dulwich.midx

module documentation

Multi-Pack-Index (MIDX) support.

A multi-pack-index (MIDX) provides a single index that covers multiple pack files, enabling fast object lookup across all packs without opening each pack index.

The MIDX file format consists of: - A header with signature, version, and hash algorithm - A chunk lookup table - Multiple chunks containing pack names, OID fanout, OID lookup, and object offsets - A trailer with checksum

This module provides: - Reading MIDX files - Writing MIDX files - Integration with pack-based object stores

Limitations: - Incremental MIDX chains are not yet supported (base_midx_files must be 0) - BTMP (bitmapped packfiles) chunk is not yet implemented - RIDX (reverse index) chunk is not yet implemented

Note: Incremental MIDX chains were introduced in Git 2.47 as an experimental feature, where multiple MIDX files can be chained together. The format includes a base_midx_files field in the header and uses a multi-pack-index.d/ directory with a multi-pack-index-chain file. This feature is not yet supported by Dulwich as the specification is still evolving.

Class	`MultiPackIndex`	Multi-pack-index for efficient object lookup across multiple pack files.
Function	`load_midx`	Load a multi-pack-index file by path.
Function	`load_midx_file`	Load a multi-pack-index from a file-like object.
Function	`write_midx`	Write a multi-pack-index file.
Function	`write_midx_file`	Write a multi-pack-index file to disk.
Constant	`CHUNK_BTMP`	Undocumented
Constant	`CHUNK_LOFF`	Undocumented
Constant	`CHUNK_OIDF`	Undocumented
Constant	`CHUNK_OIDL`	Undocumented
Constant	`CHUNK_OOFF`	Undocumented
Constant	`CHUNK_PNAM`	Undocumented
Constant	`CHUNK_RIDX`	Undocumented
Constant	`HASH_ALGORITHM_SHA1`	Undocumented
Constant	`HASH_ALGORITHM_SHA256`	Undocumented
Constant	`MIDX_SIGNATURE`	Undocumented
Constant	`MIDX_VERSION`	Undocumented
Variable	`has_mmap`	Undocumented

def load_midx(path: str | os.PathLike[str]) -> MultiPackIndex: ¶

Load a multi-pack-index file by path.

Parameters
path:`str \| os.PathLike[str]`	Path to the MIDX file

Returns
`MultiPackIndex`	A MultiPackIndex loaded from the given path

def load_midx_file(path: str | os.PathLike[str], f: IO[bytes] | _GitFile) -> MultiPackIndex: ¶

Load a multi-pack-index from a file-like object.

Parameters
path:`str \| os.PathLike[str]`	Path for the MIDX file
f:`IO[bytes] \| _GitFile`	File-like object

Returns
`MultiPackIndex`	A MultiPackIndex loaded from the given file

def write_midx(f: IO[bytes], pack_index_entries: list[tuple[str, list[tuple[RawObjectID, int, int | None]]]], hash_algorithm: int = HASH_ALGORITHM_SHA1) -> bytes: ¶

Write a multi-pack-index file.

Parameters
f:`IO[bytes]`	File-like object to write to
pack_index_entries:`list[tuple[str, list[tuple[RawObjectID, int, int \| None]]]]`	List of (pack_name, entries) tuples where entries are (sha, offset, crc32) tuples, sorted by SHA
hash_algorithm:`int`	Hash algorithm to use (1=SHA-1, 2=SHA-256)

Returns
`bytes`	SHA-1 checksum of the written MIDX file

def write_midx_file(path: str | os.PathLike[str], pack_index_entries: list[tuple[str, list[tuple[RawObjectID, int, int | None]]]], hash_algorithm: int = HASH_ALGORITHM_SHA1) -> bytes: ¶

Write a multi-pack-index file to disk.

Parameters
path:`str \| os.PathLike[str]`	Path where to write the MIDX file
pack_index_entries:`list[tuple[str, list[tuple[RawObjectID, int, int \| None]]]]`	List of (pack_name, entries) tuples where entries are (sha, offset, crc32) tuples, sorted by SHA
hash_algorithm:`int`	Hash algorithm to use (1=SHA-1, 2=SHA-256)

Returns
`bytes`	SHA-1 checksum of the written MIDX file

CHUNK_BTMP: bytes = ¶

Undocumented

Value

b'BTMP'

CHUNK_LOFF: bytes = ¶

Undocumented

Value

b'LOFF'

CHUNK_OIDF: bytes = ¶

Undocumented

Value

b'OIDF'

CHUNK_OIDL: bytes = ¶

Undocumented

Value

b'OIDL'

CHUNK_OOFF: bytes = ¶

Undocumented

Value

b'OOFF'

CHUNK_PNAM: bytes = ¶

Undocumented

Value

b'PNAM'

CHUNK_RIDX: bytes = ¶

Undocumented

Value

b'RIDX'

HASH_ALGORITHM_SHA1: int = ¶

Undocumented

Value

HASH_ALGORITHM_SHA256: int = ¶

Undocumented

Value

MIDX_SIGNATURE: bytes = ¶

Undocumented

Value

b'MIDX'

MIDX_VERSION: int = ¶

Undocumented

Value

has_mmap: bool = ¶

Undocumented