atmst.blockstore package

Submodules

atmst.blockstore.car_file module

atmst.blockstore.car_file.decode_varint(stream: BinaryIO)

atmst.blockstore.car_file.encode_varint(n: int) → bytes

class atmst.blockstore.car_file.ReadOnlyCARBlockStore(file: BinaryIO, validate_hashes: bool = True)

Bases: BlockStore

This is a sliiiightly unclean abstraction because BlockStores are indexed by bytes rather than CID, but same idea. This is convenient for verifying proofs provided in CAR format, and for testing.

car_roots: List[CID]

block_offsets: Dict[bytes, Tuple[int, int]]

put_block(key: bytes, value: bytes) → None

get_block(key: bytes) → bytes

del_block(key: bytes) → None

Module contents

class atmst.blockstore.BlockStore

Bases: ABC

A block store is a k/v store where values are immutable once set. They can be deleted, though. In practice, k==hash(v), but this API doesn’t care about that.

I’m not using the “native” __getitem__, __setitem__, __del__ methods because the semantics of these methods differ subtly.

if you call put() twice with the same args, the second call is a nop. if you call put() twice with the same key but different value, you get a ValueError

get() offers no default return value, you get a KeyError if it doesn’t exist.

if you try to delete a key that doesn’t exist, that’s a nop.

abstract put_block(key: bytes, value: bytes) → None

abstract get_block(key: bytes) → bytes

abstract del_block(key: bytes) → None

class atmst.blockstore.MemoryBlockStore(state: Dict[bytes, bytes] | None = None)

Bases: BlockStore

put_block(key: bytes, value: bytes) → None

get_block(key: bytes) → bytes

del_block(key: bytes) → None

class atmst.blockstore.SqliteBlockStore(con: Connection, table: str = 'mst_blocks')

Bases: BlockStore

NB: Caller is responsible for calling commit(), etc. TODO: consider allowing a custom table name?

put_block(key: bytes, value: bytes) → None

get_block(key: bytes) → bytes

del_block(key: bytes) → None

class atmst.blockstore.OverlayBlockStore(upper: BlockStore, lower: BlockStore)

Bases: BlockStore

reads come from “upper”, then “lower” if they don’t exist in upper. writes/deletes go only to “upper”.

put_block(key: bytes, value: bytes) → None

get_block(key: bytes) → bytes

del_block(key: bytes) → None