL for the model file. |
access_token |
str | None | An access token needed to gain access to this file. |
The AnyHttpUrl
class can be imported from pydantic.networks
.
Ordinarily, no metadata is retrieved from these sources. However, there is special-case code in the installer that looks for HuggingFace and Civitai URLs and fetches the corresponding model metadata from the corresponding repo.
HFModelSource
HuggingFace has the most complicated ModelSource
structure:
Argument | Type | Default | Description |
---|---|---|---|
repo_id |
str | None | The ID of the desired model. |
variant |
ModelRepoVariant | ModelRepoVariant('fp16') | The desired variant. |
subfolder |
Path | None | Look for the model in a subfolder of the repo. |
access_token |
str | None | An access token needed to gain access to a subscriber's-only model. |
The repo_id
is the repository ID, such as stabilityai/sdxl-turbo
.
The variant
is one of the various diffusers formats that HuggingFace
supports and is used to pick out from the hodgepodge of files that in
a typical HuggingFace repository the particular components needed for
a complete diffusers model. ModelRepoVariant
is an enum that can be
imported from invokeai.backend.model_manager
and has the following
values:
Name | String Value |
---|---|
ModelRepoVariant.DEFAULT | "default" |
ModelRepoVariant.FP16 | "fp16" |
ModelRepoVariant.FP32 | "fp32" |
ModelRepoVariant.ONNX | "onnx" |
ModelRepoVariant.OPENVINO | "openvino" |
ModelRepoVariant.FLAX | "flax" |
You can also pass the string forms to variant
directly. Note that
InvokeAI may not be able to load and run all variants. At the current
time, specifying ModelRepoVariant.DEFAULT
will retrieve model files
that are unqualified, e.g. pytorch_model.safetensors
rather than
pytorch_model.fp16.safetensors
. These are usually the 32-bit
safetensors forms of the model.
If subfolder
is specified, then the requested model resides in a
subfolder of the main model repository. This is typically used to
fetch and install VAEs.
Some models require you to be registered with HuggingFace and logged
in. To download these files, you must provide an
access_token
. Internally, if no access token is provided, then
HfFolder.get_token()
will be called to fill it in with the cached
one.
Monitoring the install job process
When you create an install job with import_model()
, it launches the
download and installation process in the background and returns a
ModelInstallJob
object for monitoring the process.
The ModelInstallJob
class has the following structure:
Attribute | Type | Description |
---|---|---|
id |
int |
Integer ID for this job |
status |
InstallStatus |
An enum of [waiting , downloading , running , completed , error and cancelled ] |
config_in |
dict |
Overriding configuration values provided by the caller |
config_out |
AnyModelConfig |
After successful completion, contains the configuration record written to the database |
inplace |
boolean |
True if the caller asked to install the model in place using its local path |
source |
ModelSource |
The local path, remote URL or repo_id of the model to be installed |
local_path |
Path |
If a remote model, holds the path of the model after it is downloaded; if a local model, same as source |
error_type |
str |
Name of the exception that led to an error status |
error |
str |
Traceback of the error |
If the event_bus
argument was provided, events will also be
broadcast to the InvokeAI event bus. The events will appear on the bus
as an event of type EventServiceBase.model_event
, a timestamp and
the following event names:
model_install_downloading
For remote models only, model_install_downloading
events will be issued at regular
intervals as the download progresses. The event's payload contains the
following keys:
Key | Type | Description |
---|---|---|
source |
str | String representation of the requested source |
local_path |
str | String representation of the path to the downloading model (usually a temporary directory) |
bytes |
int | How many bytes downloaded so far |
total_bytes |
int | Total size of all the files that make up the model |
parts |
List[Dict] | Information on the progress of the individual files that make up the model |
The parts is a list of dictionaries that give information on each of
the components pieces of the download. The dictionary's keys are
source
, local_path
, bytes
and total_bytes
, and correspond to
the like-named keys in the main event.
Note that downloading events will not be issued for local models, and that downloading events occur before the running event.
model_install_running
model_install_running
is issued when all the required downloads have completed (if applicable) and the
model probing, copying and registration process has now started.
The payload will contain the key source
.
model_install_completed
model_install_completed
is issued once at the end of a successful
installation. The payload will contain the keys source
,
total_bytes
and key
, where key
is the ID under which the model
has been registered.
model_install_error
model_install_error
is emitted if the installation process fails for
some reason. The payload will contain the keys source
, error_type
and error
. error_type
is a short message indicating the nature of
the error, and error
is the long traceback to help debug the
problem.
model_install_cancelled
model_install_cancelled
is issued if the model installation is
cancelled, or if one or more of its files' downloads are
cancelled. The payload will contain source
.
Following the model status
You may poll the ModelInstallJob
object returned by import_model()
to ascertain the state of the install. The job status can be read from
the job's status
attribute, an InstallStatus
enum which has the
enumerated values WAITING
, DOWNLOADING
, RUNNING
, COMPLETED
,
ERROR
and CANCELLED
.
For convenience, install jobs also provided the following boolean
properties: waiting
, downloading
, running
, complete
, errored
and cancelled
, as well as in_terminal_state
. The last will return
True if the job is in the complete, errored or cancelled states.
Model configuration and probing
The install service uses the invokeai.backend.model_manager.probe
module during import to determine the model's type, base type, and
other configuration parameters. Among other things, it assigns a
default name and description for the model based on probed
fields.
When downloading remote models is implemented, additional configuration information, such as list of trigger terms, will be retrieved from the HuggingFace and Civitai model repositories.
The probed values can be overriden by providing a dictionary in the
optional config
argument passed to import_model()
. You may provide
overriding values for any of the model's configuration
attributes. Here is an example of setting the
SchedulerPredictionType
and name
for an sd-2 model:
install_job = installer.import_model(
source=HFModelSource(repo_id='stabilityai/stable-diffusion-2-1',variant='fp32'),
config=dict(
prediction_type=SchedulerPredictionType('v_prediction')
name='stable diffusion 2 base model',
)
)
Other installer methods
This section describes additional methods provided by the installer class.
jobs = installer.wait_for_installs([timeout])
Block until all pending installs are completed or errored and then
returns a list of completed jobs. The optional timeout
argument will
return from the call if jobs aren't completed in the specified
time. An argument of 0 (the default) will block indefinitely.
jobs = installer.wait_for_job(job, [timeout])
Like wait_for_installs()
, but block until a specific job has
completed or errored, and then return the job. The optional timeout
argument will return from the call if the job doesn't complete in the
specified time. An argument of 0 (the default) will block
indefinitely.
jobs = installer.list_jobs()
Return a list of all active and complete ModelInstallJobs
.
jobs = installer.get_job_by_source(source)
Return a list of ModelInstallJob
corresponding to the indicated
model source.
jobs = installer.get_job_by_id(id)
Return a list of ModelInstallJob
corresponding to the indicated
model id.
jobs = installer.cancel_job(job)
Cancel the indicated job.
installer.prune_jobs
Remove jobs that are in a terminal state (i.e. complete, errored or
cancelled) from the job list returned by list_jobs()
and
get_job()
.
installer.app_config, installer.record_store, installer.event_bus
Properties that provide access to the installer's InvokeAIAppConfig
,
ModelRecordServiceBase
and EventServiceBase
objects.
key = installer.register_path(model_path, config), key = installer.install_path(model_path, config)
These methods bypass the download queue and directly register or install the model at the indicated path, returning the unique ID for the installed model.
Both methods accept a Path object corresponding to a checkpoint or diffusers folder, and an optional dict of config attributes to use to override the values derived from model probing.
The difference between register_path()
and install_path()
is that
the former creates a model configuration record without changing the
location of the model in the filesystem. The latter makes a copy of
the model inside the InvokeAI models directory before registering
it.
installer.unregister(key)
This will remove the model config record for the model at key, and is
equivalent to installer.record_store.del_model(key)
installer.delete(key)
This is similar to unregister()
but has the additional effect of
conditionally deleting the underlying model file(s) if they reside
within the InvokeAI models directory
installer.unconditionally_delete(key)
This method is similar to unregister()
, but also unconditionally
deletes the corresponding model weights file(s), regardless of whether
they are inside or outside the InvokeAI models hierarchy.
path = installer.download_and_cache(remote_source, [access_token], [timeout])
This utility routine will download the model file located at source, cache it, and return the path to the cached file. It does not attempt to determine the model type, probe its configuration values, or register it with the models database.
You may provide an access token if the remote source requires
authorization. The call will block indefinitely until the file is
completely downloaded, cancelled or raises an error of some sort. If
you provide a timeout (in seconds), the call will raise a
TimeoutError
exception if the download hasn't completed in the
specified period.
You may use this mechanism to request any type of file, not just a
model. The file will be stored in a subdirectory of
INVOKEAI_ROOT/models/.cache
. If the requested file is found in the
cache, its path will be returned without redownloading it.
Be aware that the models cache is cleared of infrequently-used files
and directories at regular intervals when the size of the cache
exceeds the value specified in Invoke's convert_cache
configuration
variable.
List[str]=installer.scan_directory(scan_dir: Path, install: bool)
This method will recursively scan the directory indicated in
scan_dir
for new models and either install them in the models
directory or register them in place, depending on the setting of
install
(default False).
The return value is the list of keys of the new installed/registered models.
installer.sync_to_config()
This method synchronizes models in the models directory and autoimport
directory to those in the ModelConfigRecordService
database. New
models are registered and orphan models are unregistered.
installer.start(invoker)
The start
method is called by the API intialization routines when
the API starts up. Its effect is to call sync_to_config()
to
synchronize the model record store database with what's currently on
disk.
Get on line: The Download Queue
InvokeAI can download arbitrary files using a multithreaded background
download queue. Internally, the download queue is used for installing
models located at remote locations. The queue is implemented by the
DownloadQueueService
defined in
invokeai.app.services.download_manager
. However, most of the
implementation is spread out among several files in
invokeai/backend/model_manager/download/*
A default download queue is located in
ApiDependencies.invoker.services.download_queue
. However, you can
create additional instances if you need to isolate your queue from the
main one.
A job for every task
The queue operates on a series of download job objects. These objects specify the source and destination of the download, and keep track of the progress of the download. Jobs come in a variety of shapes and colors as they are progressively specialized for particular download task.
The basic job is the DownloadJobBase
, a pydantic object with the
following fields:
Field | Type | Default | Description |
---|---|---|---|
id |
int | Job ID, an integer >= 0 | |
priority |
int | 10 | Job priority. Lower priorities run before higher priorities |
source |
str | Where to download from (specialized types used in subclasses) | |
destination |
Path | Where to download to | |
status |
DownloadJobStatus | Idle | Job's status (see below) |
event_handlers |
List[DownloadEventHandler] | Event handlers (see below) | |
job_started |
float | Timestamp for when the job started running | |
job_ended |
float | Timestamp for when the job completed or errored out | |
job_sequence |
int | A counter that is incremented each time a model is dequeued | |
error |
Exception | A copy of the Exception that caused an error during download |
When you create a job, you can assign it a priority
. If multiple
jobs are queued, the job with the lowest priority runs first. (Don't
blame me! The Unix developers came up with this convention.)
Every job has a source
and a destination
. source
is a string in
the base class, but subclassses redefine it more specifically.
The destination
must be the Path to a file or directory on the local
filesystem. If the Path points to a new or existing file, then the
source will be stored under that filename. If the Path ponts to an
existing directory, then the downloaded file will be stored inside the
directory, usually using the name assigned to it at the remote site in
the content-disposition
http field.
When the job is submitted, it is assigned a numeric id
. The id can
then be used to control the job, such as starting, stopping and
cancelling its download.
The status
field is updated by the queue to indicate where the job
is in its lifecycle. Values are defined in the string enum
DownloadJobStatus
, a symbol available from
invokeai.app.services.download_manager
. Possible values are:
Value | String Value | Description |
---|---|---|
IDLE |
idle | Job created, but not submitted to the queue |
ENQUEUED |
enqueued | Job is patiently waiting on the queue |
RUNNING |
running | Job is running! |
PAUSED |
paused | Job was paused and can be restarted |
COMPLETED |
completed | Job has finished its work without an error |
ERROR |
error | Job encountered an error and will not run again |
CANCELLED |
cancelled | Job was cancelled and will not run (again) |
job_started
, job_ended
and job_sequence
indicate when the job
was started (using a python timestamp), when it completed, and the
order in which it was taken off the queue. These are mostly used for
debugging and performance testing.
In case of an error, the Exception that caused the error will be
placed in the error
field, and the job's status will be set to
DownloadJobStatus.ERROR
.
After an error occurs, any partially downloaded files will be deleted
from disk, unless preserve_partial_downloads
was set to True at job
creation time (or set to True any time before the error
occurred). Note that since all InvokeAI model install operations
involve downloading files to a temporary directory that has a limited
lifetime, this flag is not used by the model installer.
There are a series of subclasses of DownloadJobBase
that provide
support for specific types of downloads. These are:
DownloadJobPath
This subclass redefines source
to be a filesystem Path. It is used
to move a file or directory from the source
to the destination
paths in the background using a uniform event-based infrastructure.
DownloadJobRemoteSource
This subclass adds the following fields to the job:
Field | Type | Default | Description |
---|---|---|---|
bytes |
int | 0 | bytes downloaded so far |
total_bytes |
int | 0 | total size to download |
access_token |
Any | None | an authorization token to present to the remote source |
The job will start out with 0/0 in its bytes/total_bytes fields. Once
it starts running, total_bytes
will be populated from information
provided in the HTTP download header (if available), and the number of
bytes downloaded so far will be progressively incremented.
DownloadJobURL
This is a subclass of DownloadJobBase
. It redefines source
to be a
Pydantic AnyHttpUrl
object, which enforces URL validation checking
on the field.
Note that the installer service defines an additional subclass of
DownloadJobRemoteSource
that accepts HuggingFace repo_ids in
addition to URLs. This is discussed later in this document.
Event handlers
While a job is being downloaded, the queue will emit events at periodic intervals. A typical series of events during a successful download session will look like this:
- enqueued
- running
- running
- running
- completed
There will be a single enqueued event, followed by one or more running
events, and finally one completed
, error
or cancelled
events.
It is possible for a caller to pause download temporarily, in which case the events may look something like this:
- enqueued
- running
- running
- paused
- running
- completed
The download queue logs when downloads start and end (unless quiet
is set to True at initialization time) but doesn't log any progress
events. You will probably want to be alerted to events during the
download job and provide more user feedback. In order to intercept and
respond to events you may install a series of one or more event
handlers in the job. Whenever the job's status changes, the chain of
event handlers is traversed and executed in the same thread that the
download job is running in.
Event handlers have the signature Callable[["DownloadJobBase"], None]
, i.e.
def handler(job: DownloadJobBase):
pass
A typical handler will examine job.status
and decide if there's
something to be done. This can include cancelling or erroring the job,
but more typically is used to report on the job status to the user
interface or to perform certain actions on successful completion of
the job.
Event handlers can be attached to a job at creation time. In addition, you can create a series of default handlers that are attached to the queue object itself. These handlers will be executed for each job after the job's own handlers (if any) have run.
During a download, running events are issued every time roughly 1% of the file is transferred. This is to provide just enough granularity to update a tqdm progress bar smoothly.
Handlers can be added to a job after the fact using the job's
add_event_handler
method:
job.add_event_handler(my_handler)
All handlers can be cleared using the job's clear_event_handlers()
method. Note that it might be a good idea to pause the job before
altering its handlers.
Creating a download queue object
The DownloadQueueService
constructor takes the following arguments:
Argument | Type | Default | Description |
---|---|---|---|
event_handlers |
List[DownloadEventHandler] | [] | Event handlers |
max_parallel_dl |
int | 5 | Maximum number of simultaneous downloads allowed |
requests_session |
requests.sessions.Session | None | An alternative requests Session object to use for the download |
quiet |
bool | False | Do work quietly without issuing log messages |
A typical initialization sequence will look like:
from invokeai.app.services.download_manager import DownloadQueueService
def log_download_event(job: DownloadJobBase):
logger.info(f'job={job.id}: status={job.status}')
queue = DownloadQueueService(
event_handlers=[log_download_event]
)
Event handlers can be provided to the queue at initialization time as shown in the example. These will be automatically appended to the handler list for any job that is submitted to this queue.
max_parallel_dl
sets the number of simultaneous active downloads
that are allowed. The default of five has not been benchmarked in any
way, but seems to give acceptable performance.
requests_session
can be used to provide a requests
module Session
object that will be used to stream remote URLs to disk. This facility
was added for use in the module's unit tests to simulate a remote web
server, but may be useful in other contexts.
quiet
will prevent the queue from issuing any log messages at the
INFO or higher levels.
Submitting a download job
You can submit a download job to the queue either by creating the job
manually and passing it to the queue's submit_download_job()
method,
or using the create_download_job()
method, which will do the same
thing on your behalf.
To use the former method, follow this example:
job = DownloadJobRemoteSource(
source='http://www.civitai.com/models/13456',
destination='/tmp/models/',
event_handlers=[my_handler1, my_handler2], # if desired
)
queue.submit_download_job(job, start=True)
submit_download_job()
takes just two arguments: the job to submit,
and a flag indicating whether to immediately start the job (defaulting
to True). If you choose not to start the job immediately, you can
start it later by calling the queue's start_job()
or
start_all_jobs()
methods, which are described later.
To have the queue create the job for you, follow this example instead:
job = queue.create_download_job(
source='http://www.civitai.com/models/13456',
destdir='/tmp/models/',
filename='my_model.safetensors',
event_handlers=[my_handler1, my_handler2], # if desired
start=True,
)
The filename
argument forces the downloader to use the specified
name for the file rather than the name provided by the remote source,
and is equivalent to manually specifying a destination of
`/tmp/models/my_model.safetensors' in the submitted job.
Here is the full list of arguments that can be provided to
create_download_job()
:
Argument | Type | Default | Description |
---|---|---|---|
source |
Union[str, Path, AnyHttpUrl] | Download remote or local source | |
destdir |
Path | Destination directory for downloaded file | |
filename |
Path | None | Filename for downloaded file |
start |
bool | True | Enqueue the job immediately |
priority |
int | 10 | Starting priority for this job |
access_token |
str | None | Authorization token for this resource |
event_handlers |
List[DownloadEventHandler] | [] | Event handlers for this job |
Internally, create_download_job()
has a little bit of internal logic
that looks at the type of the source and selects the right subclass of
DownloadJobBase
to create and enqueue.
TODO: move this logic into its own method for overriding in subclasses.
Job control
Prior to completion, jobs can be controlled with a series of queue method calls. Do not attempt to modify jobs by directly writing to their fields, as this is likely to lead to unexpected results.
Any method that accepts a job argument may raise an
UnknownJobIDException
if the job has not yet been submitted to the
queue or was not created by this queue.
queue.join()
This method will block until all the active jobs in the queue have reached a terminal state (completed, errored or cancelled).
queue.wait_for_job(job, [timeout])
This method will block until the indicated job has reached a terminal state (completed, errored or cancelled). If the optional timeout is provided, the call will block for at most timeout seconds, and raise a TimeoutError otherwise.
jobs = queue.list_jobs()
This will return a list of all jobs, including ones that have not yet been enqueued and those that have completed or errored out.
job = queue.id_to_job(int)
This method allows you to recover a submitted job using its ID.
queue.prune_jobs()
Remove completed and errored jobs from the job list.
queue.start_job(job)
If the job was submitted with start=False
, then it can be started
using this method.
queue.pause_job(job)
This will temporarily pause the job, if possible. It can later be
restarted and pick up where it left off using queue.start_job()
.
queue.cancel_job(job)
This will cancel the job if possible and clean up temporary files and other resources that it might have been using.
queue.start_all_jobs(), queue.pause_all_jobs(), queue.cancel_all_jobs()
This will start/pause/cancel all jobs that have been submitted to the queue and have not yet reached a terminal state.
This Meta be Good: Model Metadata Storage
The modules found under invokeai.backend.model_manager.metadata
provide a straightforward API for fetching model metadatda from online
repositories. Currently two repositories are supported: HuggingFace
and Civitai. However, the modules are easily extended for additional
repos, provided that they have defined APIs for metadata access.
Metadata comprises any descriptive information that is not essential
for getting the model to run. For example "author" is metadata, while
"type", "base" and "format" are not. The latter fields are part of the
model's config, as defined in invokeai.backend.model_manager.config
.
Example Usage
from invokeai.backend.model_manager.metadata import (
AnyModelRepoMetadata,
CivitaiMetadataFetch,
CivitaiMetadata
ModelMetadataStore,
)
# to access the initialized sql database
from invokeai.app.api.dependencies import ApiDependencies
civitai = CivitaiMetadataFetch()
# fetch the metadata
model_metadata = civitai.from_url("https://civitai.com/models/215796")
# get some common metadata fields
author = model_metadata.author
tags = model_metadata.tags
# get some Civitai-specific fields
assert isinstance(model_metadata, CivitaiMetadata)
trained_words = model_metadata.trained_words
base_model = model_metadata.base_model_trained_on
thumbnail = model_metadata.thumbnail_url
# cache the metadata to the database using the key corresponding to
# an existing model config record in the `model_config` table
sql_cache = ModelMetadataStore(ApiDependencies.invoker.services.db)
sql_cache.add_metadata('fb237ace520b6716adc98bcb16e8462c', model_metadata)
# now we can search the database by tag, author or model name
# matches will contain a list of model keys that match the search
matches = sql_cache.search_by_tag({"tool", "turbo"})
Structure of the Metadata objects
There is a short class hierarchy of Metadata objects, all of which
descend from the Pydantic BaseModel
.
ModelMetadataBase
This is the common base class for metadata:
Field Name | Type | Description |
---|---|---|
name |
str | Repository's name for the model |
author |
str | Model's author |
tags |
Set[str] | Model tags |
Note that the model config record also has a name
field. It is
intended that the config record version be locally customizable, while
the metadata version is read-only. However, enforcing this is expected
to be part of the business logic.
Descendents of the base add additional fields.
HuggingFaceMetadata
This descends from ModelMetadataBase
and adds the following fields:
Field Name | Type | Description |
---|---|---|
type |
Literal["huggingface"] | Used for the discriminated union of metadata classes |
id |
str | HuggingFace repo_id |
tag_dict |
Dict[str, Any] | A dictionary of tag/value pairs provided in addition to tags |
last_modified |
datetime | Date of last commit of this model to the repo |
files |
List[Path] | List of the files in the model repo |
CivitaiMetadata
This descends from ModelMetadataBase
and adds the following fields:
Field Name | Type | Description |
---|---|---|
type |
Literal["civitai"] | Used for the discriminated union of metadata classes |
id |
int | Civitai model id |
version_name |
str | Name of this version of the model (distinct from model name) |
version_id |
int | Civitai model version id (distinct from model id) |
created |
datetime | Date this version of the model was created |
updated |
datetime | Date this version of the model was last updated |
published |
datetime | Date this version of the model was published to Civitai |
description |
str | Model description. Quite verbose and contains HTML tags |
version_description |
str | Model version description, usually describes changes to the model |
nsfw |
bool | Whether the model tends to generate NSFW content |
restrictions |
LicenseRestrictions | An object that describes what is and isn't allowed with this model |
trained_words |
Set[str] | Trigger words for this model, if any |
download_url |
AnyHttpUrl | URL for downloading this version of the model |
base_model_trained_on |
str | Name of the model that this version was trained on |
thumbnail_url |
AnyHttpUrl | URL to access a representative thumbnail image of the model's output |
weight_min |
int | For LoRA sliders, the minimum suggested weight to apply |
weight_max |
int | For LoRA sliders, the maximum suggested weight to apply |
Note that weight_min
and weight_max
are not currently populated
and take the default values of (-1.0, +2.0). The issue is that these
values aren't part of the structured data but appear in the text
description. Some regular expression or LLM coding may be able to
extract these values.
Also be aware that base_model_trained_on
is free text and doesn't
correspond to our ModelType
enum.
CivitaiMetadata
also defines some convenience properties relating to
licensing restrictions: credit_required
, allow_commercial_use
,
allow_derivatives
and allow_different_license
.
AnyModelRepoMetadata
This is a discriminated Union of CivitaiMetadata
and
HuggingFaceMetadata
.
Fetching Metadata from Online Repos
The HuggingFaceMetadataFetch
and CivitaiMetadataFetch
classes will
retrieve metadata from their corresponding repositories and return
AnyModelRepoMetadata
objects. Their base class
ModelMetadataFetchBase
is an abstract class that defines two
methods: from_url()
and from_id()
. The former accepts the type of
model URLs that the user will try to cut and paste into the model
import form. The latter accepts a string ID in the format recognized
by the repository of choice. Both methods return an
AnyModelRepoMetadata
.
The base class also has a class method from_json()
which will take
the JSON representation of a ModelMetadata
object, validate it, and
return the corresponding AnyModelRepoMetadata
object.
When initializing one of the metadata fetching classes, you may
provide a requests.Session
argument. This allows you to customize
the low-level HTTP fetch requests and is used, for instance, in the
testing suite to avoid hitting the internet.
The HuggingFace and Civitai fetcher subclasses add additional repo-specific fetching methods:
HuggingFaceMetadataFetch
This overrides its base class from_json()
method to return a
HuggingFaceMetadata
object directly.
CivitaiMetadataFetch
This adds the following methods:
from_civitai_modelid()
This takes the ID of a model, finds the
default version of the model, and then retrieves the metadata for
that version, returning a CivitaiMetadata
object directly.
from_civitai_versionid()
This takes the ID of a model version and
retrieves its metadata. Functionally equivalent to from_id()
, the
only difference is that it returna a CivitaiMetadata
object rather
than an AnyModelRepoMetadata
.
Metadata Storage
The ModelMetadataStore
provides a simple facility to store model
metadata in the invokeai.db
database. The data is stored as a JSON
blob, with a few common fields (name
, author
, tags
) broken out
to be searchable.
When a metadata object is saved to the database, it is identified
using the model key, and this key must correspond to an existing
model key in the model_config table. There is a foreign key integrity
constraint between the model_config.id
field and the
model_metadata.id
field such that if you attempt to save metadata
under an unknown key, the attempt will result in an
UnknownModelException
. Likewise, when a model is deleted from
model_config
, the deletion of the corresponding metadata record will
be triggered.
Tags are stored in a normalized fashion in the tables model_tags
and
tags
. Triggers keep the tag table in sync with the model_metadata
table.
To create the storage object, initialize it with the InvokeAI
SqliteDatabase
object. This is often done this way:
from invokeai.app.api.dependencies import ApiDependencies
metadata_store = ModelMetadataStore(ApiDependencies.invoker.services.db)
You can then access the storage with the following methods:
add_metadata(key, metadata)
Add the metadata using a previously-defined model key.
There is currently no delete_metadata()
method. The metadata will
persist until the matching config is deleted from the model_config
table.
get_metadata(key) -> AnyModelRepoMetadata
Retrieve the metadata corresponding to the model key.
update_metadata(key, new_metadata)
Update an existing metadata record with new metadata.
search_by_tag(tags: Set[str]) -> Set[str]
Given a set of tags, find models that are tagged with them. If
multiple tags are provided then a matching model must be tagged with
all the tags in the set. This method returns a set of model keys and
is intended to be used in conjunction with the ModelRecordService
:
model_config_store = ApiDependencies.invoker.services.model_records
matches = metadata_store.search_by_tag({'license:other'})
models = [model_config_store.get(x) for x in matches]
`search_by_name(name: str) -> Set[str]
Find all model metadata records that have the given name and return a set of keys to the corresponding model config objects.
`search_by_author(author: str) -> Set[str]
Find all model metadata records that have the given author and return a set of keys to the corresponding model config objects.
The Lowdown on the ModelLoadService
The ModelLoadService
is responsible for loading a named model into
memory so that it can be used for inference. Despite the fact that it
does a lot under the covers, it is very straightforward to use.
An application-wide model loader is created at API initialization time
and stored in
ApiDependencies.invoker.services.model_loader
. However, you can
create alternative instances if you wish.
Creating a ModelLoadService object
The class is defined in
invokeai.app.services.model_load
. It is initialized with
an InvokeAIAppConfig object, from which it gets configuration
information such as the user's desired GPU and precision, and with a
previously-created ModelRecordServiceBase
object, from which it
loads the requested model's configuration information.
Here is a typical initialization pattern:
from invokeai.app.services.config import InvokeAIAppConfig
from invokeai.app.services.model_load import ModelLoadService, ModelLoaderRegistry
config = InvokeAIAppConfig.get_config()
ram_cache = ModelCache(
max_cache_size=config.ram_cache_size, max_vram_cache_size=config.vram_cache_size, logger=logger
)
convert_cache = ModelConvertCache(
cache_path=config.models_convert_cache_path, max_size=config.convert_cache_size
)
loader = ModelLoadService(
app_config=config,
ram_cache=ram_cache,
convert_cache=convert_cache,
registry=ModelLoaderRegistry
)
load_model(model_config, [submodel_type], [context]) -> LoadedModel
The load_model()
method takes an AnyModelConfig
returned by
ModelRecordService.get_model()
and returns the corresponding loaded
model. It loads the model into memory, gets the model ready for use,
and returns a LoadedModel
object.
The optional second argument, subtype
is a SubModelType
string
enum, such as "vae". It is mandatory when used with a main model, and
is used to select which part of the main model to load.
The optional third argument, context
can be provided by
an invocation to trigger model load event reporting. See below for
details.
The returned LoadedModel
object contains a copy of the configuration
record returned by the model record get_model()
method, as well as
the in-memory loaded model:
Attribute Name | Type | Description |
---|---|---|
config |
AnyModelConfig | A copy of the model's configuration record for retrieving base type, etc. |
model |
AnyModel | The instantiated model (details below) |
locker |
ModelLockerBase | A context manager that mediates the movement of the model into VRAM |
Because the loader can return multiple model types, it is typed to
return AnyModel
, a Union ModelMixin
, torch.nn.Module
,
IAIOnnxRuntimeModel
, IPAdapter
, IPAdapterPlus
, and
EmbeddingModelRaw
. ModelMixin
is the base class of all diffusers
models, EmbeddingModelRaw
is used for LoRA and TextualInversion
models. The others are obvious.
LoadedModel
acts as a context manager. The context loads the model
into the execution device (e.g. VRAM on CUDA systems), locks the model
in the execution device for the duration of the context, and returns
the model. Use it like this:
model_info = loader.get_model_by_key('f13dd932c0c35c22dcb8d6cda4203764', SubModelType('vae'))
with model_info as vae:
image = vae.decode(latents)[0]
get_model_by_key()
may raise any of the following exceptions:
UnknownModelException
-- key not in databaseModelNotFoundException
-- key in database but model not found at pathNotImplementedException
-- the loader doesn't know how to load this type of model
Emitting model loading events
When the context
argument is passed to load_model_*()
, it will
retrieve the invocation event bus from the passed InvocationContext
object to emit events on the invocation bus. The two events are
"model_load_started" and "model_load_completed". Both carry the
following payload:
payload=dict(
queue_id=queue_id,
queue_item_id=queue_item_id,
queue_batch_id=queue_batch_id,
graph_execution_state_id=graph_execution_state_id,
model_key=model_key,
submodel_type=submodel,
hash=model_info.hash,
location=str(model_info.location),
precision=str(model_info.precision),
)
Adding Model Loaders
Model loaders are small classes that inherit from the ModelLoader
base class. They typically implement one method _load_model()
whose
signature is:
def _load_model(
self,
model_path: Path,
model_variant: Optional[ModelRepoVariant] = None,
submodel_type: Optional[SubModelType] = None,
) -> AnyModel:
_load_model()
will be passed the path to the model on disk, an
optional repository variant (used by the diffusers loaders to select,
e.g. the fp16
variant, and an optional submodel_type for main and
onnx models.
To install a new loader, place it in
invokeai/backend/model_manager/load/model_loaders
. Inherit from
ModelLoader
and use the @ModelLoaderRegistry.register()
decorator to
indicate what type of models the loader can handle.
Here is a complete example from generic_diffusers.py
, which is able
to load several different diffusers types:
from pathlib import Path
from typing import Optional
from invokeai.backend.model_manager import (
AnyModel,
BaseModelType,
ModelFormat,
ModelRepoVariant,
ModelType,
SubModelType,
)
from .. import ModelLoader, ModelLoaderRegistry
@ModelLoaderRegistry.register(base=BaseModelType.Any, type=ModelType.CLIPVision, format=ModelFormat.Diffusers)
@ModelLoaderRegistry.register(base=BaseModelType.Any, type=ModelType.T2IAdapter, format=ModelFormat.Diffusers)
class GenericDiffusersLoader(ModelLoader):
"""Class to load simple diffusers models."""
def _load_model(
self,
model_path: Path,
model_variant: Optional[ModelRepoVariant] = None,
submodel_type: Optional[SubModelType] = None,
) -> AnyModel:
model_class = self._get_hf_load_class(model_path)
if submodel_type is not None:
raise Exception(f"There are no submodels in models of type {model_class}")
variant = model_variant.value if model_variant else None
result: AnyModel = model_class.from_pretrained(model_path, torch_dtype=self._torch_dtype, variant=variant) # type: ignore
return result
Note that a loader can register itself to handle several different model types. An exception will be raised if more than one loader tries to register the same model type.
Conversion
Some models require conversion to diffusers format before they can be loaded. These loaders should override two additional methods:
_needs_conversion(self, config: AnyModelConfig, model_path: Path, dest_path: Path) -> bool
_convert_model(self, config: AnyModelConfig, model_path: Path, output_path: Path) -> Path:
The first method accepts the model configuration, the path to where
the unmodified model is currently installed, and a proposed
destination for the converted model. This method returns True if the
model needs to be converted. It typically does this by comparing the
last modification time of the original model file to the modification
time of the converted model. In some cases you will also want to check
the modification date of the configuration record, in the event that
the user has changed something like the scheduler prediction type that
will require the model to be re-converted. See controlnet.py
for an
example of this logic.
The second method accepts the model configuration, the path to the
original model on disk, and the desired output path for the converted
model. It does whatever it needs to do to get the model into diffusers
format, and returns the Path of the resulting model. (The path should
ordinarily be the same as output_path
.)
The ModelManagerService object
For convenience, the API provides a ModelManagerService
object which
gives a single point of access to the major model manager
services. This object is created at initialization time and can be
found in the global ApiDependencies.invoker.services.model_manager
object, or in context.services.model_manager
from within an
invocation.
In the examples below, we have retrieved the manager using:
mm = ApiDependencies.invoker.services.model_manager
The following properties and methods will be available:
mm.store
This retrieves the ModelRecordService
associated with the
manager. Example:
configs = mm.store.get_model_by_attr(name='stable-diffusion-v1-5')
mm.install
This retrieves the ModelInstallService
associated with the manager.
Example:
job = mm.install.heuristic_import(`https://civitai.com/models/58390/detail-tweaker-lora-lora`)
mm.load
This retrieves the ModelLoaderService
associated with the manager. Example:
configs = mm.store.get_model_by_attr(name='stable-diffusion-v1-5')
assert len(configs) > 0
loaded_model = mm.load.load_model(configs[0])
The model manager also offers a few convenience shortcuts for loading models:
mm.load_model_by_config(model_config, [submodel], [context]) -> LoadedModel
Same as mm.load.load_model()
.
mm.load_model_by_attr(model_name, base_model, model_type, [submodel], [context]) -> LoadedModel
This accepts the combination of the model's name, type and base, which
it passes to the model record config store for retrieval. If a unique
model config is found, this method returns a LoadedModel
. It can
raise the following exceptions:
UnknownModelException -- model with these attributes not known
NotImplementedException -- the loader doesn't know how to load this type of model
ValueError -- more than one model matches this combination of base/type/name
mm.load_model_by_key(key, [submodel], [context]) -> LoadedModel
This method takes a model key, looks it up using the
ModelRecordServiceBase
object in mm.store
, and passes the returned
model configuration to load_model_by_config()
. It may raise a
NotImplementedException
.