From: Justin Hunter Date: Sat, 22 Aug 2009 21:20:55 +0000 (-0700) Subject: initial MySQL producer X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=24e6a53aca215269c9c0c6251f5d551e72098a09;p=dbsrgits%2FSQL-Translator-2.0-ish.git initial MySQL producer --- diff --git a/lib/SQL/Translator/Producer/SQL/MySQL.pm b/lib/SQL/Translator/Producer/SQL/MySQL.pm new file mode 100644 index 0000000..47a56e8 --- /dev/null +++ b/lib/SQL/Translator/Producer/SQL/MySQL.pm @@ -0,0 +1,866 @@ +use MooseX::Declare; +role SQL::Translator::Producer::SQL::MySQL { + use SQL::Translator::Constants qw(:sqlt_types :sqlt_constants); + use SQL::Translator::Types qw(Column Constraint Index Table View); + my $DEFAULT_MAX_ID_LENGTH = 64; + my %used_names; + + # + # Use only lowercase for the keys (e.g. "long" and not "LONG") + # + my %translate = ( + # + # Oracle types + # + varchar2 => 'varchar', + long => 'text', + clob => 'longtext', + + # + # Sybase types + # + int => 'integer', + money => 'float', + real => 'double', + comment => 'text', + bit => 'tinyint', + + # + # Access types + # + 'long integer' => 'integer', + 'text' => 'text', + 'datetime' => 'datetime', + + # + # PostgreSQL types + # + bytea => 'BLOB', + ); + + # + # Column types that do not support lenth attribute + # + my @no_length_attr = qw/ date time timestamp datetime year /; + + method preprocess_schema($schema) { +# my ($schema) = @_; + + # extra->{mysql_table_type} used to be the type. It belongs in options, so + # move it if we find it. Return Engine type if found in extra or options + # Similarly for mysql_charset and mysql_collate + my $extra_to_options = sub { + my ($table, $extra_name, $opt_name) = @_; + + my $extra = $table->extra; + + my $extra_type = delete $extra->{$extra_name}; + + # Now just to find if there is already an Engine or Type option... + # and lets normalize it to ENGINE since: + # + # The ENGINE table option specifies the storage engine for the table. + # TYPE is a synonym, but ENGINE is the preferred option name. + # + + # We have to use the hash directly here since otherwise there is no way + # to remove options. + my $options = ( $table->{options} ||= []); + + # If multiple option names, normalize to the first one + if (ref $opt_name) { + OPT_NAME: for ( @$opt_name[1..$#$opt_name] ) { + for my $idx ( 0..$#{$options} ) { + my ($key, $value) = %{ $options->[$idx] }; + + if (uc $key eq $_) { + $options->[$idx] = { $opt_name->[0] => $value }; + last OPT_NAME; + } + } + } + $opt_name = $opt_name->[0]; + + } + + + # This assumes that there isn't both a Type and an Engine option. + OPTION: + for my $idx ( 0..$#{$options} ) { + my ($key, $value) = %{ $options->[$idx] }; + + next unless uc $key eq $opt_name; + + # make sure case is right on option name + delete $options->[$idx]{$key}; + return $options->[$idx]{$opt_name} = $value || $extra_type; + + } + + if ($extra_type) { + push @$options, { $opt_name => $extra_type }; + return $extra_type; + } + + }; + + # Names are only specific to a given schema + my %used_names = (); + + # + # Work out which tables need to be InnoDB to support foreign key + # constraints. We do this first as we need InnoDB at both ends. + # + foreach my $table ( $schema->get_tables ) { + + $extra_to_options->($table, 'mysql_table_type', ['ENGINE', 'TYPE'] ); + $extra_to_options->($table, 'mysql_charset', 'CHARACTER SET' ); + $extra_to_options->($table, 'mysql_collate', 'COLLATE' ); + + foreach my $c ( $table->get_constraints ) { + next unless $c->type eq FOREIGN_KEY; + + # Normalize constraint names here. + my $c_name = $c->name; + # Give the constraint a name if it doesn't have one, so it doens't feel + # left out + $c_name = $table->name . '_fk' unless length $c_name; + + $c->name( $self->next_unused_name($c_name) ); + + for my $meth (qw/table reference_table/) { + my $table = $schema->get_table($c->$meth) || next; + # This normalizes the types to ENGINE and returns the value if its there + next if $extra_to_options->($table, 'mysql_table_type', ['ENGINE', 'TYPE']); + $table->options( { 'ENGINE' => 'InnoDB' } ); + } + } # foreach constraints + + my %map = ( mysql_collate => 'collate', mysql_charset => 'character set'); + foreach my $f ( $table->get_fields ) { + my $extra = $f->extra; + for (keys %map) { + $extra->{$map{$_}} = delete $extra->{$_} if exists $extra->{$_}; + } + + my @size = $f->size; + if ( !$size[0] && $f->data_type =~ /char$/ ) { + $f->size( (255) ); + } + } + + } + } + + method produce { + my $translator = $self->translator; + my $DEBUG = 0;# = $translator->debug; + #local %used_names; + my $no_comments = $translator->no_comments; + my $add_drop_table = $translator->add_drop_table; + my $schema = $translator->schema; + my $show_warnings = $translator->show_warnings || 0; + my $producer_args = $translator->producer_args; + my $mysql_version = $self->parse_mysql_version ($producer_args->{mysql_version}, 'perl') || 0; + my $max_id_length = $producer_args->{mysql_max_id_length} || $DEFAULT_MAX_ID_LENGTH; + + my ($qt, $qf, $qc) = ('','', ''); + $qt = '`' if $translator->quote_table_names; + $qf = '`' if $translator->quote_field_names; + + #debug("PKG: Beginning production\n"); + %used_names = (); + my $create = ''; + $create .= $self->header_comment unless ($no_comments); + # \todo Don't set if MySQL 3.x is set on command line + my @create = "SET foreign_key_checks=0"; + + $self->preprocess_schema($schema); + + # + # Generate sql + # + my @table_defs =(); + + for my $table ( $schema->get_tables ) { + # print $table->name, "\n"; + push @table_defs, $self->create_table($table, + { add_drop_table => $add_drop_table, + show_warnings => $show_warnings, + no_comments => $no_comments, + quote_table_names => $qt, + quote_field_names => $qf, + max_id_length => $max_id_length, + mysql_version => $mysql_version + }); + } + + if ($mysql_version >= 5.000001) { + for my $view ( $schema->get_views ) { + push @table_defs, $self->create_view($view, + { add_replace_view => $add_drop_table, + show_warnings => $show_warnings, + no_comments => $no_comments, + quote_table_names => $qt, + quote_field_names => $qf, + max_id_length => $max_id_length, + mysql_version => $mysql_version + }); + } + } + + + # print "@table_defs\n"; + push @table_defs, "SET foreign_key_checks=1"; + + return wantarray ? ($create ? $create : (), @create, @table_defs) : ($create . join('', map { $_ ? "$_;\n\n" : () } (@create, @table_defs))); + } + + method create_view($view, $options) { +# my ($view, $options) = @_; + my $qt = $options->{quote_table_names} || ''; + my $qf = $options->{quote_field_names} || ''; + + my $view_name = $view->name; + #debug("PKG: Looking at view '${view_name}'\n"); + + # Header. Should this look like what mysqldump produces? + my $create = ''; + $create .= "--\n-- View: ${qt}${view_name}${qt}\n--\n" unless $options->{no_comments}; + $create .= 'CREATE'; + $create .= ' OR REPLACE' if $options->{add_replace_view}; + $create .= "\n"; + + my $extra = $view->extra; + # ALGORITHM + if( exists($extra->{mysql_algorithm}) && defined(my $algorithm = $extra->{mysql_algorithm}) ){ + $create .= " ALGORITHM = ${algorithm}\n" if $algorithm =~ /(?:UNDEFINED|MERGE|TEMPTABLE)/i; + } + # DEFINER + if( exists($extra->{mysql_definer}) && defined(my $user = $extra->{mysql_definer}) ){ + $create .= " DEFINER = ${user}\n"; + } + # SECURITY + if( exists($extra->{mysql_security}) && defined(my $security = $extra->{mysql_security}) ){ + $create .= " SQL SECURITY ${security}\n" if $security =~ /(?:DEFINER|INVOKER)/i; + } + + #Header, cont. + $create .= " VIEW ${qt}${view_name}${qt}"; + + if( my @fields = $view->fields ){ + my $list = join ', ', map { "${qf}${_}${qf}"} @fields; + $create .= " ( ${list} )"; + } + if( my $sql = $view->sql ){ + $create .= " AS (\n ${sql}\n )"; + } + # $create .= ""; + return $create; + } + + method create_table($table, $options) { +# my ($table, $options) = @_; + + my $qt = $options->{quote_table_names} || ''; + my $qf = $options->{quote_field_names} || ''; + + my $table_name = $self->quote_table_name($table->name, $qt); + #debug("PKG: Looking at table '$table_name'\n"); + + # + # Header. Should this look like what mysqldump produces? + # + my $create = ''; + my $drop; + $create .= "--\n-- Table: $table_name\n--\n" unless $options->{no_comments}; + $drop = qq[DROP TABLE IF EXISTS $table_name] if $options->{add_drop_table}; + $create .= "CREATE TABLE $table_name (\n"; + + # + # Fields + # + my @field_defs; + for my $field ( $table->get_fields ) { + push @field_defs, $self->create_field($field, $options); + } + + # + # Indices + # + my @index_defs; + my %indexed_fields; + for my $index ( $table->get_indices ) { + push @index_defs, $self->create_index($index, $options); + $indexed_fields{ $_ } = 1 for $index->fields; + } + + # + # Constraints -- need to handle more than just FK. -ky + # + my @constraint_defs; + my @constraints = $table->get_constraints; + for my $c ( @constraints ) { + my $constr = $self->create_constraint($c, $options); + push @constraint_defs, $constr if($constr); + next unless $c->fields; + unless ( $indexed_fields{ ($c->fields())[0] } || $c->type ne FOREIGN_KEY ) { + push @index_defs, "INDEX ($qf" . ($c->fields())[0] . "$qf)"; + $indexed_fields{ ($c->fields())[0] } = 1; + } + } + + $create .= join(",\n", map { " $_" } + @field_defs, @index_defs, @constraint_defs + ); + + # + # Footer + # + $create .= "\n)"; + $create .= $self->generate_table_options($table, $options) || ''; + # $create .= ";\n\n"; + + return $drop ? ($drop,$create) : $create; + } + + method quote_table_name(Str $table_name, Str $qt) { + $table_name =~ s/\./$qt.$qt/g; + + return "$qt$table_name$qt"; + } + + method generate_table_options(Table $table, $options?) { + my $create; + + my $table_type_defined = 0; + my $qf = $options->{quote_field_names} ||= ''; + my $charset = $table->extra->{'mysql_charset'}; + my $collate = $table->extra->{'mysql_collate'}; + my $union = undef; + for my $t1_option_ref ( $table->options ) { + my($key, $value) = %{$t1_option_ref}; + $table_type_defined = 1 + if uc $key eq 'ENGINE' or uc $key eq 'TYPE'; + if (uc $key eq 'CHARACTER SET') { + $charset = $value; + next; + } elsif (uc $key eq 'COLLATE') { + $collate = $value; + next; + } elsif (uc $key eq 'UNION') { + $union = "($qf". join("$qf, $qf", @$value) ."$qf)"; + next; + } + $create .= " $key=$value"; + } + + my $mysql_table_type = $table->extra->{'mysql_table_type'}; + $create .= " ENGINE=$mysql_table_type" + if $mysql_table_type && !$table_type_defined; + my $comments = $table->comments; + + $create .= " DEFAULT CHARACTER SET $charset" if $charset; + $create .= " COLLATE $collate" if $collate; + $create .= " UNION=$union" if $union; + $create .= qq[ comment='$comments'] if $comments; + return $create; + } + + method create_field($field, $options?) { + my $qf = $options->{quote_field_names} ||= ''; + + my $field_name = $field->name; + #debug("PKG: Looking at field '$field_name'\n"); + my $field_def = "$qf$field_name$qf"; + + # data type and size + my $data_type = $field->data_type; + my @size = $field->size; + my %extra = $field->extra; + my $list = $extra{'list'} || []; + # \todo deal with embedded quotes + my $commalist = join( ', ', map { qq['$_'] } @$list ); + my $charset = $extra{'mysql_charset'}; + my $collate = $extra{'mysql_collate'}; + + my $mysql_version = $options->{mysql_version} || 0; + # + # Oracle "number" type -- figure best MySQL type + # + if ( lc $data_type eq 'number' ) { + # not an integer + if ( scalar @size > 1 ) { + $data_type = 'double'; + } + elsif ( $size[0] && $size[0] >= 12 ) { + $data_type = 'bigint'; + } + elsif ( $size[0] && $size[0] <= 1 ) { + $data_type = 'tinyint'; + } + else { + $data_type = 'int'; + } + } + # + # Convert a large Oracle varchar to "text" + # (not necessary as of 5.0.3 http://dev.mysql.com/doc/refman/5.0/en/char.html) + # + elsif ( $data_type =~ /char/i && $size[0] > 255 ) { + unless ($size[0] <= 65535 && $mysql_version >= 5.000003 ) { + $data_type = 'text'; + @size = (); + } + } + elsif ( $data_type =~ /boolean/i ) { + if ($mysql_version >= 4) { + $data_type = 'boolean'; + } else { + $data_type = 'enum'; + $commalist = "'0','1'"; + } + } +# elsif ( exists $translate{ lc $data_type } ) { +# $data_type = $translate{ lc $data_type }; +# } + + @size = () if $data_type =~ /(text|blob)/i; + + if ( $data_type =~ /(double|float)/ && scalar @size == 1 ) { + push @size, '0'; + } + + $field_def .= " $data_type"; + + if ( lc($data_type) eq 'enum' || lc($data_type) eq 'set') { + $field_def .= '(' . $commalist . ')'; + } + elsif ( + defined $size[0] && $size[0] > 0 + && + ! grep lc($data_type) eq $_, @no_length_attr + ) { + $field_def .= '(' . join( ', ', @size ) . ')'; + } + + # char sets + $field_def .= " CHARACTER SET $charset" if $charset; + $field_def .= " COLLATE $collate" if $collate; + + # MySQL qualifiers + for my $qual ( qw[ binary unsigned zerofill ] ) { + my $val = $extra{ $qual } || $extra{ uc $qual } or next; + $field_def .= " $qual"; + } + for my $qual ( 'character set', 'collate', 'on update' ) { + my $val = $extra{ $qual } || $extra{ uc $qual } or next; + $field_def .= " $qual $val"; + } + + # Null? + $field_def .= ' NOT NULL' unless $field->is_nullable; + + # Default? XXX Need better quoting! + my $default = $field->default_value; +=cut + if ( defined $default ) { + SQL::Translator::Producer->_apply_default_value( + \$field_def, + $default, + [ + 'NULL' => \'NULL', + ], + ); + } +=cut + + if ( my $comments = $field->comments ) { + $field_def .= qq[ comment '$comments']; + } + + # auto_increment? + $field_def .= " auto_increment" if $field->is_auto_increment; + + return $field_def; + } + + method alter_create_index(Index $index, $options?) { + my $qt = $options->{quote_table_names} || ''; + my $qf = $options->{quote_field_names} || ''; + + return join( ' ', + 'ALTER TABLE', + $qt.$index->table->name.$qt, + 'ADD', + create_index(@_) + ); + } + + method create_index($index, $options?) { +# my ( $index, $options ) = @_; + + my $qf = $options->{quote_field_names} || ''; + + return join( + ' ', + map { $_ || () } + lc $index->type eq 'normal' ? 'INDEX' : $index->type . ' INDEX', + $index->name + ? ( + $self->truncate_id_uniquely( + $index->name, + $options->{max_id_length} || $DEFAULT_MAX_ID_LENGTH + ) + ) + : '', + '(' . $qf . join( "$qf, $qf", $index->fields ) . $qf . ')' + ); + } + + method alter_drop_index(Index $index, $options?) { + my $qt = $options->{quote_table_names} || ''; + my $qf = $options->{quote_field_names} || ''; + + return join( ' ', + 'ALTER TABLE', + $qt.$index->table->name.$qt, + 'DROP', + 'INDEX', + $index->name || $index->fields + ); + + } + + method alter_drop_constraint(Constraint $c, $options?) { + my $qt = $options->{quote_table_names} || ''; + my $qc = $options->{quote_field_names} || ''; + + my $out = sprintf('ALTER TABLE %s DROP %s %s', + $qt . $c->table->name . $qt, + $c->type eq FOREIGN_KEY ? $c->type : "INDEX", + $qc . $c->name . $qc ); + + return $out; + } + + method alter_create_constraint($index, $options?) { + my $qt = $options->{quote_table_names} || ''; + return join( ' ', + 'ALTER TABLE', + $qt.$index->table->name.$qt, + 'ADD', + $self->create_constraint(@_) ); + } + + method create_constraint(Constraint $c, $options?) { + my $qf = $options->{quote_field_names} || ''; + my $qt = $options->{quote_table_names} || ''; + my $leave_name = $options->{leave_name} || undef; + + my @fields = $c->fields or return; + + if ( $c->type eq PRIMARY_KEY ) { + return 'PRIMARY KEY (' . $qf . join("$qf, $qf", @fields). $qf . ')'; + } + elsif ( $c->type eq UNIQUE ) { + return + 'UNIQUE '. + (defined $c->name ? $qf.$self->truncate_id_uniquely( $c->name, $options->{max_id_length} || $DEFAULT_MAX_ID_LENGTH ).$qf.' ' : ''). + '(' . $qf . join("$qf, $qf", @fields). $qf . ')'; + } + elsif ( $c->type eq FOREIGN_KEY ) { + # + # Make sure FK field is indexed or MySQL complains. + # + + my $table = $c->table; + my $c_name = $self->truncate_id_uniquely( $c->name, $options->{max_id_length} || $DEFAULT_MAX_ID_LENGTH ); + + my $def = join(' ', + map { $_ || () } + 'CONSTRAINT', + $qf . $c_name . $qf, + 'FOREIGN KEY' + ); + + + $def .= ' ('.$qf . join( "$qf, $qf", @fields ) . $qf . ')'; + + $def .= ' REFERENCES ' . $qt . $c->reference_table . $qt; + + my @rfields = map { $_ || () } $c->reference_fields; + unless ( @rfields ) { + my $rtable_name = $c->reference_table; + if ( my $ref_table = $table->schema->get_table( $rtable_name ) ) { + push @rfields, $ref_table->primary_key; + } + else { + warn "Can't find reference table '$rtable_name' " . + "in schema\n" if $options->{show_warnings}; + } + } + + if ( @rfields ) { + $def .= ' (' . $qf . join( "$qf, $qf", @rfields ) . $qf . ')'; + } + else { + warn "FK constraint on " . $table->name . '.' . + join('', @fields) . " has no reference fields\n" + if $options->{show_warnings}; + } + + if ( $c->match_type ) { + $def .= ' MATCH ' . + ( $c->match_type =~ /full/i ) ? 'FULL' : 'PARTIAL'; + } + + if ( $c->on_delete ) { + $def .= ' ON DELETE '.join( ' ', $c->on_delete ); + } + + if ( $c->on_update ) { + $def .= ' ON UPDATE '.join( ' ', $c->on_update ); + } + return $def; + } + + return undef; + } + + method alter_table(Str $to_table, $options?) { + my $qt = $options->{quote_table_names} || ''; + + my $table_options = $self->generate_table_options($to_table, $options) || ''; + my $out = sprintf('ALTER TABLE %s%s', + $qt . $to_table->name . $qt, + $table_options); + + return $out; + } + + method rename_field(@args) { alter_field(@args) } + method alter_field(Str $from_field, Str $to_field, $options?) { + my $qf = $options->{quote_field_names} || ''; + my $qt = $options->{quote_table_names} || ''; + + my $out = sprintf('ALTER TABLE %s CHANGE COLUMN %s %s', + $qt . $to_field->table->name . $qt, + $qf . $from_field->name . $qf, + $self->create_field($to_field, $options)); + + return $out; + } + + method add_field(Str $new_field, $options?) { + my $qt = $options->{quote_table_names} || ''; + + my $out = sprintf('ALTER TABLE %s ADD COLUMN %s', + $qt . $new_field->table->name . $qt, + create_field($new_field, $options)); + + return $out; + + } + + method drop_field(Str $old_field, $options?) { + my $qf = $options->{quote_field_names} || ''; + my $qt = $options->{quote_table_names} || ''; + + my $out = sprintf('ALTER TABLE %s DROP COLUMN %s', + $qt . $old_field->table->name . $qt, + $qf . $old_field->name . $qf); + + return $out; + + } + + method batch_alter_table($table, $diff_hash, $options?) { + # InnoDB has an issue with dropping and re-adding a FK constraint under the + # name in a single alter statment, see: http://bugs.mysql.com/bug.php?id=13741 + # + # We have to work round this. + + my %fks_to_alter; + my %fks_to_drop = map { + $_->type eq FOREIGN_KEY + ? ( $_->name => $_ ) + : ( ) + } @{$diff_hash->{alter_drop_constraint} }; + + my %fks_to_create = map { + if ( $_->type eq FOREIGN_KEY) { + $fks_to_alter{$_->name} = $fks_to_drop{$_->name} if $fks_to_drop{$_->name}; + ( $_->name => $_ ); + } else { ( ) } + } @{$diff_hash->{alter_create_constraint} }; + + my @drop_stmt; + if (scalar keys %fks_to_alter) { + $diff_hash->{alter_drop_constraint} = [ + grep { !$fks_to_alter{$_->name} } @{ $diff_hash->{alter_drop_constraint} } + ]; + + @drop_stmt = batch_alter_table($table, { alter_drop_constraint => [ values %fks_to_alter ] }, $options); + + } + + my @stmts = map { + if (@{ $diff_hash->{$_} || [] }) { + my $meth = __PACKAGE__->can($_) or die __PACKAGE__ . " cant $_"; + map { $meth->( (ref $_ eq 'ARRAY' ? @$_ : $_), $options ) } @{ $diff_hash->{$_} } + } else { () } + } qw/rename_table + alter_drop_constraint + alter_drop_index + drop_field + add_field + alter_field + rename_field + alter_create_index + alter_create_constraint + alter_table/; + + # rename_table makes things a bit more complex + my $renamed_from = ""; + $renamed_from = $diff_hash->{rename_table}[0][0]->name + if $diff_hash->{rename_table} && @{$diff_hash->{rename_table}}; + + return unless @stmts; + # Just zero or one stmts. return now + return (@drop_stmt,@stmts) unless @stmts > 1; + + # Now strip off the 'ALTER TABLE xyz' of all but the first one + + my $qt = $options->{quote_table_names} || ''; + my $table_name = $qt . $table->name . $qt; + + + my $re = $renamed_from + ? qr/^ALTER TABLE (?:\Q$table_name\E|\Q$qt$renamed_from$qt\E) / + : qr/^ALTER TABLE \Q$table_name\E /; + + my $first = shift @stmts; + my ($alter_table) = $first =~ /($re)/; + + my $padd = " " x length($alter_table); + + return @drop_stmt, join( ",\n", $first, map { s/$re//; $padd . $_ } @stmts); + + } + + method drop_table(Str $table, $options?) { + my $qt = $options->{quote_table_names} || ''; + + # Drop (foreign key) constraints so table drops cleanly + my @sql = batch_alter_table($table, { alter_drop_constraint => [ grep { $_->type eq 'FOREIGN KEY' } $table->get_constraints ] }, $options); + + return (@sql, "DROP TABLE $qt$table$qt"); + # return join("\n", @sql, "DROP TABLE $qt$table$qt"); + + } + + method rename_table(Str $old_table, Str $new_table, $options?) { + my $qt = $options->{quote_table_names} || ''; + + return "ALTER TABLE $qt$old_table$qt RENAME TO $qt$new_table$qt"; + } + + method next_unused_name($name?) { +# my $name = shift || ''; + if ( !defined($used_names{$name}) ) { + $used_names{$name} = $name; + return $name; + } + + my $i = 1; + while ( defined($used_names{$name . '_' . $i}) ) { + ++$i; + } + $name .= '_' . $i; + $used_names{$name} = $name; + return $name; + } + + method header_comment($producer?, $comment_char?) { + $producer ||= caller; + my $now = scalar localtime; + my $DEFAULT_COMMENT = '-- '; + + $comment_char = $DEFAULT_COMMENT + unless defined $comment_char; + + my $header_comment =<<"HEADER_COMMENT"; + ${comment_char} + ${comment_char}Created by $producer + ${comment_char}Created on $now + ${comment_char} +HEADER_COMMENT + + # Any additional stuff passed in + for my $additional_comment (@_) { + $header_comment .= "${comment_char}${additional_comment}\n"; + } + + return $header_comment; + } + + method parse_mysql_version($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'"; + } + } + +use constant COLLISION_TAG_LENGTH => 8; + +method truncate_id_uniquely(Str $desired_name, Int $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; +} + + +}