mirror/ git
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-05-24 08:26:29 +02:00
Code

Merge branch 'ma/doc-pack-format-varint-for-sizes' into next 

Doc update.

* ma/doc-pack-format-varint-for-sizes:
  pack-format.txt: document sizes at start of delta data
This commit is contained in:
Junio C Hamano 2021-01-08 00:23:32 -08:00
parent 51aaae39a1 7b77f5a13e
commit 8a448c50dd
1 changed files with 16 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
Documentation/technical/pack-format.txt
View File

@ -55,6 +55,18 @@ Valid object types are:
Type 5 is reserved for future expansion. Type 0 is invalid.
=== Size encoding
This document uses the following "size encoding" of non-negative
integers: From each byte, the seven least significant bits are
used to form the resulting integer. As long as the most significant
bit is 1, this process continues; the byte with MSB 0 provides the
last seven bits. The seven-bit chunks are concatenated. Later
values are more significant.
This size encoding should not be confused with the "offset encoding",
which is also used in this document.
=== Deltified representation
Conceptually there are only four object types: commit, tree, tag and
@ -73,7 +85,10 @@ Ref-delta can also refer to an object outside the pack (i.e. the
so-called "thin pack"). When stored on disk however, the pack should
be self contained to avoid cyclic dependency.
The delta data is a sequence of instructions to reconstruct an object
The delta data starts with the size of the base object and the
size of the object to be reconstructed. These sizes are
encoded using the size encoding from above. The remainder of
the delta data is a sequence of instructions to reconstruct the object
from the base object. If the base object is deltified, it must be
converted to canonical form first. Each instruction appends more and
more data to the target object until it's complete. There are two