schema

blobmap.schema

JSON Schema for the manifest, and a small validator that walks it.

The schema is the contract with every consumer, including ones not written yet. It is deliberately a plain dict rather than something generated from the dataclasses: the format has to outlive this package's class layout, and a consumer in another language needs the schema, not a Python model.

Validation walks the schema rather than reimplementing the rules, so the two cannot drift. Only the keywords the schema actually uses are supported, which is a fraction of the specification and about sixty lines. tests/test_schema.py cross-checks the walker against the real jsonschema library, so if the schema grows a keyword this does not handle, that test fails rather than the keyword being silently ignored.

Example

validate_document({"schema_version": 3, "scope": "s", "epoch": 1, ... "hot_always": [], "blobs": []}) validate_document({"schema_version": 3, "scope": "s", "epoch": 0, ... "hot_always": [], "blobs": []}) Traceback (most recent call last): ... blobmap.schema.SchemaError: epoch: 0 is less than the minimum 1

SchemaError

Bases: ValueError

A document does not match the manifest schema.

validate_document

validate_document(document: Any) -> None

Check a parsed manifest against SCHEMA.

Parameters:

Name	Type	Description	Default
document	Any	A parsed JSON document, before it becomes a Manifest.	required

Raises:

Type	Description
SchemaError	On the first violation, naming the path to it.

Example

validate_document({"schema_version": 3, "scope": "s", "epoch": 1, ... "hot_always": [], ... "blobs": [{"id": "b!", "prefixes": ["x"], ... "bucket": None}]}) Traceback (most recent call last): ... blobmap.schema.SchemaError: blobs[0].id: 'b!' does not match ^[a-z0-9_]+$

Source code in src/blobmap/schema.py

def validate_document(document: Any) -> None:
    """Check a parsed manifest against `SCHEMA`.

    Args:
        document: A parsed JSON document, before it becomes a
            [`Manifest`][blobmap.model.Manifest].

    Raises:
        SchemaError: On the first violation, naming the path to it.

    Example:
        >>> validate_document({"schema_version": 3, "scope": "s", "epoch": 1,
        ...                    "hot_always": [],
        ...                    "blobs": [{"id": "b!", "prefixes": ["x"],
        ...                               "bucket": None}]})
        Traceback (most recent call last):
            ...
        blobmap.schema.SchemaError: blobs[0].id: 'b!' does not match ^[a-z0-9_]+$
    """
    _check(document, SCHEMA, "")