From: Oliver Gorwits <oliver@cpan.org>
Date: Tue, 27 Apr 2010 22:35:29 +0000 (+0000)
Subject: add prepopulate_journal method based on pseudocode from frew. can it be optimized... 
X-Git-Tag: v0.900201~23
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=1d09727da140af581226bb64bcca01b8d25a060d;p=dbsrgits%2FDBIx-Class-Journal.git

add prepopulate_journal method based on pseudocode from frew. can it be optimized any?
---

diff --git a/lib/DBIx/Class/Journal.pm b/lib/DBIx/Class/Journal.pm
index 11b18fc..e6bb3c7 100644
--- a/lib/DBIx/Class/Journal.pm
+++ b/lib/DBIx/Class/Journal.pm
@@ -256,6 +256,19 @@ C<connect>.
 
 Not recommended, but present for backwards compatibility.
 
+=item prepopulate_journal
+
+Will load the current state of your original source tables into the audit
+history as fake inserts in a single initial changeset. The advantage to this
+is that later deletetions of the row will be consistent in the journal with an
+initial state.
+
+Note that this can be an intensive and time consuming task, depending on how
+much data you have in your original sources; all of it will be copied to the
+journal history. However this step is essential if you are retrofitting
+Journalling to a schema with existing data, otherwise when you delete a row
+the Journal will die because it cannot relate that to an initial row insert.
+
 =item changeset_user $user_id
 
 Set the C<user_id> for the following changeset(s). This must be an integer.
diff --git a/lib/DBIx/Class/Schema/Journal.pm b/lib/DBIx/Class/Schema/Journal.pm
index 6c1678a..e20f72c 100644
--- a/lib/DBIx/Class/Schema/Journal.pm
+++ b/lib/DBIx/Class/Schema/Journal.pm
@@ -138,6 +138,61 @@ sub create_journal_for {
     }
 }
 
+sub prepopulate_journal {
+    my $self = shift;
+
+    my %j_sources = map { $_ => 1 } $self->journal_sources
+       ? @{$self->journal_sources}
+       : $self->sources;
+
+    my $schema = $self;
+    my $j_schema = $self->_journal_schema;
+    my $changelog_rs = $j_schema->resultset('ChangeLog');
+
+    # using our own overridden txn_do (see below) will create a changeset
+    $schema->txn_do( sub {
+        my $chs_id = $j_schema->current_changeset;
+
+        foreach my $s_name ($self->sources) {
+            next unless $j_sources{$s_name};
+
+            my $from_rs = $schema->resultset($s_name);
+            my ($pk) = $from_rs->result_source->primary_columns;
+            $from_rs->result_class('DBIx::Class::ResultClass::HashRefInflator');
+
+            my $to_rs  = $j_schema->resultset("${s_name}AuditHistory");
+            my $log_rs = $j_schema->resultset("${s_name}AuditLog");
+
+            my $page = 1;
+            while (
+                my @x = $from_rs->search(undef, {
+                    rows => 1_000,
+                    page => $page++,
+                })
+            ) {
+                # get some number of change log IDs to be generated for this page
+                my @log_ids = map { $_->id }
+                            $changelog_rs->populate([
+                                map {{ changeset_id => $chs_id }} (0 .. $#x)
+                            ]);
+
+                # create the audit log entries for the rows in this page
+                $log_rs->populate([
+                    map {{ create_id => $log_ids[$_], id => $x[$_]->{$pk} }} (0 .. $#x)
+                ]);
+
+                # now populate the audit history
+                $to_rs->populate([
+                    map +{
+                        %{$x[$_]},
+                        audit_change_id => $log_ids[$_],
+                    }, (0 .. $#x)
+                ]);
+            }
+        }
+    });
+}
+
 sub txn_do {
     my ($self, $user_code, @args) = @_;