Crate tpt_archon_core 

tpt-archon-core: a no_std, zero-allocation storage engine.

This is Phase 1 of the tpt-archon stack (see the workspace-root spec.txt and TODO.md). It is a single-crate storage engine, embeddable like SQLite’s storage layer, providing:

• block — the BlockDevice backend abstraction with in-memory and (behind the std feature) file-backed backends.
• zerocopy — fixed-capacity byte buffers and zero-copy (de)serialization helpers used on the read/write hot path.
• page — a fixed-size page abstraction and an LRU buffer pool with a Free/Clean/Dirty/Pinned state machine and dirty-page writeback.
• wal — an append-only, LSN-ordered write-ahead log with crash-recovery replay.
• btree — a B-Link tree with point lookups, range scans and concurrent inserts.
• storage — a StorageEngine facade wiring the buffer pool to the WAL, so page writes actually go through the write-ahead log before main storage (not just each piece tested alone).
• faultsim — a testing tool (not a runtime feature): injects power-loss-shaped corruption (truncated tails, flipped bytes, zeroed records) and asserts StorageEngine::recover always yields a prefix-consistent state.

Zero-allocation, and the missing tpt-zero-bytes

The zerocopy module exists because there is no tpt-zero-bytes crate anywhere in the TPT ecosystem — it was never built. Do not “helpfully” add a dependency on a crate by that name; the primitives live here on purpose so the read/write hot path allocates nothing.

no_std

The crate is #![no_std] by default (it uses alloc). The default std feature only adds the file-backed BlockDevice; build with --no-default-features for a fully no_std configuration.

Modules

block

Block device abstraction: the storage backend the rest of the engine builds on.

btree

A B-Link tree: an ordered u64 -> Vec<u8> index with sibling right-links.

faultsim

Crash / fault simulation for the write-ahead log and the StorageEngine.

page

Fixed-size pages and an LRU buffer pool.

storage

An end-to-end storage facade wiring the BufferPool to the Wal.

wal

Append-only, LSN-ordered write-ahead log with crash-recovery replay.

zerocopy

Zero-allocation primitives for page-sized I/O and record framing.