chore: import upstream snapshot with attribution

invokeai/backend/model_manager/metadata/fetch/fetch_base.py

@@ -0,0 +1,68 @@
+# Copyright (c) 2023 Lincoln D. Stein and the InvokeAI Development Team
+
+"""
+This module is the base class for subclasses that fetch metadata from model repositories
+
+Usage:
+
+from invokeai.backend.model_manager.metadata.fetch import HuggingFaceMetadataFetch
+
+data = HuggingFaceMetadataFetch().from_id("<REPO_ID>")
+assert isinstance(data, HuggingFaceMetadata)
+"""
+
+from abc import ABC, abstractmethod
+from typing import Optional
+
+from pydantic.networks import AnyHttpUrl
+from requests.sessions import Session
+
+from invokeai.backend.model_manager.metadata.metadata_base import (
+    AnyModelRepoMetadata,
+    AnyModelRepoMetadataValidator,
+    BaseMetadata,
+)
+from invokeai.backend.model_manager.taxonomy import ModelRepoVariant
+
+
+class ModelMetadataFetchBase(ABC):
+    """Fetch metadata from remote generative model repositories."""
+
+    @abstractmethod
+    def __init__(self, session: Optional[Session] = None):
+        """
+        Initialize the fetcher with an optional requests.sessions.Session object.
+
+        By providing a configurable Session object, we can support unit tests on
+        this module without an internet connection.
+        """
+        pass
+
+    @abstractmethod
+    def from_url(self, url: AnyHttpUrl) -> AnyModelRepoMetadata:
+        """
+        Given a URL to a model repository, return a ModelMetadata object.
+
+        This method will raise a `UnknownMetadataException`
+        in the event that the requested model metadata is not found at the provided location.
+        """
+        pass
+
+    @abstractmethod
+    def from_id(self, id: str, variant: Optional[ModelRepoVariant] = None) -> AnyModelRepoMetadata:
+        """
+        Given an ID for a model, return a ModelMetadata object.
+
+        :param id: An ID.
+        :param variant: A model variant from the ModelRepoVariant enum.
+
+        This method will raise a `UnknownMetadataException`
+        in the event that the requested model's metadata is not found at the provided id.
+        """
+        pass
+
+    @classmethod
+    def from_json(cls, json: str) -> AnyModelRepoMetadata:
+        """Given the JSON representation of the metadata, return the corresponding Pydantic object."""
+        metadata: BaseMetadata = AnyModelRepoMetadataValidator.validate_json(json)  # type: ignore
+        return metadata