mirror of
https://github.com/rails/rails.git
synced 2022-11-09 12:12:34 -05:00
cf082927ef
Inserted spaces in the name of Rails components.
Since I was on it, also used PostgreSQL instead of Postgres
because albeit Postgres is an accepted alias, PostgreSQL is
the official name and the actual name of the adapter.
See
https://wiki.postgresql.org/wiki/ProjectName
with regard to PostgreSQL vs Postgres.
107 lines
2.9 KiB
Ruby
107 lines
2.9 KiB
Ruby
gem "pg", "~> 0.18"
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require "pg"
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require "thread"
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module ActionCable
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module SubscriptionAdapter
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class PostgreSQL < Base # :nodoc:
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def initialize(*)
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super
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@listener = nil
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end
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def broadcast(channel, payload)
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with_connection do |pg_conn|
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pg_conn.exec("NOTIFY #{pg_conn.escape_identifier(channel)}, '#{pg_conn.escape_string(payload)}'")
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end
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end
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def subscribe(channel, callback, success_callback = nil)
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listener.add_subscriber(channel, callback, success_callback)
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end
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def unsubscribe(channel, callback)
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listener.remove_subscriber(channel, callback)
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end
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def shutdown
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listener.shutdown
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end
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def with_connection(&block) # :nodoc:
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ActiveRecord::Base.connection_pool.with_connection do |ar_conn|
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pg_conn = ar_conn.raw_connection
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unless pg_conn.is_a?(PG::Connection)
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raise "The Active Record database must be PostgreSQL in order to use the PostgreSQL Action Cable storage adapter"
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end
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yield pg_conn
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end
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end
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private
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def listener
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@listener || @server.mutex.synchronize { @listener ||= Listener.new(self, @server.event_loop) }
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end
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class Listener < SubscriberMap
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def initialize(adapter, event_loop)
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super()
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@adapter = adapter
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@event_loop = event_loop
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@queue = Queue.new
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@thread = Thread.new do
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Thread.current.abort_on_exception = true
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listen
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end
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end
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def listen
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@adapter.with_connection do |pg_conn|
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catch :shutdown do
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loop do
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until @queue.empty?
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action, channel, callback = @queue.pop(true)
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case action
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when :listen
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pg_conn.exec("LISTEN #{pg_conn.escape_identifier channel}")
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@event_loop.post(&callback) if callback
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when :unlisten
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pg_conn.exec("UNLISTEN #{pg_conn.escape_identifier channel}")
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when :shutdown
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throw :shutdown
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end
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end
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pg_conn.wait_for_notify(1) do |chan, pid, message|
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broadcast(chan, message)
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end
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end
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end
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end
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end
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def shutdown
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@queue.push([:shutdown])
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Thread.pass while @thread.alive?
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end
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def add_channel(channel, on_success)
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@queue.push([:listen, channel, on_success])
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end
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def remove_channel(channel)
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@queue.push([:unlisten, channel])
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end
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def invoke_callback(*)
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@event_loop.post { super }
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end
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end
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end
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end
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end
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