postgresql_extender.rb in rubyrep-1.0.2

- old
+ new

@@ -1,36 +1,7 @@
 require 'time'
 
-# A cursor to iterate over the records returned by select_cursor.
-# Only one row is kept in memory at a time.
-class PGresult
-  # Returns true if there are more rows to read.
-  def next?
-    @current_row_num ||= 0
-    @num_rows ||= self.ntuples()
-    @current_row_num < @num_rows
-  end
-  
-  # Returns the row as a column => value hash and moves the cursor to the next row.
-  def next_row
-    raise("no more rows available") unless next?
-    row = {}
-    @fields ||= self.fields
-    @fields.each_with_index do |field, field_index| 
-      if self.getisnull(@current_row_num, field_index)
-        value = nil
-      else
-        value = self.getvalue @current_row_num, field_index
-      end
-      
-      row[@fields[field_index]] = value
-    end
-    @current_row_num += 1
-    row
-  end
-end
-
 # Hack:
 # For some reasons these methods were removed in Rails 2.2.2, thus breaking
 # the binary and multi-lingual data loading.
 # So here they are again.
 module ActiveRecord
@@ -108,86 +79,13 @@
 end
 
 module RR
   module ConnectionExtenders
 
-    # Fetches results from a PostgreSQL cursor object.
-    class PostgreSQLFetcher
-
-      # The current database connection
-      attr_accessor :connection
-
-      # Name of the cursor from which to fetch
-      attr_accessor :cursor_name
-
-      # Number of rows to be read at once
-      attr_accessor :row_buffer_size
-
-      # Creates a new fetcher.
-      # * +connection+: the current database connection
-      # * +cursor_name+: name of the cursor from which to fetch
-      # * +row_buffer_size+: number of records to read at once
-      def initialize(connection, cursor_name, row_buffer_size)
-        self.connection = connection
-        self.cursor_name = cursor_name
-        self.row_buffer_size = row_buffer_size
-      end
-
-      # Executes the specified SQL staements, returning the result
-      def execute(sql)
-        connection.execute sql
-      end
-
-      # Returns true if there are more rows to read.
-      def next?
-        @current_result ||= execute("FETCH FORWARD #{row_buffer_size} FROM #{cursor_name}")
-        @current_result.next?
-      end
-
-      # Returns the row as a column => value hash and moves the cursor to the next row.
-      def next_row
-        raise("no more rows available") unless next?
-        row = @current_result.next_row
-        unless @current_result.next?
-          @current_result.clear
-          @current_result = nil
-        end
-        row
-      end
-
-      # Closes the cursor and frees up all ressources
-      def clear
-        if @current_result
-          @current_result.clear
-          @current_result = nil
-        end
-        result = execute("CLOSE #{cursor_name}")
-        result.clear if result
-      end
-    end
-
     # Provides various PostgreSQL specific functionality required by Rubyrep.
     module PostgreSQLExtender
       RR::ConnectionExtenders.register :postgresql => self
 
-      # Executes the given sql query with the otional name written in the 
-      # ActiveRecord log file.
-      #
-      # :+row_buffer_size+ controls how many records are ready into memory at a
-      # time. Implemented using the PostgeSQL "DECLARE CURSOR" and "FETCH" constructs.
-      # This is necessary as the postgresql driver always reads the
-      # complete resultset into memory.
-      #
-      # Returns the results as a Cursor object supporting
-      #   * next? - returns true if there are more rows to read
-      #   * next_row - returns the row as a column => value hash and moves the cursor to the next row
-      #   * clear - clearing the cursor (making allocated memory available for GC)
-      def select_cursor(sql, row_buffer_size = 1000)
-        cursor_name = "RR_#{Time.now.to_i}#{rand(1_000_000)}"
-        execute("DECLARE #{cursor_name} NO SCROLL CURSOR WITH HOLD FOR " + sql)
-        PostgreSQLFetcher.new(self, cursor_name, row_buffer_size)
-      end
-      
       # Returns an ordered list of primary key column names of the given table
       def primary_key_names(table)
         row = self.select_one(<<-end_sql)
           SELECT relname
           FROM pg_class