git/repo-settings.c
Derrick Stolee 17194b195d features: feature.manyFiles implies fast index writes
The recent addition of the index.skipHash config option allows index
writes to speed up by skipping the hash computation for the trailing
checksum. This is particularly critical for repositories with many files
at HEAD, so add this config option to two cases where users in that
scenario may opt-in to such behavior:

 1. The feature.manyFiles config option enables some options that are
    helpful for repositories with many files at HEAD.

 2. 'scalar register' and 'scalar reconfigure' set config options that
    optimize for large repositories.

In both of these cases, set index.skipHash=true to gain this
speedup. Add tests that demonstrate the proper way that
index.skipHash=true can override feature.manyFiles=true.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-07 07:46:14 +09:00

117 lines
3.9 KiB
C

#include "cache.h"
#include "config.h"
#include "repository.h"
#include "midx.h"
#include "compat/fsmonitor/fsm-listen.h"
static void repo_cfg_bool(struct repository *r, const char *key, int *dest,
int def)
{
if (repo_config_get_bool(r, key, dest))
*dest = def;
}
static void repo_cfg_int(struct repository *r, const char *key, int *dest,
int def)
{
if (repo_config_get_int(r, key, dest))
*dest = def;
}
void prepare_repo_settings(struct repository *r)
{
int experimental;
int value;
const char *strval;
int manyfiles;
if (!r->gitdir)
BUG("Cannot add settings for uninitialized repository");
if (r->settings.initialized++)
return;
/* Defaults */
r->settings.index_version = -1;
r->settings.core_untracked_cache = UNTRACKED_CACHE_KEEP;
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE;
/* Booleans config or default, cascades to other settings */
repo_cfg_bool(r, "feature.manyfiles", &manyfiles, 0);
repo_cfg_bool(r, "feature.experimental", &experimental, 0);
/* Defaults modified by feature.* */
if (experimental) {
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
r->settings.gc_cruft_packs = 1;
}
if (manyfiles) {
r->settings.index_version = 4;
r->settings.index_skip_hash = 1;
r->settings.core_untracked_cache = UNTRACKED_CACHE_WRITE;
}
/* Commit graph config or default, does not cascade (simple) */
repo_cfg_bool(r, "core.commitgraph", &r->settings.core_commit_graph, 1);
repo_cfg_int(r, "commitgraph.generationversion", &r->settings.commit_graph_generation_version, 2);
repo_cfg_bool(r, "commitgraph.readchangedpaths", &r->settings.commit_graph_read_changed_paths, 1);
repo_cfg_bool(r, "gc.writecommitgraph", &r->settings.gc_write_commit_graph, 1);
repo_cfg_bool(r, "fetch.writecommitgraph", &r->settings.fetch_write_commit_graph, 0);
/* Boolean config or default, does not cascade (simple) */
repo_cfg_bool(r, "pack.usesparse", &r->settings.pack_use_sparse, 1);
repo_cfg_bool(r, "core.multipackindex", &r->settings.core_multi_pack_index, 1);
repo_cfg_bool(r, "index.sparse", &r->settings.sparse_index, 0);
repo_cfg_bool(r, "index.skiphash", &r->settings.index_skip_hash, r->settings.index_skip_hash);
/*
* The GIT_TEST_MULTI_PACK_INDEX variable is special in that
* either it *or* the config sets
* r->settings.core_multi_pack_index if true. We don't take
* the environment variable if it exists (even if false) over
* any config, as in most other cases.
*/
if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0))
r->settings.core_multi_pack_index = 1;
/*
* Non-boolean config
*/
if (!repo_config_get_int(r, "index.version", &value))
r->settings.index_version = value;
if (!repo_config_get_string_tmp(r, "core.untrackedcache", &strval)) {
int v = git_parse_maybe_bool(strval);
/*
* If it's set to "keep", or some other non-boolean
* value then "v < 0". Then we do nothing and keep it
* at the default of UNTRACKED_CACHE_KEEP.
*/
if (v >= 0)
r->settings.core_untracked_cache = v ?
UNTRACKED_CACHE_WRITE : UNTRACKED_CACHE_REMOVE;
}
if (!repo_config_get_string_tmp(r, "fetch.negotiationalgorithm", &strval)) {
int fetch_default = r->settings.fetch_negotiation_algorithm;
if (!strcasecmp(strval, "skipping"))
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
else if (!strcasecmp(strval, "noop"))
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_NOOP;
else if (!strcasecmp(strval, "consecutive"))
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE;
else if (!strcasecmp(strval, "default"))
r->settings.fetch_negotiation_algorithm = fetch_default;
else
die("unknown fetch negotiation algorithm '%s'", strval);
}
/*
* This setting guards all index reads to require a full index
* over a sparse index. After suitable guards are placed in the
* codebase around uses of the index, this setting will be
* removed.
*/
r->settings.command_requires_full_index = 1;
}