From: Nigel Metheringham <nigelm@cpan.org>
Date: Thu, 14 Jan 2010 15:52:50 +0000 (+0000)
Subject: Changes to support multiple step schema version updates
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=d2bc7045e78e5bc547e32133e48d2f994d158491;p=dbsrgits%2FDBIx-Class-Historic.git

Changes to support multiple step schema version updates
---

diff --git a/lib/DBIx/Class/Schema/Versioned.pm b/lib/DBIx/Class/Schema/Versioned.pm
index e6af6e0..c7a89d7 100644
--- a/lib/DBIx/Class/Schema/Versioned.pm
+++ b/lib/DBIx/Class/Schema/Versioned.pm
@@ -181,7 +181,7 @@ use warnings;
 use base 'DBIx::Class::Schema';
 
 use Carp::Clan qw/^DBIx::Class/;
-use POSIX 'strftime';
+use Time::HiRes qw/gettimeofday/;
 
 __PACKAGE__->mk_classdata('_filedata');
 __PACKAGE__->mk_classdata('upgrade_directory');
@@ -271,32 +271,129 @@ sub create_upgrade_path {
 	## override this method
 }
 
+=head2 ordered_schema_versions
+
+=over 4
+
+=item Returns: a list of version numbers, ordered from lowest to highest
+
+=back
+
+Virtual method that should be overriden to return an ordered list
+of schema versions. This is then used to produce a set of steps to
+upgrade through to achieve the required schema version.
+
+You may want the db_version retrieved via $self->get_db_version
+and the schema_version which is retrieved via $self->schema_version 
+
+=cut
+
+sub ordered_schema_versions {
+	## override this method
+}
+
 =head2 upgrade
 
-Call this to attempt to upgrade your database from the version it is at to the version
-this DBIC schema is at. If they are the same it does nothing.
+Call this to attempt to upgrade your database from the version it
+is at to the version this DBIC schema is at. If they are the same
+it does nothing.
 
-It requires an SQL diff file to exist in you I<upgrade_directory>, normally you will
-have created this using L<DBIx::Class::Schema/create_ddl_dir>.
+It will call L</ordered_schema_versions> to retrieve an ordered
+list of schema versions (if ordered_schema_versions returns nothing
+then it is assumed you can do the upgrade as a single step). It
+then iterates through the list of versions between the current db
+version and the schema version applying one update at a time until
+all relvant updates are applied.
 
-If successful the dbix_class_schema_versions table is updated with the current
-DBIC schema version.
+The individual update steps are performed by using
+L</upgrade_single_step>, which will apply the update and also
+update the dbix_class_schema_versions table.
 
 =cut
 
-sub upgrade
-{
-  my ($self) = @_;
-  my $db_version = $self->get_db_version();
+sub upgrade {
+    my ($self) = @_;
+    my $db_version = $self->get_db_version();
 
-  # db unversioned
-  unless ($db_version) {
-    carp 'Upgrade not possible as database is unversioned. Please call install first.';
-    return;
-  }
+    # db unversioned
+    unless ($db_version) {
+        carp 'Upgrade not possible as database is unversioned. Please call install first.';
+        return;
+    }
+
+    # db and schema at same version. do nothing
+    if ( $db_version eq $self->schema_version ) {
+        carp "Upgrade not necessary\n";
+        return;
+    }
+
+    my @version_list = $self->ordered_schema_versions;
+
+    # if nothing returned then we preload with min/max
+    @version_list = ( $db_version, $self->schema_version )
+      unless ( scalar(@version_list) );
+
+    # catch the case of someone returning an arrayref
+    @version_list = @{ $version_list[0] }
+      if ( ref( $version_list[0] ) eq 'ARRAY' );
+
+    # remove all versions in list above the required version
+    while ( scalar(@version_list)
+        && ( $version_list[-1] ne $self->schema_version ) )
+    {
+        pop @version_list;
+    }
+
+    # remove all versions in list below the current version
+    while ( scalar(@version_list) && ( $version_list[0] ne $db_version ) ) {
+        shift @version_list;
+    }
+
+    # check we have an appropriate list of versions
+    if ( scalar(@version_list) < 2 ) {
+        die;
+    }
+
+    # do sets of upgrade
+    while ( scalar(@version_list) >= 2 ) {
+        $self->upgrade_single_step( $version_list[0], $version_list[1] );
+        shift @version_list;
+    }
+}
+
+=head2 upgrade_single_step
+
+=over 4
+
+=item Arguments: db_version - the version currently within the db
+
+=item Arguments: target_version - the version to upgrade to
+
+=back
+
+Call this to attempt to upgrade your database from the
+I<db_version> to the I<target_version>. If they are the same it
+does nothing.
+
+It requires an SQL diff file to exist in your I<upgrade_directory>,
+normally you will have created this using L<DBIx::Class::Schema/create_ddl_dir>.
+
+If successful the dbix_class_schema_versions table is updated with
+the I<target_version>.
+
+This method may be called repeatedly by the upgrade method to
+upgrade through a series of updates.
+
+=cut
+
+sub upgrade_single_step
+{
+  my ($self,
+      $db_version,
+      $target_version) = @_;
 
   # db and schema at same version. do nothing
-  if ($db_version eq $self->schema_version) {
+  if ($db_version eq $target_version) {
     carp "Upgrade not necessary\n";
     return;
   }
@@ -309,7 +406,7 @@ sub upgrade
 
   my $upgrade_file = $self->ddl_filename(
                                          $self->storage->sqlt_type,
-                                         $self->schema_version,
+                                         $target_version,
                                          $self->upgrade_directory,
                                          $db_version,
                                         );
@@ -329,7 +426,7 @@ sub upgrade
   $self->txn_do(sub { $self->do_upgrade() });
 
   # set row in dbix_class_schema_versions table
-  $self->_set_db_version;
+  $self->_set_db_version({version => $target_version});
 }
 
 =head2 do_upgrade
@@ -574,10 +671,33 @@ sub _set_db_version {
 
   my $version = $params->{version} ? $params->{version} : $self->schema_version;
   my $vtable = $self->{vschema}->resultset('Table');
-  $vtable->create({ version => $version,
-                      installed => strftime("%Y-%m-%d %H:%M:%S", gmtime())
-                      });
 
+  ##############################################################################
+  #                             !!! NOTE !!!
+  ##############################################################################
+  #
+  # The travesty below replaces the old nice timestamp format of %Y-%m-%d %H:%M:%S
+  # This is necessary since there are legitimate cases when upgrades can happen
+  # back to back within the same second. This breaks things since we relay on the
+  # ability to sort by the 'installed' value. The logical choice of an autoinc
+  # is not possible, as it will break multiple legacy installations. Also it is 
+  # not possible to format the string sanely, as the column is a varchar(20).
+  # The 'v' character is added to the front of the string, so that any version
+  # formatted by this new function will sort _after_ any existing 200... strings.
+  my @tm = gettimeofday();
+  my @dt = gmtime ($tm[0]);
+  my $o = $vtable->create({ 
+    version => $version,
+    installed => sprintf("v%04d%02d%02d_%02d%02d%02d.%03.0f",
+      $dt[5] + 1900,
+      $dt[4] + 1,
+      $dt[3],
+      $dt[2],
+      $dt[1],
+      $dt[0],
+      $tm[1] / 1000, # convert to millisecs, format as up/down rounded int above
+    ),
+  });
 }
 
 sub _read_sql_file {
diff --git a/t/94versioning.t b/t/94versioning.t
index 674a855..4d3c780 100644
--- a/t/94versioning.t
+++ b/t/94versioning.t
@@ -32,56 +32,56 @@ my $ddl_dir = File::Spec->catdir ('t', 'var');
 my $fn = {
     v1 => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-1.0-MySQL.sql'),
     v2 => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-2.0-MySQL.sql'),
-    trans => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-1.0-2.0-MySQL.sql'),
+    v3 => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-3.0-MySQL.sql'),
+    trans_v12 => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-1.0-2.0-MySQL.sql'),
+    trans_v23 => File::Spec->catfile($ddl_dir, 'DBICVersion-Schema-2.0-3.0-MySQL.sql'),
 };
 
 use lib qw(t/lib);
 use DBICTest; # do not remove even though it is not used
 
-use_ok('DBICVersionOrig');
+use_ok('DBICVersion_v1');
 
-my $schema_orig = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_version => 1 });
-eval { $schema_orig->storage->dbh->do('drop table ' . $version_table_name) };
-eval { $schema_orig->storage->dbh->do('drop table ' . $old_table_name) };
+my $schema_v1 = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_version => 1 });
+eval { $schema_v1->storage->dbh->do('drop table ' . $version_table_name) };
+eval { $schema_v1->storage->dbh->do('drop table ' . $old_table_name) };
 
-is($schema_orig->ddl_filename('MySQL', '1.0', $ddl_dir), $fn->{v1}, 'Filename creation working');
+is($schema_v1->ddl_filename('MySQL', '1.0', $ddl_dir), $fn->{v1}, 'Filename creation working');
 unlink( $fn->{v1} ) if ( -e $fn->{v1} );
-$schema_orig->create_ddl_dir('MySQL', undef, $ddl_dir);
+$schema_v1->create_ddl_dir('MySQL', undef, $ddl_dir);
 
 ok(-f $fn->{v1}, 'Created DDL file');
-$schema_orig->deploy({ add_drop_table => 1 });
+$schema_v1->deploy({ add_drop_table => 1 });
 
-my $tvrs = $schema_orig->{vschema}->resultset('Table');
-is($schema_orig->_source_exists($tvrs), 1, 'Created schema from DDL file');
+my $tvrs = $schema_v1->{vschema}->resultset('Table');
+is($schema_v1->_source_exists($tvrs), 1, 'Created schema from DDL file');
 
 # loading a new module defining a new version of the same table
 DBICVersion::Schema->_unregister_source ('Table');
-eval "use DBICVersionNew";
+eval "use DBICVersion_v2";
 
-my $schema_upgrade = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_version => 1 });
+my $schema_v2 = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_version => 1 });
 {
   unlink($fn->{v2});
-  unlink($fn->{trans});
+  unlink($fn->{trans_v12});
 
-  is($schema_upgrade->get_db_version(), '1.0', 'get_db_version ok');
-  is($schema_upgrade->schema_version, '2.0', 'schema version ok');
-  $schema_upgrade->create_ddl_dir('MySQL', '2.0', $ddl_dir, '1.0');
-  ok(-f $fn->{trans}, 'Created DDL file');
+  is($schema_v2->get_db_version(), '1.0', 'get_db_version ok');
+  is($schema_v2->schema_version, '2.0', 'schema version ok');
+  $schema_v2->create_ddl_dir('MySQL', '2.0', $ddl_dir, '1.0');
+  ok(-f $fn->{trans_v12}, 'Created DDL file');
 
   {
     my $w;
     local $SIG{__WARN__} = sub { $w = shift };
 
-    sleep 1;    # remove this when TODO below is completed
-
-    $schema_upgrade->upgrade();
+    $schema_v2->upgrade();
     like ($w, qr/Attempting upgrade\.$/, 'Warn before upgrade');
   }
 
-  is($schema_upgrade->get_db_version(), '2.0', 'db version number upgraded');
+  is($schema_v2->get_db_version(), '2.0', 'db version number upgraded');
 
   eval {
-    $schema_upgrade->storage->dbh->do('select NewVersionName from TestVersion');
+    $schema_v2->storage->dbh->do('select NewVersionName from TestVersion');
   };
   is($@, '', 'new column created');
 
@@ -95,11 +95,11 @@ my $schema_upgrade = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_v
       warn @_;
     }
   };
-  $schema_upgrade->create_ddl_dir('MySQL', '2.0', $ddl_dir, '1.0');
+  $schema_v2->create_ddl_dir('MySQL', '2.0', $ddl_dir, '1.0');
 
   is (2, @w, 'A warning generated for both the DDL and the diff');
   like ($w[0], qr/Overwriting existing DDL file - $fn->{v2}/, 'New version DDL overwrite warning');
-  like ($w[1], qr/Overwriting existing diff file - $fn->{trans}/, 'Upgrade diff overwrite warning');
+  like ($w[1], qr/Overwriting existing diff file - $fn->{trans_v12}/, 'Upgrade diff overwrite warning');
 }
 
 {
@@ -125,6 +125,63 @@ my $schema_upgrade = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_v
 
 }
 
+# repeat the v1->v2 process for v2->v3 before testing v1->v3
+DBICVersion::Schema->_unregister_source ('Table');
+eval "use DBICVersion_v3";
+
+my $schema_v3 = DBICVersion::Schema->connect($dsn, $user, $pass, { ignore_version => 1 });
+{
+  unlink($fn->{v3});
+  unlink($fn->{trans_v23});
+
+  is($schema_v3->get_db_version(), '2.0', 'get_db_version 2.0 ok');
+  is($schema_v3->schema_version, '3.0', 'schema version 3.0 ok');
+  $schema_v3->create_ddl_dir('MySQL', '3.0', $ddl_dir, '2.0');
+  ok(-f $fn->{trans_v23}, 'Created DDL 2.0 -> 3.0 file');
+
+  {
+    my $w;
+    local $SIG{__WARN__} = sub { $w = shift };
+
+    $schema_v3->upgrade();
+    like ($w, qr/Attempting upgrade\.$/, 'Warn before upgrade');
+  }
+
+  is($schema_v3->get_db_version(), '3.0', 'db version number upgraded');
+
+  eval {
+    $schema_v3->storage->dbh->do('select ExtraColumn from TestVersion');
+  };
+  is($@, '', 'new column created');
+}
+
+# now put the v1 schema back again
+{
+  # drop all the tables...
+  eval { $schema_v1->storage->dbh->do('drop table ' . $version_table_name) };
+  eval { $schema_v1->storage->dbh->do('drop table ' . $old_table_name) };
+  eval { $schema_v1->storage->dbh->do('drop table TestVersion') };
+
+  {
+    local $DBICVersion::Schema::VERSION = '1.0';
+    $schema_v1->deploy;
+  }
+  is($schema_v1->get_db_version(), '1.0', 'get_db_version 1.0 ok');
+}
+
+# attempt v1 -> v3 upgrade....
+{
+  {
+    my $w;
+    local $SIG{__WARN__} = sub { $w = shift };
+
+    $schema_v3->upgrade();
+    like ($w, qr/Attempting upgrade\.$/, 'Warn before upgrade');
+  }
+
+  is($schema_v3->get_db_version(), '3.0', 'db version number upgraded');
+}
+
 # check behaviour of DBIC_NO_VERSION_CHECK env var and ignore_version connect attr
 {
   my $schema_version = DBICVersion::Schema->connect($dsn, $user, $pass);
@@ -162,9 +219,9 @@ TODO: {
 
   local $TODO = 'To fix this properly the table must be extended with an autoinc column, mst will not accept anything less';
 
-  eval { $schema_orig->storage->dbh->do('drop table ' . $version_table_name) };
-  eval { $schema_orig->storage->dbh->do('drop table ' . $old_table_name) };
-  eval { $schema_orig->storage->dbh->do('drop table TestVersion') };
+  eval { $schema_v2->storage->dbh->do('drop table ' . $version_table_name) };
+  eval { $schema_v2->storage->dbh->do('drop table ' . $old_table_name) };
+  eval { $schema_v2->storage->dbh->do('drop table TestVersion') };
 
   # this attempts to sleep until the turn of the second
   my $t = time();
@@ -172,14 +229,14 @@ TODO: {
   diag ('Fast deploy/upgrade start: ', time() );
 
   {
-    local $DBICVersion::Schema::VERSION = '1.0';
-    $schema_orig->deploy;
+    local $DBICVersion::Schema::VERSION = '2.0';
+    $schema_v2->deploy;
   }
 
   local $SIG{__WARN__} = sub { warn if $_[0] !~ /Attempting upgrade\.$/ };
-  $schema_upgrade->upgrade();
+  $schema_v2->upgrade();
 
-  is($schema_upgrade->get_db_version(), '2.0', 'Fast deploy/upgrade');
+  is($schema_v2->get_db_version(), '3.0', 'Fast deploy/upgrade');
 };
 
 unless ($ENV{DBICTEST_KEEP_VERSIONING_DDL}) {
diff --git a/t/lib/DBICVersionOrig.pm b/t/lib/DBICVersion_v1.pm
similarity index 93%
rename from t/lib/DBICVersionOrig.pm
rename to t/lib/DBICVersion_v1.pm
index 3bdc0e2..56c01e2 100644
--- a/t/lib/DBICVersionOrig.pm
+++ b/t/lib/DBICVersion_v1.pm
@@ -42,4 +42,8 @@ sub upgrade_directory
     return 't/var/';
 }
 
+sub ordered_schema_versions {
+  return('1.0','2.0','3.0');
+}
+
 1;
diff --git a/t/lib/DBICVersionNew.pm b/t/lib/DBICVersion_v2.pm
similarity index 100%
copy from t/lib/DBICVersionNew.pm
copy to t/lib/DBICVersion_v2.pm
diff --git a/t/lib/DBICVersionNew.pm b/t/lib/DBICVersion_v3.pm
similarity index 82%
rename from t/lib/DBICVersionNew.pm
rename to t/lib/DBICVersion_v3.pm
index b6508ca..29caaae 100644
--- a/t/lib/DBICVersionNew.pm
+++ b/t/lib/DBICVersion_v3.pm
@@ -30,6 +30,14 @@ __PACKAGE__->add_columns
         'is_foreign_key' => 0,
         'is_nullable' => 1,
         'size' => '20'
+        },
+      'ExtraColumn' => {
+        'data_type' => 'VARCHAR',
+        'is_auto_increment' => 0,
+        'default_value' => undef,
+        'is_foreign_key' => 0,
+        'is_nullable' => 1,
+        'size' => '20'
         }
       );
 
@@ -40,16 +48,11 @@ use base 'DBIx::Class::Schema';
 use strict;
 use warnings;
 
-our $VERSION = '2.0';
+our $VERSION = '3.0';
 
 __PACKAGE__->register_class('Table', 'DBICVersion::Table');
 __PACKAGE__->load_components('+DBIx::Class::Schema::Versioned');
 __PACKAGE__->upgrade_directory('t/var/');
 __PACKAGE__->backup_directory('t/var/backup/');
 
-#sub upgrade_directory
-#{
-#    return 't/var/';
-#}
-
 1;