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| author | Benjamin Sanders <ben@Benjamins-MacBook-Pro.local> | 2025-10-11 10:34:24 -0400 |
|---|---|---|
| committer | Benjamin Sanders <ben@Benjamins-MacBook-Pro.local> | 2025-10-11 10:34:24 -0400 |
| commit | 5571dc766e2143e39762ff0b47c41d1c2e154f4c (patch) | |
| tree | f4f124d314a7e76c04484515aa0fd1f2e271a601 /vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb | |
| parent | 359f3309c97fc894b63e0a295c76ab298504d635 (diff) | |
Vendor bundled gems for deployment
Diffstat (limited to 'vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb')
| -rw-r--r-- | vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb b/vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb new file mode 100644 index 0000000..926535f --- /dev/null +++ b/vendor/bundle/ruby/3.4.0/gems/eventmachine-1.2.7/lib/em/completion.rb @@ -0,0 +1,304 @@ +# = EM::Completion +# +# A completion is a callback container for various states of completion. In +# its most basic form it has a start state and a finish state. +# +# This implementation includes some hold-back from the EM::Deferrable +# interface in order to be compatible - but it has a much cleaner +# implementation. +# +# In general it is preferred that this implementation be used as a state +# callback container than EM::DefaultDeferrable or other classes including +# EM::Deferrable. This is because it is generally more sane to keep this level +# of state in a dedicated state-back container. This generally leads to more +# malleable interfaces and software designs, as well as eradicating nasty bugs +# that result from abstraction leakage. +# +# == Basic Usage +# +# As already mentioned, the basic usage of a Completion is simply for its two +# final states, :succeeded and :failed. +# +# An asynchronous operation will complete at some future point in time, and +# users often want to react to this event. API authors will want to expose +# some common interface to react to these events. +# +# In the following example, the user wants to know when a short lived +# connection has completed its exchange with the remote server. The simple +# protocol just waits for an ack to its message. +# +# class Protocol < EM::Connection +# include EM::P::LineText2 +# +# def initialize(message, completion) +# @message, @completion = message, completion +# @completion.completion { close_connection } +# @completion.timeout(1, :timeout) +# end +# +# def post_init +# send_data(@message) +# end +# +# def receive_line(line) +# case line +# when /ACK/i +# @completion.succeed line +# when /ERR/i +# @completion.fail :error, line +# else +# @completion.fail :unknown, line +# end +# end +# +# def unbind +# @completion.fail :disconnected unless @completion.completed? +# end +# end +# +# class API +# attr_reader :host, :port +# +# def initialize(host = 'example.org', port = 8000) +# @host, @port = host, port +# end +# +# def request(message) +# completion = EM::Deferrable::Completion.new +# EM.connect(host, port, Protocol, message, completion) +# completion +# end +# end +# +# api = API.new +# completion = api.request('stuff') +# completion.callback do |line| +# puts "API responded with: #{line}" +# end +# completion.errback do |type, line| +# case type +# when :error +# puts "API error: #{line}" +# when :unknown +# puts "API returned unknown response: #{line}" +# when :disconnected +# puts "API server disconnected prematurely" +# when :timeout +# puts "API server did not respond in a timely fashion" +# end +# end +# +# == Advanced Usage +# +# This completion implementation also supports more state callbacks and +# arbitrary states (unlike the original Deferrable API). This allows for basic +# stateful process encapsulation. One might use this to setup state callbacks +# for various states in an exchange like in the basic usage example, except +# where the applicaiton could be made to react to "connected" and +# "disconnected" states additionally. +# +# class Protocol < EM::Connection +# def initialize(completion) +# @response = [] +# @completion = completion +# @completion.stateback(:disconnected) do +# @completion.succeed @response.join +# end +# end +# +# def connection_completed +# @host, @port = Socket.unpack_sockaddr_in get_peername +# @completion.change_state(:connected, @host, @port) +# send_data("GET http://example.org/ HTTP/1.0\r\n\r\n") +# end +# +# def receive_data(data) +# @response << data +# end +# +# def unbind +# @completion.change_state(:disconnected, @host, @port) +# end +# end +# +# completion = EM::Deferrable::Completion.new +# completion.stateback(:connected) do |host, port| +# puts "Connected to #{host}:#{port}" +# end +# completion.stateback(:disconnected) do |host, port| +# puts "Disconnected from #{host}:#{port}" +# end +# completion.callback do |response| +# puts response +# end +# +# EM.connect('example.org', 80, Protocol, completion) +# +# == Timeout +# +# The Completion also has a timeout. The timeout is global and is not aware of +# states apart from completion states. The timeout is only engaged if #timeout +# is called, and it will call fail if it is reached. +# +# == Completion states +# +# By default there are two completion states, :succeeded and :failed. These +# states can be modified by subclassing and overrding the #completion_states +# method. Completion states are special, in that callbacks for all completion +# states are explcitly cleared when a completion state is entered. This +# prevents errors that could arise from accidental unterminated timeouts, and +# other such user errors. +# +# == Other notes +# +# Several APIs have been carried over from EM::Deferrable for compatibility +# reasons during a transitionary period. Specifically cancel_errback and +# cancel_callback are implemented, but their usage is to be strongly +# discouraged. Due to the already complex nature of reaction systems, dynamic +# callback deletion only makes the problem much worse. It is always better to +# add correct conditionals to the callback code, or use more states, than to +# address such implementaiton issues with conditional callbacks. + +module EventMachine + + class Completion + # This is totally not used (re-implemented), it's here in case people check + # for kind_of? + include EventMachine::Deferrable + + attr_reader :state, :value + + def initialize + @state = :unknown + @callbacks = Hash.new { |h,k| h[k] = [] } + @value = [] + @timeout_timer = nil + end + + # Enter the :succeeded state, setting the result value if given. + def succeed(*args) + change_state(:succeeded, *args) + end + # The old EM method: + alias set_deferred_success succeed + + # Enter the :failed state, setting the result value if given. + def fail(*args) + change_state(:failed, *args) + end + # The old EM method: + alias set_deferred_failure fail + + # Statebacks are called when you enter (or are in) the named state. + def stateback(state, *a, &b) + # The following is quite unfortunate special casing for :completed + # statebacks, but it's a necessary evil for latent completion + # definitions. + + if :completed == state || !completed? || @state == state + @callbacks[state] << EM::Callback(*a, &b) + end + execute_callbacks + self + end + + # Callbacks are called when you enter (or are in) a :succeeded state. + def callback(*a, &b) + stateback(:succeeded, *a, &b) + end + + # Errbacks are called when you enter (or are in) a :failed state. + def errback(*a, &b) + stateback(:failed, *a, &b) + end + + # Completions are called when you enter (or are in) either a :failed or a + # :succeeded state. They are stored as a special (reserved) state called + # :completed. + def completion(*a, &b) + stateback(:completed, *a, &b) + end + + # Enter a new state, setting the result value if given. If the state is one + # of :succeeded or :failed, then :completed callbacks will also be called. + def change_state(state, *args) + @value = args + @state = state + + EM.schedule { execute_callbacks } + end + + # The old EM method: + alias set_deferred_status change_state + + # Indicates that we've reached some kind of completion state, by default + # this is :succeeded or :failed. Due to these semantics, the :completed + # state is reserved for internal use. + def completed? + completion_states.any? { |s| state == s } + end + + # Completion states simply returns a list of completion states, by default + # this is :succeeded and :failed. + def completion_states + [:succeeded, :failed] + end + + # Schedule a time which if passes before we enter a completion state, this + # deferrable will be failed with the given arguments. + def timeout(time, *args) + cancel_timeout + @timeout_timer = EM::Timer.new(time) do + fail(*args) unless completed? + end + end + + # Disable the timeout + def cancel_timeout + if @timeout_timer + @timeout_timer.cancel + @timeout_timer = nil + end + end + + # Remove an errback. N.B. Some errbacks cannot be deleted. Usage is NOT + # recommended, this is an anti-pattern. + def cancel_errback(*a, &b) + @callbacks[:failed].delete(EM::Callback(*a, &b)) + end + + # Remove a callback. N.B. Some callbacks cannot be deleted. Usage is NOT + # recommended, this is an anti-pattern. + def cancel_callback(*a, &b) + @callbacks[:succeeded].delete(EM::Callback(*a, &b)) + end + + private + # Execute all callbacks for the current state. If in a completed state, then + # call any statebacks associated with the completed state. + def execute_callbacks + execute_state_callbacks(state) + if completed? + execute_state_callbacks(:completed) + clear_dead_callbacks + cancel_timeout + end + end + + # Iterate all callbacks for a given state, and remove then call them. + def execute_state_callbacks(state) + while callback = @callbacks[state].shift + callback.call(*value) + end + end + + # If we enter a completion state, clear other completion states after all + # callback chains are completed. This means that operation specific + # callbacks can't be dual-called, which is most common user error. + def clear_dead_callbacks + completion_states.each do |state| + @callbacks[state].clear + end + end + end +end |
