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author | Taylor Blau <me@ttaylorr.com> | 2020-04-14 07:04:17 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2020-04-15 19:20:28 +0300 |
commit | 8a6ac287b2ba5f75bb2d9409dd97e9b501daf253 (patch) | |
tree | ed0fc9f67c9d9369cd12530cf885da21128d797d /t/t5324-split-commit-graph.sh | |
parent | fdbde82fe523374b3c5d1f0f01f3c43dcaca9465 (diff) |
builtin/commit-graph.c: introduce split strategy 'replace'
When using split commit-graphs, it is sometimes useful to completely
replace the commit-graph chain with a new base.
For example, consider a scenario in which a repository builds a new
commit-graph incremental for each push. Occasionally (say, after some
fixed number of pushes), they may wish to rebuild the commit-graph chain
with all reachable commits.
They can do so with
$ git commit-graph write --reachable
but this removes the chain entirely and replaces it with a single
commit-graph in 'objects/info/commit-graph'. Unfortunately, this means
that the next push will have to move this commit-graph into the first
layer of a new chain, and then write its new commits on top.
Avoid such copying entirely by allowing the caller to specify that they
wish to replace the entirety of their commit-graph chain, while also
specifying that the new commit-graph should become the basis of a fresh,
length-one chain.
This addresses the above situation by making it possible for the caller
to instead write:
$ git commit-graph write --reachable --split=replace
which writes a new length-one chain to 'objects/info/commit-graphs',
making the commit-graph incremental generated by the subsequent push
relatively cheap by avoiding the aforementioned copy.
In order to do this, remove an assumption in 'write_commit_graph_file'
that chains are always at least two incrementals long.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/t5324-split-commit-graph.sh')
-rwxr-xr-x | t/t5324-split-commit-graph.sh | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh index 29de47e834..87a9148fbe 100755 --- a/t/t5324-split-commit-graph.sh +++ b/t/t5324-split-commit-graph.sh @@ -355,4 +355,23 @@ test_expect_success '--split=no-merge always writes an incremental' ' test_line_count = 2 $graphdir/commit-graph-chain ' +test_expect_success '--split=replace replaces the chain' ' + rm -rf $graphdir $infodir/commit-graph && + git reset --hard commits/3 && + git rev-list -1 HEAD~2 >a && + git rev-list -1 HEAD~1 >b && + git rev-list -1 HEAD >c && + git commit-graph write --split=no-merge --stdin-commits <a && + git commit-graph write --split=no-merge --stdin-commits <b && + git commit-graph write --split=no-merge --stdin-commits <c && + test_line_count = 3 $graphdir/commit-graph-chain && + git commit-graph write --stdin-commits --split=replace <b && + test_path_is_missing $infodir/commit-graph && + test_path_is_file $graphdir/commit-graph-chain && + ls $graphdir/graph-*.graph >graph-files && + test_line_count = 1 graph-files && + verify_chain_files_exist $graphdir && + graph_read_expect 2 +' + test_done |