package irmin-pack

This module defines abstractions over entries in the pack file, which are encoded as follows:

      ┌────────┬────────┬──────────────┬─────────┐
      │  Hash  │  Kind  │  Len(Value)? │  Value  │
      └────────┴────────┴──────────────┴─────────┘
      ┆<┄ H ┄┄>┆<┄ K ┄┄>┆<┄┄┄┄ L? ┄┄┄┄>┆<┄┄ V ┄┄>┆
      ┆<┄┄┄┄┄┄┄┄┄┄┄ entry length, E ┄┄┄┄┄┄┄┄┄┄┄┄>┆

The fields are as follows:

• Hash: the (fixed-length) hash of the data stored in this entry;

• Kind: the kind of data being stored (contents, nodes, commits etc.), encoded as a single "magic" character;

• Len(Value): an optional length header for the Value section of the entry (not including the length of the length header itself), encoded using a variable-length encoding (LEB128). The presence of a length header is determined by the Kind character.

• Value: the data itself.

The length of the overall pack entry, as referenced in the Pack_index or in a direct Pack_key.t, is equal to E = H + K + L + V.