Class: Knj::Db::Query_buffer

Inherits:
Object
  • Object
show all
Defined in:
lib/knj/knjdb/query_buffer.rb

Overview

This class buffers a lot of queries and flushes them out via transactions.

Instance Method Summary collapse

Constructor Details

#initialize(args) ⇒ Query_buffer

Constructor. Takes arguments to be used and a block.



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# File 'lib/knj/knjdb/query_buffer.rb', line 4

def initialize(args)
  @args = args
  @queries = []
  @inserts = {}
  @queries_count = 0
  @debug = @args[:debug]
  @lock = Mutex.new
  
  STDOUT.puts "Query buffer started." if @debug
  
  begin
    yield(self)
  ensure
    self.flush
  end
end

Instance Method Details

#delete(table, where) ⇒ Object

Delete as on a normal Knj::Db.

Examples

db.q_buffer do |buffer|

buffer.delete(:users, {:id => 5})

end



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# File 'lib/knj/knjdb/query_buffer.rb', line 38

def delete(table, where)
  STDOUT.puts "Delete called on table #{table} with arguments: '#{where}'." if @debug
  self.query(@args[:db].delete(table, where, :return_sql => true))
  return nil
end

#flush ⇒ Object

Flushes all queries out in a transaction. This will automatically be called for every 1000 queries.



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# File 'lib/knj/knjdb/query_buffer.rb', line 61

def flush
  return nil if @queries_count <= 0
  
  @lock.synchronize do
    @args[:db].transaction do
      @queries.shift(1000).each do |str|
        STDOUT.print "Executing via buffer: #{str}\n" if @debug
        @args[:db].q(str)
      end
      
      @inserts.each do |table, datas_arr|
        while !datas_arr.empty?
          datas_chunk_arr = datas_arr.shift(1000)
          @args[:db].insert_multi(table, datas_chunk_arr)
        end
      end
    end
    
    @inserts.clear
    @queries_count = 0
  end
  
  return nil
end

#insert(table, data) ⇒ Object

Plans to inset a hash into a table. It will only be inserted when flush is called.

Examples

db.q_buffer do |buffer|

buffer.insert(:users, {:name => "John Doe"})

end



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# File 'lib/knj/knjdb/query_buffer.rb', line 49

def insert(table, data)
  @lock.synchronize do
    @inserts[table] = [] if !@inserts.key?(table)
    @inserts[table] << data
    @queries_count += 1
  end
  
  self.flush if @queries_count >= 1000
  return nil
end

#query(str) ⇒ Object

Adds a query to the buffer.



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# File 'lib/knj/knjdb/query_buffer.rb', line 22

def query(str)
  @lock.synchronize do
    STDOUT.print "Adding to buffer: #{str}\n" if @debug
    @queries << str
    @queries_count += 1
  end
  
  self.flush if @queries_count >= 1000
  return nil
end