fetch: use manifest.js.gz for v1

This is gentler to the remote HTTP server in the no-op case and
will allow client migrations to some v2-ish format without
forcing the client to redownload everything.

1 files changed, 87 insertions, 60 deletions

diff --git a/lib/PublicInbox/Fetch.pm b/lib/PublicInbox/Fetch.pm
index d795731c..9613a582 100644
--- a/lib/PublicInbox/Fetch.pm
+++ b/lib/PublicInbox/Fetch.pm
@@ -35,49 +35,13 @@ sub remote_url ($$) {
         my $fh = popen_rd($cmd, undef, { -C => $dir, 2 => $lei->{2} });
         my $url = <$fh>;
         close $fh or return;
-        chomp $url;
+        $url =~ s!/*\n!!s;
         $url;
 }
 
-sub do_fetch {
-        my ($cls, $lei, $cd) = @_;
-        my $ibx_ver;
-        my $curl = PublicInbox::LeiCurl->new($lei) or return;
-        my $dir = PublicInbox::Admin::resolve_inboxdir($cd, \$ibx_ver);
-        if ($ibx_ver == 1) {
-                my $url = remote_url($lei, $dir) //
-                        die "E: $dir missing remote.origin.url\n";
-                my $uri = URI->new($url);
-                my $torsocks = $curl->torsocks($lei, $uri);
-                my $opt = { -C => $dir };
-                my $cmd = [ @$torsocks, fetch_cmd($lei, $opt) ];
-                my $cerr = PublicInbox::LeiMirror::run_reap($lei, $cmd, $opt);
-                $lei->child_error($cerr, "@$cmd failed") if $cerr;
-                return;
-        }
-        # v2:
-        opendir my $dh, "$dir/git" or die "opendir $dir/git: $!";
-        my @epochs = sort { $b <=> $a } map { substr($_, 0, -4) + 0 }
-                                grep(/\A[0-9]+\.git\z/, readdir($dh));
-        my ($git_url, $epoch);
-        for my $nr (@epochs) { # try newest epoch, first
-                my $edir = "$dir/git/$nr.git";
-                if (defined(my $url = remote_url($lei, $edir))) {
-                        $git_url = $url;
-                        $epoch = $nr;
-                        last;
-                } else {
-                        warn "W: $edir missing remote.origin.url\n";
-                }
-        }
-        $git_url or die "Unable to determine git URL\n";
-        my $inbox_url = $git_url;
-        $inbox_url =~ s!/git/$epoch(?:\.git)?/?\z!! or
-                $inbox_url =~ s!/$epoch(?:\.git)?/?\z!! or die <<EOM;
-Unable to infer inbox URL from <$git_url>
-EOM
-        $lei->qerr("# inbox URL: $inbox_url/");
-        my $muri = URI->new("$inbox_url/manifest.js.gz");
+sub do_manifest ($$$) {
+        my ($lei, $dir, $ibx_uri) = @_;
+        my $muri = URI->new("$ibx_uri/manifest.js.gz");
         my $ft = File::Temp->new(TEMPLATE => 'manifest-XXXX',
                                 UNLINK => 1, DIR => $dir);
         my $fn = $ft->filename;
@@ -91,13 +55,16 @@ EOM
                 $lei->err($@) if $@;
                 push @opt, '-z', $mf if defined($m0);
         }
-        my $curl_cmd = $curl->for_uri($lei, $muri, @opt);
+        my $curl_cmd = $lei->{curl}->for_uri($lei, $muri, @opt);
         my $opt = {};
         $opt->{$_} = $lei->{$_} for (0..2);
         my $cerr = PublicInbox::LeiMirror::run_reap($lei, $curl_cmd, $opt);
-        return $lei->child_error($cerr, "@$curl_cmd failed") if $cerr;
-        return if !-s $ft; # 304 Not Modified via curl -z
-
+        if ($cerr) {
+                return [ 404 ] if ($cerr >> 8) == 22; # 404 Missing
+                $lei->child_error($cerr, "@$curl_cmd failed");
+                return;
+        }
+        return [ 304 ] if !-s $ft; # 304 Not Modified via curl -z
         my $m1 = PublicInbox::LeiMirror::decode_manifest($ft, $fn, $muri);
         my $mdiff = { %$m1 };
 
@@ -110,36 +77,96 @@ EOM
                 my $t1 = $cur->{modified} // next;
                 delete($mdiff->{$k}) if $f0 eq $f1 && $t0 == $t1;
         }
-        my $ibx_uri = URI->new("$inbox_url/");
         my ($path_pfx, $v1_bare, @v2_epochs) =
                 PublicInbox::LeiMirror::deduce_epochs($mdiff, $ibx_uri->path);
-        defined($v1_bare) and die <<EOM;
+        [ 200, $path_pfx, $v1_bare, \@v2_epochs, $muri, $ft, $mf ];
+}
+
+sub do_fetch {
+        my ($cls, $lei, $cd) = @_;
+        my $ibx_ver;
+        $lei->{curl} //= PublicInbox::LeiCurl->new($lei) or return;
+        my $dir = PublicInbox::Admin::resolve_inboxdir($cd, \$ibx_ver);
+        my ($ibx_uri, @git_dir, @epochs);
+        if ($ibx_ver == 1) {
+                my $url = remote_url($lei, $dir) //
+                        die "E: $dir missing remote.origin.url\n";
+                $ibx_uri = URI->new($url);
+        } else { # v2:
+                opendir my $dh, "$dir/git" or die "opendir $dir/git: $!";
+                @epochs = sort { $b <=> $a } map { substr($_, 0, -4) + 0 }
+                                        grep(/\A[0-9]+\.git\z/, readdir($dh));
+                my ($git_url, $epoch);
+                for my $nr (@epochs) { # try newest epoch, first
+                        my $edir = "$dir/git/$nr.git";
+                        if (defined(my $url = remote_url($lei, $edir))) {
+                                $git_url = $url;
+                                $epoch = $nr;
+                                last;
+                        } else {
+                                warn "W: $edir missing remote.origin.url\n";
+                        }
+                }
+                $git_url or die "Unable to determine git URL\n";
+                my $inbox_url = $git_url;
+                $inbox_url =~ s!/git/$epoch(?:\.git)?/?\z!! or
+                        $inbox_url =~ s!/$epoch(?:\.git)?/?\z!! or die <<EOM;
+Unable to infer inbox URL from <$git_url>
+EOM
+                $ibx_uri = URI->new($inbox_url);
+        }
+        $lei->qerr("# inbox URL: $ibx_uri/");
+        my $res = do_manifest($lei, $dir, $ibx_uri) or return;
+        my ($code, $path_pfx, $v1_bare, $v2_epochs, $muri, $ft, $mf) = @$res;
+        return if $code == 304;
+        if ($code == 404) {
+                # any pre-manifest.js.gz instances running? Just fetch all
+                # existing ones and unconditionally try cloning the next
+                $v2_epochs = [ map {;
+                                "$dir/git/$_.git";
+                                } @epochs ];
+                push @$v2_epochs, "$dir/git/".($epochs[-1] + 1) if @epochs;
+        } else {
+                $code == 200 or die "BUG unexpected code $code\n";
+        }
+        if ($ibx_ver == 2) {
+                defined($v1_bare) and warn <<EOM;
 E: got v1 `$v1_bare' when expecting v2 epoch(s) in <$muri>, WTF?
 EOM
-        my @epoch_nr = sort { $a <=> $b }
-                map { my ($nr) = (m!/([0-9]+)\.git\z!g) } @v2_epochs;
-
+                @git_dir = map { "$dir/git/$_.git" } sort { $a <=> $b }
+                        map { my ($nr) = (m!/([0-9]+)\.git\z!g) } @$v2_epochs;
+        } else {
+                $v1_bare eq $dir or warn "$v1_bare != $dir";
+                $git_dir[0] = $v1_bare // $dir;
+        }
         # n.b. this expects all epochs are from the same host
-        my $torsocks = $curl->torsocks($lei, $muri);
-        for my $nr (@epoch_nr) {
-                my $dir = "$dir/git/$nr.git";
+        my $torsocks = $lei->{curl}->torsocks($lei, $muri);
+        for my $d (@git_dir) {
                 my $cmd;
-                my $opt = {};
-                if (-d $dir) {
-                        $opt->{-C} = $dir;
+                my $opt = {}; # for spawn
+                if (-d $d) {
+                        $opt->{-C} = $d;
                         $cmd = [ @$torsocks, fetch_cmd($lei, $opt) ];
                 } else {
                         my $e_uri = $ibx_uri->clone;
-                        $e_uri->path($ibx_uri->path."git/$nr.git");
+                        my ($epath) = ($d =~ m!/(git/[0-9]+\.git)\z!);
+                        $e_uri->path($ibx_uri->path.$epath);
                         $cmd = [ @$torsocks,
                                 PublicInbox::LeiMirror::clone_cmd($lei, $opt),
-                                $$e_uri, $dir ];
+                                $$e_uri, $d];
                 }
                 my $cerr = PublicInbox::LeiMirror::run_reap($lei, $cmd, $opt);
-                return $lei->child_error($cerr, "@$cmd failed") if $cerr;
+                # do not bail on clone failure if we didn't have a manifest
+                if ($cerr && ($code == 200 || -d $d)) {
+                        $lei->child_error($cerr, "@$cmd failed");
+                        return;
+                }
+        }
+        if ($ft) {
+                my $fn = $ft->filename;
+                rename($fn, $mf) or die "E: rename($fn, $mf): $!\n";
+                $ft->unlink_on_destroy(0);
         }
-        rename($fn, $mf) or die "E: rename($fn, $mf): $!\n";
-        $ft->unlink_on_destroy(0);
 }
 
 1;