Module: Switchman::ActiveRecord::ConnectionHandler
- Defined in:
- lib/switchman/active_record/connection_handler.rb
Class Method Summary collapse
Instance Method Summary collapse
- #clear_idle_connections!(since_when) ⇒ Object
- #establish_connection_with_sharding(owner, spec) ⇒ Object
- #initialize_categories(model = ::ActiveRecord::Base) ⇒ Object
- #remove_connection_with_sharding(model) ⇒ Object
- #retrieve_connection_pool(klass) ⇒ Object
- #uninitialize_ar(model = ::ActiveRecord::Base) ⇒ Object
Class Method Details
.included(klass) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 26 def self.included(klass) klass.alias_method_chain(:establish_connection, :sharding) klass.alias_method_chain(:remove_connection, :sharding) klass.send(:remove_method, :retrieve_connection_pool) if ::Rails.version >= '4' end |
.make_sharing_automagic(config) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 7 def self.make_sharing_automagic(config) key = config[:adapter] == 'postgresql' ? :schema_search_path : :database # only load the shard name from the db if we have to if config[key] || !config[:shard_name] # we may not be able to connect to this shard yet, cause it might be an empty database server shard_name = Shard.current.name rescue nil return unless shard_name config[:shard_name] ||= shard_name end if !config[key] || config[key] == shard_name # this may truncate the schema_search_path if it was not specified in database.yml # but that's what our old behavior was anyway, so I guess it's okay config[key] = '%{shard_name}' end end |
Instance Method Details
#clear_idle_connections!(since_when) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 153 def clear_idle_connections!(since_when) # TODO in rails 4.2+ s/connection_pools.values/connection_pool_list/ connection_pools.values.each{ |pool| pool.clear_idle_connections!(since_when) } end |
#establish_connection_with_sharding(owner, spec) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 32 def establish_connection_with_sharding(owner, spec) establish_connection_without_sharding(owner, spec) # this is the first place that the adapter would have been required; but now we # need this addition ASAP since it will be called when loading the default shard below if defined?(::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) require "switchman/active_record/postgresql_adapter" ::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.send(:include, ActiveRecord::PostgreSQLAdapter) end # AR3 uses the name, AR4 uses the model model = case owner when String owner.constantize when Class owner else raise "unknown owner #{owner}" end pool = ::Rails.version < '4' ? connection_pools[spec] : owner_to_pool[owner.name] first_time = !Shard.instance_variable_get(:@default) if first_time # Have to cache the default shard before we insert sharding, otherwise the first access # to sharding will recurse onto itself trying to access column information Shard.default # automatically change config to allow for sharing connections with simple config ConnectionHandler.make_sharing_automagic(spec.config) ConnectionHandler.make_sharing_automagic(Shard.default.database_server.config) ::ActiveRecord::Base.configurations[::Rails.env] = spec.config.stringify_keys end @shard_connection_pools ||= { [:master, Shard.default.database_server.shareable? ? ::Rails.env : Shard.default] => pool} proxy = ConnectionPoolProxy.new(model.shard_category, pool, @shard_connection_pools) if ::Rails.version < '4' connection_pools[spec] = proxy else owner_to_pool[owner.name] = proxy class_to_pool.clear end if first_time if Shard.default.database_server.config[:prefer_slave] Shard.default.database_server.shackle! end if Shard.default.is_a?(DefaultShard) && Shard.default.database_server.config[:slave] Shard.default.database_server.shackle! Shard.default(true) end end if ::Rails.version < '4' initialize_categories(model) class_to_pool[model.name] = proxy end # reload the default shard if we just got a new connection # to where the Shards table is # DON'T do it if we're not the current connection handler - that means # we're in the middle of switching environments, and we don't want to # establish a connection with incorrect settings if (model == ::ActiveRecord::Base || model == Shard) && self == ::ActiveRecord::Base.connection_handler && !first_time Shard.default(true) unless first_time proxy.disconnect! end if first_time # do the change for other database servers, now that we can switch shards if Shard.default.is_a?(Shard) DatabaseServer.all.each do |server| next if server == Shard.default.database_server shard = server.shards.where(:name => nil).first shard ||= Shard.new(:database_server => server) shard.activate do ConnectionHandler.make_sharing_automagic(server.config) ConnectionHandler.make_sharing_automagic(proxy.current_pool.spec.config) end end end # we may have established some connections above trying to infer the shard's name. # close them, so that someone that doesn't expect them doesn't try to fork # without closing them self.clear_all_connections! end end |
#initialize_categories(model = ::ActiveRecord::Base) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 199 def initialize_categories(model = ::ActiveRecord::Base) if ::Rails.version < '4' # now set up pools for models that inherit from this model, but with a different # sharding category Shard.const_get(:CATEGORIES).each do |category, models| next if category == :default next if category == model.shard_category this_proxy = nil Array(models).each do |category_model| category_model = category_model.constantize if category_model.is_a? String next unless category_model < model # don't replace existing connections next if class_to_pool[category_model.name] default_pool = retrieve_connection_pool(model) default_pool = default_pool.default_pool if default_pool.is_a?(ConnectionPoolProxy) # look for an existing compatible proxy for this category this_proxy ||= ConnectionPoolProxy.new(category_model.shard_category, default_pool, @shard_connection_pools) class_to_pool[category_model.name] = this_proxy end end else class_to_pool.clear end end |
#remove_connection_with_sharding(model) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 123 def remove_connection_with_sharding(model) uninitialize_ar(model) if (::Rails.version < '4' ? class_to_pool : owner_to_pool)[model.name].is_a?(ConnectionPoolProxy) result = remove_connection_without_sharding(model) initialize_categories if ::Rails.version >= '4' result end |
#retrieve_connection_pool(klass) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 131 def retrieve_connection_pool(klass) class_to_pool[klass.name] ||= begin original_klass = klass until pool = pool_for(klass) klass = klass.superclass break unless klass <= Base end if pool.is_a?(ConnectionPoolProxy) && pool.category != original_klass.shard_category default_pool = pool.default_pool pool = nil class_to_pool.each_value { |p| pool = p if p.is_a?(ConnectionPoolProxy) && p.category == original_klass.shard_category && p.default_pool == default_pool } pool ||= ConnectionPoolProxy.new(original_klass.shard_category, default_pool, @shard_connection_pools) end class_to_pool[original_klass.name] = pool end end |
#uninitialize_ar(model = ::ActiveRecord::Base) ⇒ Object
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# File 'lib/switchman/active_record/connection_handler.rb', line 168 def uninitialize_ar(model = ::ActiveRecord::Base) # take the proxies out if ::Rails.version >= '4' pool = owner_to_pool[model.name] owner_to_pool[model.name] = pool.default_pool if pool else class_to_pool.each_key do |model_name| pool_model = model_name.constantize # only de-proxify models that inherit from what we're uninitializing next unless pool_model == model || pool_model < model proxy = class_to_pool[model_name] next unless proxy.is_a?(ConnectionPoolProxy) # make sure we're switched back to the default shard for the # connection that will remain if proxy.connected? Shard.default.activate(proxy.category) { proxy.connection } end connection_pools[proxy.spec] = proxy.default_pool class_to_pool[model_name] = proxy.default_pool end # prune dups that were created for implementing shard categories class_to_pool.each_key do |model_name| next if model_name == ::ActiveRecord::Base.name pool_model = model_name.constantize class_to_pool.delete(model_name) if retrieve_connection_pool(pool_model.superclass) == class_to_pool[model_name] end end end |