Module | Sequel::Postgres::StaticCacheUpdater |
In: |
lib/sequel/extensions/pg_static_cache_updater.rb
|
Add the static cache update function to the PostgreSQL database. This must be added before any triggers using this function are added.
Options:
:channel_name : | Override the channel name to use. |
:function_name : | Override the function name to use. |
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 76 76: def create_static_cache_update_function(opts=OPTS) 77: create_function(opts[:function_name]||default_static_cache_update_name, "BEGIN\n PERFORM pg_notify(\#{literal((opts[:channel_name]||default_static_cache_update_name).to_s)}, TG_RELID::text);\n RETURN NULL;\nEND\n", :returns=>:trigger, :language=>:plpgsql) 78: end
Add a trigger to the given table that calls the function which will notify about table changes.
Options:
:function_name : | Override the function name to use. |
:trigger_name : | Override the trigger name to use. |
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 92 92: def create_static_cache_update_trigger(table, opts=OPTS) 93: create_trigger(table, opts[:trigger_name]||default_static_cache_update_name, opts[:function_name]||default_static_cache_update_name, :after=>true) 94: end
The default name for the function, trigger, and notification channel for this extension.
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 98 98: def default_static_cache_update_name 99: :sequel_static_cache_update 100: end
Listen on the notification channel for changes to any of tables for the models given in a new thread. If notified about a change to one of the tables, reload the cache for the related model. Options given are also passed to Database#listen.
Note that this implementation does not currently support multiple models that use the same underlying table.
Options:
:channel_name : | Override the channel name to use. |
:before_thread_exit : | An object that responds to call that is called before the the created thread exits. |
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 114 114: def listen_for_static_cache_updates(models, opts=OPTS) 115: raise Error, "this database object does not respond to listen, use the postgres adapter with the pg driver" unless respond_to?(:listen) 116: models = [models] unless models.is_a?(Array) 117: raise Error, "array of models to listen for changes cannot be empty" if models.empty? 118: 119: oid_map = {} 120: models.each do |model| 121: raise Error, "#{model.inspect} does not use the static_cache plugin" unless model.respond_to?(:load_cache, true) 122: oid_map[get(regclass_oid(model.dataset.first_source_table))] = model 123: end 124: 125: Thread.new do 126: begin 127: listen(opts[:channel_name]||default_static_cache_update_name, {:loop=>true}.merge(opts)) do |_, _, oid| 128: if model = oid_map[oid.to_i] 129: model.send(:load_cache) 130: end 131: end 132: ensure 133: opts[:before_thread_exit].call if opts[:before_thread_exit] 134: end 135: end 136: end