mirror/ git
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-05-05 17:36:18 +02:00
Code

send-email: lazily load config for a big speedup 

Reduce the time it takes git-send-email to get to even the most
trivial of tasks (such as serving up its "-h" output) by first listing
config keys that exist, and only then only call e.g. "git config
--bool" on them if they do.

Over a lot of runs this speeds the time to "-h" up for me from ~250ms
to ~150ms, and the runtime of t9001-send-email.sh goes from ~25s to
~20s.

This introduces a race condition where we'll do the "wrong" thing if a
config key were to be inserted between us discovering the list and
calling read_config(), i.e. we won't know about the racily added
key. In theory this is a change in behavior, in practice it doesn't
matter.

The config_regexp() function being changed here was added in
dd84e528a3 (git-send-email: die if sendmail.* config is set,
2020-07-23) for use by git-send-email. So we can change its odd return
value in the case where no values are found by "git config". The
difference in the *.pm code would matter if it was invoked in scalar
context, but now it no longer is.

Arguably this caching belongs in Git.pm itself, but in lieu of
modifying it for all its callers let's only do this for "git
send-email". The other big potential win would be "git svn", but
unlike "git send-email" it doesn't check tens of config variables one
at a time at startup (in my brief testing it doesn't check any).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Ævar Arnfjörð Bjarmason 2021-05-28 11:23:45 +02:00 committed by Junio C Hamano
parent 2b110e9ba2
commit 9264d29bf6
1 changed files with 26 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
git-send-email.perl
View File

@ -347,11 +347,13 @@ sub signal_handler {
# Read our sendemail.* config
sub read_config {
my ($configured, $prefix) = @_;
my ($known_keys, $configured, $prefix) = @_;
foreach my $setting (keys %config_bool_settings) {
my $target = $config_bool_settings{$setting};
my $v = Git::config_bool(@repo, "$prefix.$setting");
my $key = "$prefix.$setting";
next unless exists $known_keys->{$key};
my $v = Git::config_bool(@repo, $key);
next unless defined $v;
next if $configured->{$setting}++;
$$target = $v;
@ -359,8 +361,10 @@ sub read_config {
foreach my $setting (keys %config_path_settings) {
my $target = $config_path_settings{$setting};
my $key = "$prefix.$setting";
next unless exists $known_keys->{$key};
if (ref($target) eq "ARRAY") {
my @values = Git::config_path(@repo, "$prefix.$setting");
my @values = Git::config_path(@repo, $key);
next unless @values;
next if $configured->{$setting}++;
@$target = @values;
@ -375,14 +379,16 @@ sub read_config {
foreach my $setting (keys %config_settings) {
my $target = $config_settings{$setting};
my $key = "$prefix.$setting";
next unless exists $known_keys->{$key};
if (ref($target) eq "ARRAY") {
my @values = Git::config(@repo, "$prefix.$setting");
my @values = Git::config(@repo, $key);
next unless @values;
next if $configured->{$setting}++;
@$target = @values;
}
else {
my $v = Git::config(@repo, "$prefix.$setting");
my $v = Git::config(@repo, $key);
next unless defined $v;
next if $configured->{$setting}++;
$$target = $v;
@ -408,9 +414,20 @@ sub config_regexp {
return @ret;
}
# Save ourselves a lot of work of shelling out to 'git config' (it
# parses 'bool' etc.) by only doing so for config keys that exist.
my %known_config_keys;
{
my @known_config_keys = config_regexp("^sende?mail[.]");
@known_config_keys{@known_config_keys} = ();
}
# sendemail.identity yields to --identity. We must parse this
# special-case first before the rest of the config is read.
$identity = Git::config(@repo, "sendemail.identity");
{
my $key = "sendemail.identity";
$identity = Git::config(@repo, $key) if exists $known_config_keys{$key};
}
my $rc = GetOptions(
"identity=s" => \$identity,
"no-identity" => \$no_identity,
@ -421,8 +438,8 @@ sub config_regexp {
# Now we know enough to read the config
{
my %configured;
read_config(\%configured, "sendemail.$identity") if defined $identity;
read_config(\%configured, "sendemail");
read_config(\%known_config_keys, \%configured, "sendemail.$identity") if defined $identity;
read_config(\%known_config_keys, \%configured, "sendemail");
}
# Begin by accumulating all the variables (defined above), that we will end up
@ -506,7 +523,7 @@ sub config_regexp {
usage();
}
if ($forbid_sendmail_variables && (scalar config_regexp("^sendmail[.]")) != 0) {
if ($forbid_sendmail_variables && grep { /^sendmail/s } keys %known_config_keys) {
die __("fatal: found configuration options for 'sendmail'\n" .
"git-send-email is configured with the sendemail.* options - note the 'e'.\n" .
"Set sendemail.forbidSendmailVariables to false to disable this check.\n");