Git: show total file size difference between two commits?

Question

Is it possible to show the total file size difference between two commits? Something like:

$ git file-size-diff 7f3219 bad418 # I wish this worked :)
-1234 bytes

I’ve tried:

$ git diff --patch-with-stat

And that shows the file size difference for each binary file in the diff — but not for text files, and not the total file size difference.

Any ideas?

Solution 1

git cat-file -s will output the size in bytes of an object in git. git diff-tree can tell you the differences between one tree and another.

Putting this together into a script called git-file-size-diff located somewhere on your PATH will give you the ability to call git file-size-diff <tree-ish> <tree-ish>. We can try something like the following:

#!/bin/bash
USAGE='[--cached] [<rev-list-options>...]

Show file size changes between two commits or the index and a commit.'

. "$(git --exec-path)/git-sh-setup"
args=$(git rev-parse --sq "$@")
[ -n "$args" ] || usage
cmd="diff-tree -r"
[[ $args =~ "--cached" ]] && cmd="diff-index"
eval "git $cmd $args" | {
  total=0
  while read A B C D M P
  do
    case $M in
      M) bytes=$(( $(git cat-file -s $D) - $(git cat-file -s $C) )) ;;
      A) bytes=$(git cat-file -s $D) ;;
      D) bytes=-$(git cat-file -s $C) ;;
      *)
        echo >&2 warning: unhandled mode $M in \"$A $B $C $D $M $P\"
        continue
        ;;
    esac
    total=$(( $total + $bytes ))
    printf '%d\t%s\n' $bytes "$P"
  done
  echo total $total
}

In use this looks like the following:

$ git file-size-diff HEAD~850..HEAD~845
-234   Documentation/RelNotes/1.7.7.txt
112    Documentation/git.txt
-4     GIT-VERSION-GEN
43     builtin/grep.c
42     diff-lib.c
594    git-rebase--interactive.sh
381    t/t3404-rebase-interactive.sh
114    t/test-lib.sh
743    tree-walk.c
28     tree-walk.h
67     unpack-trees.c
28     unpack-trees.h
total 1914

By using git-rev-parse it should accept all the usual ways of specifying commit ranges.

EDIT: updated to record the cumulative total. Note that bash runs the while read in a subshell, hence the additional curly braces to avoid losing the total when the subshell exits.

EDIT: added support for comparing the index against another tree-ish by using a --cached argument to call git diff-index instead of git diff-tree. eg:

$ git file-size-diff --cached master
-570    Makefile
-134    git-gui.sh
-1  lib/browser.tcl
931 lib/commit.tcl
18  lib/index.tcl
total 244

Solution 2

You can pipe the out put of

git show some-ref:some-path-to-file | wc -c
git show some-other-ref:some-path-to-file | wc -c

and compare the 2 numbers.

Solution 3

I made a bash script to compare branches/commits etc by actual file/content size. It can be found at https://github.com/matthiaskrgr/gitdiffbinstat and also detects file renames.

Solution 4

Expanding on matthiaskrgr's answer, https://github.com/matthiaskrgr/gitdiffbinstat can be used like the other scripts:

gitdiffbinstat.sh HEAD..HEAD~4

Imo it really works well, much faster than anything else posted here. Sample output:

$ gitdiffbinstat.sh HEAD~6..HEAD~7
 HEAD~6..HEAD~7
 704a8b56161d8c69bfaf0c3e6be27a68f27453a6..40a8563d082143d81e622c675de1ea46db706f22
 Recursively getting stat for path "./c/data/gitrepo" from repo root......
 105 files changed in total
  3 text files changed, 16 insertions(+), 16 deletions(-) => [±0 lines]
  102 binary files changed 40374331 b (38 Mb) -> 39000258 b (37 Mb) => [-1374073 b (-1 Mb)]
   0 binary files added, 3 binary files removed, 99 binary files modified => [-3 files]
    0 b  added in new files, 777588 b (759 kb) removed => [-777588 b (-759 kb)]
    file modifications: 39596743 b (37 Mb) -> 39000258 b (37 Mb) => [-596485 b (-582 kb)]
    / ==>  [-1374073 b (-1 Mb)]

The output directory is funky with ./c/data... as /c is actually the filesytem root.

Solution 5

A comment to the script: git-file-size-diff, suggested by patthoyts. The script is very useful, however, I have found two issues:

1. When someone change permissions on the file, git returns a another type in the case statement:

   T) echo >&2 "Skipping change of type"
   continue ;;
   

2. If a sha-1 value doesn't exist anymore (for some reason), the script crashes. You need to validate the sha before getting the file size:

   $(git cat-file -e $D) if [ "$?" = 1 ]; then continue; fi

The complete case statement will then look like this:

case $M in
      M) $(git cat-file -e $D)
         if [ "$?" = 1 ]; then continue; fi
         $(git cat-file -e $C)
         if [ "$?" = 1 ]; then continue; fi
         bytes=$(( $(git cat-file -s $D) - $(git cat-file -s $C) )) ;;
      A) $(git cat-file -e $D)
         if [ "$?" = 1 ]; then continue; fi
         bytes=$(git cat-file -s $D) ;;
      D) $(git cat-file -e $C)
         if [ "$?" = 1 ]; then continue; fi
         bytes=-$(git cat-file -s $C) ;;
      T) echo >&2 "Skipping change of type"
         continue ;;
      *)
        echo >&2 warning: unhandled mode $M in \"$A $B $C $D $M $P\"
        continue
        ;;
    esac

View more solutions

Comments

[Stas Dashkovsky]

Here is the 3-lines bashscript giving you size of certain commit stackoverflow.com/a/23985353/2062041

[Mathias Bynens]

+1 This is great for quickly checking the size difference of a file between versions. But how can this be used to get the total file difference between two commits? I want to see how many bytes were added/removed project-wide between two refs.

[Mathias Bynens]

+1 Thanks! This would be absolutely perfect if it would print out the total size difference at the bottom. I want to see how many bytes were added/removed project-wide between two refs (not just per file, but in total, too).

[Mathias Bynens]

Another question: why are you sourcing git-sh-setup here? You don’t seem to be using any of the functions it defines. Just wondering!

[patthoyts]

It does basic checks like producing a sensible message if you run this command in a directory that is not a git repository. It also can help abstract out some platform differences. Mostly habit though. When writing a git script - first bring in the git-sh-setup file.

[AlecRust]

Got an example usage of this?

[csch]

Thanks for the script! I archived it in a gist (gist.github.com/cschell/9386715), I hope you do not mind. Impatient ones can now do something like curl -s https://gist.githubusercontent.com/cschell/9386715/raw/43996‌​adb0f785a5afc17358be‌​7a43ff7ee973215/git-‌​file-size-diff | bash -s <tree-ish> <tree-ish>

[Aziz Alto]

Thanks for the awesome script! I was looking for someway to monitor the increase of size after each commit and this helps a lot. I made a small gist to show only the total increase between all (some of) the commits in the repository gist.github.com/iamaziz/1019e5a9261132ac2a9a thanks again!

[Mogsdad]

You didn't need to comment on Matthias' post - you could have suggested an edit to it instead, with these details that he didn't provide. By current standards, his answer would be considered a "link-only answer", and be deleted, so these sorts of details are important.

[guest]

who can take my answer and include it into matthias?

[Mogsdad]

If you want, you can make a suggested edit yourself. (In my experience, it would tend to get get rejected by reviewers, but a clear explanation in the Edit Summary could help.) But maybe I wasn't clear in my comment to you... your answer is a stand-alone answer, a good update of Matthias' older answer. You didn't need to include the text that explained that you meant to comment, is all. I edited the answer in a way that gives appropriate credit to Matthias. You don't need to do more.

[escapecharacter]

The use case I'm looking for is to preview large commits before I make them. Is there a way I can find the size changes of the currently staged changes? I've read through the tree-ish documentation, and I could not find a way to reference "current staged changes".

[patthoyts]

Added support for comparing against the index using git-diff-index.

[Josh]

you can run echo $PATH to see your path directories to see where you can put this script file. I put mine in /usr/local/git/bin and it worked great. You can also add a path to your $PATH if you want to put the script somewhere else.

[Dee Choksi]

You can skip the | wc -c if you use cat-file -s instead of show

[mr5]

How do I use this? What is HEAD~850? Can I just use instead the commit id?

[patthoyts]

@mr5 HEAD~850 is 850 commits before HEAD. It is just another notation for a commit and yes you can use a specific commit id or a tag or anything that can be resolved to a commit. The script uses git rev-parse so see the manual section "Specifying Revisions" in the git-rev-parse documentation for the full details. (git-scm.com/docs/git-rev-parse)

[webninja]

Using the improvement suggested by @neu242, I wrote this bash function: gdbytes () { echo "$(git cat-file -s $1:$3) -> $(git cat-file -s $2:$3)" } Which makes it easy to see how file size changed since last commit with e.g., gdbytes @~ @ index.html

[40detectives]

if the some-ref: part is skipped, do you obtain the file size in the working directory?

[Philzen]

How would i be able to see what size the files had before? I am currently preparing a pull request that optimizes file output structure and would like to calculate a percentage of size decrease.