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?

Answer 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