reader.rb in dbf-0.5.4

- old
+ new

@@ -4,13 +4,10 @@
     attr_reader :field_count
     
     # An array of DBF::Field records
     attr_reader :fields
     
-    # The total number of records.  This number includes records marked as deleted.
-    attr_reader :record_count
-    
     # Internal dBase version number
     attr_reader :version
     
     # Last updated datetime
     attr_reader :last_updated
@@ -22,12 +19,14 @@
     attr_reader :memo_block_size
     
     # Initialize a new DBF::Reader.
     # Example:
     #   reader = DBF::Reader.new 'data.dbf'
-    def initialize(filename)
-      @in_memory = true
+    def initialize(filename, options = {})
+      options = {:in_memory => true}.merge(options)
+      
+      @in_memory = options[:in_memory]
       @data_file = File.open(filename, 'rb')
       @memo_file = open_memo(filename)
       reload!
     end
     
@@ -35,26 +34,28 @@
     def reload!
       @records = nil
       get_header_info
       get_memo_header_info if @memo_file
       get_field_descriptors
+      build_db_index
     end
     
     # Returns true if there is a corresponding memo file
     def has_memo_file?
       @memo_file ? true : false
     end
     
     # If true, DBF::Reader will load all records into memory.  If false, records are retrieved using file I/O.
+    # You can set this option is set during initialization of the DBF::Reader. Defaults to true. Example:
+    #   reader = DBF::Reader.new 'data.dbf', :in_memory => false
     def in_memory?
       @in_memory
     end
     
-    # Tells DBF::Reader whether to load all records into memory.  Defaults to true.
-    # You may need to set this to false if the database is very large in order to reduce memory usage.
-    def in_memory=(boolean)
-      @in_memory = boolean
+    # The total number of active records.
+    def record_count
+      @db_index.size
     end
     
     # Returns an instance of DBF::Field for <b>field_name</b>.  <b>field_name</b>
     # can be a symbol or a string.
     def field(field_name)
@@ -237,25 +238,35 @@
       
       # Returns the record at <tt>index</tt> by seeking to the record in the
       # physical database file. See the documentation for the records method for
       # information on how these two methods differ.
       def get_record_from_file(index)
-        seek_to_record(index)
+        seek_to_record(@db_index[index])
         active_record? ? Record.new(self, @data_file, @memo_file) : nil
       end
       
       def get_all_records_from_file
         all_records = []
         0.upto(@record_count - 1) do |n|
           seek_to_record(n)
           if active_record?
             all_records << DBF::Record.new(self, @data_file, @memo_file)
-          else
-            all_records << nil
           end
         end
         all_records
       end
     
+      def build_db_index
+        @db_index = []
+        @deleted_records = []
+        0.upto(@record_count - 1) do |n|
+          seek_to_record(n)
+          if active_record?
+            @db_index << n
+          else
+            @deleted_records << n
+          end
+        end
+      end
   end
   
 end
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