Module import 

The git→mkit import driver (SPEC-GIT-IMPORT §3).

Pure translation engine: reads git objects through a GitSource, writes serialized mkit objects through an ObjectSink, signs through caller-supplied callbacks (the crate stays crypto-free — the CLI passes its CommitSigner), and records sha1→blake3 pairs plus retained raw commit/tag bytes through caller-supplied hooks.

Everything here is deterministic given (git bytes, signing key, import-spec version): deterministic Ed25519 means the engine can be re-run idempotently and the map is a rebuildable cache under the same key (SPEC-GIT-IMPORT §1.2).

Structs

DepthMemo

Memoized tree heights and tag-chain lengths, keyed by git id. Needed because a map hit skips recursion: a previously-imported LEGAL subtree (or tag chain) re-referenced deeper in a new parent could compose past the normative caps without it.

ImportOptions

Per-run options.

ImportSigner

Signing callbacks: given the unsigned object (zeroed signature), return the 64-byte signature. The signer pubkey is supplied separately so the engine can fill the signer field first.

ImportedRef

Outcome of importing one ref tip.

Importer

The import engine. map is the sha1→blake3 cache (load it from the state dir; pairs accumulate across calls).

MemGitSource

In-memory source for tests and golden vectors.

MemSink

In-memory sink for tests.

Constants

CHUNK_THRESHOLD

SPEC-GIT-IMPORT §3.1: the normative chunking threshold.

IMPORT_SPEC_VERSION

This implementation’s import-spec version (SPEC-GIT-IMPORT §1.2).

MAX_TAG_CHAIN

SPEC-GIT-IMPORT §3.4: tag→tag chains beyond this depth refuse.

MAX_TREE_DEPTH

Tree nesting cap, matching mkit-core’s MAX_TREE_DEPTH defense (the importer is the most untrusted boundary in the system).

Traits

GitSource

Where the driver reads git objects from. CatFileBatch for real repositories; an in-memory map for hermetic tests/vectors.

ObjectSink

Where serialized mkit objects land. Implemented for mkit_core::ObjectStore (per-object fsync) and the CLI’s bulk writer; tests use an in-memory map.

Type Aliases

RetainRawFn

Hook receiving (upstream sha1, framed raw git bytes) for retention. The explicit lifetime keeps the trait object bound to the borrower’s scope (a bare dyn alias would default to 'static).