githttpbackend: split out wwwstatic

Make it easier to share code between our GitHTTPBackend and Cgit
packages, for now, and possibly other packages in the future.

We can avoid inline_object and anonymous subs at the same
time, reducing per-request memory overhead.

3 files changed, 111 insertions, 91 deletions

diff --git a/lib/PublicInbox/Cgit.pm b/lib/PublicInbox/Cgit.pm
index 094f146e..68da9178 100644
--- a/lib/PublicInbox/Cgit.pm
+++ b/lib/PublicInbox/Cgit.pm
@@ -13,9 +13,9 @@ use PublicInbox::GitHTTPBackend;
 *input_prepare = *PublicInbox::GitHTTPBackend::input_prepare;
 *parse_cgi_headers = *PublicInbox::GitHTTPBackend::parse_cgi_headers;
 *serve = *PublicInbox::GitHTTPBackend::serve;
-*static_result = *PublicInbox::GitHTTPBackend::static_result;
 use warnings;
 use PublicInbox::Qspawn;
+use PublicInbox::WwwStatic;
 use Plack::MIME;
 
 sub locate_cgit ($) {
@@ -115,8 +115,8 @@ sub call {
         } elsif ($path_info =~ m!$self->{static}! &&
                  defined($cgit_data = $self->{cgit_data})) {
                 my $f = $1;
-                my $type = Plack::MIME->mime_type($f);
-                return static_result($env, [], $cgit_data.$f, $type);
+                return PublicInbox::WwwStatic::response($env, [], $cgit_data.$f,
+                                                Plack::MIME->mime_type($f));
         }
 
         my $cgi_env = { PATH_INFO => $path_info };
diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm
index 537a1947..b7640d42 100644
--- a/lib/PublicInbox/GitHTTPBackend.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -10,9 +10,9 @@ use Fcntl qw(:seek);
 use IO::Handle;
 use HTTP::Date qw(time2str);
 use HTTP::Status qw(status_message);
-use Plack::Util;
 use PublicInbox::Qspawn;
 use PublicInbox::Tmpfile;
+use PublicInbox::WwwStatic;
 
 # 32 is same as the git-daemon connection limit
 my $default_limiter = PublicInbox::Qspawn::Limiter->new(32);
@@ -66,12 +66,6 @@ sub err ($@) {
         $env->{'psgi.errors'}->print(@msg, "\n");
 }
 
-sub drop_client ($) {
-        if (my $io = $_[0]->{'psgix.io'}) {
-                $io->close; # this is PublicInbox::DS::close
-        }
-}
-
 my $prev = 0;
 my $exp;
 sub cache_one_year {
@@ -81,44 +75,6 @@ sub cache_one_year {
                 'Cache-Control', 'public, max-age=31536000';
 }
 
-sub static_result ($$$$) {
-        my ($env, $h, $f, $type) = @_;
-        return r(404) unless -f $f && -r _; # just in case it's a FIFO :P
-
-        # TODO: If-Modified-Since and Last-Modified?
-        open my $in, '<', $f or return r(404);
-        my $size = -s $in;
-        my $len = $size;
-        my $code = 200;
-        push @$h, 'Content-Type', $type;
-        if (($env->{HTTP_RANGE} || '') =~ /\bbytes=([0-9]*)-([0-9]*)\z/) {
-                ($code, $len) = prepare_range($env, $in, $h, $1, $2, $size);
-                if ($code == 416) {
-                        push @$h, 'Content-Range', "bytes */$size";
-                        return [ 416, $h, [] ];
-                }
-        }
-        push @$h, 'Content-Length', $len;
-        my $n = 65536;
-        [ $code, $h, Plack::Util::inline_object(close => sub { close $in },
-                getline => sub {
-                        return if $len == 0;
-                        $n = $len if $len < $n;
-                        my $r = sysread($in, my $buf, $n);
-                        if (!defined $r) {
-                                err($env, "$f read error: $!");
-                        } elsif ($r <= 0) {
-                                err($env, "$f EOF with $len bytes left");
-                        } else {
-                                $len -= $r;
-                                $n = 8192;
-                                return $buf;
-                        }
-                        drop_client($env);
-                        return;
-                })]
-}
-
 sub serve_dumb {
         my ($env, $git, $path) = @_;
 
@@ -139,49 +95,8 @@ sub serve_dumb {
         } else {
                 return r(404);
         }
-
-        static_result($env, $h, "$git->{git_dir}/$path", $type);
-}
-
-sub prepare_range {
-        my ($env, $in, $h, $beg, $end, $size) = @_;
-        my $code = 200;
-        my $len = $size;
-        if ($beg eq '') {
-                if ($end ne '') { # "bytes=-$end" => last N bytes
-                        $beg = $size - $end;
-                        $beg = 0 if $beg < 0;
-                        $end = $size - 1;
-                        $code = 206;
-                } else {
-                        $code = 416;
-                }
-        } else {
-                if ($beg > $size) {
-                        $code = 416;
-                } elsif ($end eq '' || $end >= $size) {
-                        $end = $size - 1;
-                        $code = 206;
-                } elsif ($end < $size) {
-                        $code = 206;
-                } else {
-                        $code = 416;
-                }
-        }
-        if ($code == 206) {
-                $len = $end - $beg + 1;
-                if ($len <= 0) {
-                        $code = 416;
-                } else {
-                        sysseek($in, $beg, SEEK_SET) or return [ 500, [], [] ];
-                        push @$h, qw(Accept-Ranges bytes Content-Range);
-                        push @$h, "bytes $beg-$end/$size";
-
-                        # FIXME: Plack::Middleware::Deflater bug?
-                        $env->{'psgix.no-compress'} = 1;
-                }
-        }
-        ($code, $len);
+        $path = "$git->{git_dir}/$path";
+        PublicInbox::WwwStatic::response($env, $h, $path, $type) // r(404);
 }
 
 sub git_parse_hdr { # {parse_hdr} for Qspawn
diff --git a/lib/PublicInbox/WwwStatic.pm b/lib/PublicInbox/WwwStatic.pm
new file mode 100644
index 00000000..76e50c78
--- /dev/null
+++ b/lib/PublicInbox/WwwStatic.pm
@@ -0,0 +1,105 @@
+# Copyright (C) 2016-2019 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+package PublicInbox::WwwStatic;
+use strict;
+use Fcntl qw(:seek);
+
+sub prepare_range {
+        my ($env, $in, $h, $beg, $end, $size) = @_;
+        my $code = 200;
+        my $len = $size;
+        if ($beg eq '') {
+                if ($end ne '') { # "bytes=-$end" => last N bytes
+                        $beg = $size - $end;
+                        $beg = 0 if $beg < 0;
+                        $end = $size - 1;
+                        $code = 206;
+                } else {
+                        $code = 416;
+                }
+        } else {
+                if ($beg > $size) {
+                        $code = 416;
+                } elsif ($end eq '' || $end >= $size) {
+                        $end = $size - 1;
+                        $code = 206;
+                } elsif ($end < $size) {
+                        $code = 206;
+                } else {
+                        $code = 416;
+                }
+        }
+        if ($code == 206) {
+                $len = $end - $beg + 1;
+                if ($len <= 0) {
+                        $code = 416;
+                } else {
+                        sysseek($in, $beg, SEEK_SET) or return [ 500, [], [] ];
+                        push @$h, qw(Accept-Ranges bytes Content-Range);
+                        push @$h, "bytes $beg-$end/$size";
+
+                        # FIXME: Plack::Middleware::Deflater bug?
+                        $env->{'psgix.no-compress'} = 1;
+                }
+        }
+        ($code, $len);
+}
+
+sub response {
+        my ($env, $h, $path, $type) = @_;
+        return unless -f $path && -r _; # just in case it's a FIFO :P
+
+        # TODO: If-Modified-Since and Last-Modified?
+        open my $in, '<', $path or return;
+        my $size = -s $in;
+        my $len = $size;
+        my $code = 200;
+        push @$h, 'Content-Type', $type;
+        if (($env->{HTTP_RANGE} || '') =~ /\bbytes=([0-9]*)-([0-9]*)\z/) {
+                ($code, $len) = prepare_range($env, $in, $h, $1, $2, $size);
+                if ($code == 416) {
+                        push @$h, 'Content-Range', "bytes */$size";
+                        return [ 416, $h, [] ];
+                }
+        }
+        push @$h, 'Content-Length', $len;
+        my $body = bless {
+                initial_rd => 65536,
+                len => $len,
+                in => $in,
+                path => $path,
+                env => $env,
+        }, __PACKAGE__;
+        [ $code, $h, $body ];
+}
+
+# called by PSGI servers:
+sub getline {
+        my ($self) = @_;
+        my $len = $self->{len};
+        return if $len == 0;
+        my $n = delete($self->{initial_rd}) // 8192;
+        $n = $len if $len < $n;
+        my $r = sysread($self->{in}, my $buf, $n);
+        if (!defined $r) {
+                $self->{env}->{'psgi.errors'}->print(
+                        "$self->{path} read error: $!\n");
+        } elsif ($r > 0) { # success!
+                $self->{len} = $len - $r;
+                return $buf;
+        } else {
+                $self->{env}->{'psgi.errors'}->print(
+                        "$self->{path} EOF with $len bytes left\n");
+        }
+
+        # drop the client on error
+        if (my $io = $self->{env}->{'psgix.io'}) {
+                $io->close; # this is PublicInbox::DS::close
+        }
+        undef;
+}
+
+sub close {} # noop, just let everything go out-of-scope
+
+1;