X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FTranslator%2FUtils.pm;h=89b26424e695f4e7f9e6505f3bfd454a6188ce1f;hb=da06ac74ada30aacf656943306679a28605ad5c8;hp=57b455c57d8479e627a0b4a2c16881fc2b6faddb;hpb=51bb6fe019947909d936313f76277b24184a0373;p=dbsrgits%2FSQL-Translator.git

diff --git a/lib/SQL/Translator/Utils.pm b/lib/SQL/Translator/Utils.pm
index 57b455c..89b2642 100644
--- a/lib/SQL/Translator/Utils.pm
+++ b/lib/SQL/Translator/Utils.pm
@@ -1,9 +1,9 @@
 package SQL::Translator::Utils;
 
 # ----------------------------------------------------------------------
-# $Id: Utils.pm,v 1.9 2003-09-26 21:04:32 kycl4rk Exp $
+# $Id: Utils.pm 1440 2009-01-17 16:31:57Z jawnsy $
 # ----------------------------------------------------------------------
-# Copyright (C) 2003 darren chamberlain <darren@cpan.org>
+# Copyright (C) 2002-2009 SQLFairy Authors
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License as
@@ -24,12 +24,14 @@ use strict;
 use base qw(Exporter);
 use vars qw($VERSION $DEFAULT_COMMENT @EXPORT_OK);
 
+use Digest::SHA1 qw( sha1_hex );
+
 use Exporter;
 
-$VERSION = sprintf "%d.%02d", q$Revision: 1.9 $ =~ /(\d+)\.(\d+)/;
+$VERSION = '1.99';
 $DEFAULT_COMMENT = '-- ';
 @EXPORT_OK = qw(
-    debug normalize_name header_comment parse_list_arg $DEFAULT_COMMENT
+    debug normalize_name header_comment parse_list_arg truncate_id_uniquely $DEFAULT_COMMENT parse_mysql_version
 );
 
 # ----------------------------------------------------------------------
@@ -72,7 +74,7 @@ sub debug {
 
 # ----------------------------------------------------------------------
 sub normalize_name {
-    my $name = shift;
+    my $name = shift or return '';
 
     # The name can only begin with a-zA-Z_; if there's anything
     # else, prefix with _
@@ -143,6 +145,81 @@ sub parse_list_arg {
     }
 }
 
+# ----------------------------------------------------------------------
+# truncate_id_uniquely( $desired_name, $max_symbol_length )
+#
+# Truncates the name $desired_name to the $max_symbol_length by
+# including part of the hash of the full name at the end of the
+# truncated name, giving a high probability that the symbol will be
+# unique.
+# ----------------------------------------------------------------------
+my $COLLISION_TAG_LENGTH = 8;
+sub truncate_id_uniquely {
+    my ( $desired_name, $max_symbol_length ) = @_;
+
+    return $desired_name unless defined $desired_name && length $desired_name > $max_symbol_length;
+
+    my $truncated_name = substr $desired_name, 0, $max_symbol_length - $COLLISION_TAG_LENGTH - 1;
+
+    # Hex isn't the most space-efficient, but it skirts around allowed
+    # charset issues
+    my $digest = sha1_hex($desired_name);
+    my $collision_tag = substr $digest, 0, $COLLISION_TAG_LENGTH;
+
+    return $truncated_name
+         . '_'
+         . $collision_tag;
+}
+
+
+#---------------------------------------------------------------------
+# parse_mysql_version ( $version_string, $result_target)
+#
+# Attempts to parse an arbitrary string as a mysql version number. 
+# Returns either a floating point perl style string, or a mysql style
+# 5 digit string, depending on the supplied $result_target
+#---------------------------------------------------------------------
+sub parse_mysql_version {
+    my ($v, $target) = @_;
+
+    return undef unless $v;
+
+    $target ||= 'perl';
+
+    my @vers;
+
+    # X.Y.Z style 
+    if ( $v =~ / ^ (\d+) \. (\d{1,3}) (?: \. (\d{1,3}) )? $ /x ) {
+        push @vers, $1, $2, $3;
+    }
+
+    # XYYZZ (mysql) style 
+    elsif ( $v =~ / ^ (\d) (\d{2}) (\d{2}) $ /x ) {
+        push @vers, $1, $2, $3;
+    }
+
+    # XX.YYYZZZ (perl) style or simply X 
+    elsif ( $v =~ / ^ (\d+) (?: \. (\d{3}) (\d{3}) )? $ /x ) {
+        push @vers, $1, $2, $3;
+    }
+    else {
+        #how do I croak sanely here?
+        die "Unparseable MySQL version '$v'";
+    }
+
+    if ($target eq 'perl') {
+        return sprintf ('%d.%03d%03d', map { $_ || 0 } (@vers) );
+    }
+    elsif ($target eq 'mysql') {
+        return sprintf ('%d%02d%02d', map { $_ || 0 } (@vers) );
+    }
+    else {
+        #how do I croak sanely here?
+        die "Unknown version target '$target'";
+    }
+}
+
+
 1;
 
 # ----------------------------------------------------------------------
@@ -250,16 +327,46 @@ All of the following will return equivalent values:
   parse_list_arg( [ 'id', 'name' ] );
   parse_list_arg( qw[ id name ] );
 
+=head2 truncate_id_uniquely
+
+Takes a string ($desired_name) and int ($max_symbol_length). Truncates
+$desired_name to $max_symbol_length by including part of the hash of
+the full name at the end of the truncated name, giving a high
+probability that the symbol will be unique. For example,
+
+  truncate_id_uniquely( 'a' x 100, 64 )
+  truncate_id_uniquely( 'a' x 99 . 'b', 64 );
+  truncate_id_uniquely( 'a' x 99,  64 )
+
+Will give three different results; specifically:
+
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_7f900025
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_6191e39a
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_8cd96af2
+
 =head2 $DEFAULT_COMMENT
 
 This is the default comment string, '-- ' by default.  Useful for
 C<header_comment>.
 
+=head2 parse_mysql_version
+
+Used by both L<Parser::MySQL|SQL::Translator::Parser::MySQL> and 
+L<Producer::MySQL|SQL::Translator::Producer::MySQL> in order to provide a
+consistent format for both C<< parser_args->{mysql_parser_version} >> and
+C<< producer_args->{mysql_version} >> respectively. Takes any of the following
+version specifications:
+
+  5.0.3
+  4.1
+  3.23.2
+  5
+  5.001005  (perl style)
+  30201     (mysql style)
+
 =head1 AUTHORS
 
 Darren Chamberlain E<lt>darren@cpan.orgE<gt>,
 Ken Y. Clark E<lt>kclark@cpan.orgE<gt>.
 
 =cut
-
-=cut