[PATCH 03/11] wwwstream: introduce oneshot API to avoid ->getline

[Eric Wong <e@yhbt.net>]

The ->getline API is only useful for limiting memory use when
streaming responses containing multiple emails or log messages.
However it's unnecessary complexity and overhead for callers
(PublicInbox::HTTP) when there's only a single message.
---
 lib/PublicInbox/ViewVCS.pm   |  8 +-------
 lib/PublicInbox/WwwStream.pm | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index 2f8e1c4f..6714e67c 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -31,17 +31,11 @@ my %QP_MAP = ( A => 'oid_a', B => 'oid_b', a => 'path_a', b => 'path_b' );
 our $MAX_SIZE = 1024 * 1024; # TODO: configurable
 my $BIN_DETECT = 8000; # same as git
 
-sub html_i { # WwwStream::getline callback
-	my ($nr, $ctx) =  @_;
-	$nr == 1 ? ${delete $ctx->{obuf}} : undef;
-}
-
 sub html_page ($$$) {
 	my ($ctx, $code, $strref) = @_;
 	my $wcb = delete $ctx->{-wcb};
 	$ctx->{-upfx} = '../../'; # from "/$INBOX/$OID/s/"
-	$ctx->{obuf} = $strref;
-	my $res = PublicInbox::WwwStream->response($ctx, $code, \&html_i);
+	my $res = PublicInbox::WwwStream::oneshot($ctx, $code, $strref);
 	$wcb ? $wcb->($res) : $res;
 }
 
diff --git a/lib/PublicInbox/WwwStream.pm b/lib/PublicInbox/WwwStream.pm
index 3a867ec3..2dd8b157 100644
--- a/lib/PublicInbox/WwwStream.pm
+++ b/lib/PublicInbox/WwwStream.pm
@@ -16,16 +16,21 @@ our $CODE_URL = 'https://public-inbox.org/public-inbox.git';
 # noop for HTTP.pm (and any other PSGI servers)
 sub close {}
 
+sub base_url ($) {
+	my $ctx = shift;
+	my $base_url = $ctx->{-inbox}->base_url($ctx->{env});
+	chop $base_url; # no trailing slash for clone
+	$base_url;
+}
+
 sub new {
 	my ($class, $ctx, $cb) = @_;
 
-	my $base_url = $ctx->{-inbox}->base_url($ctx->{env});
-	chop $base_url; # no trailing slash for clone
 	bless {
 		nr => 0,
 		cb => $cb || \&close,
 		ctx => $ctx,
-		base_url => $base_url,
+		base_url => base_url($ctx),
 	}, $class;
 }
 
@@ -164,4 +169,14 @@ sub getline {
 	delete $self->{cb} ? _html_end($self) : undef;
 }
 
+sub oneshot {
+	my ($ctx, $code, $strref) = @_;
+	my $self = bless {
+		ctx => $ctx,
+		base_url => base_url($ctx),
+	}, __PACKAGE__;
+	[ $code, [ 'Content-Type', 'text/html; charset=UTF-8' ],
+		[ _html_top($self), $$strref, _html_end($self) ] ]
+}
+
 1;