From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: q: faster way to integrate/merge lots of topic branches?
Date: Wed, 23 Jul 2008 16:56:22 +0200
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References: <20080723130518.GA17462@elte.hu> <20080723131736.GA9100@elte.hu> <20080723134926.GA12888@elte.hu> <76718490807230747w5d0350b8v6feba00fb8837617@mail.gmail.com>
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To: Jay Soffian <jaysoffian@gmail.com>
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* Jay Soffian <jaysoffian@gmail.com> wrote:

> > CACHE=$MERGECACHE/$HEAD_SHA1/$BRANCH_SHA1
> >
> > [ -f "$CACHE" -a "$CACHE" -nt .git/refs/heads/$BRANCH_SHA1 ] && {
> 
> Shouldn't this be:
> 
> [ -f "$CACHE" -a "$CACHE" -nt .git/refs/heads/$BRANCH ] && {
> 
> ?

yeah, i just figured it out too ... the hard way :)

Updated script below. This works fine across resets in the master 
branch.

While it's fast in the empty-merge case, it's not as fast as i'd like it 
to be in the almost-empty-merge case.

	Ingo

--------------{ git-fastmerge }-------------------->
#!/bin/bash

usage () {
  echo 'usage: tip-fastmerge <refspec>..'
  exit -1
}

[ $# = 0 ] && usage

BRANCH=$1

MERGECACHE=.git/mergecache

[ ! -d $MERGECACHE ] && { mkdir $MERGECACHE || usage; }

HEADREF=.git/$(cut -d' ' -f2 .git/HEAD)

HEAD_SHA1=$(git-log -1 --pretty=format:"%H")
BRANCH_SHA1=$(git-log -1 --pretty=format:"%H" $BRANCH)

CACHE=$MERGECACHE/$HEAD_SHA1/$BRANCH_SHA1

[ -f "$CACHE" -a "$CACHE" -nt "$HEADREF" ] && {
# echo "merge-cache hit on HEAD <= $1"
  exit 0
}

git-merge $1 && {
  mkdir -p $(dirname $CACHE)
  touch $CACHE
}