cadrumo.adapters.outbound.storage.path_budget module

Worst-case on-disk object-path length for the local provider layout.

This package owns the local_provider_object_sidecar grammar (<root>/buckets/<bucket_id>/blobs/<namespace>/<hmac_prefix>--<label>.meta.json, declared with owner="cadrumo.adapters.outbound.storage" in STORAGE_NAMESPACE_REGISTRY), so the deepest suffix that grammar can produce is derived here and handed to windows_storage_root_long_path_margin() rather than duplicated as a literal beneath it.

The <namespace> segment is the load-bearing one, and it was previously mis-sourced. LocalFileSystemProvider fans one directory out per namespace (self._root / namespace), and the namespaces it is handed in production are registered secure-object namespaces: the mirror push loop passes SecureObjectRawRow.namespace straight to put(), and the mirror preflight refuses any namespace absent from the registry. Those values are dotted and long (the longest shipped is 72 characters). The prior constant instead spelled a bucket-event object type into the arithmetic — a disjoint vocabulary whose values are never registered storage namespaces at all — and so understated the worst case by 54 characters, which could let the preflight margin accept a storage root from which a real outbound write then exceeds MAX_PATH.

Deriving from STORAGE_NAMESPACE_REGISTRY makes the ceiling structural over the whole shipped domain: a newly registered namespace longer than today’s longest raises the budget automatically instead of silently re-opening the gap.

The registry field caps namespace at 128 characters, which is the only hard structural bound available. Budgeting against that cap rather than the shipped maximum would put the suffix alone at 265 characters — past WINDOWS_MAX_PATH (260) before any root is prepended — so every margin would be negative and the preflight probe would refuse every storage root on every Windows workstation. The shipped-longest derivation is the honest budget: it measures the deepest path this build can actually write.

windows_worst_case_object_path_suffix_length()

Return the longest object-path suffix this build’s layout can append.

Measured from the leading separator through the sidecar extension, using the real grammar constants: the bucket/blob directory names, a 36-character bucket id, the longest namespace registered in STORAGE_NAMESPACE_REGISTRY, the HMAC prefix width, and the operator-label cap.

The .meta.json sidecar is measured rather than the .bin payload because it is the longer of the two names the provider writes for one object, so a path that fits the sidecar fits the payload.

Return type:

int

Returns:

The suffix length in characters, for windows_storage_root_long_path_margin().