Class: Octopus::Proxy

Inherits:
Object
  • Object
show all
Defined in:
lib/octopus/proxy.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = Octopus.config) ⇒ Proxy

Returns a new instance of Proxy.



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# File 'lib/octopus/proxy.rb', line 6

def initialize(config = Octopus.config)
  initialize_shards(config)
  initialize_replication(config) if !config.nil? && config["replicated"]
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/octopus/proxy.rb', line 200

def method_missing(method, *args, &block)
  if should_clean_connection?(method)
    conn = select_connection()
    self.last_current_shard = self.current_shard
    clean_proxy()
    conn.send(method, *args, &block)
  elsif should_send_queries_to_replicated_databases?(method)
    send_queries_to_selected_slave(method, *args, &block)
  else
    select_connection().send(method, *args, &block)
  end
end

Instance Attribute Details

#config ⇒ Object

Returns the value of attribute config.



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# File 'lib/octopus/proxy.rb', line 4

def config
  @config
end

Instance Method Details

#block ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 98

def block
  Thread.current["octopus.block"]
end

#block=(block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 102

def block=(block)
  Thread.current["octopus.block"] = block
end

#check_schema_migrations(shard) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 184

def check_schema_migrations(shard)
  if !OctopusModel.using(shard).connection.table_exists?(ActiveRecord::Migrator.schema_migrations_table_name())
    OctopusModel.using(shard).connection.initialize_schema_migrations_table
  end
end

#clean_proxy ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 178

def clean_proxy()
  self.current_shard = :master
  self.current_group = nil
  self.block = false
end

#clear_all_query_caches! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 233

def clear_all_query_caches!
  @shards.each { |k, v| safe_connection(v).clear_query_cache_without_octopus }
end

#connection_pool ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 217

def connection_pool
  return @shards[current_shard]
end

#current_group ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 85

def current_group
  Thread.current["octopus.current_group"]
end

#current_group=(group_symbol) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 89

def current_group=(group_symbol)
  # TODO: Error message should include all groups if given more than one bad name.
  [group_symbol].flatten.compact.each do |group|
    raise "Nonexistent Group Name: #{group}" unless has_group?(group)
  end

  Thread.current["octopus.current_group"] = group_symbol
end

#current_model ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 63

def current_model
  Thread.current["octopus.current_model"]
end

#current_model=(model) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 67

def current_model=(model)
  Thread.current["octopus.current_model"] = model.is_a?(ActiveRecord::Base) ? model.class : model
end

#current_shard ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 71

def current_shard
  Thread.current["octopus.current_shard"] ||= :master
end

#current_shard=(shard_symbol) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 75

def current_shard=(shard_symbol)
  if shard_symbol.is_a?(Array)
    shard_symbol.each {|symbol| raise "Nonexistent Shard Name: #{symbol}" if @shards[symbol].nil? }
  else
    raise "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
  end

  Thread.current["octopus.current_shard"] = shard_symbol
end

#disable_query_cache! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 229

def disable_query_cache!
  @shards.each { |k, v| safe_connection(v).disable_query_cache! }
end

#enable_query_cache! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 221

def enable_query_cache!
  @shards.each do |k, v|
    c = safe_connection(v)
    c.clear_query_cache_without_octopus
    c.enable_query_cache!
  end
end

#has_group?(group) ⇒ Boolean

Public: Whether or not a group exists with the given name converted to a string.

Returns a boolean.

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 118

def has_group?(group)
  @groups.has_key?(group.to_s)
end

#initialize_replication(config) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 50

def initialize_replication(config)
  @replicated = true
  if config.has_key?("fully_replicated")
    @fully_replicated = config["fully_replicated"]
  else
    @fully_replicated = true
  end

  @slaves_list = @shards.keys.map {|sym| sym.to_s}.sort
  @slaves_list.delete('master')
  @slave_index = 0
end

#initialize_shards(config) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 11

def initialize_shards(config)
  @shards = HashWithIndifferentAccess.new
  @groups = {}
  @adapters = Set.new
  @shards[:master] = ActiveRecord::Base.connection_pool_without_octopus()
  @config = ActiveRecord::Base.connection_pool_without_octopus.connection.instance_variable_get(:@config)

  if !config.nil?
    @entire_sharded = config['entire_sharded']
    shards_config = config[Octopus.rails_env()]
  end

  shards_config ||= []

  shards_config.each do |key, value|
    if value.is_a?(String) 
      value = resolve_string_connection(value).merge(:octopus_shard => key)
      initialize_adapter(value['adapter'])
      @shards[key.to_sym] = connection_pool_for(value, "#{value['adapter']}_connection")
    elsif value.is_a?(Hash) && value.has_key?("adapter")
      value.merge!(:octopus_shard => key)
      initialize_adapter(value['adapter'])
      @shards[key.to_sym] = connection_pool_for(value, "#{value['adapter']}_connection")
    elsif value.is_a?(Hash)
      @groups[key.to_s] = []

      value.each do |k, v|
        raise "You have duplicated shard names!" if @shards.has_key?(k.to_sym)

        initialize_adapter(v['adapter'])
        config_with_octopus_shard = v.merge(:octopus_shard => k)

        @shards[k.to_sym] = connection_pool_for(config_with_octopus_shard, "#{v['adapter']}_connection")
        @groups[key.to_s] << k.to_sym
      end
    end
  end
end

#last_current_shard ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 106

def last_current_shard
  Thread.current["octopus.last_current_shard"]
end

#last_current_shard=(last_current_shard) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 110

def last_current_shard=(last_current_shard)
  Thread.current["octopus.last_current_shard"] = last_current_shard
end

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

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 213

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

#run_queries_on_shard(shard, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 158

def run_queries_on_shard(shard, &block)
  older_shard = self.current_shard
  last_block = self.block

  begin
    self.block = true
    self.current_shard = shard
    yield
  ensure
    self.block = last_block || false
    self.current_shard = older_shard
  end
end

#safe_connection(connection_pool) ⇒ Object

Rails 3.1 sets automatic_reconnect to false when it removes connection pool. Octopus can potentially retain a reference to a closed connection pool. Previously, that would work since the pool would just reconnect, but in Rails 3.1 the flag prevents this.



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# File 'lib/octopus/proxy.rb', line 141

def safe_connection(connection_pool)
  connection_pool.automatic_reconnect ||= true
  connection_pool.connection()
end

#select_connection ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 146

def select_connection
  safe_connection(@shards[shard_name])
end

#send_queries_to_multiple_shards(shards, &block) ⇒ Object 



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

def send_queries_to_multiple_shards(shards, &block)
  shards.each do |shard|
    self.run_queries_on_shard(shard, &block)
  end
end

#shard_name ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 150

def shard_name
  current_shard.is_a?(Array) ? current_shard.first : current_shard
end

#shard_names ⇒ Object

Public: Retrieves names of all loaded shards.

Returns an array of shard names as symbols



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# File 'lib/octopus/proxy.rb', line 125

def shard_names
  @shards.keys
end

#shards_for_group(group) ⇒ Object

Public: Retrieves the defined shards for a given group.

Returns an array of shard names as symbols or nil if the group is not defined.



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

def shards_for_group(group)
  @groups.fetch(group.to_s, nil)
end

#should_clean_table_name? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 154

def should_clean_table_name?
  @adapters.size > 1
end

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



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# File 'lib/octopus/proxy.rb', line 190

def transaction(options = {}, &block)
  if @replicated && (current_model.replicated || @fully_replicated)
    self.run_queries_on_shard(:master) do
      select_connection.transaction(options, &block)
    end
  else
    select_connection.transaction(options, &block)
  end
end