#!/bin/sh
#
# Copyright (c) 2005 Linus Torvalds
#

OPTIONS_KEEPDASHDASH=
OPTIONS_SPEC="\
git repack [options]
--
a               pack everything in a single pack
A               same as -a, and turn unreachable objects loose
d               remove redundant packs, and run git-prune-packed
f               pass --no-reuse-delta to git-pack-objects
F               pass --no-reuse-object to git-pack-objects
n               do not run git-update-server-info
q,quiet         be quiet
l               pass --local to git-pack-objects
unpack-unreachable=  with -A, do not loosen objects older than this
 Packing constraints
window=         size of the window used for delta compression
window-memory=  same as the above, but limit memory size instead of entries count
depth=          limits the maximum delta depth
max-pack-size=  maximum size of each packfile
"
SUBDIRECTORY_OK='Yes'
. git-sh-setup

no_update_info= all_into_one= remove_redundant= unpack_unreachable=
local= no_reuse= extra=
while test $# != 0
do
        case "$1" in
        -n)     no_update_info=t ;;
        -a)     all_into_one=t ;;
        -A)     all_into_one=t
                unpack_unreachable=--unpack-unreachable ;;
        --unpack-unreachable)
                unpack_unreachable="--unpack-unreachable=$2"; shift ;;
        -d)     remove_redundant=t ;;
        -q)     GIT_QUIET=t ;;
        -f)     no_reuse=--no-reuse-delta ;;
        -F)     no_reuse=--no-reuse-object ;;
        -l)     local=--local ;;
        --max-pack-size|--window|--window-memory|--depth)
                extra="$extra $1=$2"; shift ;;
        --) shift; break;;
        *)      usage ;;
        esac
        shift
done

case "$(git config --bool repack.usedeltabaseoffset || echo true)" in
true)
        extra="$extra --delta-base-offset" ;;
esac

PACKDIR="$GIT_OBJECT_DIRECTORY/pack"
PACKTMP="$PACKDIR/.tmp-$$-pack"
rm -f "$PACKTMP"-*
trap 'rm -f "$PACKTMP"-*' 0 1 2 3 15

# There will be more repacking strategies to come...
case ",$all_into_one," in
,,)
        args='--unpacked --incremental'
        ;;
,t,)
        args= existing=
        if [ -d "$PACKDIR" ]; then
                for e in `cd "$PACKDIR" && find . -type f -name '*.pack' \
                        | sed -e 's/^\.\///' -e 's/\.pack$//'`
                do
                        if [ -e "$PACKDIR/$e.keep" ]; then
                                : keep
                        else
                                existing="$existing $e"
                        fi
                done
                if test -n "$existing" -a -n "$unpack_unreachable" -a \
                        -n "$remove_redundant"
                then
                        # This may have arbitrary user arguments, so we
                        # have to protect it against whitespace splitting
                        # when it gets run as "pack-objects $args" later.
                        # Fortunately, we know it's an approxidate, so we
                        # can just use dots instead.
                        args="$args $(echo "$unpack_unreachable" | tr ' ' .)"
                fi
        fi
        ;;
esac

mkdir -p "$PACKDIR" || exit

args="$args $local ${GIT_QUIET:+-q} $no_reuse$extra"
names=$(git pack-objects --keep-true-parents --honor-pack-keep --non-empty --all --reflog $args </dev/null "$PACKTMP") ||
        exit 1
if [ -z "$names" ]; then
        say Nothing new to pack.
fi

# Ok we have prepared all new packfiles.

# First see if there are packs of the same name and if so
# if we can move them out of the way (this can happen if we
# repacked immediately after packing fully.
rollback=
failed=
for name in $names
do
        for sfx in pack idx
        do
                file=pack-$name.$sfx
                test -f "$PACKDIR/$file" || continue
                rm -f "$PACKDIR/old-$file" &&
                mv "$PACKDIR/$file" "$PACKDIR/old-$file" || {
                        failed=t
                        break
                }
                rollback="$rollback $file"
        done
        test -z "$failed" || break
done

# If renaming failed for any of them, roll the ones we have
# already renamed back to their original names.
if test -n "$failed"
then
        rollback_failure=
        for file in $rollback
        do
                mv "$PACKDIR/old-$file" "$PACKDIR/$file" ||
                rollback_failure="$rollback_failure $file"
        done
        if test -n "$rollback_failure"
        then
                echo >&2 "WARNING: Some packs in use have been renamed by"
                echo >&2 "WARNING: prefixing old- to their name, in order to"
                echo >&2 "WARNING: replace them with the new version of the"
                echo >&2 "WARNING: file.  But the operation failed, and"
                echo >&2 "WARNING: attempt to rename them back to their"
                echo >&2 "WARNING: original names also failed."
                echo >&2 "WARNING: Please rename them in $PACKDIR manually:"
                for file in $rollback_failure
                do
                        echo >&2 "WARNING:   old-$file -> $file"
                done
        fi
        exit 1
fi

# Now the ones with the same name are out of the way...
fullbases=
for name in $names
do
        fullbases="$fullbases pack-$name"
        chmod a-w "$PACKTMP-$name.pack"
        chmod a-w "$PACKTMP-$name.idx"
        mv -f "$PACKTMP-$name.pack" "$PACKDIR/pack-$name.pack" &&
        mv -f "$PACKTMP-$name.idx"  "$PACKDIR/pack-$name.idx" ||
        exit
done

# Remove the "old-" files
for name in $names
do
        rm -f "$PACKDIR/old-pack-$name.idx"
        rm -f "$PACKDIR/old-pack-$name.pack"
done

# End of pack replacement.

if test "$remove_redundant" = t
then
        # We know $existing are all redundant.
        if [ -n "$existing" ]
        then
                ( cd "$PACKDIR" &&
                  for e in $existing
                  do
                        case " $fullbases " in
                        *" $e "*) ;;
                        *)      rm -f "$e.pack" "$e.idx" "$e.keep" ;;
                        esac
                  done
                )
        fi
        git prune-packed ${GIT_QUIET:+-q}
fi

case "$no_update_info" in
t) : ;;
*) git update-server-info ;;
esac