www: start making gzipfilter the parent response class

Virtually all of our responses are going to be gzipped, anyways.
This will allow us to utilize zlib as a buffering layer and
share common code for async blob retrieval responses.

To streamline this and allow GzipFilter to be a parent class,
we'll replace the NoopFilter with a similar CompressNoop class
which emulates the two Compress::Raw::Zlib::Deflate methods we
use.

This drops a bunch of redundant code and will hopefully make
upcoming WwwStream changes easier to reason about.

1 files changed, 25 insertions, 65 deletions

diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index 895f828c..abdf43c9 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -9,13 +9,11 @@
 # more common "push" model)
 package PublicInbox::Mbox;
 use strict;
-use warnings;
+use parent 'PublicInbox::GzipFilter';
 use PublicInbox::MID qw/mid_escape/;
 use PublicInbox::Hval qw/to_filename/;
 use PublicInbox::Smsg;
 use PublicInbox::Eml;
-use PublicInbox::GitAsyncCat;
-use PublicInbox::GzipFilter qw(gzf_maybe);
 
 # called by PSGI server as body response
 # this gets called twice for every message, once to return the header,
@@ -25,49 +23,35 @@ sub getline {
         my $smsg = $ctx->{smsg} or return;
         my $ibx = $ctx->{-inbox};
         my $eml = $ibx->smsg_eml($smsg) or return;
-        $ctx->{smsg} = $ibx->over->next_by_mid($ctx->{mid}, @{$ctx->{id_prev}});
-        msg_hdr($ctx, $eml, $smsg->{mid}) . msg_body($eml);
-}
-
-sub close { !!delete($_[0]->{http_out}) }
-
-sub mbox_async_step ($) { # public-inbox-httpd-only
-        my ($ctx) = @_;
-        if (my $smsg = $ctx->{smsg}) {
-                git_async_cat($ctx->{-inbox}->git, $smsg->{blob},
-                                \&mbox_blob_cb, $ctx);
-        } elsif (my $out = delete $ctx->{http_out}) {
-                $out->close;
+        my $n = $ctx->{smsg} = $ibx->over->next_by_mid(@{$ctx->{next_arg}});
+        $ctx->zmore(msg_hdr($ctx, $eml, $smsg->{mid}));
+        if ($n) {
+                $ctx->translate(msg_body($eml));
+        } else { # last message
+                $ctx->zmore(msg_body($eml));
+                $ctx->zflush;
         }
 }
 
 # called by PublicInbox::DS::write
-sub mbox_async_next {
+sub async_next {
         my ($http) = @_; # PublicInbox::HTTP
         my $ctx = $http->{forward} or return; # client aborted
         eval {
-                $ctx->{smsg} = $ctx->{-inbox}->over->next_by_mid(
-                                        $ctx->{mid}, @{$ctx->{id_prev}});
-                mbox_async_step($ctx);
+                my $smsg = $ctx->{smsg} or return $ctx->close;
+                $ctx->smsg_blob($smsg);
         };
+        warn "E: $@" if $@;
 }
 
-# this is public-inbox-httpd-specific
-sub mbox_blob_cb { # git->cat_async callback
-        my ($bref, $oid, $type, $size, $ctx) = @_;
-        my $http = $ctx->{env}->{'psgix.io'} or return; # client abort
-        my $smsg = delete $ctx->{smsg} or die 'BUG: no smsg';
-        if (!defined($oid)) {
-                # it's possible to have TOCTOU if an admin runs
-                # public-inbox-(edit|purge), just move onto the next message
-                return $http->next_step(\&mbox_async_next);
-        } else {
-                $smsg->{blob} eq $oid or die "BUG: $smsg->{blob} != $oid";
-        }
-        my $eml = PublicInbox::Eml->new($bref);
-        $ctx->{http_out}->write(msg_hdr($ctx, $eml, $smsg->{mid}));
-        $ctx->{http_out}->write(msg_body($eml));
-        $http->next_step(\&mbox_async_next);
+sub async_eml { # ->{async_eml} for async_blob_cb
+        my ($ctx, $eml) = @_;
+        my $smsg = delete $ctx->{smsg};
+        # next message
+        $ctx->{smsg} = $ctx->{-inbox}->over->next_by_mid(@{$ctx->{next_arg}});
+
+        $ctx->zmore(msg_hdr($ctx, $eml, $smsg->{mid}));
+        $ctx->{http_out}->write($ctx->translate(msg_body($eml)));
 }
 
 sub res_hdr ($$) {
@@ -97,41 +81,17 @@ sub no_over_raw ($) {
                 [ msg_hdr($ctx, $eml, $ctx->{mid}) . msg_body($eml) ] ]
 }
 
-sub stream_raw { # MboxGz response callback
-        my ($ctx) = @_;
-        delete($ctx->{smsg}) //
-                $ctx->{-inbox}->over->next_by_mid($ctx->{mid},
-                                                @{$ctx->{id_prev}});
-}
-
 # /$INBOX/$MESSAGE_ID/raw
 sub emit_raw {
         my ($ctx) = @_;
-        my $env = $ctx->{env};
-        $ctx->{base_url} = $ctx->{-inbox}->base_url($env);
+        $ctx->{base_url} = $ctx->{-inbox}->base_url($ctx->{env});
         my $over = $ctx->{-inbox}->over or return no_over_raw($ctx);
         my ($id, $prev);
-        my $smsg = $over->next_by_mid($ctx->{mid}, \$id, \$prev) or return;
-        $ctx->{smsg} = $smsg;
+        my $mip = $ctx->{next_arg} = [ $ctx->{mid}, \$id, \$prev ];
+        my $smsg = $ctx->{smsg} = $over->next_by_mid(@$mip) or return;
         my $res_hdr = res_hdr($ctx, $smsg->{subject});
-        $ctx->{id_prev} = [ \$id, \$prev ];
-
-        if (my $gzf = gzf_maybe($res_hdr, $env)) {
-                $ctx->{gz} = delete $gzf->{gz};
-                require PublicInbox::MboxGz;
-                PublicInbox::MboxGz::response($ctx, \&stream_raw, $res_hdr);
-        } elsif ($env->{'pi-httpd.async'}) {
-                sub {
-                        my ($wcb) = @_; # -httpd provided write callback
-                        $ctx->{http_out} = $wcb->([200, $res_hdr]);
-                        $ctx->{env}->{'psgix.io'}->{forward} = $ctx;
-                        bless $ctx, __PACKAGE__;
-                        mbox_async_step($ctx); # start stepping
-                };
-        } else { # generic PSGI code path
-                bless $ctx, __PACKAGE__; # respond to ->getline
-                [ 200, $res_hdr, $ctx ];
-        }
+        bless $ctx, __PACKAGE__;
+        $ctx->psgi_response(200, $res_hdr, \&async_next, \&async_eml);
 }
 
 sub msg_hdr ($$;$) {