repobrowse: raw display avoids forking for small files

This is more efficient for the majority of source files
which fit into a stock 64K Linux pipe buffer used by
our interaction with git-cat-file.

diff --git a/lib/PublicInbox/RepoGitRaw.pm b/lib/PublicInbox/RepoGitRaw.pm
index fabc237bc5ebcb11d0bf92ac2b469fca39e3c7cf..449934afc3d9888cc4df6d649faca87c07969f99 100644 (file)
--- a/lib/PublicInbox/RepoGitRaw.pm
+++ b/lib/PublicInbox/RepoGitRaw.pm
@@ -7,39 +7,59 @@ use base qw(PublicInbox::RepoBase);
 use PublicInbox::Hval qw(utf8_html);
 use PublicInbox::Qspawn;
 my $MAX_ASYNC = 65536;
+my $BIN_DETECT = 8000;
+
+sub git_raw_check_res ($$$) {
+       my ($self, $req, $res) = @_;
+       sub {
+               my ($info) = @_;
+               my ($hex, $type, $size) = @$info;
+               if (!defined $type || $type eq 'missing') {
+                       return $res->($self->rt(404, 'plain', 'Not Found'));
+               }
+               my $ct;
+               if ($type eq 'blob') {
+                       my $base = $req->{extra}->[-1];
+                       $ct = $self->mime_type($base) if defined $base;
+                       $ct ||= 'text/plain; charset=UTF-8' if !$size;
+               } elsif ($type eq 'commit' || $type eq 'tag') {
+                       $ct = 'text/plain; charset=UTF-8';
+               } elsif ($type eq 'tree') {
+                       return git_tree_raw($self, $req, $res, $hex);
+               } else {
+                       $ct = 'application/octet-stream';
+               }
+
+               $size > $MAX_ASYNC and
+                       return show_big($self, $req, $res, $ct, $info);
+
+               # buffer small files in full
+               my $buf = '';
+               $req->{-repo}->{git}->cat_async($req->{env}, $hex, sub {
+                       my ($r) = @_;
+                       return if ref($r) ne 'SCALAR';
+                       $buf .= $$r;
+                       return if bytes::length($buf) < $size;
+                       $ct ||= index($buf, "\0") >= 0 ?
+                                       'application/octet-stream' :
+                                       'text/plain; charset=UTF-8';
+                       $res->([200, ['Content-Type', $ct,
+                                       'Content-Length', $size ],
+                               [ $buf ]]);
+               });
+       }
+}
 
 sub call_git_raw {
        my ($self, $req) = @_;
        my $repo = $req->{-repo};
-       my $git = $repo->{git};
-       my $tip = $req->{tip} || $repo->tip;
+       my $obj = $req->{tip} || $repo->tip;
        my $expath = $req->{expath};
-       my $obj = $tip;
        $obj .= ":$expath" if $expath ne '';
-       my $env = $req->{env};
        sub {
                my ($res) = @_;
-               $git->check_async($env, $obj, sub {
-                       my ($info) = @_;
-                       my ($hex, $type, $size) = @$info;
-                       if (!defined $type || $type eq 'missing') {
-                               return $res->($self->rt(404, 'plain',
-                                               'Not Found'));
-                       }
-                       my $ct;
-                       if ($type eq 'blob') {
-                               my $base = $req->{extra}->[-1];
-                               $ct = $self->mime_type($base) if defined $base;
-                               $ct ||= 'text/plain; charset=UTF-8' if !$size;
-                       } elsif ($type eq 'commit' || $type eq 'tag') {
-                               $ct = 'text/plain; charset=UTF-8';
-                       } elsif ($type eq 'tree') {
-                               return git_tree_raw($self, $req, $res, $hex);
-                       } else {
-                               $ct = 'application/octet-stream';
-                       }
-                       show_raw($self, $req, $res, $ct, $hex, $type, $size);
-               });
+               $repo->{git}->check_async($req->{env}, $obj,
+                       git_raw_check_res($self, $req, $res));
        }
 }
 
@@ -103,38 +123,36 @@ sub git_tree_raw {
        });
 }
 
-sub show_raw {
-       my ($self, $req, $res, $ct, $hex, $type, $size) = @_;
+sub show_big {
+       my ($self, $req, $res, $ct, $info) = @_;
+       my ($hex, $type, $size) = @$info;
        my $env = $req->{env};
        my $git = $req->{-repo}->{git};
-       if (1 || $size > $MAX_ASYNC) {
-               my $rdr = { 2 => $git->err_begin };
-               my $cmd = $git->cmd('cat-file', $type, $hex);
-               my $qsp = PublicInbox::Qspawn->new($cmd, undef, $rdr);
-               $env->{'qspawn.response'} = $res;
-               my $n = 0;
-               my $buf = '';
-               $qsp->psgi_return($env, undef, sub {
-                       my ($r, $bref) = @_;
-                       if (!defined $r) {
-                               $self->rt(500, 'plain', $git->err);
-                       } elsif (defined $ct) {
-                               [ 200, [ 'Content-Type', $ct ] ];
-                       } else {
-                               return $self->rt(200, 'plain');
-                               if (index($$bref, "\0") >= 0) {
-                                       $ct = 'application/octet-stream';
-                                       return [200, ['Content-Type', $ct]];
-                               }
-                               my $n = bytes::length($$bref);
-                               if ($n >= 8000 || $n == $size) {
-                                       return $self->rt(200, 'plain');
-                               }
-                               # else: bref will keep growing...
+       my $rdr = { 2 => $git->err_begin };
+       my $cmd = $git->cmd('cat-file', $type, $hex);
+       my $qsp = PublicInbox::Qspawn->new($cmd, undef, $rdr);
+       $env->{'qspawn.response'} = $res;
+       my @cl = ('Content-Length', $size);
+       $qsp->psgi_return($env, undef, sub {
+               my ($r, $bref) = @_;
+               if (!defined $r) {
+                       $self->rt(500, 'plain', $git->err);
+               } elsif (defined $ct) {
+                       [ 200, [ 'Content-Type', $ct, @cl ] ];
+               } else {
+                       return $self->rt(200, 'plain');
+                       if (index($$bref, "\0") >= 0) {
+                               $ct = 'application/octet-stream';
+                               return [200, ['Content-Type', $ct, @cl ] ];
                        }
-               });
-       }
-       # TODO: forkless for small files
+                       my $n = bytes::length($$bref);
+                       if ($n >= $BIN_DETECT || $n == $size) {
+                               $ct ||= 'text/plain; charset=UTF-8';
+                               return [200, ['Content-Type', $ct, @cl] ];
+                       }
+                       # else: bref will keep growing...
+               }
+       });
 }
 
 1;