From: Peter Rabbitson <ribasushi@cpan.org>
Date: Mon, 28 Sep 2015 15:58:07 +0000 (+0200)
Subject: Even more aggressive streamline of SQL scanning in _resolve_aliastypes
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=892035682c81ff85a92861e173f72ae14b380ed7;p=dbsrgits%2FDBIx-Class-Historic.git

Even more aggressive streamline of SQL scanning in _resolve_aliastypes

No longer try to match individual pieces at all, simply treat every single
fragment as a single string. While rather barbaric, we are doing it anyway
in order to catch fragments, thus it makes no sense to keep the "proper"
codepath at all.

This concludes the shenanigans in this function
---

diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm
index a51a4d0..20966ac 100644
--- a/lib/DBIx/Class/Storage/DBIHacks.pm
+++ b/lib/DBIx/Class/Storage/DBIHacks.pm
@@ -464,27 +464,31 @@ sub _resolve_aliastypes_from_select_args {
     ],
   };
 
+  # we will be bulk-scanning anyway - pieces will not matter in that case,
+  # thus join everything up
   # throw away empty-string chunks, and make sure no binds snuck in
   # note that we operate over @{$to_scan->{$type}}, hence the
   # semi-mindbending ... map ... for values ...
-  ( $_ = [ map {
+  ( $_ = join ' ', map {
 
-      (not $_)        ? ()
-    : (length ref $_) ? (require Data::Dumper::Concise && $self->throw_exception(
+    ( ! defined $_ )  ? ()
+  : ( length ref $_ ) ? (require Data::Dumper::Concise && $self->throw_exception(
                           "Unexpected ref in scan-plan: " . Data::Dumper::Concise::Dumper($_)
                         ))
-    :                   $_
+  : ( $_ =~ /^\s*$/ ) ? ()
+                      : $_
 
-  } @$_ ] ) for values %$to_scan;
+  } @$_ ) for values %$to_scan;
 
   # throw away empty to-scan's
   (
-    @{$to_scan->{$_}}
+    length $to_scan->{$_}
       or
     delete $to_scan->{$_}
   ) for keys %$to_scan;
 
 
+
   # these will be used for matching in the loop below
   my $all_aliases = join ' | ', map { quotemeta $_ } keys %$alias_list;
   my $fq_col_re = qr/
@@ -493,6 +497,7 @@ sub _resolve_aliastypes_from_select_args {
     \b ( $all_aliases ) \. ( [^\s\)\($rquote]+ )?
   /x;
 
+
   my $all_unq_columns = join ' | ',
     map
       { quotemeta $_ }
@@ -502,7 +507,11 @@ sub _resolve_aliastypes_from_select_args {
         keys %$colinfo
   ;
   my $unq_col_re = $all_unq_columns
-    ? qr/ $lquote ( $all_unq_columns ) $rquote /x
+    ? qr/
+      $lquote ( $all_unq_columns ) $rquote
+        |
+      (?: \A | \s ) ( $all_unq_columns ) (?: \s | \z )
+    /x
     : undef
   ;
 
@@ -510,26 +519,13 @@ sub _resolve_aliastypes_from_select_args {
   # the actual scan, per type
   for my $type (keys %$to_scan) {
 
-    # first see if we have any exact matches (qualified or unqualified)
-    for my $piece (@{$to_scan->{$type}}) {
-      if ($colinfo->{$piece} and my $alias = $colinfo->{$piece}{-source_alias}) {
-        $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
-        $aliases_by_type->{$type}{$alias}{-seen_columns}{$colinfo->{$piece}{-fq_colname}} = $piece;
-      }
-    }
-
-
-    # we will be bulk-scanning anyway - pieces will not matter in that case
-    # (unlike in the direct-equivalence above)
-    my $scan_string = join ' ', @{$to_scan->{$type}};
-
 
     # now loop through all fully qualified columns and get the corresponding
     # alias (should work even if they are in scalarrefs)
     #
-    # The regex matches in multiples of 4, with one of the two pairs being
+    # The regex captures in multiples of 4, with one of the two pairs being
     # undef. There may be a *lot* of matches, hence the convoluted loop
-    my @matches = $scan_string =~ /$fq_col_re/g;
+    my @matches = $to_scan->{$type} =~ /$fq_col_re/g;
     my $i = 0;
     while( $i < $#matches ) {
 
@@ -551,7 +547,10 @@ sub _resolve_aliastypes_from_select_args {
     # now loop through unqualified column names, and try to locate them within
     # the chunks, if there are any unqualified columns in the 1st place
     next unless $unq_col_re;
-    for ( $scan_string =~ /$unq_col_re/g ) {
+
+    # The regex captures in multiples of 2, one of the two being undef
+    for ( $to_scan->{$type} =~ /$unq_col_re/g ) {
+      defined $_ or next;
       my $alias = $colinfo->{$_}{-source_alias} or next;
       $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
       $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = $_