[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Schema / Versioned.pm

package DBIx::Class::Version::Table;
use base 'DBIx::Class';
use strict;
use warnings;

__PACKAGE__->load_components(qw/ Core/);
__PACKAGE__->table('SchemaVersions');

__PACKAGE__->add_columns
    ( 'Version' => {
        'data_type' => 'VARCHAR',
        'is_auto_increment' => 0,
        'default_value' => undef,
        'is_foreign_key' => 0,
        'name' => 'Version',
        'is_nullable' => 0,
        'size' => '10'
        },
      'Installed' => {
          'data_type' => 'VARCHAR',
          'is_auto_increment' => 0,
          'default_value' => undef,
          'is_foreign_key' => 0,
          'name' => 'Installed',
          'is_nullable' => 0,
          'size' => '20'
          },
      );
__PACKAGE__->set_primary_key('Version');

package DBIx::Class::Version;
use base 'DBIx::Class::Schema';
use strict;
use warnings;

__PACKAGE__->register_class('Table', 'DBIx::Class::Version::Table');


# ---------------------------------------------------------------------------
package DBIx::Class::Schema::Versioned;

use strict;
use warnings;
use base 'DBIx::Class';
use POSIX 'strftime';
use Data::Dumper;

__PACKAGE__->mk_classdata('_filedata');
__PACKAGE__->mk_classdata('upgrade_directory');
__PACKAGE__->mk_classdata('backup_directory');

sub schema_version {
  my ($self) = @_;
  my $class = ref($self)||$self;
  my $version;
  {
    no strict 'refs';
    $version = ${"${class}::VERSION"};
  }
  return $version;
}

sub connection {
  my $self = shift;
  $self->next::method(@_);
  $self->_on_connect;
  return $self;
}

sub _on_connect
{
    my ($self) = @_;
    my $vschema = DBIx::Class::Version->connect(@{$self->storage->connect_info()});
    my $vtable = $vschema->resultset('Table');
    my $pversion;

    if(!$self->_source_exists($vtable))
    {
#        $vschema->storage->debug(1);
        $vschema->storage->ensure_connected();
        $vschema->deploy();
        $pversion = 0;
    }
    else
    {
        my $psearch = $vtable->search(undef, 
                                      { select => [
                                                   { 'max' => 'Installed' },
                                                   ],
                                            as => ['maxinstall'],
                                        })->first;
        $pversion = $vtable->search({ Installed => $psearch->get_column('maxinstall'),
                                  })->first;
        $pversion = $pversion->Version if($pversion);
    }
#    warn("Previous version: $pversion\n");
    if($pversion eq $self->schema_version)
    {
        warn "This version is already installed\n";
        return 1;
    }

## use IC::DT?    

    if(!$pversion)
    {
        $vtable->create({ Version => $self->schema_version,
                          Installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
                          });
        ## If we let the user do this, where does the Version table get updated?
        warn "No previous version found, calling deploy to install this version.\n";
        $self->deploy();
        return 1;
    }

    my $file = $self->ddl_filename(
                                   $self->storage->sqlt_type,
                                   $self->upgrade_directory,
                                   $self->schema_version
                                   );
    if(!$file)
    {
        # No upgrade path between these two versions
        return 1;
    }

     $file = $self->ddl_filename(
                                 $self->storage->sqlt_type,
                                 $self->upgrade_directory,
                                 $self->schema_version,
                                 $pversion,
                                 );
#    $file =~ s/@{[ $self->schema_version ]}/"${pversion}-" . $self->schema_version/e;
    if(!-f $file)
    {
        warn "Upgrade not possible, no upgrade file found ($file)\n";
        return;
    }

    my $fh;
    open $fh, "<$file" or warn("Can't open upgrade file, $file ($!)");
    my @data = split(/;\n/, join('', <$fh>));
    close($fh);
    @data = grep { $_ && $_ !~ /^-- / } @data;
    @data = grep { $_ !~ /^(BEGIN TRANACTION|COMMIT)/m } @data;

    $self->_filedata(\@data);

    ## Don't do this yet, do only on command?
    ## If we do this later, where does the Version table get updated??
    warn "Versions out of sync. This is " . $self->schema_version . 
        ", your database contains version $pversion, please call upgrade on your Schema.\n";
#    $self->upgrade($pversion, $self->schema_version);
}

sub _source_exists
{
    my ($self, $rs) = @_;

    my $c = eval {
        $rs->search({ 1, 0 })->count;
    };
    return 0 if $@ || !defined $c;

    return 1;
}

sub backup
{
    my ($self) = @_;
    ## Make each ::DBI::Foo do this
    $self->storage->backup($self->backup_directory());
}

sub upgrade
{
    my ($self) = @_;

    ## overridable sub, per default just run all the commands.

    $self->backup();

    $self->run_upgrade();

    my $vschema = DBIx::Class::Version->connect(@{$self->storage->connect_info()});
    my $vtable = $vschema->resultset('Table');
    $vtable->create({ Version => $self->schema_version,
                      Installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
                      });
}


sub run_upgrade
{
    my ($self, $stm) = @_;
    $stm ||= qr//;
#    print "Reg: $stm\n";
    my @statements = grep { $_ =~ $stm } @{$self->_filedata};
#    print "Statements: ", join("\n", @statements), "\n";
    $self->_filedata([ grep { $_ !~ /$stm/i } @{$self->_filedata} ]);

    for (@statements)
    {
        $self->storage->debugobj->query_start($_) if $self->storage->debug;
        $self->storage->dbh->do($_) or warn "SQL was:\n $_";
        $self->storage->debugobj->query_end($_) if $self->storage->debug;
    }

    return 1;
}

1;

=head1 NAME

DBIx::Class::Schema::Versioned - DBIx::Class::Schema plugin for Schema upgrades

=head1 SYNOPSIS

  package Library::Schema;
  use base qw/DBIx::Class::Schema/;   
  # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
  __PACKAGE__->load_classes(qw/CD Book DVD/);

  __PACKAGE__->load_components(qw/+DBIx::Class::Schema::Versioned/);
  __PACKAGE__->upgrade_directory('/path/to/upgrades/');
  __PACKAGE__->backup_directory('/path/to/backups/');

  sub backup
  {
    my ($self) = @_;
    # my special backup process
  }

=head1 DESCRIPTION

This module is a component designed to extend L<DBIx::Class::Schema>
classes, to enable them to upgrade to newer schema layouts. To use this
module, you need to have called C<create_ddl_dir> on your Schema to
create your upgrade files to include with your delivery.

A table called I<SchemaVersions> is created and maintained by the
module. This contains two fields, 'Version' and 'Installed', which
contain each VERSION of your Schema, and the date+time it was installed.

If you would like to influence which levels of version change need
upgrades in your Schema, you can override the method C<ddl_filename>
in L<DBIx::Class::Schema>. Return a false value if there is no upgrade
path between the two versions supplied. By default, every change in
your VERSION is regarded as needing an upgrade.

The actual upgrade is called manually by calling C<upgrade> on your
schema object. Code is run at connect time to determine whether an
upgrade is needed, if so, a warning "Versions out of sync" is
produced.

NB: At the moment, SQLite upgrading is rather spotty, as SQL::Translator::Diff
returns SQL statements that SQLite does not support.


=head1 METHODS

=head2 backup

This is an overwritable method which is called just before the upgrade, to
allow you to make a backup of the database. Per default this method attempts
to call C<< $self->storage->backup >>, to run the standard backup on each
database type. 

This method should return the name of the backup file, if appropriate.

C<backup> is called from C<upgrade>, make sure you call it, if you write your
own <upgrade> method.

=head2 upgrade

This is an overwritable method used to run your upgrade. The freeform method
allows you to run your upgrade any way you please, you can call C<run_upgrade>
any number of times to run the actual SQL commands, and in between you can
sandwich your data upgrading. For example, first run all the B<CREATE>
commands, then migrate your data from old to new tables/formats, then 
issue the DROP commands when you are finished.

=head2 run_upgrade

 $self->run_upgrade(qr/create/i);

Runs a set of SQL statements matching a passed in regular expression. The
idea is that this method can be called any number of times from your
C<upgrade> method, running whichever commands you specify via the
regex in the parameter.

B<NOTE:> Since SQL::Translator 0.09000 it is better to just run all statmets
in the order given, since the SQL produced is of better quality.

=head2 upgrade_directory

Use this to set the directory your upgrade files are stored in.

=head2 backup_directory

Use this to set the directory you want your backups stored in.

=head2 schema_version

Returns the current schema class' $VERSION; does -not- use $schema->VERSION
since that varies in results depending on if version.pm is installed, and if
so the perl or XS versions. If you want this to change, bug the version.pm
author to make vpp and vxs behave the same.

=head1 AUTHOR

Jess Robinson <castaway@desert-island.demon.co.uk>
Commit	Line	Data
c9d2e0a2	1	package DBIx::Class::Version::Table;
	2	use base 'DBIx::Class';
	3	use strict;
	4	use warnings;
	5
	6	__PACKAGE__->load_components(qw/ Core/);
	7	__PACKAGE__->table('SchemaVersions');
	8
	9	__PACKAGE__->add_columns
	10	( 'Version' => {
	11	'data_type' => 'VARCHAR',
	12	'is_auto_increment' => 0,
	13	'default_value' => undef,
	14	'is_foreign_key' => 0,
	15	'name' => 'Version',
	16	'is_nullable' => 0,
	17	'size' => '10'
	18	},
	19	'Installed' => {
	20	'data_type' => 'VARCHAR',
	21	'is_auto_increment' => 0,
	22	'default_value' => undef,
	23	'is_foreign_key' => 0,
	24	'name' => 'Installed',
	25	'is_nullable' => 0,
	26	'size' => '20'
	27	},
	28	);
	29	__PACKAGE__->set_primary_key('Version');
	30
	31	package DBIx::Class::Version;
	32	use base 'DBIx::Class::Schema';
	33	use strict;
	34	use warnings;
	35
	36	__PACKAGE__->register_class('Table', 'DBIx::Class::Version::Table');
	37
	38
	39	# ---------------------------------------------------------------------------
	40	package DBIx::Class::Schema::Versioned;
	41
	42	use strict;
	43	use warnings;
	44	use base 'DBIx::Class';
	45	use POSIX 'strftime';
	46	use Data::Dumper;
	47
	48	__PACKAGE__->mk_classdata('_filedata');
	49	__PACKAGE__->mk_classdata('upgrade_directory');
8795fefb	50	__PACKAGE__->mk_classdata('backup_directory');
c9d2e0a2	51
42416a0b	52	sub schema_version {
	53	my ($self) = @_;
	54	my $class = ref($self)\|\|$self;
	55	my $version;
	56	{
	57	no strict 'refs';
	58	$version = ${"${class}::VERSION"};
	59	}
	60	return $version;
	61	}
	62
a2800991	63	sub connection {
	64	my $self = shift;
	65	$self->next::method(@_);
	66	$self->_on_connect;
	67	return $self;
	68	}
	69
737416a4	70	sub _on_connect
c9d2e0a2	71	{
	72	my ($self) = @_;
	73	my $vschema = DBIx::Class::Version->connect(@{$self->storage->connect_info()});
	74	my $vtable = $vschema->resultset('Table');
	75	my $pversion;
e2c0df8e	76
a2800991	77	if(!$self->_source_exists($vtable))
c9d2e0a2	78	{
	79	# $vschema->storage->debug(1);
	80	$vschema->storage->ensure_connected();
	81	$vschema->deploy();
	82	$pversion = 0;
	83	}
	84	else
	85	{
	86	my $psearch = $vtable->search(undef,
	87	{ select => [
	88	{ 'max' => 'Installed' },
	89	],
	90	as => ['maxinstall'],
	91	})->first;
	92	$pversion = $vtable->search({ Installed => $psearch->get_column('maxinstall'),
	93	})->first;
	94	$pversion = $pversion->Version if($pversion);
	95	}
	96	# warn("Previous version: $pversion\n");
42416a0b	97	if($pversion eq $self->schema_version)
c9d2e0a2	98	{
	99	warn "This version is already installed\n";
	100	return 1;
	101	}
	102
	103	## use IC::DT?
	104
	105	if(!$pversion)
	106	{
42416a0b	107	$vtable->create({ Version => $self->schema_version,
c9d2e0a2	108	Installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
	109	});
	110	## If we let the user do this, where does the Version table get updated?
	111	warn "No previous version found, calling deploy to install this version.\n";
	112	$self->deploy();
	113	return 1;
	114	}
	115
	116	my $file = $self->ddl_filename(
	117	$self->storage->sqlt_type,
	118	$self->upgrade_directory,
42416a0b	119	$self->schema_version
c9d2e0a2	120	);
	121	if(!$file)
	122	{
	123	# No upgrade path between these two versions
	124	return 1;
	125	}
	126
	127	$file = $self->ddl_filename(
	128	$self->storage->sqlt_type,
	129	$self->upgrade_directory,
42416a0b	130	$self->schema_version,
c9d2e0a2	131	$pversion,
c9d2e0a2	132	);
42416a0b	133	# $file =~ s/@{[ $self->schema_version ]}/"${pversion}-" . $self->schema_version/e;
c9d2e0a2	134	if(!-f $file)
	135	{
	136	warn "Upgrade not possible, no upgrade file found ($file)\n";
	137	return;
	138	}
	139
	140	my $fh;
	141	open $fh, "<$file" or warn("Can't open upgrade file, $file ($!)");
	142	my @data = split(/;\n/, join('', <$fh>));
	143	close($fh);
	144	@data = grep { $_ && $_ !~ /^-- / } @data;
	145	@data = grep { $_ !~ /^(BEGIN TRANACTION\|COMMIT)/m } @data;
	146
	147	$self->_filedata(\@data);
	148
	149	## Don't do this yet, do only on command?
	150	## If we do this later, where does the Version table get updated??
42416a0b	151	warn "Versions out of sync. This is " . $self->schema_version .
c9d2e0a2	152	", your database contains version $pversion, please call upgrade on your Schema.\n";
42416a0b	153	# $self->upgrade($pversion, $self->schema_version);
c9d2e0a2	154	}
c9d2e0a2	155
a2800991	156	sub _source_exists
c9d2e0a2	157	{
	158	my ($self, $rs) = @_;
	159
	160	my $c = eval {
	161	$rs->search({ 1, 0 })->count;
	162	};
	163	return 0 if $@ \|\| !defined $c;
	164
	165	return 1;
	166	}
	167
	168	sub backup
	169	{
	170	my ($self) = @_;
	171	## Make each ::DBI::Foo do this
8795fefb	172	$self->storage->backup($self->backup_directory());
c9d2e0a2	173	}
	174
	175	sub upgrade
	176	{
	177	my ($self) = @_;
	178
	179	## overridable sub, per default just run all the commands.
	180
	181	$self->backup();
	182
dd018f09	183	$self->run_upgrade();
c9d2e0a2	184
	185	my $vschema = DBIx::Class::Version->connect(@{$self->storage->connect_info()});
	186	my $vtable = $vschema->resultset('Table');
42416a0b	187	$vtable->create({ Version => $self->schema_version,
c9d2e0a2	188	Installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
	189	});
	190	}
	191
	192
	193	sub run_upgrade
	194	{
	195	my ($self, $stm) = @_;
dd018f09	196	$stm \|\|= qr//;
c9d2e0a2	197	# print "Reg: $stm\n";
	198	my @statements = grep { $_ =~ $stm } @{$self->_filedata};
	199	# print "Statements: ", join("\n", @statements), "\n";
	200	$self->_filedata([ grep { $_ !~ /$stm/i } @{$self->_filedata} ]);
	201
	202	for (@statements)
	203	{
70f39278	204	$self->storage->debugobj->query_start($_) if $self->storage->debug;
c9d2e0a2	205	$self->storage->dbh->do($_) or warn "SQL was:\n $_";
70f39278	206	$self->storage->debugobj->query_end($_) if $self->storage->debug;
c9d2e0a2	207	}
	208
	209	return 1;
	210	}
	211
e2c0df8e	212	1;
e2c0df8e	213
c9d2e0a2	214	=head1 NAME
c9d2e0a2	215
7d9fbacf	216	DBIx::Class::Schema::Versioned - DBIx::Class::Schema plugin for Schema upgrades
c9d2e0a2	217
	218	=head1 SYNOPSIS
	219
	220	package Library::Schema;
	221	use base qw/DBIx::Class::Schema/;
	222	# load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
	223	__PACKAGE__->load_classes(qw/CD Book DVD/);
	224
	225	__PACKAGE__->load_components(qw/+DBIx::Class::Schema::Versioned/);
	226	__PACKAGE__->upgrade_directory('/path/to/upgrades/');
8795fefb	227	__PACKAGE__->backup_directory('/path/to/backups/');
c9d2e0a2	228
	229	sub backup
	230	{
	231	my ($self) = @_;
	232	# my special backup process
	233	}
	234
c9d2e0a2	235	=head1 DESCRIPTION
	236
	237	This module is a component designed to extend L<DBIx::Class::Schema>
	238	classes, to enable them to upgrade to newer schema layouts. To use this
	239	module, you need to have called C<create_ddl_dir> on your Schema to
	240	create your upgrade files to include with your delivery.
	241
	242	A table called I<SchemaVersions> is created and maintained by the
	243	module. This contains two fields, 'Version' and 'Installed', which
	244	contain each VERSION of your Schema, and the date+time it was installed.
	245
	246	If you would like to influence which levels of version change need
	247	upgrades in your Schema, you can override the method C<ddl_filename>
	248	in L<DBIx::Class::Schema>. Return a false value if there is no upgrade
	249	path between the two versions supplied. By default, every change in
	250	your VERSION is regarded as needing an upgrade.
	251
8795fefb	252	The actual upgrade is called manually by calling C<upgrade> on your
	253	schema object. Code is run at connect time to determine whether an
	254	upgrade is needed, if so, a warning "Versions out of sync" is
	255	produced.
	256
c9d2e0a2	257	NB: At the moment, SQLite upgrading is rather spotty, as SQL::Translator::Diff
	258	returns SQL statements that SQLite does not support.
	259
	260
	261	=head1 METHODS
	262
	263	=head2 backup
	264
	265	This is an overwritable method which is called just before the upgrade, to
	266	allow you to make a backup of the database. Per default this method attempts
	267	to call C<< $self->storage->backup >>, to run the standard backup on each
	268	database type.
	269
	270	This method should return the name of the backup file, if appropriate.
	271
	272	C<backup> is called from C<upgrade>, make sure you call it, if you write your
	273	own <upgrade> method.
	274
	275	=head2 upgrade
	276
	277	This is an overwritable method used to run your upgrade. The freeform method
	278	allows you to run your upgrade any way you please, you can call C<run_upgrade>
	279	any number of times to run the actual SQL commands, and in between you can
	280	sandwich your data upgrading. For example, first run all the B<CREATE>
	281	commands, then migrate your data from old to new tables/formats, then
	282	issue the DROP commands when you are finished.
	283
	284	=head2 run_upgrade
	285
	286	$self->run_upgrade(qr/create/i);
	287
	288	Runs a set of SQL statements matching a passed in regular expression. The
	289	idea is that this method can be called any number of times from your
	290	C<upgrade> method, running whichever commands you specify via the
	291	regex in the parameter.
	292
dd018f09	293	B<NOTE:> Since SQL::Translator 0.09000 it is better to just run all statmets
	294	in the order given, since the SQL produced is of better quality.
	295
8795fefb	296	=head2 upgrade_directory
	297
	298	Use this to set the directory your upgrade files are stored in.
	299
	300	=head2 backup_directory
	301
	302	Use this to set the directory you want your backups stored in.
	303
42416a0b	304	=head2 schema_version
	305
	306	Returns the current schema class' $VERSION; does -not- use $schema->VERSION
	307	since that varies in results depending on if version.pm is installed, and if
	308	so the perl or XS versions. If you want this to change, bug the version.pm
	309	author to make vpp and vxs behave the same.
	310
c9d2e0a2	311	=head1 AUTHOR
	312
	313	Jess Robinson <castaway@desert-island.demon.co.uk>