git/hook.c
Ævar Arnfjörð Bjarmason a082345372 hook API: fix v2.36.0 regression: hooks should be connected to a TTY
Fix a regression reported[1] against f443246b9f (commit: convert
{pre-commit,prepare-commit-msg} hook to hook.h, 2021-12-22): Due to
using the run_process_parallel() API in the earlier 96e7225b31 (hook:
add 'run' subcommand, 2021-12-22) we'd capture the hook's stderr and
stdout, and thus lose the connection to the TTY in the case of
e.g. the "pre-commit" hook.

As a preceding commit notes GNU parallel's similar --ungroup option
also has it emit output faster. While we're unlikely to have hooks
that emit truly massive amounts of output (or where the performance
thereof matters) it's still informative to measure the overhead. In a
similar "seq" test we're now ~30% faster:

	$ cat .git/hooks/seq-hook; git hyperfine -L rev origin/master,HEAD~0 -s 'make CFLAGS=-O3' './git hook run seq-hook'
	#!/bin/sh

	seq 100000000
	Benchmark 1: ./git hook run seq-hook' in 'origin/master
	  Time (mean ± σ):     787.1 ms ±  13.6 ms    [User: 701.6 ms, System: 534.4 ms]
	  Range (min … max):   773.2 ms … 806.3 ms    10 runs

	Benchmark 2: ./git hook run seq-hook' in 'HEAD~0
	  Time (mean ± σ):     603.4 ms ±   1.6 ms    [User: 573.1 ms, System: 30.3 ms]
	  Range (min … max):   601.0 ms … 606.2 ms    10 runs

	Summary
	  './git hook run seq-hook' in 'HEAD~0' ran
	    1.30 ± 0.02 times faster than './git hook run seq-hook' in 'origin/master'

1. https://lore.kernel.org/git/CA+dzEBn108QoMA28f0nC8K21XT+Afua0V2Qv8XkR8rAeqUCCZw@mail.gmail.com/

Reported-by: Anthony Sottile <asottile@umich.edu>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
[jc: minor fix-up to tests for consistency]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-07 11:13:20 -07:00

182 lines
3.8 KiB
C

#include "cache.h"
#include "hook.h"
#include "run-command.h"
#include "config.h"
const char *find_hook(const char *name)
{
static struct strbuf path = STRBUF_INIT;
strbuf_reset(&path);
strbuf_git_path(&path, "hooks/%s", name);
if (access(path.buf, X_OK) < 0) {
int err = errno;
#ifdef STRIP_EXTENSION
strbuf_addstr(&path, STRIP_EXTENSION);
if (access(path.buf, X_OK) >= 0)
return path.buf;
if (errno == EACCES)
err = errno;
#endif
if (err == EACCES && advice_enabled(ADVICE_IGNORED_HOOK)) {
static struct string_list advise_given = STRING_LIST_INIT_DUP;
if (!string_list_lookup(&advise_given, name)) {
string_list_insert(&advise_given, name);
advise(_("The '%s' hook was ignored because "
"it's not set as executable.\n"
"You can disable this warning with "
"`git config advice.ignoredHook false`."),
path.buf);
}
}
return NULL;
}
return path.buf;
}
int hook_exists(const char *name)
{
return !!find_hook(name);
}
static int pick_next_hook(struct child_process *cp,
struct strbuf *out,
void *pp_cb,
void **pp_task_cb)
{
struct hook_cb_data *hook_cb = pp_cb;
const char *hook_path = hook_cb->hook_path;
if (!hook_path)
return 0;
cp->no_stdin = 1;
strvec_pushv(&cp->env_array, hook_cb->options->env.v);
cp->stdout_to_stderr = 1;
cp->trace2_hook_name = hook_cb->hook_name;
cp->dir = hook_cb->options->dir;
strvec_push(&cp->args, hook_path);
strvec_pushv(&cp->args, hook_cb->options->args.v);
/* Provide context for errors if necessary */
*pp_task_cb = (char *)hook_path;
/*
* This pick_next_hook() will be called again, we're only
* running one hook, so indicate that no more work will be
* done.
*/
hook_cb->hook_path = NULL;
return 1;
}
static int notify_start_failure(struct strbuf *out,
void *pp_cb,
void *pp_task_cp)
{
struct hook_cb_data *hook_cb = pp_cb;
const char *hook_path = pp_task_cp;
hook_cb->rc |= 1;
strbuf_addf(out, _("Couldn't start hook '%s'\n"),
hook_path);
return 1;
}
static int notify_hook_finished(int result,
struct strbuf *out,
void *pp_cb,
void *pp_task_cb)
{
struct hook_cb_data *hook_cb = pp_cb;
struct run_hooks_opt *opt = hook_cb->options;
hook_cb->rc |= result;
if (opt->invoked_hook)
*opt->invoked_hook = 1;
return 0;
}
static void run_hooks_opt_clear(struct run_hooks_opt *options)
{
strvec_clear(&options->env);
strvec_clear(&options->args);
}
int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options)
{
struct strbuf abs_path = STRBUF_INIT;
struct hook_cb_data cb_data = {
.rc = 0,
.hook_name = hook_name,
.options = options,
};
const char *const hook_path = find_hook(hook_name);
int jobs = 1;
int ret = 0;
if (!options)
BUG("a struct run_hooks_opt must be provided to run_hooks");
if (options->invoked_hook)
*options->invoked_hook = 0;
if (!hook_path && !options->error_if_missing)
goto cleanup;
if (!hook_path) {
ret = error("cannot find a hook named %s", hook_name);
goto cleanup;
}
cb_data.hook_path = hook_path;
if (options->dir) {
strbuf_add_absolute_path(&abs_path, hook_path);
cb_data.hook_path = abs_path.buf;
}
run_processes_parallel_ungroup = 1;
run_processes_parallel_tr2(jobs,
pick_next_hook,
notify_start_failure,
notify_hook_finished,
&cb_data,
"hook",
hook_name);
ret = cb_data.rc;
cleanup:
strbuf_release(&abs_path);
run_hooks_opt_clear(options);
return ret;
}
int run_hooks(const char *hook_name)
{
struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
return run_hooks_opt(hook_name, &opt);
}
int run_hooks_l(const char *hook_name, ...)
{
struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
va_list ap;
const char *arg;
va_start(ap, hook_name);
while ((arg = va_arg(ap, const char *)))
strvec_push(&opt.args, arg);
va_end(ap);
return run_hooks_opt(hook_name, &opt);
}