[PATCH 9/9] use popen_rd for bidirectional pipes

[Eric Wong <e@yhbt.net>]

popen_rd accepts arbitrary redirects, so we can reuse its
code to setup the pipe end we want to read, saving each
caller a few lines of code compared to calling pipe+spawn.
---
 lib/PublicInbox/Git.pm        | 19 ++++++++-----------
 lib/PublicInbox/Import.pm     |  8 +++-----
 lib/PublicInbox/V2Writable.pm | 11 +++--------
 t/solver_git.t                |  9 ++++-----
 4 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 15f53495..4f230197 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -12,7 +12,7 @@ use warnings;
 use POSIX qw(dup2);
 use IO::Handle; # ->autoflush
 use File::Glob qw(bsd_glob GLOB_NOSORT);
-use PublicInbox::Spawn qw(spawn popen_rd);
+use PublicInbox::Spawn qw(popen_rd);
 use PublicInbox::Tmpfile;
 use base qw(Exporter);
 our @EXPORT_OK = qw(git_unquote git_quote);
@@ -104,27 +104,24 @@ sub _bidi_pipe {
 		}
 		return;
 	}
-	my ($in_r, $in_w, $out_r, $out_w);
-
-	pipe($in_r, $in_w) or fail($self, "pipe failed: $!");
+	my ($out_r, $out_w);
 	pipe($out_r, $out_w) or fail($self, "pipe failed: $!");
-	if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ
-		fcntl($out_w, 1031, 4096);
-		fcntl($in_w, 1031, 4096) if $batch eq '--batch-check';
-	}
-
 	my @cmd = (qw(git), "--git-dir=$self->{git_dir}",
 			qw(-c core.abbrev=40 cat-file), $batch);
-	my $redir = { 0 => $out_r, 1 => $in_w };
+	my $redir = { 0 => $out_r };
 	if ($err) {
 		my $id = "git.$self->{git_dir}$batch.err";
 		my $fh = tmpfile($id) or fail($self, "tmpfile($id): $!");
 		$self->{$err} = $fh;
 		$redir->{2} = $fh;
 	}
-	my $p = spawn(\@cmd, undef, $redir);
+	my ($in_r, $p) = popen_rd(\@cmd, undef, $redir);
 	$self->{$pid} = $p;
 	$out_w->autoflush(1);
+	if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ
+		fcntl($out_w, 1031, 4096);
+		fcntl($in_r, 1031, 4096) if $batch eq '--batch-check';
+	}
 	$self->{$out} = $out_w;
 	$self->{$in} = $in_r;
 }
diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index 6ac43d37..d279fea1 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -9,7 +9,7 @@ package PublicInbox::Import;
 use strict;
 use warnings;
 use base qw(PublicInbox::Lock);
-use PublicInbox::Spawn qw(spawn);
+use PublicInbox::Spawn qw(spawn popen_rd);
 use PublicInbox::MID qw(mids mid2path);
 use PublicInbox::Address;
 use PublicInbox::MsgTime qw(msg_timestamp msg_datestamp);
@@ -46,8 +46,7 @@ sub gfi_start {
 
 	return ($self->{in}, $self->{out}) if $self->{pid};
 
-	my ($in_r, $in_w, $out_r, $out_w);
-	pipe($in_r, $in_w) or die "pipe failed: $!";
+	my ($out_r, $out_w);
 	pipe($out_r, $out_w) or die "pipe failed: $!";
 	my $git = $self->{git};
 
@@ -66,8 +65,7 @@ sub gfi_start {
 	my $git_dir = $git->{git_dir};
 	my @cmd = ('git', "--git-dir=$git_dir", qw(fast-import
 			--quiet --done --date-format=raw));
-	my $rdr = { 0 => $out_r, 1 => $in_w };
-	my $pid = spawn(\@cmd, undef, $rdr);
+	my ($in_r, $pid) = popen_rd(\@cmd, undef, { 0 => $out_r });
 	$out_w->autoflush(1);
 	$self->{in} = $in_r;
 	$self->{out} = $out_w;
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 51794326..9073d9ef 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -16,7 +16,7 @@ use PublicInbox::ContentId qw(content_id content_digest);
 use PublicInbox::Inbox;
 use PublicInbox::OverIdx;
 use PublicInbox::Msgmap;
-use PublicInbox::Spawn qw(spawn);
+use PublicInbox::Spawn qw(spawn popen_rd);
 use PublicInbox::SearchIdx;
 use IO::Handle; # ->autoflush
 use File::Temp qw(tempfile);
@@ -471,17 +471,12 @@ sub git_hash_raw ($$) {
 	print $tmp_fh $$raw or die "print \$tmp_fh: $!";
 	sysseek($tmp_fh, 0, 0) or die "seek failed: $!";
 
-	my ($r, $w);
-	pipe($r, $w) or die "failed to create pipe: $!";
-	my $rdr = { 0 => $tmp_fh, 1 => $w };
 	my $git_dir = $self->{-inbox}->git->{git_dir};
 	my $cmd = ['git', "--git-dir=$git_dir", qw(hash-object --stdin)];
-	my $pid = spawn($cmd, undef, $rdr);
-	close $w;
+	my $r = popen_rd($cmd, undef, { 0 => $tmp_fh });
 	local $/ = "\n";
 	chomp(my $oid = <$r>);
-	waitpid($pid, 0) == $pid or die "git hash-object did not finish";
-	die "git hash-object failed: $?" if $?;
+	close $r or die "git hash-object failed: $?";
 	$oid =~ /\A[a-f0-9]{40}\z/ or die "OID not expected: $oid";
 	$oid;
 }
diff --git a/t/solver_git.t b/t/solver_git.t
index 98317fae..92402c3a 100644
--- a/t/solver_git.t
+++ b/t/solver_git.t
@@ -6,7 +6,7 @@ use Test::More;
 use Cwd qw(abs_path);
 use PublicInbox::TestCommon;
 require_git(2.6);
-use PublicInbox::Spawn qw(spawn);
+use PublicInbox::Spawn qw(popen_rd);
 require_mods(qw(DBD::SQLite Search::Xapian Plack::Util));
 chomp(my $git_dir = `git rev-parse --git-dir 2>/dev/null`);
 plan skip_all => "$0 must be run from a git working tree" if $?;
@@ -120,14 +120,13 @@ SKIP: {
 	my $cmd = [ qw(git hash-object -w --stdin) ];
 	my $env = { GIT_DIR => $binfoo };
 	while (my ($label, $size) = each %bin) {
-		pipe(my ($rout, $wout)) or die;
 		pipe(my ($rin, $win)) or die;
-		my $rdr = { 0 => $rin, 1 => $wout };
-		my $pid = spawn($cmd , $env, $rdr);
-		$wout = $rin = undef;
+		my $rout = popen_rd($cmd , $env, { 0 => $rin });
+		$rin = undef;
 		print { $win } ("\0" x $size) or die;
 		close $win or die;
 		chomp($oid{$label} = <$rout>);
+		close $rout or die "$?";
 	}
 
 	# ensure the PSGI frontend (ViewVCS) works: