fetch: add fetch.writeCommitGraph config setting
The commit-graph feature is now on by default, and is being written during 'git gc' by default. Typically, Git only writes a commit-graph when a 'git gc --auto' command passes the gc.auto setting to actualy do work. This means that a commit-graph will typically fall behind the commits that are being used every day. To stay updated with the latest commits, add a step to 'git fetch' to write a commit-graph after fetching new objects. The fetch.writeCommitGraph config setting enables writing a split commit-graph, so on average the cost of writing this file is very small. Occasionally, the commit-graph chain will collapse to a single level, and this could be slow for very large repos. For additional use, adjust the default to be true when feature.experimental is enabled. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee committed
Sep 2, 2019 at 19:22 UTC
50f26bd035816c2bb79582b834d59b49292502a9
6 files changed
+51
Documentation/config/feature.txt
+8
@@ -17,6 +17,14 @@ which can improve `git push` performance in repos with many files.
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+
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* `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
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skipping more commits at a time, reducing the number of round trips.
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++
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+* `fetch.writeCommitGraph=true` writes a commit-graph after every `git fetch`
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+command that downloads a pack-file from a remote. Using the `--split` option,
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+most executions will create a very small commit-graph file on top of the
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+existing commit-graph file(s). Occasionally, these files will merge and the
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+write may take longer. Having an updated commit-graph file helps performance
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+of many Git commands, including `git merge-base`, `git push -f`, and
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+`git log --graph`.
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feature.manyFiles::
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Enable config options that optimize for repos with many files in the
Documentation/config/fetch.txt
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@@ -69,3 +69,13 @@ fetch.showForcedUpdates::
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Set to false to enable `--no-show-forced-updates` in
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linkgit:git-fetch[1] and linkgit:git-pull[1] commands.
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Defaults to true.
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+
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+fetch.writeCommitGraph::
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+ Set to true to write a commit-graph after every `git fetch` command
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+ that downloads a pack-file from a remote. Using the `--split` option,
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+ most executions will create a very small commit-graph file on top of
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+ the existing commit-graph file(s). Occasionally, these files will
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+ merge and the write may take longer. Having an updated commit-graph
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+ file helps performance of many Git commands, including `git merge-base`,
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+ `git push -f`, and `git log --graph`. Defaults to false, unless
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+ `feature.experimental` is true.
builtin/fetch.c
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@@ -23,6 +23,7 @@
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#include "packfile.h"
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#include "list-objects-filter-options.h"
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#include "commit-reach.h"
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+#include "commit-graph.h"
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#define FORCED_UPDATES_DELAY_WARNING_IN_MS (10 * 1000)
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@@ -1715,6 +1716,20 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
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string_list_clear(&list, 0);
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+ prepare_repo_settings(the_repository);
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+ if (the_repository->settings.fetch_write_commit_graph) {
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+ int commit_graph_flags = COMMIT_GRAPH_SPLIT;
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+ struct split_commit_graph_opts split_opts;
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+ memset(&split_opts, 0, sizeof(struct split_commit_graph_opts));
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+
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+ if (progress)
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+ commit_graph_flags |= COMMIT_GRAPH_PROGRESS;
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+
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+ write_commit_graph_reachable(get_object_directory(),
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+ commit_graph_flags,
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+ &split_opts);
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+ }
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+
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close_object_store(the_repository->objects);
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if (enable_auto_gc) {
repo-settings.c
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@@ -49,10 +49,14 @@ void prepare_repo_settings(struct repository *r)
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UPDATE_DEFAULT_BOOL(r->settings.index_version, 4);
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UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache, UNTRACKED_CACHE_WRITE);
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}
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+ if (!repo_config_get_bool(r, "fetch.writecommitgraph", &value))
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+ r->settings.fetch_write_commit_graph = value;
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if (!repo_config_get_bool(r, "feature.experimental", &value) && value) {
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UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
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UPDATE_DEFAULT_BOOL(r->settings.fetch_negotiation_algorithm, FETCH_NEGOTIATION_SKIPPING);
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+ UPDATE_DEFAULT_BOOL(r->settings.fetch_write_commit_graph, 1);
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}
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+ UPDATE_DEFAULT_BOOL(r->settings.fetch_write_commit_graph, 0);
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/* Hack for test programs like test-dump-untracked-cache */
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if (ignore_untracked_cache_config)
repository.h
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@@ -30,6 +30,7 @@ struct repo_settings {
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int core_commit_graph;
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int gc_write_commit_graph;
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+ int fetch_write_commit_graph;
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int index_version;
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enum untracked_cache_setting core_untracked_cache;
t/t5510-fetch.sh
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@@ -570,6 +570,19 @@ test_expect_success 'LHS of refspec follows ref disambiguation rules' '
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)
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'
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+test_expect_success 'fetch.writeCommitGraph' '
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+ git clone three write &&
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+ (
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+ cd three &&
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+ test_commit new
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+ ) &&
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+ (
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+ cd write &&
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+ git -c fetch.writeCommitGraph fetch origin &&
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+ test_path_is_file .git/objects/info/commit-graphs/commit-graph-chain
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+ )
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+'
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+
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# configured prune tests
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set_config_tristate () {