submodule update: expose parallelism to the user

Expose possible parallelism either via the "--jobs" CLI parameter or the "submodule.fetchJobs" setting. By having the variable initialized to -1, we make sure 0 can be passed into the parallel processing machine, which will then pick as many parallel workers as there are CPUs. Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Stefan Beller committed Feb 29, 2016 at 18:07 UTC 2335b870fa7942d9ca9e73e96e35171fda741376
4 files changed +34 -2
Documentation/git-submodule.txt
+6 -1
@@ -16,7 +16,7 @@ SYNOPSIS
16 'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
17 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
18 [-f|--force] [--rebase|--merge] [--reference <repository>]
19 - [--depth <depth>] [--recursive] [--] [<path>...]
19 + [--depth <depth>] [--recursive] [--jobs <n>] [--] [<path>...]
20 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
21 [commit] [--] [<path>...]
22 'git submodule' [--quiet] foreach [--recursive] <command>
@@ -377,6 +377,11 @@ for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
377 clone with a history truncated to the specified number of revisions.
378 See linkgit:git-clone[1]
379
380 +-j <n>::
381 +--jobs <n>::
382 + This option is only valid for the update command.
383 + Clone new submodules in parallel with as many jobs.
384 + Defaults to the `submodule.fetchJobs` option.
385
386 <path>...::
387 Paths to submodule(s). When specified this will restrict the command
builtin/submodule--helper.c
+7 -1
@@ -430,6 +430,7 @@ static int update_clone_task_finished(int result,
430 static int update_clone(int argc, const char **argv, const char *prefix)
431 {
432 const char *update = NULL;
433 + int max_jobs = -1;
434 struct string_list_item *item;
435 struct pathspec pathspec;
436 struct submodule_update_clone suc = SUBMODULE_UPDATE_CLONE_INIT;
@@ -450,6 +451,8 @@ static int update_clone(int argc, const char **argv, const char *prefix)
451 OPT_STRING(0, "depth", &suc.depth, "<depth>",
452 N_("Create a shallow clone truncated to the "
453 "specified number of revisions")),
454 + OPT_INTEGER('j', "jobs", &max_jobs,
455 + N_("parallel jobs")),
456 OPT__QUIET(&suc.quiet, N_("don't print cloning progress")),
457 OPT_END()
458 };
@@ -477,7 +480,10 @@ static int update_clone(int argc, const char **argv, const char *prefix)
480 gitmodules_config();
481 git_config(submodule_config, NULL);
482
480 - run_processes_parallel(1,
483 + if (max_jobs < 0)
484 + max_jobs = parallel_submodules();
485 +
486 + run_processes_parallel(max_jobs,
487 update_clone_get_next_task,
488 update_clone_start_failure,
489 update_clone_task_finished,
git-submodule.sh
+9
@@ -645,6 +645,14 @@ cmd_update()
645 --depth=*)
646 depth=$1
647 ;;
648 + -j|--jobs)
649 + case "$2" in '') usage ;; esac
650 + jobs="--jobs=$2"
651 + shift
652 + ;;
653 + --jobs=*)
654 + jobs=$1
655 + ;;
656 --)
657 shift
658 break
@@ -671,6 +679,7 @@ cmd_update()
679 ${update:+--update "$update"} \
680 ${reference:+--reference "$reference"} \
681 ${depth:+--depth "$depth"} \
682 + ${jobs:+$jobs} \
683 "$@" || echo "#unmatched"
684 } | {
685 err=
t/t7406-submodule-update.sh
+12
@@ -774,4 +774,16 @@ test_expect_success 'submodule update --recursive drops module name before recur
774 test_i18ngrep "Submodule path .deeper/submodule/subsubmodule.: checked out" actual
775 )
776 '
777 +
778 +test_expect_success 'submodule update can be run in parallel' '
779 + (cd super2 &&
780 + GIT_TRACE=$(pwd)/trace.out git submodule update --jobs 7 &&
781 + grep "7 tasks" trace.out &&
782 + git config submodule.fetchJobs 8 &&
783 + GIT_TRACE=$(pwd)/trace.out git submodule update &&
784 + grep "8 tasks" trace.out &&
785 + GIT_TRACE=$(pwd)/trace.out git submodule update --jobs 9 &&
786 + grep "9 tasks" trace.out
787 + )
788 +'
789 test_done