X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSQLAHacks%2FOracle.pm;h=23c12857337c5c2a4ac823bcf520d713b0c95607;hb=7fca91be5671c61be5c766bd93df741bc00d9c15;hp=5c407b6599daff9e040579f162c7665a2f6c0fff;hpb=5c810af7e33bf13daa46ce03a34f162dbfc7699a;p=dbsrgits%2FDBIx-Class-Historic.git

diff --git a/lib/DBIx/Class/SQLAHacks/Oracle.pm b/lib/DBIx/Class/SQLAHacks/Oracle.pm
index 5c407b6..23c1285 100644
--- a/lib/DBIx/Class/SQLAHacks/Oracle.pm
+++ b/lib/DBIx/Class/SQLAHacks/Oracle.pm
@@ -7,12 +7,6 @@ use strict;
 use base qw( DBIx::Class::SQLAHacks );
 use Carp::Clan qw/^DBIx::Class|^SQL::Abstract/;
 
-# 
-#  TODO:
-#   - Review by experienced DBIC/SQL:A developers :-)
-#   - Problem with count and connect_by look the TODO in t/73oracle.t
-# 
-
 sub new {
   my $self = shift;
   my %opts = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
@@ -24,22 +18,22 @@ sub new {
   $self->SUPER::new (\%opts);
 }
 
-sub select {
-    my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_;
-
-    my $sql = $self->SUPER::select($table, $fields, $where, $rs_attrs, @rest);
-
-    return wantarray ? ($sql, @{$self->{from_bind}}, @{$self->{where_bind}}, @{$self->{_oracle_connect_by_binds}}, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
+sub _assemble_binds {
+  my $self = shift;
+  return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/from where oracle_connect_by having order/);
 }
 
-sub _emulate_limit {
-    my ( $self, $syntax, $sql, $rs_attrs, $rows, $offset ) = @_;
+
+sub _parse_rs_attrs {
+    my $self = shift;
+    my ($rs_attrs) = @_;
 
     my ($cb_sql, @cb_bind) = $self->_connect_by($rs_attrs);
-    $sql .= $cb_sql;
-    $self->{_oracle_connect_by_binds} = \@cb_bind;
+    push @{$self->{oracle_connect_by_bind}}, @cb_bind;
+
+    my $sql = $self->SUPER::_parse_rs_attrs(@_);
 
-    return $self->SUPER::_emulate_limit($syntax, $sql, $rs_attrs, $rows, $offset);
+    return "$cb_sql $sql";
 }
 
 sub _connect_by {
@@ -108,6 +102,87 @@ sub _where_field_PRIOR {
   return ($sql, @bind);
 }
 
+# this takes an identifier and shortens it if necessary
+# optionally keywords can be passed as an arrayref to generate useful
+# identifiers
+sub _shorten_identifier {
+  my ($self, $to_shorten, $keywords) = @_;
+
+  # 30 characters is the identifier limit for Oracle
+  my $max_len = 30;
+  # we want at least 10 characters of the base36 md5
+  my $min_entropy = 10;
+
+  my $max_trunc = $max_len - $min_entropy - 1;
+
+  return $to_shorten
+    if length($to_shorten) <= $max_len;
+
+  croak 'keywords needs to be an arrayref'
+    if defined $keywords && ref $keywords ne 'ARRAY';
+
+  # if no keywords are passed use the identifier as one
+  my @keywords = @{$keywords || []};
+  @keywords = $to_shorten unless @keywords;
+
+  # get a base36 md5 of the identifier
+  require Digest::MD5;
+  require Math::BigInt;
+  require Math::Base36;
+  my $b36sum = Math::Base36::encode_base36(
+    Math::BigInt->from_hex (
+      '0x' . Digest::MD5::md5_hex ($to_shorten)
+    )
+  );
+
+  # switch from perl to java
+  # get run-length
+  my ($concat_len, @lengths);
+  for (@keywords) {
+    $_ = ucfirst (lc ($_));
+    $_ =~ s/\_+(\w)/uc ($1)/eg;
+
+    push @lengths, length ($_);
+    $concat_len += $lengths[-1];
+  }
+
+  # if we are still too long - try to disemvowel non-capitals (not keyword starts)
+  if ($concat_len > $max_trunc) {
+    $concat_len = 0;
+    @lengths = ();
+
+    for (@keywords) {
+      $_ =~ s/[aeiou]//g;
+
+      push @lengths, length ($_);
+      $concat_len += $lengths[-1];
+    }
+  }
+
+  # still too long - just start cuting proportionally
+  if ($concat_len > $max_trunc) {
+    my $trim_ratio = $max_trunc / $concat_len;
+
+    for my $i (0 .. $#keywords) {
+      $keywords[$i] = substr ($keywords[$i], 0, int ($trim_ratio * $lengths[$i] ) );
+    }
+  }
+
+  my $fin = join ('', @keywords);
+  my $fin_len = length $fin;
+
+  return sprintf ('%s_%s',
+    $fin,
+    substr ($b36sum, 0, $max_len - $fin_len - 1),
+  );
+}
+
+sub _unqualify_colname {
+  my ($self, $fqcn) = @_;
+
+  return $self->_shorten_identifier($self->next::method($fqcn));
+}
+
 1;
 
 __END__
@@ -120,7 +195,7 @@ DBIx::Class::SQLAHacks::Oracle - adds hierarchical query support for Oracle to S
 
 =head1 DESCRIPTION
 
-See L<DBIx::Class::Storage::DBI::Oracle::Generic> for more informations about
+See L<DBIx::Class::Storage::DBI::Oracle::Generic> for more information about
 how to use hierarchical queries with DBIx::Class.
 
 =cut