Merge branch 'ds/feature-macros' into pu

A mechanism to affect the default setting for a (related) group of
configuration variables is introduced.

* ds/feature-macros:
  repo-settings: create feature.experimental setting
  repo-settings: create feature.manyFiles setting
  repo-settings: parse core.untrackedCache
  commit-graph: turn on commit-graph by default
  t6501: use 'git gc' in quiet mode
  repo-settings: consolidate some config settings

Documentation/config.txt

@@ -345,6 +345,8 @@ include::config/difftool.txt[]
 
 include::config/fastimport.txt[]
 
+include::config/feature.txt[]
+
 include::config/fetch.txt[]
 
 include::config/format.txt[]

Documentation/config/core.txt

@@ -86,7 +86,9 @@ core.untrackedCache::
 	it will automatically be removed, if set to `false`. Before
 	setting it to `true`, you should check that mtime is working
 	properly on your system.
-	See linkgit:git-update-index[1]. `keep` by default.
+	See linkgit:git-update-index[1]. `keep` by default, unless
+	`feature.manyFiles` is enabled which sets this setting to
+	`true` by default.
 
 core.checkStat::
 	When missing or is set to `default`, many fields in the stat
@@ -577,7 +579,7 @@ the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
 core.commitGraph::
 	If true, then git will read the commit-graph file (if it exists)
-	to parse the graph structure of commits. Defaults to false. See
+	to parse the graph structure of commits. Defaults to true. See
 	linkgit:git-commit-graph[1] for more information.
 
 core.useReplaceRefs::

Documentation/config/feature.txt

@@ -0,0 +1,29 @@
+feature.*::
+	The config settings that start with `feature.` modify the defaults of
+	a group of other config settings. These groups are created by the Git
+	developer community as recommended defaults and are subject to change.
+	In particular, new config options may be added with different defaults.
+
+feature.experimental::
+	Enable config options that are new to Git, and are being considered for
+	future defaults. Config settings included here may be added or removed
+	with each release, including minor version updates. These settings may
+	have unintended interactions since they are so new. Please enable this
+	setting if you are interested in providing feedback on experimental
+	features. The new default values are:
++
+* `pack.useSparse=true` uses a new algorithm when constructing a pack-file
+which can improve `git push` performance in repos with many files.
++
+* `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
+skipping more commits at a time, reducing the number of round trips.
+
+feature.manyFiles::
+	Enable config options that optimize for repos with many files in the
+	working directory. With many files, commands such as `git status` and
+	`git checkout` may be slow and these new defaults improve performance:
++
+* `index.version=4` enables path-prefix compression in the index.
++
+* `core.untrackedCache=true` enables the untracked cache. This setting assumes
+that mtime is working on your machine.

Documentation/config/fetch.txt

@@ -59,7 +59,8 @@ fetch.negotiationAlgorithm::
 	effort to converge faster, but may result in a larger-than-necessary
 	packfile; The default is "default" which instructs Git to use the default algorithm
 	that never skips commits (unless the server has acknowledged it or one
-	of its descendants).
+	of its descendants). If `feature.experimental` is enabled, then this
+	setting defaults to "skipping".
 	Unknown values will cause 'git fetch' to error out.
 +
 See also the `--negotiation-tip` option for linkgit:git-fetch[1].

Documentation/config/gc.txt

@@ -63,7 +63,7 @@ gc.writeCommitGraph::
 	If true, then gc will rewrite the commit-graph file when
 	linkgit:git-gc[1] is run. When using `git gc --auto`
 	the commit-graph will be updated if housekeeping is
-	required. Default is false. See linkgit:git-commit-graph[1]
+	required. Default is true. See linkgit:git-commit-graph[1]
 	for details.
 
 gc.logExpiry::

Documentation/config/index.txt

@@ -24,3 +24,4 @@ index.threads::
 index.version::
 	Specify the version with which new index files should be
 	initialized.  This does not affect existing repositories.
+	If `feature.manyFiles` is enabled, then the default is 4.

Documentation/config/pack.txt

@@ -112,7 +112,8 @@ pack.useSparse::
 	objects. This can have significant performance benefits when
 	computing a pack to send a small change. However, it is possible
 	that extra objects are added to the pack-file if the included
-	commits contain certain types of direct renames.
+	commits contain certain types of direct renames. Default is `false`
+	unless `feature.experimental` is enabled.
 
 pack.writeBitmaps (deprecated)::
 	This is a deprecated synonym for `repack.writeBitmaps`.

Makefile

@@ -968,6 +968,7 @@ LIB_OBJS += refspec.o
 LIB_OBJS += ref-filter.o
 LIB_OBJS += remote.o
 LIB_OBJS += replace-object.o
+LIB_OBJS += repo-settings.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
 LIB_OBJS += resolve-undo.o

builtin/gc.c

@@ -42,7 +42,6 @@ static int aggressive_depth = 50;
 static int aggressive_window = 250;
 static int gc_auto_threshold = 6700;
 static int gc_auto_pack_limit = 50;
-static int gc_write_commit_graph;
 static int detach_auto = 1;
 static timestamp_t gc_log_expire_time;
 static const char *gc_log_expire = "1.day.ago";
@@ -149,7 +148,6 @@ static void gc_config(void)
 	git_config_get_int("gc.aggressivedepth", &aggressive_depth);
 	git_config_get_int("gc.auto", &gc_auto_threshold);
 	git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
-	git_config_get_bool("gc.writecommitgraph", &gc_write_commit_graph);
 	git_config_get_bool("gc.autodetach", &detach_auto);
 	git_config_get_expiry("gc.pruneexpire", &prune_expire);
 	git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
@@ -686,11 +684,11 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 		clean_pack_garbage();
 	}
 
-	if (gc_write_commit_graph &&
-	    write_commit_graph_reachable(get_object_directory(),
-					 !quiet && !daemonized ? COMMIT_GRAPH_WRITE_PROGRESS : 0,
-					 NULL))
-		return 1;
+	prepare_repo_settings(the_repository);
+	if (the_repository->settings.gc_write_commit_graph == 1)
+		write_commit_graph_reachable(get_object_directory(),
+					     !quiet && !daemonized ? COMMIT_GRAPH_WRITE_PROGRESS : 0,
+					     NULL);
 
 	if (auto_gc && too_many_loose_objects())
 		warning(_("There are too many unreachable loose objects; "

builtin/pack-objects.c

@@ -2704,10 +2704,6 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 		use_bitmap_index_default = git_config_bool(k, v);
 		return 0;
 	}
-	if (!strcmp(k, "pack.usesparse")) {
-		sparse = git_config_bool(k, v);
-		return 0;
-	}
 	if (!strcmp(k, "pack.threads")) {
 		delta_search_threads = git_config_int(k, v);
 		if (delta_search_threads < 0)
@@ -3332,6 +3328,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	read_replace_refs = 0;
 
 	sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
+	prepare_repo_settings(the_repository);
+	if (!sparse && the_repository->settings.pack_use_sparse != -1)
+		sparse = the_repository->settings.pack_use_sparse;
+
 	reset_pack_idx_option(&pack_idx_opts);
 	git_config(git_pack_config, NULL);
 

builtin/update-index.c

@@ -966,6 +966,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 	struct parse_opt_ctx_t ctx;
 	strbuf_getline_fn getline_fn;
 	int parseopt_state = PARSE_OPT_UNKNOWN;
+	struct repository *r = the_repository;
 	struct option options[] = {
 		OPT_BIT('q', NULL, &refresh_args.flags,
 			N_("continue refresh even when index needs update"),
@@ -1180,11 +1181,12 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		remove_split_index(&the_index);
 	}
 
+	prepare_repo_settings(r);
 	switch (untracked_cache) {
 	case UC_UNSPECIFIED:
 		break;
 	case UC_DISABLE:
-		if (git_config_get_untracked_cache() == 1)
+		if (r->settings.core_untracked_cache == UNTRACKED_CACHE_WRITE)
 			warning(_("core.untrackedCache is set to true; "
 				  "remove or change it, if you really want to "
 				  "disable the untracked cache"));
@@ -1196,7 +1198,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		return !test_if_untracked_cache_is_supported();
 	case UC_ENABLE:
 	case UC_FORCE:
-		if (git_config_get_untracked_cache() == 0)
+		if (r->settings.core_untracked_cache == UNTRACKED_CACHE_REMOVE)
 			warning(_("core.untrackedCache is set to false; "
 				  "remove or change it, if you really want to "
 				  "enable the untracked cache"));

commit-graph.c

@@ -467,7 +467,6 @@ static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
 static int prepare_commit_graph(struct repository *r)
 {
 	struct object_directory *odb;
-	int config_value;
 
 	if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
 		die("dying as requested by the '%s' variable on commit-graph load!",
@@ -477,9 +476,10 @@ static int prepare_commit_graph(struct repository *r)
 		return !!r->objects->commit_graph;
 	r->objects->commit_graph_attempted = 1;
 
+	prepare_repo_settings(r);
+
 	if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
-	    (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
-	    !config_value))
+	    r->settings.core_commit_graph != 1)
 		/*
 		 * This repository is not configured to use commit graphs, so
 		 * do not load one. (But report commit_graph_attempted anyway

config.c

@@ -2283,30 +2283,6 @@ int git_config_get_expiry_in_days(const char *key, timestamp_t *expiry, timestam
 	return -1; /* thing exists but cannot be parsed */
 }
 
-int git_config_get_untracked_cache(void)
-{
-	int val = -1;
-	const char *v;
-
-	/* Hack for test programs like test-dump-untracked-cache */
-	if (ignore_untracked_cache_config)
-		return -1;
-
-	if (!git_config_get_maybe_bool("core.untrackedcache", &val))
-		return val;
-
-	if (!git_config_get_value("core.untrackedcache", &v)) {
-		if (!strcasecmp(v, "keep"))
-			return -1;
-
-		error(_("unknown core.untrackedCache value '%s'; "
-			"using 'keep' default value"), v);
-		return -1;
-	}
-
-	return -1; /* default value */
-}
-
 int git_config_get_split_index(void)
 {
 	int val;

fetch-negotiator.c

@@ -2,19 +2,20 @@
 #include "fetch-negotiator.h"
 #include "negotiator/default.h"
 #include "negotiator/skipping.h"
+#include "repository.h"
 
-void fetch_negotiator_init(struct fetch_negotiator *negotiator,
-			   const char *algorithm)
+void fetch_negotiator_init(struct repository *r,
+			   struct fetch_negotiator *negotiator)
 {
-	if (algorithm) {
-		if (!strcmp(algorithm, "skipping")) {
-			skipping_negotiator_init(negotiator);
-			return;
-		} else if (!strcmp(algorithm, "default")) {
-			/* Fall through to default initialization */
-		} else {
-			die("unknown fetch negotiation algorithm '%s'", algorithm);
-		}
+	prepare_repo_settings(r);
+	switch(r->settings.fetch_negotiation_algorithm) {
+	case FETCH_NEGOTIATION_SKIPPING:
+		skipping_negotiator_init(negotiator);
+		return;
+
+	case FETCH_NEGOTIATION_DEFAULT:
+	default:
+		default_negotiator_init(negotiator);
+		return;
 	}
-	default_negotiator_init(negotiator);
 }

fetch-negotiator.h

@@ -2,6 +2,7 @@
 #define FETCH_NEGOTIATOR_H
 
 struct commit;
+struct repository;
 
 /*
  * An object that supplies the information needed to negotiate the contents of
@@ -52,7 +53,7 @@ struct fetch_negotiator {
 	void *data;
 };
 
-void fetch_negotiator_init(struct fetch_negotiator *negotiator,
-			   const char *algorithm);
+void fetch_negotiator_init(struct repository *r,
+			   struct fetch_negotiator *negotiator);
 
 #endif

fetch-pack.c

@@ -36,7 +36,6 @@ static int agent_supported;
 static int server_supports_filtering;
 static struct lock_file shallow_lock;
 static const char *alternate_shallow_file;
-static char *negotiation_algorithm;
 static struct strbuf fsck_msg_types = STRBUF_INIT;
 
 /* Remember to update object flag allocation in object.h */
@@ -889,12 +888,13 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 				 struct shallow_info *si,
 				 char **pack_lockfile)
 {
+	struct repository *r = the_repository;
 	struct ref *ref = copy_ref_list(orig_ref);
 	struct object_id oid;
 	const char *agent_feature;
 	int agent_len;
 	struct fetch_negotiator negotiator;
-	fetch_negotiator_init(&negotiator, negotiation_algorithm);
+	fetch_negotiator_init(r, &negotiator);
 
 	sort_ref_list(&ref, ref_compare_name);
 	QSORT(sought, nr_sought, cmp_ref_by_name);
@@ -908,7 +908,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 
 	if (server_supports("shallow"))
 		print_verbose(args, _("Server supports %s"), "shallow");
-	else if (args->depth > 0 || is_repository_shallow(the_repository))
+	else if (args->depth > 0 || is_repository_shallow(r))
 		die(_("Server does not support shallow clients"));
 	if (args->depth > 0 || args->deepen_since || args->deepen_not)
 		args->deepen = 1;
@@ -1373,14 +1373,15 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 				    struct shallow_info *si,
 				    char **pack_lockfile)
 {
+	struct repository *r = the_repository;
 	struct ref *ref = copy_ref_list(orig_ref);
 	enum fetch_state state = FETCH_CHECK_LOCAL;
 	struct oidset common = OIDSET_INIT;
 	struct packet_reader reader;
 	int in_vain = 0;
 	int haves_to_send = INITIAL_FLUSH;
 	struct fetch_negotiator negotiator;
-	fetch_negotiator_init(&negotiator, negotiation_algorithm);
+	fetch_negotiator_init(r, &negotiator);
 	packet_reader_init(&reader, fd[0], NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_DIE_ON_ERR_PACKET);
@@ -1499,8 +1500,6 @@ static void fetch_pack_config(void)
 	git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
 	git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
 	git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
-	git_config_get_string("fetch.negotiationalgorithm",
-			      &negotiation_algorithm);
 
 	git_config(fetch_pack_config_cb, NULL);
 }