module Sequel::Postgres::StaticCacheUpdater
Public Instance Methods
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 def create_static_cache_update_function(opts=OPTS) create_function(opts[:function_name]||default_static_cache_update_name, "BEGIN PERFORM pg_notify(#{literal((opts[:channel_name]||default_static_cache_update_name).to_s)}, TG_RELID::text); RETURN NULL; END ", :returns=>:trigger, :language=>:plpgsql) 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 91 def create_static_cache_update_trigger(table, opts=OPTS) create_trigger(table, opts[:trigger_name]||default_static_cache_update_name, opts[:function_name]||default_static_cache_update_name, :after=>true) end
The default name for the function, trigger, and notification channel for this extension.
# File lib/sequel/extensions/pg_static_cache_updater.rb, line 97 def default_static_cache_update_name :sequel_static_cache_update 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 Sequel::Postgres::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 113 def listen_for_static_cache_updates(models, opts=OPTS) raise Error, "this database object does not respond to listen, use the postgres adapter with the pg driver" unless respond_to?(:listen) models = [models] unless models.is_a?(Array) raise Error, "array of models to listen for changes cannot be empty" if models.empty? oid_map = {} models.each do |model| raise Error, "#{model.inspect} does not use the static_cache plugin" unless model.respond_to?(:load_cache, true) oid_map[get(regclass_oid(model.dataset.first_source_table))] = model end Thread.new do begin listen(opts[:channel_name]||default_static_cache_update_name, {:loop=>true}.merge(opts)) do |_, _, oid| if model = oid_map[oid.to_i] model.send(:load_cache) end end ensure opts[:before_thread_exit].call if opts[:before_thread_exit] end end end