Class: Async::HTTP::Pool

Inherits:
Object
  • Object
show all
Defined in:
lib/async/http/pool.rb

Overview

Pool behaviours

  • Single request per connection (HTTP/1 without keep-alive)

  • Multiple sequential requests per connection (HTTP1 with keep-alive)

  • Multiplex requests per connection (HTTP2)

In general we don’t know the policy until connection is established.

This pool doesn’t impose a maximum number of open resources, but it WILL block if there are no available resources and trying to allocate another one fails.

Resources must respond to #multiplex -> 1 or more. #reusable? -> can be used again.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(limit = nil, &block) ⇒ Pool

Returns a new instance of Pool.



41
42
43
44
45
46
47
48
49
 
# File 'lib/async/http/pool.rb', line 41

def initialize(limit = nil, &block)
	@resources = {} # resource => count
	@available = Async::Notification.new
	
	@limit = limit
	
	@constructor = block
	@guard = Async::Semaphore.new(1)
end

Instance Attribute Details

#resources ⇒ Object (readonly)

All allocated resources.



71
72
73
 
# File 'lib/async/http/pool.rb', line 71

def resources
  @resources
end

Instance Method Details

#acquire ⇒ Object 



77
78
79
80
81
82
83
84
85
86
87
 
# File 'lib/async/http/pool.rb', line 77

def acquire
	resource = wait_for_resource
	
	return resource unless block_given?
	
	begin
		yield resource
	ensure
		release(resource)
	end
end

#active ⇒ Object

The number of allocated resources.



52
53
54
 
# File 'lib/async/http/pool.rb', line 52

def active
	@resources.count
end

#busy? ⇒ Boolean

Whether there are resources which are currently in use.

Returns:

  • (Boolean) 


57
58
59
60
61
62
63
 
# File 'lib/async/http/pool.rb', line 57

def busy?
	@resources.collect do |_, usage|
		return true if usage > 0
	end
	
	return false
end

#close ⇒ Object 



99
100
101
102
 
# File 'lib/async/http/pool.rb', line 99

def close
	@resources.each_key(&:close)
	@resources.clear
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


73
74
75
 
# File 'lib/async/http/pool.rb', line 73

def empty?
	@resources.empty?
end

#release(resource) ⇒ Object

Make the resource resources and let waiting tasks know that there is something resources.



90
91
92
93
94
95
96
97
 
# File 'lib/async/http/pool.rb', line 90

def release(resource)
	# A resource that is not good should also not be reusable.
	if resource.reusable?
		reuse(resource)
	else
		retire(resource)
	end
end

#to_s ⇒ Object 



104
105
106
 
# File 'lib/async/http/pool.rb', line 104

def to_s
	"\#<#{self.class} resources=#{availability_string} limit=#{@limit.inspect}>"
end

#wait ⇒ Object

Wait until a pool resource has been freed.



66
67
68
 
# File 'lib/async/http/pool.rb', line 66

def wait
	@available.wait
end