Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
> We might make it something like: "if you use an url, we don't default to
> local", so the difference would be that
>
> git clone file:///directory/to/repo
>
> would work the way it does now, but
>
> git clone /directory/to/repo
>
> would default to "-l" behaviour. That kind of would make sense (and should
> be easy to implement: it would be a trivial fixup to "connect.c".
The attached does not default to "-l", but filesystem level copy
behaviour, which is what happens with "clone -l" across
filesystem boundaries with the current code.
Clone of linux-2.6 repository (the source is well packed)
(hardlink -- obviously, almost no cost)
$ /usr/bin/time git clone -l --bare linux-2.6 l-clone.git
Initialized empty Git repository in /git/l-clone.git/
0 blocks
0.55user 1.00system 0:01.56elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+206724minor)pagefaults 0swaps
(same-as-network)
$ /usr/bin/time git clone --bare file://`pwd`/linux-2.6 n-clone.git
Initialized empty Git repository in /git/n-clone.git/
remote: Generating pack...
remote: Counting objects: 1076746
remote: Done counting 1169654 objects.
remote: Deltifying 1169654 objects...
remote: 100% (1169654/1169654) done
Indexing 1169654 objects...
100% (1169654/1169654) done
remote: Total 1169654 (delta 959223), reused 1160595 (delta 950164)
Resolving 959223 deltas...
100% (959223/959223) done
172.85user 20.94system 4:25.88elapsed 72%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (6294major+2019874minor)pagefaults 0swaps
(copy -- takes a lot more than hardlink but cheaper than net)
$ /usr/bin/time git clone --bare linux-2.6 c-clone.git
Initialized empty Git repository in /git/c-clone.git/
1266644 blocks
0.92user 10.81system 0:38.38elapsed 30%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (406major+204775minor)pagefaults 0swaps
I am ambivalent between -l vs no -l.
* Without -l (i.e. have all objects/ copied via cpio) would not
catch the source repository corruption, and also risks
corrupted recipient repository if an alpha-particle hits
memory cell while indexing and resolving deltas. As long as
the recipient is made uncorrupted, you have a good back-up.
* same-as-network is expensive, but it would catch if the
source is already corrupted. It still risks corrupted
recipient repository. As long as the recipient is made
uncorrupted, you have a good back-up.
* With -l, as long as the source repository is healthy, it is
very likely that the recipient would be, too. Also it is
very cheap. You do not get any back-up benefit.
None of the method is resilient against the source repository
corruption, so let's discount that from the comparison. Then
the differences between -l and non -l matters primarily if you
value the back-up benefit or not. If you want to use the cloned
repository as a back-up, then it is cheaper to do a non -l clone
and two git-fsck (source before clone, recipient after clone)
than same-as-network clone, especially as you are likely to do a
git-fsck on the recipient if you are so paranoid anyway.
Which leads me to believe that being able to use file:/// is
probably a good idea, if only for testability, but probably of
little practical value, and we can default to -l for everyday
use, and paranoids can use non -l as a way to make a back-up.
---
git-clone.sh | 61 +++++++++++++++++++++++---------------------
t/t5500-fetch-pack.sh | 2 +-
t/t5700-clone-reference.sh | 2 +-
t/t5701-clone-local.sh | 17 ++++++++++++
4 files changed, 51 insertions(+), 31 deletions(-)
diff --git a/git-clone.sh b/git-clone.sh
index 0922554..0583f64 100755
--- a/git-clone.sh
+++ b/git-clone.sh
@@ -87,7 +87,7 @@ Perhaps git-update-server-info needs to be run there?"
quiet=
local=no
-use_local=no
+use_local_hardlink=no
local_shared=no
unset template
no_checkout=
@@ -108,9 +108,10 @@ while
no_checkout=yes ;;
*,--na|*,--nak|*,--nake|*,--naked|\
*,-b|*,--b|*,--ba|*,--bar|*,--bare) bare=yes ;;
- *,-l|*,--l|*,--lo|*,--loc|*,--loca|*,--local) use_local=yes ;;
+ *,-l|*,--l|*,--lo|*,--loc|*,--loca|*,--local)
+ use_local_hardlink=yes ;;
*,-s|*,--s|*,--sh|*,--sha|*,--shar|*,--share|*,--shared)
- local_shared=yes; use_local=yes ;;
+ local_shared=yes; ;;
1,--template) usage ;;
*,--template)
shift; template="--template=$1" ;;
@@ -249,34 +250,36 @@ fi
rm -f "$GIT_DIR/CLONE_HEAD"
# We do local magic only when the user tells us to.
-case "$local,$use_local" in
-yes,yes)
+case "$local" in
+yes)
( cd "$repo/objects" ) ||
- die "-l flag seen but repository '$repo' is not local."
+ die "cannot chdir to local '$repo/objects'."
- case "$local_shared" in
- no)
- # See if we can hardlink and drop "l" if not.
- sample_file=$(cd "$repo" && \
- find objects -type f -print | sed -e 1q)
-
- # objects directory should not be empty since we are cloning!
- test -f "$repo/$sample_file" || exit
-
- l=
- if ln "$repo/$sample_file" "$GIT_DIR/objects/sample" 2>/dev/null
- then
- l=l
- fi &&
- rm -f "$GIT_DIR/objects/sample" &&
- cd "$repo" &&
- find objects -depth -print | cpio -pumd$l "$GIT_DIR/" || exit 1
- ;;
- yes)
- mkdir -p "$GIT_DIR/objects/info"
- echo "$repo/objects" >> "$GIT_DIR/objects/info/alternates"
- ;;
- esac
+ if test "$local_shared" = yes
+ then
+ mkdir -p "$GIT_DIR/objects/info"
+ echo "$repo/objects" >>"$GIT_DIR/objects/info/alternates"
+ else
+ l= &&
+ if test "$use_local_hardlink" = yes
+ then
+ # See if we can hardlink and drop "l" if not.
+ sample_file=$(cd "$repo" && \
+ find objects -type f -print | sed -e 1q)
+ # objects directory should not be empty because
+ # we are cloning!
+ test -f "$repo/$sample_file" || exit
+ if ln "$repo/$sample_file" "$GIT_DIR/objects/sample" 2>/dev/null
+ then
+ rm -f "$GIT_DIR/objects/sample"
+ l=l
+ else
+ echo >&2 "Warning: -l asked but cannot hardlink to $repo"
+ fi
+ fi &&
+ cd "$repo" &&
+ find objects -depth -print | cpio -pumd$l "$GIT_DIR/" || exit 1
+ fi
git-ls-remote "$repo" >"$GIT_DIR/CLONE_HEAD" || exit 1
;;
*)
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 7da5153..7b6798d 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -129,7 +129,7 @@ pull_to_client 2nd "B" $((64*3))
pull_to_client 3rd "A" $((1*3)) # old fails
-test_expect_success "clone shallow" "git-clone --depth 2 . shallow"
+test_expect_success "clone shallow" "git-clone --depth 2 file://`pwd`/. shallow"
(cd shallow; git count-objects -v) > count.shallow
diff --git a/t/t5700-clone-reference.sh b/t/t5700-clone-reference.sh
index 6d43252..4e93aaa 100755
--- a/t/t5700-clone-reference.sh
+++ b/t/t5700-clone-reference.sh
@@ -51,7 +51,7 @@ diff expected current'
cd "$base_dir"
test_expect_success 'cloning with reference (no -l -s)' \
-'git clone --reference B A D'
+'git clone --reference B file://`pwd`/A D'
cd "$base_dir"
diff --git a/t/t5701-clone-local.sh b/t/t5701-clone-local.sh
index b093327..032c498 100755
--- a/t/t5701-clone-local.sh
+++ b/t/t5701-clone-local.sh
@@ -43,4 +43,21 @@ test_expect_success 'local clone from x.git that does not exist' '
fi
'
+test_expect_success 'Without -l, local will make a copy' '
+ cd "$D" &&
+ git clone --bare x w &&
+ cd w &&
+ linked=$(find objects -type f ! -links 1 | wc -l) &&
+ test "$linked" = 0
+'
+
+test_expect_success 'With -l, local will make a hardlink' '
+ cd "$D" &&
+ rm -fr w &&
+ git clone -l --bare x w &&
+ cd w &&
+ copied=$(find objects -type f -links 1 | wc -l) &&
+ test "$copied" = 0
+'
+
test_done
-
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