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| author | Derrick Stolee <dstolee@microsoft.com> | 2020-09-17 21:11:46 +0300 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2020-09-17 21:30:05 +0300 |
| commit | 663b2b1b90bf76275044824ddeca96aaec240f09 (patch) | |
| tree | 1d52df4f64a22b1d9e6d99e9d11432bbe21a669e /Documentation/git-maintenance.txt | |
| parent | 3103e9848f7b7534eac14c0521d7b49b32466b70 (diff) | |
maintenance: add commit-graph task
The first new task in the 'git maintenance' builtin is the
'commit-graph' task. This updates the commit-graph file
incrementally with the command
git commit-graph write --reachable --split
By writing an incremental commit-graph file using the "--split"
option we minimize the disruption from this operation. The default
behavior is to merge layers until the new "top" layer is less than
half the size of the layer below. This provides quick writes most
of the time, with the longer writes following a power law
distribution.
Most importantly, concurrent Git processes only look at the
commit-graph-chain file for a very short amount of time, so they
will verly likely not be holding a handle to the file when we try
to replace it. (This only matters on Windows.)
If a concurrent process reads the old commit-graph-chain file, but
our job expires some of the .graph files before they can be read,
then those processes will see a warning message (but not fail).
This could be avoided by a future update to use the --expire-time
argument when writing the commit-graph.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'Documentation/git-maintenance.txt')
| -rw-r--r-- | Documentation/git-maintenance.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/git-maintenance.txt b/Documentation/git-maintenance.txt index 04fa0fe329..fc5dbcf0b9 100644 --- a/Documentation/git-maintenance.txt +++ b/Documentation/git-maintenance.txt @@ -35,6 +35,14 @@ run:: TASKS ----- +commit-graph:: + The `commit-graph` job updates the `commit-graph` files incrementally, + then verifies that the written data is correct. The incremental + write is safe to run alongside concurrent Git processes since it + will not expire `.graph` files that were in the previous + `commit-graph-chain` file. They will be deleted by a later run based + on the expiration delay. + gc:: Clean up unnecessary files and optimize the local repository. "GC" stands for "garbage collection," but this task performs many |