This patch series adds a new pack-refs task to the maintenance builtin. This operation already happens within git gc (and hence the gc task) but it is easy to extract. Packing refs does not delete any data, only collects loose objects into a combined file. This makes things faster in subtle ways, especially when a command needs to iterate through refs (especially tags). Credit for inspiring this goes to Suolong, who asked for this to be added to Scalar [1]. I've been waiting instead to add it directly to Git and its background maintenance. Now is the time! [1] https://github.com/microsoft/scalar/issues/382 I chose to add it to the incremental maintenance strategy at a weekly cadence. I'm not sure there is significant value to the difference between weekly and daily. It just seems to me that weekly is often enough. Feel free to correct me if you have a different opinion. My hope is that this patch series could be used as an example for further extracting tasks out of the gc task and making them be full maintenance tasks. Doing more of these extractions could be a good project for a new contributor. One thing that is not implemented in this series is a notion of the behavior for the pack-refs task during git maintenance run --auto. This could be added in the future, but I wanted to focus on getting this behavior into the incremental maintenance schedule. Updates in V2 ============= * Fixed doc typo. Thanks, Eric! * Updated commit messages to make it clear that the 'pack-refs' step will still happen within the 'gc' task. * Updated the test to check that we run the correct subcommand. * maintenance_task_pack_refs() uses MAYBE_UNUSED on its parameter. Thanks, -Stolee Cc: gitster@xxxxxxxxx Cc: sluongng@xxxxxxxxx Cc: martin.agren@xxxxxxxxx Cc: sunshine@xxxxxxxxxxxxxx Derrick Stolee (2): maintenance: add pack-refs task maintenance: incremental strategy runs pack-refs weekly Documentation/config/maintenance.txt | 5 +++-- Documentation/git-maintenance.txt | 6 ++++++ builtin/gc.c | 23 +++++++++++++++++++---- t/t7900-maintenance.sh | 26 ++++++++++++++++++++++++++ 4 files changed, 54 insertions(+), 6 deletions(-) base-commit: fb7fa4a1fd273f22efcafdd13c7f897814fd1eb9 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-871%2Fderrickstolee%2Fmaintenance%2Fpack-refs-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-871/derrickstolee/maintenance/pack-refs-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/871 Range-diff vs v1: 1: 33b7a74af4eb ! 1: bedaeb548b06 maintenance: add pack-refs task @@ Commit message by terminal prompts to show when a detatched HEAD is pointing to an existing tag, so having it be slow causes significant delays for users. - Add a new 'pack-refs' maintenance task. This is already a sub-step of - the 'gc' task, but users could run this at other intervals if they are - interested. Also, if users opt-in to the default background maintenance - schedule, then the 'gc' task is disabled. + Add a new 'pack-refs' maintenance task. It runs 'git pack-refs --all + --prune' to move loose refs into a packed form. For now, that is the + packed-refs file, but could adjust to other file formats in the future. + + This is the first of several sub-tasks of the 'gc' task that could be + extracted to their own tasks. In this process, we should not change the + behavior of the 'gc' task since that remains the default way to keep + repositories maintained. Creating a new task for one of these sub-tasks + only provides more customization options for those choosing to not use + the 'gc' task. It is certainly possible to have both the 'gc' and + 'pack-refs' tasks enabled and run regularly. While they may repeat + effort, they do not conflict in a destructive way. + + The 'auto_condition' function pointer is left NULL for now. We could + extend this in the future to have a condition check if pack-refs should + be run during 'git maintenance run --auto'. Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> @@ Documentation/git-maintenance.txt: incremental-repack:: +pack-refs:: + The `pack-refs` task collects the loose reference files and + collects them into a single file. This speeds up operations that -+ need to iterate across many refereences. See linkgit:git-pack-refs[1] ++ need to iterate across many references. See linkgit:git-pack-refs[1] + for more information. + OPTIONS @@ builtin/gc.c: static void gc_config(void) } +struct maintenance_run_opts; -+static int maintenance_task_pack_refs(struct maintenance_run_opts *opts) ++static int maintenance_task_pack_refs(MAYBE_UNUSED struct maintenance_run_opts *opts) +{ + struct strvec pack_refs_cmd = STRVEC_INIT; + strvec_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL); @@ t/t7900-maintenance.sh: test_expect_success 'maintenance.incremental-repack.auto + do + git branch -f to-pack/$n HEAD || return 1 + done && -+ git maintenance run --task=pack-refs && ++ GIT_TRACE2_EVENT="$(pwd)/pack-refs.txt" \ ++ git maintenance run --task=pack-refs && + ls .git/refs/heads/ >after && -+ test_must_be_empty after ++ test_must_be_empty after && ++ test_subcommand git pack-refs --all --prune <pack-refs.txt +' + test_expect_success '--auto and --schedule incompatible' ' 2: 8012d2dc1420 = 2: c38fc9a4170e maintenance: incremental strategy runs pack-refs weekly -- gitgitgadget
