git: move rbuf handling to PublicInbox::IO

The long-term plan is to share non-blocking read buffering logic
with HTTP/NNTP/IMAP/POP3 and also XapClient.

3 files changed, 61 insertions, 52 deletions

diff --git a/lib/PublicInbox/Gcf2Client.pm b/lib/PublicInbox/Gcf2Client.pm
index 48d8c5ac..19d77e32 100644
--- a/lib/PublicInbox/Gcf2Client.pm
+++ b/lib/PublicInbox/Gcf2Client.pm
@@ -21,7 +21,6 @@ use autodie qw(socketpair);
 #        pid.owner => process which spawned {pid}
 #        in => same as {sock}, for compatibility with PublicInbox::Git
 #        inflight => array (see PublicInbox::Git)
-#        rbuf => scalarref, may be non-existent or empty
 sub new  {
         my ($opt) = @_;
         my $self = bless {}, __PACKAGE__;
diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index bef524aa..93736cf0 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -14,11 +14,11 @@ use autodie qw(socketpair read);
 use POSIX ();
 use Socket qw(AF_UNIX SOCK_STREAM);
 use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
-use Errno qw(EINTR EAGAIN);
+use Errno qw(EAGAIN);
 use File::Glob qw(bsd_glob GLOB_NOSORT);
 use File::Spec ();
 use PublicInbox::Spawn qw(spawn popen_rd run_qx which);
-use PublicInbox::IO qw(poll_in read_all try_cat);
+use PublicInbox::IO qw(read_all try_cat);
 use PublicInbox::Tmpfile;
 use Carp qw(croak carp);
 use PublicInbox::SHA qw(sha_all);
@@ -166,43 +166,6 @@ sub _sock_cmd {
         $self->{sock} = PublicInbox::IO::attach_pid($s1, $pid);
 }
 
-sub my_read ($$$) {
-        my ($fh, $rbuf, $len) = @_;
-        my $left = $len - length($$rbuf);
-        my $r;
-        while ($left > 0) {
-                $r = sysread($fh, $$rbuf, $left, length($$rbuf));
-                if ($r) {
-                        $left -= $r;
-                } elsif (defined($r)) { # EOF
-                        return 0;
-                } else {
-                        next if ($! == EAGAIN and poll_in($fh));
-                        next if $! == EINTR; # may be set by sysread or poll_in
-                        return; # unrecoverable error
-                }
-        }
-        my $no_pad = substr($$rbuf, 0, $len, '');
-        \$no_pad;
-}
-
-sub my_readline ($$) {
-        my ($fh, $rbuf) = @_;
-        while (1) {
-                if ((my $n = index($$rbuf, "\n")) >= 0) {
-                        return substr($$rbuf, 0, $n + 1, '');
-                }
-                my $r = sysread($fh, $$rbuf, 65536, length($$rbuf)) and next;
-
-                # return whatever's left on EOF
-                return substr($$rbuf, 0, length($$rbuf)+1, '') if defined($r);
-
-                next if ($! == EAGAIN and poll_in($fh));
-                next if $! == EINTR; # may be set by sysread or poll_in
-                return; # unrecoverable error
-        }
-}
-
 sub cat_async_retry ($$) {
         my ($self, $old_inflight) = @_;
 
@@ -234,16 +197,15 @@ sub cat_async_step ($$) {
         my ($self, $inflight) = @_;
         die 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
         my ($req, $cb, $arg) = @$inflight[0, 1, 2];
-        my $rbuf = delete($self->{rbuf}) // \(my $new = '');
         my ($bref, $oid, $type, $size);
-        my $head = my_readline($self->{sock}, $rbuf);
+        my $head = $self->{sock}->my_readline;
         my $cmd = ref($req) ? $$req : $req;
         # ->fail may be called via Gcf2Client.pm
         my $info = $self->{-bc} && substr($cmd, 0, 5) eq 'info ';
         if ($head =~ /^([0-9a-f]{40,}) (\S+) ([0-9]+)$/) {
                 ($oid, $type, $size) = ($1, $2, $3 + 0);
                 unless ($info) { # --batch-command
-                        $bref = my_read($self->{sock}, $rbuf, $size + 1) or
+                        $bref = $self->{sock}->my_bufread($size + 1) or
                                 $self->fail(defined($bref) ?
                                                 'read EOF' : "read: $!");
                         chop($$bref) eq "\n" or
@@ -268,7 +230,6 @@ sub cat_async_step ($$) {
                 my $err = $! ? " ($!)" : '';
                 $self->fail("bad result from async cat-file: $head$err");
         }
-        $self->{rbuf} = $rbuf if $$rbuf ne '';
         splice(@$inflight, 0, 3); # don't retry $cb on ->fail
         eval { $cb->($bref, $oid, $type, $size, $arg) };
         async_err($self, $req, $oid, $@, $info ? 'check' : 'cat') if $@;
@@ -312,17 +273,15 @@ sub check_async_step ($$) {
         my ($ck, $inflight) = @_;
         die 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
         my ($req, $cb, $arg) = @$inflight[0, 1, 2];
-        my $rbuf = delete($ck->{rbuf}) // \(my $new = '');
-        chomp(my $line = my_readline($ck->{sock}, $rbuf));
+        chomp(my $line = $ck->{sock}->my_readline);
         my ($hex, $type, $size) = split(/ /, $line);
 
         # git <2.21 would show `dangling' (2.21+ shows `ambiguous')
         # https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/
         if ($hex eq 'dangling') {
-                my $ret = my_read($ck->{sock}, $rbuf, $type + 1);
+                my $ret = $ck->{sock}->my_bufread($type + 1);
                 $ck->fail(defined($ret) ? 'read EOF' : "read: $!") if !$ret;
         }
-        $ck->{rbuf} = $rbuf if $$rbuf ne '';
         splice(@$inflight, 0, 3); # don't retry $cb on ->fail
         eval { $cb->(undef, $hex, $type, $size, $arg) };
         async_err($ck, $req, $hex, $@, 'check') if $@;
@@ -643,8 +602,8 @@ sub event_step {
                 $self->cat_async_step($inflight);
                 return $self->close unless $self->{sock};
                 # don't loop here to keep things fair, but we must requeue
-                # if there's already-read data in rbuf
-                $self->requeue if exists($self->{rbuf});
+                # if there's already-read data in pi_io_rbuf
+                $self->requeue if $self->{sock}->has_rbuf;
         }
 }
 
@@ -670,7 +629,7 @@ sub close {
                         warn "E: (in abort) $req: $@" if $@;
                 }
         }
-        delete @$self{qw(-bc err_c inflight rbuf)};
+        delete @$self{qw(-bc err_c inflight)};
         delete($self->{epwatch}) ? $self->SUPER::close : delete($self->{sock});
 }
 
diff --git a/lib/PublicInbox/IO.pm b/lib/PublicInbox/IO.pm
index 63ae3ef4..fcebac59 100644
--- a/lib/PublicInbox/IO.pm
+++ b/lib/PublicInbox/IO.pm
@@ -9,6 +9,7 @@ use PublicInbox::DS qw(awaitpid);
 our @EXPORT_OK = qw(poll_in read_all try_cat write_file);
 use Carp qw(croak);
 use IO::Poll qw(POLLIN);
+use Errno qw(EINTR EAGAIN);
 # don't autodie in top-level for Perl 5.16.3 (and maybe newer versions)
 # we have our own ->close, so we scope autodie into each sub
 
@@ -18,7 +19,7 @@ sub waitcb { # awaitpid callback
         $cb->($pid, @args) if $cb;
 }
 
-sub attach_pid ($$;@) {
+sub attach_pid {
         my ($io, $pid, @cb_arg) = @_;
         bless $io, __PACKAGE__;
         # we share $err (and not $self) with awaitpid to avoid a ref cycle
@@ -87,4 +88,54 @@ sub try_cat ($) {
         read_all $fh;
 }
 
+# TODO: move existing HTTP/IMAP/NNTP/POP3 uses of rbuf here
+sub my_bufread {
+        my ($io, $len) = @_;
+        my $rbuf = ${*$io}{pi_io_rbuf} //= \(my $new = '');
+        my $left = $len - length($$rbuf);
+        my $r;
+        while ($left > 0) {
+                $r = sysread($io, $$rbuf, $left, length($$rbuf));
+                if ($r) {
+                        $left -= $r;
+                } elsif (defined($r)) { # EOF
+                        return 0;
+                } else {
+                        next if ($! == EAGAIN and poll_in($io));
+                        next if $! == EINTR; # may be set by sysread or poll_in
+                        return; # unrecoverable error
+                }
+        }
+        my $no_pad = substr($$rbuf, 0, $len, '');
+        delete(${*$io}{pi_io_rbuf}) if $$rbuf eq '';
+        \$no_pad;
+}
+
+# always uses "\n"
+sub my_readline {
+        my ($io) = @_;
+        my $rbuf = ${*$io}{pi_io_rbuf} //= \(my $new = '');
+        while (1) {
+                if ((my $n = index($$rbuf, "\n")) >= 0) {
+                        my $ret = substr($$rbuf, 0, $n + 1, '');
+                        delete(${*$io}{pi_io_rbuf}) if $$rbuf eq '';
+                        return $ret;
+                }
+                my $r = sysread($io, $$rbuf, 65536, length($$rbuf));
+                if (!defined($r)) {
+                        next if ($! == EAGAIN and poll_in($io));
+                        next if $! == EINTR; # may be set by sysread or poll_in
+                        return; # unrecoverable error
+                } elsif ($r == 0) { # return whatever's left on EOF
+                        delete(${*$io}{pi_io_rbuf});
+                        return $$rbuf;
+                } # else { continue
+        }
+}
+
+sub has_rbuf {
+        my ($io) = @_;
+        defined(${*$io}{pi_io_rbuf});
+}
+
 1;