qspawn: remove some anonymous subs for psgi_qx

By passing a user-supplied arg to $qx_cb, we can eliminate the
callers' need to capture on-stack variables with a closure.
This saves several kilobytes of memory allocation at the expense
of some extra hash table lookups in user-supplied callbacks.  It
also reduces the risk of memory leaks by eliminating a common
source of circular references.

3 files changed, 71 insertions, 54 deletions

diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index c2856609..22603ca7 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -155,13 +155,13 @@ sub start {
 # $env is the PSGI env.  As with ``/qx; only use this when output is small
 # and safe to slurp.
 sub psgi_qx {
-        my ($self, $env, $limiter, $qx_cb) = @_;
+        my ($self, $env, $limiter, $qx_cb, $cb_arg) = @_;
         my $scalar = '';
         open(my $qx, '+>', \$scalar) or die; # PerlIO::scalar
         my $end = sub {
                 my $err = $_[0]; # $!
                 log_err($env, "psgi_qx: $err") if defined($err);
-                finish($self, $env, sub { $qx_cb->(\$scalar) });
+                finish($self, $env, sub { $qx_cb->(\$scalar, $cb_arg) });
                 $qx = undef;
         };
         my $rpipe; # comes from popen_rd
diff --git a/lib/PublicInbox/SolverGit.pm b/lib/PublicInbox/SolverGit.pm
index b3fc5bef..fd43940f 100644
--- a/lib/PublicInbox/SolverGit.pm
+++ b/lib/PublicInbox/SolverGit.pm
@@ -221,6 +221,16 @@ sub find_extract_diffs ($$$) {
         @di ? \@di : undef;
 }
 
+sub update_index_result ($$) {
+        my ($bref, $self) = @_;
+        my ($qsp, $msg) = delete @$self{qw(-qsp -msg)};
+        if (my $err = $qsp->{err}) {
+                ERR($self, "git update-index error: $err");
+        }
+        dbg($self, $msg);
+        next_step($self); # onto do_git_apply
+}
+
 sub prepare_index ($) {
         my ($self) = @_;
         my $patches = $self->{patches};
@@ -248,15 +258,10 @@ sub prepare_index ($) {
         my $rdr = { 0 => fileno($in), -hold => $in };
         my $cmd = [ qw(git update-index -z --index-info) ];
         my $qsp = PublicInbox::Qspawn->new($cmd, $self->{git_env}, $rdr);
-        $qsp->psgi_qx($self->{psgi_env}, undef, sub {
-                my ($bref) = @_;
-                if (my $err = $qsp->{err}) {
-                        ERR($self, "git update-index error: $err");
-                }
-                dbg($self, "index prepared:\n" .
-                        "$mode_a $oid_full\t" . git_quote($path_a));
-                next_step($self); # onto do_git_apply
-        });
+        $path_a = git_quote($path_a);
+        $self->{-qsp} = $qsp;
+        $self->{-msg} = "index prepared:\n$mode_a $oid_full\t$path_a";
+        $qsp->psgi_qx($self->{psgi_env}, undef, \&update_index_result, $self);
 }
 
 # pure Perl "git init"
@@ -383,8 +388,9 @@ sub mark_found ($$$) {
         }
 }
 
-sub parse_ls_files ($$$$) {
-        my ($self, $qsp, $bref, $di) = @_;
+sub parse_ls_files ($$) {
+        my ($self, $bref) = @_;
+        my ($qsp, $di) = delete @$self{qw(-qsp -cur_di)};
         if (my $err = $qsp->{err}) {
                 die "git ls-files error: $err";
         }
@@ -410,15 +416,10 @@ sub parse_ls_files ($$$$) {
         next_step($self); # onto the next patch
 }
 
-sub start_ls_files ($$) {
-        my ($self, $di) = @_;
-        my $cmd = [qw(git ls-files -s -z)];
-        my $qsp = PublicInbox::Qspawn->new($cmd, $self->{git_env});
-        $qsp->psgi_qx($self->{psgi_env}, undef, sub {
-                my ($bref) = @_;
-                eval { parse_ls_files($self, $qsp, $bref, $di) };
-                ERR($self, $@) if $@;
-        });
+sub ls_files_result {
+        my ($bref, $self) = @_;
+        eval { parse_ls_files($self, $bref) };
+        ERR($self, $@) if $@;
 }
 
 sub oids_same_ish ($$) {
@@ -438,6 +439,31 @@ sub skip_identical ($$$) {
         }
 }
 
+sub apply_result ($$) {
+        my ($bref, $self) = @_;
+        my ($qsp, $di) = delete @$self{qw(-qsp -cur_di)};
+        dbg($self, $$bref);
+        my $patches = $self->{patches};
+        if (my $err = $qsp->{err}) {
+                my $msg = "git apply error: $err";
+                my $nxt = $patches->[0];
+                if ($nxt && oids_same_ish($nxt->{oid_b}, $di->{oid_b})) {
+                        dbg($self, $msg);
+                        dbg($self, 'trying '.di_url($self, $nxt));
+                } else {
+                        ERR($self, $msg);
+                }
+        } else {
+                skip_identical($self, $patches, $di->{oid_b});
+        }
+
+        my @cmd = qw(git ls-files -s -z);
+        $qsp = PublicInbox::Qspawn->new(\@cmd, $self->{git_env});
+        $self->{-cur_di} = $di;
+        $self->{-qsp} = $qsp;
+        $qsp->psgi_qx($self->{psgi_env}, undef, \&ls_files_result, $self);
+}
+
 sub do_git_apply ($) {
         my ($self) = @_;
         my $dn = $self->{tmp}->dirname;
@@ -465,24 +491,9 @@ sub do_git_apply ($) {
 
         my $rdr = { 2 => 1 };
         my $qsp = PublicInbox::Qspawn->new(\@cmd, $self->{git_env}, $rdr);
-        $qsp->psgi_qx($self->{psgi_env}, undef, sub {
-                my ($bref) = @_;
-                dbg($self, $$bref);
-                if (my $err = $qsp->{err}) {
-                        my $msg = "git apply error: $err";
-                        my $nxt = $patches->[0];
-                        if ($nxt && oids_same_ish($nxt->{oid_b}, $prv_oid_b)) {
-                                dbg($self, $msg);
-                                dbg($self, 'trying '.di_url($self, $nxt));
-                        } else {
-                                ERR($self, $msg);
-                        }
-                } else {
-                        skip_identical($self, $patches, $di->{oid_b});
-                }
-                eval { start_ls_files($self, $di) };
-                ERR($self, $@) if $@;
-        });
+        $self->{-cur_di} = $di;
+        $self->{-qsp} = $qsp;
+        $qsp->psgi_qx($self->{psgi_env}, undef, \&apply_result, $self);
 }
 
 sub di_url ($$) {
@@ -564,6 +575,7 @@ sub new {
         bless {
                 gits => $ibx->{-repo_objs},
                 user_cb => $user_cb,
+                # -cur_di, -qsp, -msg => temporary fields for Qspawn callbacks
 
                 # TODO: config option for searching related inboxes
                 inboxes => [ $ibx ],
diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index 842c873c..886e10cb 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -73,6 +73,22 @@ sub stream_large_blob ($$$$) {
         });
 }
 
+sub show_other_result ($$) {
+        my ($bref, $ctx) = @_;
+        my ($qsp, $logref) = delete @$ctx{qw(-qsp -logref)};
+        if (my $err = $qsp->{err}) {
+                utf8::decode($$err);
+                $$logref .= "git show error: $err";
+                return html_page($ctx, 500, $logref);
+        }
+        my $l = PublicInbox::Linkify->new;
+        utf8::decode($$bref);
+        $l->linkify_1($$bref);
+        $$bref = '<pre>'. $l->linkify_2(ascii_html($$bref));
+        $$bref .= '</pre><hr>' . $$logref;
+        html_page($ctx, 200, $bref);
+}
+
 sub show_other ($$$$) {
         my ($ctx, $res, $logref, $fn) = @_;
         my ($git, $oid, $type, $size) = @$res;
@@ -84,20 +100,9 @@ sub show_other ($$$$) {
                 qw(show --encoding=UTF-8 --no-color --no-abbrev), $oid ];
         my $qsp = PublicInbox::Qspawn->new($cmd);
         my $env = $ctx->{env};
-        $qsp->psgi_qx($env, undef, sub {
-                my ($bref) = @_;
-                if (my $err = $qsp->{err}) {
-                        utf8::decode($$err);
-                        $$logref .= "git show error: $err";
-                        return html_page($ctx, 500, $logref);
-                }
-                my $l = PublicInbox::Linkify->new;
-                utf8::decode($$bref);
-                $l->linkify_1($$bref);
-                $$bref = '<pre>'. $l->linkify_2(ascii_html($$bref));
-                $$bref .= '</pre><hr>' . $$logref;
-                html_page($ctx, 200, $bref);
-        });
+        $ctx->{-qsp} = $qsp;
+        $ctx->{-logref} = $logref;
+        $qsp->psgi_qx($env, undef, \&show_other_result, $ctx);
 }
 
 sub solve_result {