perl/Git/SVN/Utils.pm

   1 package Git::SVN::Utils;
   2
   3 use strict;
   4 use warnings;
   5
   6 use SVN::Core;
   7
   8 use base qw(Exporter);
   9
  10 our @EXPORT_OK = qw(
  11         fatal
  12         can_compress
  13         canonicalize_path
  14         canonicalize_url
  15 );
  16
  17
  18 =head1 NAME
  19
  20 Git::SVN::Utils - utility functions used across Git::SVN
  21
  22 =head1 SYNOPSIS
  23
  24     use Git::SVN::Utils qw(functions to import);
  25
  26 =head1 DESCRIPTION
  27
  28 This module contains functions which are useful across many different
  29 parts of Git::SVN.  Mostly it's a place to put utility functions
  30 rather than duplicate the code or have classes grabbing at other
  31 classes.
  32
  33 =head1 FUNCTIONS
  34
  35 All functions can be imported only on request.
  36
  37 =head3 fatal
  38
  39     fatal(@message);
  40
  41 Display a message and exit with a fatal error code.
  42
  43 =cut
  44
  45 # Note: not certain why this is in use instead of die.  Probably because
  46 # the exit code of die is 255?  Doesn't appear to be used consistently.
  47 sub fatal (@) { print STDERR "@_\n"; exit 1 }
  48
  49
  50 =head3 can_compress
  51
  52     my $can_compress = can_compress;
  53
  54 Returns true if Compress::Zlib is available, false otherwise.
  55
  56 =cut
  57
  58 my $can_compress;
  59 sub can_compress {
  60         return $can_compress if defined $can_compress;
  61
  62         return $can_compress = eval { require Compress::Zlib; };
  63 }
  64
  65
  66 =head3 canonicalize_path
  67
  68     my $canoncalized_path = canonicalize_path($path);
  69
  70 Converts $path into a canonical form which is safe to pass to the SVN
  71 API as a file path.
  72
  73 =cut
  74
  75 # Turn foo/../bar into bar
  76 sub _collapse_dotdot {
  77         my $path = shift;
  78
  79         1 while $path =~ s{/[^/]+/+\.\.}{};
  80         1 while $path =~ s{[^/]+/+\.\./}{};
  81         1 while $path =~ s{[^/]+/+\.\.}{};
  82
  83         return $path;
  84 }
  85
  86
  87 sub canonicalize_path {
  88         my ($path) = @_;
  89         my $dot_slash_added = 0;
  90         if (substr($path, 0, 1) ne "/") {
  91                 $path = "./" . $path;
  92                 $dot_slash_added = 1;
  93         }
  94         # File::Spec->canonpath doesn't collapse x/../y into y (for a
  95         # good reason), so let's do this manually.
  96         $path =~ s#/+#/#g;
  97         $path =~ s#/\.(?:/|$)#/#g;
  98         $path = _collapse_dotdot($path);
  99         $path =~ s#/$##g;
 100         $path =~ s#^\./## if $dot_slash_added;
 101         $path =~ s#^/##;
 102         $path =~ s#^\.$##;
 103         return $path;
 104 }
 105
 106
 107 =head3 canonicalize_url
 108
 109     my $canonicalized_url = canonicalize_url($url);
 110
 111 Converts $url into a canonical form which is safe to pass to the SVN
 112 API as a URL.
 113
 114 =cut
 115
 116 sub canonicalize_url {
 117         my $url = shift;
 118
 119         # The 1.7 way to do it
 120         if ( defined &SVN::_Core::svn_uri_canonicalize ) {
 121                 return SVN::_Core::svn_uri_canonicalize($url);
 122         }
 123         # There wasn't a 1.6 way to do it, so we do it ourself.
 124         else {
 125                 return _canonicalize_url_ourselves($url);
 126         }
 127 }
 128
 129
 130 sub _canonicalize_url_ourselves {
 131         my ($url) = @_;
 132         $url =~ s#^([^:]+://[^/]*/)(.*)$#$1 . canonicalize_path($2)#e;
 133         return $url;
 134 }
 135
 136
 137 1;