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 80 80: def create_static_cache_update_function(opts=OPTS) 81: 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) 82: 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 96 96: def create_static_cache_update_trigger(table, opts=OPTS) 97: create_trigger(table, opts[:trigger_name]||default_static_cache_update_name, opts[:function_name]||default_static_cache_update_name, :after=>true) 98: end
The default name for the function, trigger, and notification channel for this extension.
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 102 102: def default_static_cache_update_name 103: :sequel_static_cache_update 104: 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 118 118: def listen_for_static_cache_updates(models, opts=OPTS) 119: raise Error, "this database object does not respond to listen, use the postgres adapter with the pg driver" unless respond_to?(:listen) 120: models = [models] unless models.is_a?(Array) 121: raise Error, "array of models to listen for changes cannot be empty" if models.empty? 122: 123: oid_map = {} 124: models.each do |model| 125: raise Error, "#{model.inspect} does not use the static_cache plugin" unless model.respond_to?(:load_cache, true) 126: oid_map[get(regclass_oid(model.dataset.first_source_table))] = model 127: end 128: 129: Thread.new do 130: begin 131: listen(opts[:channel_name]||default_static_cache_update_name, {:loop=>true}.merge!(opts)) do |_, _, oid| 132: if model = oid_map[oid.to_i] 133: model.send(:load_cache) 134: end 135: end 136: ensure 137: opts[:before_thread_exit].call if opts[:before_thread_exit] 138: end 139: end 140: end