From: Luke Robison <robison@arlut.utexas.edu>
Date: Tue, 20 Mar 2018 15:43:50 GMT
Subject: Understanding Binary Deltas within Packfile
Message-ID: <f301d093-af93-016b-79b9-3102475260cf@arlut.utexas.edu>

Is there any documentation of the contents of the binary delta datain a 
packfile, and how to interpret them?  I found 
https://github.com/git/git/blob/master/Documentation/technical/pack-format.txt 
documenting the packfile itself, but the "compressed delta data" seems 
largely undocumented.  The source code of 
https://github.com/git/git/blob/master/diff-delta.c is pretty dense.  
This is what I've got so for:

+-------------+
| Varint src_size
| Varint trg_size
| 1-byte inscnt
| N-bytes up to 16 bytes of trg_buf
|
| A series of Operations
|
+-------------


Any details on how to interpret the opcodes would be greatly appreciated.

Thanks,
Luke