feat: introduce asset caching for sqlmesh related assets

apps/docs/docs/contribute-data/dagster.md

@@ -150,3 +150,99 @@ gitcoin_passport_scores = interval_gcs_import_asset(
     ),
 )
 ```
+
+## Creating an asset factory that needs resources
+
+If your asset factory needs resources, to generate the assets you will need to
+use the `EarlyResourcesAssetFactory` class. To do this, you can simply use the
+`@early_resources_asset_factory` decorator. This decorator automatically sets up
+the underlying `EarlyResourcesAssetFactory` instance based on your decorated
+function. The decorated function can also declare the resources it needs by
+annotating the function arguments with the resource types. To get the
+`global_config` resource that uses a class called `DagsterConfig` in your asset
+factory you would just do this:
+
+```python
+import dagster as dg
+from oso_dagster.factories import early_resources_asset_factory
+
+@early_resources_asset_factory()
+def my_asset_factory(
+    global_config: DagsterConfig,
+):
+    @dg.asset
+    def my_asset(context: dg.AssetExecutionContext):
+        # Use the global_config resource to create the asset
+        some_value = global_config.some_setting
+
+        ...
+
+    return AssetFactoryResponse(
+        assets=assets
+    )
+```
+
+This can be useful in many cases where you need to preprocess before the assets
+are loaded.
+
+## Defining cacheable asset factories
+
+Many of the assets in the system can are created using an asset factory.
+However, we have discovered that often these factories can add significant
+overhead to the start time of dagster. To mitigate this, we can cache the
+results of these factories (some at build time) and some at runtime. To do this
+we define a new way to create assets that can be cached.
+
+To do this you need to use the `cacheable_asset_factory` decorator. This
+decorator expects the decorated function to take at least the `cache_context`
+argument and any other resources that it might need (resources are resolved with
+the ResourceResolver).
+
+`CacheableDagsterContext` allows us to _mostly_ cacheable `AssetFactoryResponse` objects.
+We say _mostly_, because due to the complexity of the dagster object model we
+don't actually cache the dagster objects but instead cache objects that allow
+for fast hydration of dagster objects. In order to accomplish this, we
+separate the generation cacheable objects (must be inherit from
+`pydantic.BaseModel`) from the hydration of those cached objects into an
+`AssetFactoryResponse`. You can have any number of cacheable object generation
+functions and only a single hydration function.
+
+This would generally look like the following:
+
+```python
+import dagster as dg
+
+class SomeCacheableResponse(BaseModel):
+    responses: List[str]
+
+@cacheable_asset_factory
+def my_asset_factory(cache_context: CacheableDagsterContext) -> CacheableAssetFactoryResponse:
+    @cache_context.register_generator()
+    def cacheable_response(some_resource: SomeResource) -> SomeCacheableResponse:
+        responses = []
+        for response in some_resource.some_slow_iterator():
+            responses.append(response)
+        return SomeCacheableResponse(responses=responses)
+
+
+    @cache_context.hydrator()
+    def hydrate_cacheable_response(
+        cacheable_response: SomeCacheableResponse,
+    ) -> AssetFactoryResponse:
+        # Convert the cacheable response to a set of dagster objects
+
+        assets: list[dg.AssetsDefinition] = []
+
+        for response in cacheable_response.responses:
+            # Create dagster assets, sensors, jobs, etc. based on the response
+            @dg.asset(name=response)
+            def my_asset(context: dg.AssetExecutionContext):
+                # Do something that creates an asset
+                pass
+            assets.append(my_asset)
+
+        return AssetFactoryResponse(
+            assets=assets
+        )
+
+```

docker/images/oso/Dockerfile

@@ -13,4 +13,11 @@ ENV UV_PROJECT_ENVIRONMENT=/usr/local/
 
 RUN uv sync --all-packages --locked
 
-ENTRYPOINT  []
+# Build the dagster for production
+ENV DAGSTER_ASSET_CACHE_DIR=/dagster_assets_cache
+ENV DAGSTER_ASSET_CACHE_ENABLED=1
+ENV DAGSTER_SQLMESH_GATEWAY=trino
+ENV GOOGLE_PROJECT_ID=opensource-observer
+RUN uv run oso_dagster build
+
+ENTRYPOINT  []

lib/oso-core/oso_core/cache/__init__.py

@@ -0,0 +1,3 @@
+# ruff: noqa: F403
+from .file import *
+from .types import *

lib/oso-core/oso_core/cache/file.py

@@ -0,0 +1,100 @@
+import hashlib
+import logging
+import typing as t
+from pathlib import Path
+
+import arrow
+from pydantic import BaseModel
+
+from .types import (
+    CacheBackend,
+    CacheInvalidError,
+    CacheKey,
+    CacheMetadata,
+    CacheMetadataOptions,
+)
+
+T = t.TypeVar("T", bound=BaseModel)
+K = t.TypeVar("K", bound=BaseModel)
+
+logger = logging.getLogger(__name__)
+
+
+class FileCacheBackend(CacheBackend):
+    """A generic cache for pydantic models"""
+
+    def __init__(self, cache_dir: str):
+        self.cache_dir = cache_dir
+
+    def store_object(
+        self, key: CacheKey, value: BaseModel, options: CacheMetadataOptions
+    ) -> None:
+        """Store a single object in the cache
+
+        The file cache stores everything as a jsonl file. The first object in
+        the file is the metadata, which contains the creation time and
+        expiration time of the cache entry.
+        """
+        # Ensure the cache directory exists
+        self._ensure_cache_dir()
+        # Create a file path based on the key
+        file_path = self._cache_key_path(key)
+
+        metadata = CacheMetadata(
+            created_at=arrow.now().isoformat(),
+            valid_until=(
+                arrow.now().shift(seconds=options.ttl_seconds).isoformat()
+                if options.ttl_seconds > 0
+                else None
+            ),
+        )
+
+        # Write the value to the file
+        with open(file_path, "w") as f:
+            f.write(metadata.model_dump_json() + "\n")
+            f.write(value.model_dump_json())
+
+    def retrieve_object(
+        self,
+        key: CacheKey,
+        model_type: type[T],
+        options: CacheMetadataOptions,
+    ) -> T:
+        """Retrieve a single object from the cache"""
+        self._ensure_cache_dir()
+        file_path = self._cache_key_path(key)
+
+        if not file_path.exists():
+            logger.debug(
+                f"Cache file not found: {file_path}", extra={"file_path": file_path}
+            )
+            raise CacheInvalidError(f"Cache file not found: {file_path}")
+
+        with open(file_path, "r") as f:
+            # Read the metadata and check if it is valid
+            metadata = CacheMetadata.model_validate_json(f.readline().strip())
+
+            if not metadata.is_valid(options):
+                logger.debug(
+                    f"Cache entry is invalid: {metadata}", extra={"metadata": metadata}
+                )
+                raise CacheInvalidError(f"Cache entry is invalid: {metadata}")
+
+            return model_type.model_validate_json(f.read())
+
+    def _cache_dir_path(self):
+        """Get the cache directory path"""
+        return Path(self.cache_dir)
+
+    def _ensure_cache_dir(self):
+        """Ensure the cache directory exists"""
+        self._cache_dir_path().mkdir(parents=True, exist_ok=True)
+
+    def _cache_key(self, key: CacheKey) -> str:
+        """Generate a cache key from the pydantic model"""
+        key_str = hashlib.sha256(str(key).encode()).hexdigest()
+        return f"{key_str}.json"
+
+    def _cache_key_path(self, key: CacheKey) -> Path:
+        """Get the cache file path for a given key"""
+        return self._cache_dir_path() / self._cache_key(key)

lib/oso-core/oso_core/cache/test_file.py

@@ -0,0 +1,51 @@
+import tempfile
+
+import pytest
+from pydantic import BaseModel
+
+from .file import FileCacheBackend
+from .types import CacheMetadataOptions
+
+
+class FakeModel(BaseModel):
+    """A simple Pydantic model for testing purposes."""
+
+    name: str
+    value: int
+
+
+class FakeNestedModel(BaseModel):
+    """A nested Pydantic model for testing purposes."""
+
+    name: str
+    nested: FakeModel
+
+
+@pytest.fixture
+def temp_dir():
+    """Create a temporary directory for file system tests."""
+    with tempfile.TemporaryDirectory() as tmpdirname:
+        yield tmpdirname
+
+
+def test_write_file_to_temp_dir(temp_dir):
+    """Test writing a file to the temporary directory."""
+    cache_backend = FileCacheBackend(cache_dir=temp_dir)
+
+    test0 = FakeModel(name="test", value=42)
+
+    options = CacheMetadataOptions(ttl_seconds=60)
+
+    cache_backend.store_object(key="test_key0", value=test0, options=options)
+    stored_test0 = cache_backend.retrieve_object(
+        key="test_key0", model_type=FakeModel, options=options
+    )
+
+    assert test0 == stored_test0, "Stored and retrieved objects should match"
+
+    test1 = FakeNestedModel(name="nested_test", nested=test0)
+    cache_backend.store_object(key="test_key1", value=test1, options=options)
+    stored_test1 = cache_backend.retrieve_object(
+        key="test_key1", model_type=FakeNestedModel, options=options
+    )
+    assert test1 == stored_test1, "Nested stored and retrieved objects should match"

lib/oso-core/oso_core/cache/test_types.py

@@ -0,0 +1,15 @@
+import arrow
+
+from .types import CacheMetadata
+
+
+def test_metadata_is_valid():
+    """Test that metadata is valid when created and not expired."""
+    now = arrow.now()
+
+    created_at = now.shift(seconds=-60)
+    valid_until = now.shift(seconds=60)
+    metadata = CacheMetadata(
+        created_at=created_at.isoformat(), valid_until=valid_until.isoformat()
+    )
+    assert metadata.is_valid() is True