Speed up Model.primary_key_hash and .qualified_primary_key_hash

The greater speedup is for .qualified_primary_key hash, since that
no longer calls primary_key_hash and then modifies the output.
Instead, it just uses a similar implementation.

In both cases, move the Symbol check first as that is the common
case, and raise an exception via else instead of at the top
of the method.

Also, for composite primary keys, use zip instead of
each_with_index, which should be slightly faster.

diff --git a/lib/sequel/model/base.rb b/lib/sequel/model/base.rb
index 2951ef9bbee087365431c4273334bedff39fd7bb..847dca679800fa951168710cd6be8ee82559d1d9 100644 (file)
--- a/lib/sequel/model/base.rb
+++ b/lib/sequel/model/base.rb
@@ -580,14 +580,15 @@ module Sequel
       #   Artist.primary_key_hash(1) # => {:id=>1}
       #   Artist.primary_key_hash([1, 2]) # => {:id1=>1, :id2=>2}
       def primary_key_hash(value)
-        raise(Error, "#{self} does not have a primary key") unless key = @primary_key
-        case key
+        case key = @primary_key
+        when Symbol
+          {key => value}
         when Array
           hash = {}
-          key.each_with_index{|k,i| hash[k] = value[i]}
+          key.zip(Array(value)){|k,v| hash[k] = v}
           hash
         else
-          {key => value}
+          raise(Error, "#{self} does not have a primary key")
         end
       end
 
@@ -599,9 +600,16 @@ module Sequel
       #   Artist.filter(Artist.qualified_primary_key_hash(1))
       #   # SELECT * FROM artists WHERE (artists.id = 1)
       def qualified_primary_key_hash(value, qualifier=table_name)
-        h = primary_key_hash(value)
-        h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)}
-        h
+        case key = @primary_key
+        when Symbol
+          {SQL::QualifiedIdentifier.new(qualifier, key) => value}
+        when Array
+          hash = {}
+          key.zip(Array(value)){|k,v| hash[SQL::QualifiedIdentifier.new(qualifier, k)] = v}
+          hash
+        else
+          raise(Error, "#{self} does not have a primary key")
+        end
       end
   
       # Similar to finder, but uses a prepared statement instead of a placeholder