Crate sui_cache 

Built-in binary cache server and push pipeline for sui.

Replaces Attic, Cachix, and nix-serve with a single integrated component. Implements the standard Nix binary cache HTTP protocol (narinfo + NAR).

Architecture

• sui_castore — pluggable storage backends (shared with sui-registry); re-exported from here for backward compatibility.
• server — axum HTTP server implementing the cache protocol
• signing — ed25519 key management and narinfo signing
• push — pipeline to push store paths to the cache
• gc — garbage collection of unreferenced cache entries
• config — cache configuration types (CacheConfig; BackendConfig is in sui-castore)

Re-exports

pub use config::CACHE_TIER_ENV;

pub use config::CacheConfig;

pub use gc::GcResult;

pub use push::LevelOutOfRange;

pub use push::NarCodec;

pub use push::PushResult;

pub use push::XzLevel;

pub use push::ZstdLevel;

pub use server::AppState;

pub use server::build_router;

pub use server::serve;

pub use signing::CacheSigner;

pub use signing::verify_narinfo_signature;

Modules

config

Cache configuration types.

gc

Garbage collection for the binary cache.

push

Push pipeline — build output to NAR to sign to upload.

server

Axum HTTP server implementing the Nix binary cache protocol.

signing

Ed25519 signing for narinfo metadata.

Structs

BytesNarSource

A NarSource over bytes already in memory.

FileNarSource

A NarSource over a file on disk.

LocalStorage

Filesystem-backed binary cache storage.

MemNarRefIndex

In-memory NarRefIndex — the reference semantics, and what every test double uses.

NarRefKey

The typed key of one reverse edge: “hash’s narinfo advertises nar_path”.

NarRefScan

The typed key prefix enumerating every edge into one NAR.

PgStorageBackend

L2 durable cache tier: content-addressed key → value over Postgres, shared across pods, survives a roll.

RedisBackend

L1 hot cache: content-addressed key → value, sub-ms hits, TTL/eviction-aware.

S3Storage

S3-compatible object storage backend.

SpooledNarSource

A NarSource over a spool file, deleted when the source is dropped.

StorageIndex

Ephemeral metadata index backed by redb.

TieredBackend

Three-tier read-through / write-through cache resolver.

Enums

BackendConfig

Storage backend selection.

CacheError

CacheError is now sui_castore::StoreError (same variants, same derives). This type alias preserves every existing sui_cache::CacheError use site. Error type for content-addressed store operations.

ExpandEnvError

A ${VAR} token referenced an environment variable that is not set.

NarResidency

What a backend’s NAR path costs in resident memory.

PgTable

The three logical tables the cache tier keeps: narinfo text, NAR blobs, and the reverse edges between them.

TieredTier

The honest self-description of what TieredBackend has been proven against — asserted by the honest gate so a claim cannot be silently rounded up.

WritePolicy

How a put propagates across the tiers. See the module docs for the full contract; every policy persists both durable tiers before returning.

Constants

DEFAULT_INGEST_MEMORY_CAP

Default cap for the in-memory ingest fallback — see spool_or_buffer.

NAR_CHUNK_BYTES

The bounded chunk size every streaming NAR path moves bytes in.

NAR_REF_PREFIX

Key-space prefix owning every reverse edge.

TIERED_BACKEND_TIER

The shipped tier of TieredBackend. Asserted by the honest gate; bumping it to LiveClusterProven without a live integration test is a build-failing round-up.

Traits

NarRefIndex

The reverse index of a single StorageBackend.

NarSource

A re-openable NAR byte source.

PgCacheConn

The minimal typed Postgres row-verb surface PgStorageBackend depends on.

RedisConn

The minimal async redis verb surface RedisBackend depends on.

StorageBackend

Abstraction over binary cache storage.

Functions

advertised_nar_url

The NAR path a stored narinfo advertises, if it advertises an addressable one.

advertised_url_line

The raw URL: field of a narinfo, unjudged.

build_backend

Config-select factory: build the concrete StorageBackend a BackendConfig names.

bytes_stream

Yield in-memory bytes as bounded chunks (zero-copy slices of one allocation).

collect_nar

Drain a NarStream into one buffer.

empty_stream

A stream that yields nothing.

expand_env_vars

Expand ${VAR} tokens in text against the process environment.

file_stream

Read an open file as bounded chunks. O(chunk) resident.

is_addressable_nar_path

Whether a narinfo’s URL: is a NAR path this store can safely address.

is_servable_narinfo

Is this narinfo text usable by a Nix client at all?

referrer_of

Recover the referring store-path hash from a scanned edge key.

spool_or_buffer

Turn a one-shot byte stream into a re-openable NarSource, bounded either way.

whole_value_stream

A stream that yields exactly one chunk — the whole value.

Type Aliases

NarStream

A NAR byte stream — bounded chunks, consumed exactly once.