Performance improvements.

lib/dbf/column.rb

@@ -46,11 +46,7 @@ def initialize(table, name, type, length, decimal)
     # @param [String] value
     # @return [Fixnum, Float, Date, DateTime, Boolean, String]
     def type_cast(value)
-      return nil if length == 0
-
-      klass = TYPE_CAST_CLASS[type.to_sym]
-      cast_value = klass.new(value, decimal).type_cast
-      binary? ? cast_value : encode(cast_value)
+      type_cast_class.type_cast(value)
     end
 
     # Returns true if the column is a memo
@@ -98,6 +94,15 @@ def to_hash
 
     private
 
+    def type_cast_class # nodoc
+      @type_cast_class ||=
+        if @length == 0
+          ColumnType::Nil
+        else
+          TYPE_CAST_CLASS[type.to_sym]
+        end.new(@decimal, @encoding)
+    end
+
     def encode(value, strip_output = false) # nodoc
       return value if !value.respond_to?(:encoding)
 

lib/dbf/column_type.rb

@@ -1,52 +1,58 @@
 module DBF
   module ColumnType
     class Base
-      attr_reader :value, :decimal
+      attr_reader :decimal, :encoding
 
-      def initialize(value, decimal)
-        @value = value
+      def initialize(decimal, encoding)
         @decimal = decimal
+        @encoding = encoding
+      end
+    end
+
+    class Nil < Base
+      def type_cast(value)
+        nil
       end
     end
 
     class Number < Base
-      def type_cast
-        decimal.zero? ? value.to_i : value.to_f
+      def type_cast(value)
+        @decimal.zero? ? value.to_i : value.to_f
       end
     end
 
     class Currency < Base
-      def type_cast
+      def type_cast(value)
         (value.unpack('q<')[0] / 10_000.0).to_f
       end
     end
 
     class SignedLong < Base
-      def type_cast
+      def type_cast(value)
         value.unpack('l<')[0]
       end
     end
 
     class Float < Base
-      def type_cast
+      def type_cast(value)
         value.to_f
       end
     end
 
     class Double < Base
-      def type_cast
+      def type_cast(value)
         value.unpack('E')[0]
       end
     end
 
     class Boolean < Base
-      def type_cast
+      def type_cast(value)
         value.strip =~ /^(y|t)$/i ? true : false
       end
     end
 
     class Date < Base
-      def type_cast
+      def type_cast(value)
         v = value.tr(' ', '0')
         v !~ /\S/ ? nil : ::Date.parse(v)
       rescue
@@ -55,7 +61,7 @@ def type_cast
     end
 
     class DateTime < Base
-      def type_cast
+      def type_cast(value)
         days, msecs = value.unpack('l2')
         secs = (msecs / 1000).to_i
         ::DateTime.jd(days, (secs / 3600).to_i, (secs / 60).to_i % 60, secs % 60)
@@ -65,21 +71,37 @@ def type_cast
     end
 
     class Memo < Base
-      def type_cast
-        value
+      ENCODING_ARGS = [
+        Encoding.default_external,
+        {undef: :replace, invalid: :replace}
+      ]
+
+      def type_cast(value)
+        if encoding and not value.nil?
+          value.force_encoding(@encoding).encode(*ENCODING_ARGS)
+        else
+          value
+        end
       end
     end
 
     class General < Base
-      def type_cast
+      def type_cast(value)
         value
       end
     end
 
     class String < Base
-      def type_cast
-        value.strip
+      ENCODING_ARGS = [
+        Encoding.default_external,
+        {undef: :replace, invalid: :replace}
+      ]
+
+      def type_cast(value)
+        value = value.strip
+        @encoding ? value.force_encoding(@encoding).encode(*ENCODING_ARGS) : value
       end
     end
+
   end
 end

lib/dbf/record.rb

@@ -90,7 +90,7 @@ def underscored_column_names # nodoc
     end
 
     def init_attribute(column) # nodoc
-      value = column.memo? ? memo(column) : unpack_data(column)
+      value = column.memo? ? memo(column) : get_data(column)
       column.type_cast(value)
     end
 
@@ -105,13 +105,15 @@ def memo(column) # nodoc
     end
 
     def memo_start_block(column) # nodoc
-      format = 'V' if %w(30 31).include?(@version)
-      unpack_data(column, format).to_i
+      data = get_data(column)
+      if %w(30 31).include?(@version)
+        data = data.unpack('V').first
+      end
+      data.to_i
     end
 
-    def unpack_data(column, format = nil) # nodoc
-      format ||= "a#{column.length}"
-      @data.read(column.length).unpack(format).first
+    def get_data(column) # nodoc
+      @data.read(column.length)
     end
   end
 end