Class: XBar::Proxy

Inherits:
Object
  • Object
show all
Includes:
Colors, Mapper
Defined in:
lib/xbar/proxy.rb

Constant Summary

Constants included from Colors

Colors::BLACK_BACK, Colors::BLACK_TEXT, Colors::BLINK_OFF, Colors::BLINK_ON, Colors::BLUE_BACK, Colors::BLUE_TEXT, Colors::BOLD_OFF, Colors::BOLD_ON, Colors::BROWN_BACK, Colors::BROWN_TEXT, Colors::CYAN_BACK, Colors::CYAN_TEXT, Colors::GRAY_TEXT, Colors::GREEN_BACK, Colors::GREEN_TEXT, Colors::MAGENTA_BACK, Colors::MAGENTA_TEXT, Colors::RED_BACK, Colors::RED_TEXT, Colors::RESET_COLORS, Colors::REVERSE_OFF, Colors::REVERSE_ON, Colors::WHITE_BACK

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Mapper

exports, #register, #reset_config

Methods included from Mapper::ClassMethods

#app_env, #config, #config_file_name, #config_from_file, #connection_file_name, #disconnect_all!, #environments, #initialize_options, #register, #reset, #shards=, #unregister, #xbar_env

Constructor Details

#initialize ⇒ Proxy

Returns a new instance of Proxy.



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# File 'lib/xbar/proxy.rb', line 24

def initialize
  if XBar.debug
    puts "Proxy##{ BLUE_TEXT}{initialize}#{RESET_COLORS}: Initializing new proxy."
  end
  @reset = false
  @pause = false
  register
  reset_shards
  clean_proxy
  @adapters = XBar::Mapper.adapters
  @mylock = Mutex.new
  @pause_lock = Mutex.new
  @pause_cv = ConditionVariable.new
  @paused = false
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 152

def method_missing(method, *args, &block)
  if XBar.debug
    puts("\nProxy##{BLUE_TEXT}method_missing#{RESET_COLORS}: " + 
      "method = #{RED_TEXT}#{method}#{RESET_COLORS}, " +
      "current_shard=#{current_shard}, " +
      "in_block_scope=#{in_block_scope?}")
  end
  if method.to_s =~ /insert|select|execute/ && !in_block_scope? # should clean connection
    shard = @last_current_shard = current_shard
    clean_proxy
    @shard_list[shard].run_queries(method, *args, &block)
  else
    select_shard.run_queries(method, *args, &block)
  end
end

Instance Attribute Details

#adapters ⇒ Object (readonly)

Returns the value of attribute adapters.



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# File 'lib/xbar/proxy.rb', line 20

def adapters
  @adapters
end

#current_model ⇒ Object

Setters for these are written by hand below.



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# File 'lib/xbar/proxy.rb', line 18

def current_model
  @current_model
end

#current_shard ⇒ Object

Setters for these are written by hand below.



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# File 'lib/xbar/proxy.rb', line 18

def current_shard
  @current_shard
end

#last_current_shard ⇒ Object (readonly)

No setter method.



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# File 'lib/xbar/proxy.rb', line 15

def last_current_shard
  @last_current_shard
end

#shard_list ⇒ Object (readonly)

Returns the value of attribute shard_list.



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# File 'lib/xbar/proxy.rb', line 20

def shard_list
  @shard_list
end

#slave_read_allowed ⇒ Object

Returns the value of attribute slave_read_allowed.



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# File 'lib/xbar/proxy.rb', line 22

def slave_read_allowed
  @slave_read_allowed
end

Instance Method Details

#check_for_pause ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 230

def check_for_pause
  if @pause && (open_transactions == 0)
    @pause_lock.synchronize do
      @pause = true
      @pause_cv.wait(@pause_lock)
      @pause = false
    end
 end
end

#check_for_reset ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 269

def check_for_reset
  if @reset && (open_transactions == 0)
    do_reset
  end
end

#check_schema_migrations(shard_name) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 129

def check_schema_migrations(shard_name)
  @shard_list[shard_name].check_schema_migrations
end

#clean_proxy ⇒ Object

Called from migration.



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# File 'lib/xbar/proxy.rb', line 41

def clean_proxy
  if XBar.debug
    puts "Proxy##{BLUE_TEXT}clean_proxy:#{RESET_COLORS}: " +
      "current shard = #{@current_shard}"
  end
  @current_shard = :master
  clear_block_scope
end

#clear_block_scope ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 88

def clear_block_scope
  @in_block = @old_in_block = false
  @depth = 0
end

#clear_cache! ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 147

def clear_cache!
  check_for_reset    
  select_shard.run_queries(:clear_cache!)
end

#connection_pool ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 172

def connection_pool
  # Or we could make a case for selecting master replica from
  # the master shard, rather than the current shard. XXX.
  cp = select_shard.master
  cp.automatic_reconnect = true if XBar.rails31?
  cp
end

#do_reset ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 259

def do_reset
  reset_shards
  @adapters = adapters
  @mylock.synchronize do
    @reset = false
    clean_proxy if @hard_reset
    @hard_reset = false
  end
end

#enter_block_scope ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 72

def enter_block_scope
  @old_in_block = @in_block
  @depth += 1
  @in_block = true
end

#enter_statistics(shard_name, config, method) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 180

def enter_statistics(shard_name, config, method)
 
  return unless XBar.collect_stats?
 
  saved_current_model = current_model
  if UsageStatistics.connection.kind_of?(XBar::Proxy)
    connection_pool = UsageStatistics.connection.shards[:master][0]
    connection_pool.automatic_reconnect = true
    connection = connection_pool.connection
   
    return unless connection.table_exists? :usage_statistics

    # We have an AbstractAdapter.  We must insert statistics using this
    # adapter, not the Proxy, because otherwise the insertion triggers
    # 'enter_statistics' again and we would be in an infinite loop.

=begin
    params = {
      shard_name: shard_name,
      method: method.to_s,
      adapter: config[:adapter],
      username: config[:username],
      thread_id: Thread.current.object_id.to_s,
      port: (config[:port] || "default"),
      host: config[:host],
      database_name: config[:database]}
    insert(connection, params) -- alternatively
=end
   
    sql = "INSERT INTO usage_statistics " +
      "(shard_name, method, adapter, username, thread_id, port, host, database_name) " +
      "VALUES (\'#{shard_name}\', \'#{method.to_s}\', \'#{config[:adapter]}\', " +
      "\'#{config[:username]}\', \'#{Thread.current.object_id.to_s}\', " +
      "#{config[:port] || "default"}, \'#{config[:host]}\', \'#{config[:database]}\')"
    connection.execute(sql)

    self.current_model = saved_current_model
  end
end

#in_block_scope? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xbar/proxy.rb', line 84

def in_block_scope?
  @in_block
end

#leave_block_scope ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 78

def leave_block_scope
  @in_block = @old_in_block
  @old_in_block = false
  @depth -= 1
end

#paused? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xbar/proxy.rb', line 226

def paused?
  @pause
end

#quote_table_name(table_name) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 143

def quote_table_name(table_name)
  select_shard.quote_table_name(table_name)
end

#request_pause ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 220

def request_pause
  @pause_lock.synchronize do
    @pause = true
  end
end

#request_reset(opts = {}) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 244

def request_reset(opts = {})
  @mylock.synchronize do
    @reset = true
    if opts[:hard_reset]
      @hard_reset = true
    end
  end
end

#reset_complete? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xbar/proxy.rb', line 253

def reset_complete?
  @mylock.synchronize do
    @reset == false
  end
end

#respond_to?(method, include_private = false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xbar/proxy.rb', line 168

def respond_to?(method, include_private = false)
  super || current_shard.respond_to?(method, include_private)
end

#run_queries_on_shard(shard_name, use_scope = true) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 101

def run_queries_on_shard(shard_name, use_scope = true)
  check_for_reset
  check_for_pause
  older_shard = current_shard 
  enter_block_scope if use_scope
  self.current_shard = shard_name
  if XBar.debug
    puts "Proxy##{BLUE_TEXT}run_queries_on_shard#{RESET_COLORS}: " +
      "current shard = #{current_shard}, use_scope = #{use_scope}, " +
      "previous shard = #{older_shard}"
  end
  result = yield
ensure
  if XBar.debug
    puts "Proxy##{BLUE_TEXT}run_queries_on_shard#{RESET_COLORS}: " +
      "restoring previous shard = #{older_shard}"
  end
  leave_block_scope if use_scope
  self.current_shard = older_shard
end

#schema_cache ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 139

def schema_cache
  select_shard.schema_cache
end

#send_queries_to_multiple_shards(shard_names, &block) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 122

def send_queries_to_multiple_shards(shard_names, &block)
  shard_names = Array(shard_names)
  shard_names.each do |name|
    run_queries_on_shard(name, &block)
  end
end

#should_clean_table_name? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xbar/proxy.rb', line 93

def should_clean_table_name?
  @adapters.size > 1
end

#transaction(options = {}, &block) ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 133

def transaction(options = {}, &block)
  check_for_reset
  check_for_pause
  select_shard.transaction(options, &block)
end

#unpause ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 240

def unpause
  @pause_cv.signal
end

#verify_connection ⇒ Object 



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# File 'lib/xbar/proxy.rb', line 97

def verify_connection
  XBar::Mapper.options[:verify_connection]
end