Re: What's in git.git (stable)

Andy Parkins [off-list ref] wrote:

I wonder if the number of objects is a reasonable measure of progress.  Let's 
say we're transferring 100,000 objects.  Let's also say that the average size 
of objects is 100 bytes.  Let's finally say that the object sizes are evenly 
distributed throughout the 100,000 objects.  This would mean that the first 
1,000 objects are just as representative as the last 1,000 objects; or any 
other randomly chosen 1,000 objects.  In which case, the size of the first 
thousand objects would be approximately one hundredth the size of the total 
transfer.  Volia: an estimate of the total size of the transfer.

Ah, but much like those stock scam emails, "prior performance does
not predict future results"...  The size of objects in the pack
tends to be small up front (commits/trees) and larger in the back
(blobs).  The size distribution probably also gets more erratic
near the back as the blob sizes may not follow a nice distribution.

E.g. I have a repository with a blob that is 23 MiB.  But I also
have some 5 MiB blobs, and then a very large number of relatively
small blobs.  That 23 MiB blob really gums up any estimate.

But as you state, its easy to refine it over time, and the closer we
get to the end the more likely it is to be correct.  Unless its that
23 MiB blob.  As it takes up about 85% of that repository's pack.

--