Class: RR::TableScan

Inherits:
Object
  • Object
show all
Includes:
TableScanHelper
Defined in:
lib/rubyrep/table_scan.rb

Overview

Shared functionality for DirectTableScan and ProxiedTableScan

Direct Known Subclasses

DirectTableScan, ProxiedTableScan, TableSync

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from TableScanHelper

#rank_rows, scan_class

Constructor Details

#initialize(session, left_table, right_table = nil) ⇒ TableScan

Creates a new DirectTableScan instance

* session: a Session object representing the current database session
* left_table: name of the table in the left database
* right_table: name of the table in the right database. If not given, same like left_table



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# File 'lib/rubyrep/table_scan.rb', line 44

def initialize(session, left_table, right_table = nil)
  if session.left.primary_key_names(left_table).empty?
    raise "Table '#{left_table}' doesn't have a primary key. Cannot scan."
  end
  
  self.session, self.left_table, self.right_table = session, left_table, right_table
  self.right_table ||= self.left_table
  self.primary_key_names = session.left.primary_key_names left_table
end

Instance Attribute Details

#left_table ⇒ Object

Name of the left table



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# File 'lib/rubyrep/table_scan.rb', line 11

def left_table
  @left_table
end

#primary_key_names ⇒ Object

Cached array of primary key names



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# File 'lib/rubyrep/table_scan.rb', line 17

def primary_key_names
  @primary_key_names
end

#progress_printer ⇒ Object

Receives the active ScanProgressPrinters class



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# File 'lib/rubyrep/table_scan.rb', line 20

def progress_printer
  @progress_printer
end

#right_table ⇒ Object

Name of the right table



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# File 'lib/rubyrep/table_scan.rb', line 14

def right_table
  @right_table
end

#session ⇒ Object

The current Session object



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# File 'lib/rubyrep/table_scan.rb', line 8

def session
  @session
end

Instance Method Details

#scan_options ⇒ Object

Returns a hash of scan options for this table scan.



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# File 'lib/rubyrep/table_scan.rb', line 23

def scan_options
  @scan_options ||= session.configuration.options_for_table(left_table)
end

#update_progress(steps) ⇒ Object

Inform new progress to progress printer steps is the number of processed records.



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# File 'lib/rubyrep/table_scan.rb', line 29

def update_progress(steps)
  return unless progress_printer
  unless @progress_printer_instance
    total_records =
      session.left.select_one("select count(*) as n from #{session.left.quote_table_name(left_table)}")['n'].to_i +
      session.right.select_one("select count(*) as n from #{session.right.quote_table_name(right_table)}")['n'].to_i
    @progress_printer_instance = progress_printer.new(total_records, session, left_table, right_table)
  end
  @progress_printer_instance.step(steps)
end