v2writable: allow setting nproc via creat options

Avoiding reliance on environment variables is a bit cleaner
for writing tests

1 files changed, 11 insertions, 2 deletions

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index b92d8d24..afcac4d2 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -24,7 +24,14 @@ use IO::Handle;
 my $PACKING_FACTOR = 0.4;
 
 # assume 2 cores if GNU nproc(1) is not available
-sub nproc_parts () {
+sub nproc_parts ($) {
+        my ($creat_opt) = @_;
+        if (ref($creat_opt) eq 'HASH') {
+                if (defined(my $n = $creat_opt->{nproc})) {
+                        return $n
+                }
+        }
+
         my $n = int($ENV{NPROC} || `nproc 2>/dev/null` || 2);
         # subtract for the main process and git-fast-import
         $n -= 1;
@@ -52,6 +59,8 @@ sub count_partitions ($) {
 }
 
 sub new {
+        # $creat may be any true value, or 0/undef.  A hashref is true,
+        # and $creat->{nproc} may be set to an integer
         my ($class, $v2ibx, $creat) = @_;
         my $dir = $v2ibx->{mainrepo} or die "no mainrepo in inbox\n";
         unless (-d $dir) {
@@ -80,7 +89,7 @@ sub new {
                 rotate_bytes => int((1024 * 1024 * 1024) / $PACKING_FACTOR),
                 last_commit => [], # git repo -> commit
         };
-        $self->{partitions} = count_partitions($self) || nproc_parts();
+        $self->{partitions} = count_partitions($self) || nproc_parts($creat);
         bless $self, $class;
 }