[script] find largest pack objects

Blog post about git pruning history and finding large objects in your repo: http://stubbisms.wordpress.com/2009/07/10/git-script-to-show-largest-pack-objects-and-trim-your-waist-line/

This is a script I put together after migrating the Spring Modules project from CVS, using git-cvsimport (which I also had to patch, to get to work on OS X / MacPorts). I wrote it because I wanted to get rid of all the large jar files, and documentation etc, that had been put into source control. However, if _large files_ are deleted in the latest revision, then they can be hard to track down.

#!/bin/bash #set -x

# Shows you the largest objects in your repo's pack file. # Written for osx. # # @see http://stubbisms.wordpress.com/2009/07/10/git-script-to-show-largest-pack-objects-and-trim-your-waist-line/ # @author Antony Stubbs

# set the internal field spereator to line break, so that we can iterate easily over the verify-pack output IFS=$'\n';

# list all objects including their size, sort by size, take top 10 objects=`git verify-pack -v .git/objects/pack/pack-*.idx | grep -v chain | sort -k3nr | head`

echo "All sizes are in kB's. The pack column is the size of the object, compressed, inside the pack file."

output="size,pack,SHA,location"
for y in $objects
do
	# extract the size in bytes
	size=$((`echo $y | cut -f 5 -d ' '`/1024))
	# extract the compressed size in bytes
	compressedSize=$((`echo $y | cut -f 6 -d ' '`/1024))
	# extract the SHA
	sha=`echo $y | cut -f 1 -d ' '`
	# find the objects location in the repository tree
	other=`git rev-list --all --objects | grep $sha`
	#lineBreak=`echo -e "\n"`
	output="${output}\n${size},${compressedSize},${other}"
done

echo -e $output | column -t -s ', '

More info on the blog post: http://stubbisms.wordpress.com/2009/07/10/git-script-to-show-largest-pack-objects-and-trim-your-waist-line/

Regards, Antony Stubbs

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On Fri, 10 Jul 2009, Antony Stubbs wrote:

This is certainly useful. Mind submitting a patch adding this script to contrib/stats/ ?

Nicolas

Sorry Nicolas, Completely missed your message amongst the torrent of the git mailing list - which I'm now unsubscribed from.. But sure, I'll ad this to my todo list :)

Cheers, Antony Stubbs,

sharca.com

On 10/07/2009, at 5:34 AM, Nicolas Pitre wrote:

On 2009.07.10 13:16:50 +1200, Antony Stubbs wrote:

Here's my script, basically for the same purpose, but instead of looking at the packfiles, it looks at the rev-list output to find those objects that aren't prunable (ignoring the reflog). I'm also using some kind of ugly sed invocation to run rev-list only twice, regardless of the number of objects to be shown, which greatly reduces the time required to run the script.

#!/bin/sh
git rev-list --all --objects |
	sed -n $(git rev-list --objects --all |
		cut -f1 -d' ' | git cat-file --batch-check | grep blob |
		sort -n -k3 | tail -n$1 | while read hash type size;
		do
			echo -n "-e s/$hash/$size/p ";
		done) |
	sort -n -k1

It takes the number of objects to be shown as an argument, so for the top ten run as "git find-large 10" (assuming that the script is in $PATH and called git-find-large).

It doesn't list as much information as yours does, e.g. the compressed size is missing, but it's good enough for me, and speed was far more important for me, especially since the "rev-list --all --objects" trick gets you only a single filename for the blob, so if there were renames, you may need to run it again after having deleted one version via filter-branch.

Something similar applies to deltified stuff. As verify-pack shows the size of the delta, your script might miss some file B if that is a currently stored as a delta against some other large file A. Only after the blob for A got deleted, B will be shown (as it is no longer deltified).

OTOH, this means that the output of my script is likely to have the same filename over and over again. If that gets out of hand, I usually do something like: git find-large 100 | cut -d' ' -f2 | sort -u

So I get just the filenames, hoping that the top 100 include all interesting things ;-)

Maybe this helps someone to come up with a smart combination of our scripts.

Björn