Re: GSoC - Some questions on the idea of

On Mon, Apr 2, 2012 at 6:30 AM, Bo Chen [off-list ref] wrote:

One question,  can anyone help me clear?

My .git/objects has 3 blobs, a, b, and c. a is a unique file, b and c
two sequential versions of the same file. When I run "git gc", what
exactly happens here, e.g., how exactly git (in the latest version)
delta compresses-the blobs here?

See Documentation/technical/pack-heuristics.txt for how pack-objects
(called by"git gc") decides to delta either b or c based on the other
one. Once it chooses, say, b to be delta against c, it generates delta
using diff-delta.c, then store the delta in either ref-delta or
ofs-delta format. The former stores sha-1 of c, the latter the offset
of c in the pack.
-- 
Duy