gitweb: snapshot cleanups & support for offering multiple formats

- Centralize knowledge about snapshot formats (mime types, extensions,
  commands) in %known_snapshot_formats and improve how some of that
  information is specified.  In particular, zip files are no longer a
  special case.

- Add support for offering multiple snapshot formats to the user so
  that he/she can download a snapshot in the format he/she prefers.
  The site-wide or project configuration now gives a list of formats
  to offer, and if more than one format is offered, the "_snapshot_"
  link becomes something like "snapshot (_tar.bz2_ _zip_)".

- If only one format is offered, a tooltip on the "_snapshot_" link
  tells the user what it is.

- Fix out-of-date "tarball" -> "archive" in comment.

Alert for gitweb site administrators: This patch changes the format of
$feature{'snapshot'}{'default'} in gitweb_config.perl from a list of
three pieces of information about a single format to a list of one or
more formats you wish to offer from the set ('tgz', 'tbz2', 'zip').
Update your gitweb_config.perl appropriately.  There was taken care
for old-style gitweb configuration to work as it used to, but this
backward compatibility works only for the values which correspond to
gitweb.snapshot values of 'gzip', 'bzip2' and 'zip', i.e.
  ['x-gzip', 'gz', 'gzip']
  ['x-bzip2', 'bz2', 'bzip2']
  ['x-zip', 'zip', '']

The preferred names for gitweb.snapshot in repository configuration
have also changed from 'gzip' and 'bzip2' to 'tgz' and 'tbz2', but
the old names are still recognized for compatibility.

Signed-off-by: Matt McCutchen <hashproduct@gmail.com>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 6754e2687330eca94c26ac7515cabaf9715956ac..c4f88245aa23ccbab07cc109a8478f1dd9ed8fdb 100755 (executable)
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -114,6 +114,49 @@ our $fallback_encoding = 'latin1';
 # - one might want to include '-B' option, e.g. '-B', '-M'
 our @diff_opts = ('-M'); # taken from git_commit
 
+# information about snapshot formats that gitweb is capable of serving
+our %known_snapshot_formats = (
+       # name => {
+       #       'display' => display name,
+       #       'type' => mime type,
+       #       'suffix' => filename suffix,
+       #       'format' => --format for git-archive,
+       #       'compressor' => [compressor command and arguments]
+       #                       (array reference, optional)}
+       #
+       'tgz' => {
+               'display' => 'tar.gz',
+               'type' => 'application/x-gzip',
+               'suffix' => '.tar.gz',
+               'format' => 'tar',
+               'compressor' => ['gzip']},
+
+       'tbz2' => {
+               'display' => 'tar.bz2',
+               'type' => 'application/x-bzip2',
+               'suffix' => '.tar.bz2',
+               'format' => 'tar',
+               'compressor' => ['bzip2']},
+
+       'zip' => {
+               'display' => 'zip',
+               'type' => 'application/x-zip',
+               'suffix' => '.zip',
+               'format' => 'zip'},
+);
+
+# Aliases so we understand old gitweb.snapshot values in repository
+# configuration.
+our %known_snapshot_format_aliases = (
+       'gzip'  => 'tgz',
+       'bzip2' => 'tbz2',
+
+       # backward compatibility: legacy gitweb config support
+       'x-gzip' => undef, 'gz' => undef,
+       'x-bzip2' => undef, 'bz2' => undef,
+       'x-zip' => undef, '' => undef,
+);
+
 # You define site-wide feature defaults here; override them with
 # $GITWEB_CONFIG as necessary.
 our %feature = (
@@ -144,20 +187,22 @@ our %feature = (
                'override' => 0,
                'default' => [0]},
 
-       # Enable the 'snapshot' link, providing a compressed tarball of any
+       # Enable the 'snapshot' link, providing a compressed archive of any
        # tree. This can potentially generate high traffic if you have large
        # project.
 
+       # Value is a list of formats defined in %known_snapshot_formats that
+       # you wish to offer.
        # To disable system wide have in $GITWEB_CONFIG
-       # $feature{'snapshot'}{'default'} = [undef];
+       # $feature{'snapshot'}{'default'} = [];
        # To have project specific config enable override in $GITWEB_CONFIG
        # $feature{'snapshot'}{'override'} = 1;
-       # and in project config gitweb.snapshot = none|gzip|bzip2|zip;
+       # and in project config, a comma-separated list of formats or "none"
+       # to disable.  Example: gitweb.snapshot = tbz2,zip;
        'snapshot' => {
                'sub' => \&feature_snapshot,
                'override' => 0,
-               #         => [content-encoding, suffix, program]
-               'default' => ['x-gzip', 'gz', 'gzip']},
+               'default' => ['tgz']},
 
        # Enable text search, which will list the commits which match author,
        # committer or commit text to a given string.  Enabled by default.
@@ -256,28 +301,19 @@ sub feature_blame {
 }
 
 sub feature_snapshot {
-       my ($ctype, $suffix, $command) = @_;
+       my (@fmts) = @_;
 
        my ($val) = git_get_project_config('snapshot');
 
-       if ($val eq 'gzip') {
-               return ('x-gzip', 'gz', 'gzip');
-       } elsif ($val eq 'bzip2') {
-               return ('x-bzip2', 'bz2', 'bzip2');
-       } elsif ($val eq 'zip') {
-               return ('x-zip', 'zip', '');
-       } elsif ($val eq 'none') {
-               return ();
+       if ($val) {
+               @fmts = ($val eq 'none' ? () : split /\s*[,\s]\s*/, $val);
+               @fmts = grep { defined } map {
+                       exists $known_snapshot_format_aliases{$_} ?
+                               $known_snapshot_format_aliases{$_} : $_ } @fmts;
+               @fmts = grep(exists $known_snapshot_formats{$_}, @fmts);
        }
 
-       return ($ctype, $suffix, $command);
-}
-
-sub gitweb_have_snapshot {
-       my ($ctype, $suffix, $command) = gitweb_check_feature('snapshot');
-       my $have_snapshot = (defined $ctype && defined $suffix);
-
-       return $have_snapshot;
+       return @fmts;
 }
 
 sub feature_grep {
@@ -563,6 +599,7 @@ sub href(%) {
                order => "o",
                searchtext => "s",
                searchtype => "st",
+               snapshot_format => "sf",
        );
        my %mapping = @mapping;
 
@@ -1257,6 +1294,39 @@ sub format_diff_line {
        return "<div class=\"diff$diff_class\">" . esc_html($line, -nbsp=>1) . "</div>\n";
 }
 
+# Generates undef or something like "_snapshot_" or "snapshot (_tbz2_ _zip_)",
+# linked.  Pass the hash of the tree/commit to snapshot.
+sub format_snapshot_links {
+       my ($hash) = @_;
+       my @snapshot_fmts = gitweb_check_feature('snapshot');
+       my $num_fmts = @snapshot_fmts;
+       if ($num_fmts > 1) {
+               # A parenthesized list of links bearing format names.
+               return "snapshot (" . join(' ', map
+                       $cgi->a({
+                               -href => href(
+                                       action=>"snapshot",
+                                       hash=>$hash,
+                                       snapshot_format=>$_
+                               )
+                       }, $known_snapshot_formats{$_}{'display'})
+               , @snapshot_fmts) . ")";
+       } elsif ($num_fmts == 1) {
+               # A single "snapshot" link whose tooltip bears the format name.
+               my ($fmt) = @snapshot_fmts;
+               return $cgi->a({
+                               -href => href(
+                                       action=>"snapshot",
+                                       hash=>$hash,
+                                       snapshot_format=>$fmt
+                               ),
+                               -title => "in format: $known_snapshot_formats{$fmt}{'display'}"
+                       }, "snapshot");
+       } else { # $num_fmts == 0
+               return undef;
+       }
+}
+
 ## ----------------------------------------------------------------------
 ## git utility subroutines, invoking git commands
 
@@ -3321,8 +3391,6 @@ sub git_shortlog_body {
        # uses global variable $project
        my ($commitlist, $from, $to, $refs, $extra) = @_;
 
-       my $have_snapshot = gitweb_have_snapshot();
-
        $from = 0 unless defined $from;
        $to = $#{$commitlist} if (!defined $to || $#{$commitlist} < $to);
 
@@ -3349,8 +3417,9 @@ sub git_shortlog_body {
                      $cgi->a({-href => href(action=>"commit", hash=>$commit)}, "commit") . " | " .
                      $cgi->a({-href => href(action=>"commitdiff", hash=>$commit)}, "commitdiff") . " | " .
                      $cgi->a({-href => href(action=>"tree", hash=>$commit, hash_base=>$commit)}, "tree");
-               if ($have_snapshot) {
-                       print " | " . $cgi->a({-href => href(action=>"snapshot", hash=>$commit)}, "snapshot");
+               my $snapshot_links = format_snapshot_links($commit);
+               if (defined $snapshot_links) {
+                       print " | " . $snapshot_links;
                }
                print "</td>\n" .
                      "</tr>\n";
@@ -4132,8 +4201,6 @@ sub git_blob {
 }
 
 sub git_tree {
-       my $have_snapshot = gitweb_have_snapshot();
-
        if (!defined $hash_base) {
                $hash_base = "HEAD";
        }
@@ -4167,11 +4234,10 @@ sub git_tree {
                                                       hash_base=>"HEAD", file_name=>$file_name)},
                                        "HEAD"),
                }
-               if ($have_snapshot) {
+               my $snapshot_links = format_snapshot_links($hash);
+               if (defined $snapshot_links) {
                        # FIXME: Should be available when we have no hash base as well.
-                       push @views_nav,
-                               $cgi->a({-href => href(action=>"snapshot", hash=>$hash)},
-                                       "snapshot");
+                       push @views_nav, $snapshot_links;
                }
                git_print_page_nav('tree','', $hash_base, undef, undef, join(' | ', @views_nav));
                git_print_header_div('commit', esc_html($co{'title'}) . $ref, $hash_base);
@@ -4235,33 +4301,36 @@ sub git_tree {
 }
 
 sub git_snapshot {
-       my ($ctype, $suffix, $command) = gitweb_check_feature('snapshot');
-       my $have_snapshot = (defined $ctype && defined $suffix);
-       if (!$have_snapshot) {
-               die_error('403 Permission denied', "Permission denied");
+       my @supported_fmts = gitweb_check_feature('snapshot');
+
+       my $format = $cgi->param('sf');
+       unless ($format =~ m/[a-z0-9]+/
+               && exists($known_snapshot_formats{$format})
+               && grep($_ eq $format, @supported_fmts)) {
+               die_error(undef, "Unsupported snapshot format");
        }
 
        if (!defined $hash) {
                $hash = git_get_head_hash($project);
        }
 
-       my $git = git_cmd_str();
+       my $git_command = git_cmd_str();
        my $name = $project;
        $name =~ s,([^/])/*\.git$,$1,;
        $name = basename($name);
        my $filename = to_utf8($name);
        $name =~ s/\047/\047\\\047\047/g;
        my $cmd;
-       if ($suffix eq 'zip') {
-               $filename .= "-$hash.$suffix";
-               $cmd = "$git archive --format=zip --prefix=\'$name\'/ $hash";
-       } else {
-               $filename .= "-$hash.tar.$suffix";
-               $cmd = "$git archive --format=tar --prefix=\'$name\'/ $hash | $command";
+       $filename .= "-$hash$known_snapshot_formats{$format}{'suffix'}";
+       $cmd = "$git_command archive " .
+               "--format=$known_snapshot_formats{$format}{'format'}" .
+               "--prefix=\'$name\'/ $hash";
+       if (exists $known_snapshot_formats{$format}{'compressor'}) {
+               $cmd .= ' | ' . join ' ', @{$known_snapshot_formats{$format}{'compressor'}};
        }
 
        print $cgi->header(
-               -type => "application/$ctype",
+               -type => $known_snapshot_formats{$format}{'type'},
                -content_disposition => 'inline; filename="' . "$filename" . '"',
                -status => '200 OK');
 
@@ -4271,7 +4340,6 @@ sub git_snapshot {
        print <$fd>;
        binmode STDOUT, ':utf8'; # as set at the beginning of gitweb.cgi
        close $fd;
-
 }
 
 sub git_log {
@@ -4390,8 +4458,6 @@ sub git_commit {
        my $refs = git_get_references();
        my $ref = format_ref_marker($refs, $co{'id'});
 
-       my $have_snapshot = gitweb_have_snapshot();
-
        git_header_html(undef, $expires);
        git_print_page_nav('commit', '',
                           $hash, $co{'tree'}, $hash,
@@ -4430,9 +4496,9 @@ sub git_commit {
              "<td class=\"link\">" .
              $cgi->a({-href => href(action=>"tree", hash=>$co{'tree'}, hash_base=>$hash)},
                      "tree");
-       if ($have_snapshot) {
-               print " | " .
-                     $cgi->a({-href => href(action=>"snapshot", hash=>$hash)}, "snapshot");
+       my $snapshot_links = format_snapshot_links($hash);
+       if (defined $snapshot_links) {
+               print " | " . $snapshot_links;
        }
        print "</td>" .
              "</tr>\n";