Class: LongPolling

Inherits:

Object

• Object
• LongPolling

show all

Defined in:

backend/app/lib/longpolling.rb

Instance Method Summary (collapse)

• - (Object) blocking_updates_since(seq)
• - (LongPolling) initialize(ms_to_keep) constructor

  A new instance of LongPolling.

• - (Object) record_update(values)
• - (Object) reset!
• - (Object) shutdown
• - (Object) updates_since(seq)

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# File 'backend/app/lib/longpolling.rb', line 5

def initialize(ms_to_keep)
  @lock = Mutex.new
  @waiting_list = ConditionVariable.new
  @sequence = Time.now.to_i
  @updates = []
  @ms_to_keep = ms_to_keep
end

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# File 'backend/app/lib/longpolling.rb', line 49

def blocking_updates_since(seq)
  @lock.synchronize do
    updates = updates_after(seq)

    if updates.empty?
      # Block until an update wakes us up (or until we time out)
      @waiting_list.wait(@lock, @ms_to_keep / 1000.0)
      updates_after(seq)
    else
      updates
    end
  end
end

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# File 'backend/app/lib/longpolling.rb', line 27

def record_update(values)
  @lock.synchronize do
    @sequence += 1
    now = (Time.now.to_f * 1000).to_i
    @updates << values.merge(:sequence => @sequence,
                             :timestamp => now)

    expire_older_than(now - @ms_to_keep)

    # Wake up any threads waiting for updates
    @waiting_list.broadcast
  end
end

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# File 'backend/app/lib/longpolling.rb', line 20

def reset!
  @lock.synchronize do
    @updates = []
  end
end

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# File 'backend/app/lib/longpolling.rb', line 14

def shutdown
  @lock.synchronize do
    @waiting_list.broadcast
  end
end

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# File 'backend/app/lib/longpolling.rb', line 42

def updates_since(seq)
  @lock.synchronize do
    updates_after(seq)
  end
end