class Bundler::ConnectionPool::TimedStack

Examples:

ts = TimedStack.new(1) { MyConnection.new }

# fetch a connection
conn = ts.pop

# return a connection
ts.push conn

conn = ts.pop
ts.pop timeout: 5
#=> raises Bundler::ConnectionPool::TimeoutError after 5 seconds

Attributes

max[R]

Public Class Methods

new(size = 0, &block) click to toggle source

Creates a new pool with size connections that are created from the given block.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 27
def initialize(size = 0, &block)
  @create_block = block
  @created = 0
  @que = []
  @max = size
  @mutex = Thread::Mutex.new
  @resource = Thread::ConditionVariable.new
  @shutdown_block = nil
end

Public Instance Methods

<<(obj, options = {})
Alias for: push
empty?() click to toggle source

Returns true if there are no available connections.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 104
def empty?
  (@created - @que.length) >= @max
end
length() click to toggle source

The number of connections available on the stack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 111
def length
  @max - @created + @que.length
end
pop(timeout = 0.5, options = {}) click to toggle source

Retrieves a connection from the stack. If a connection is available it is immediately returned. If no connection is available within the given timeout a Bundler::ConnectionPool::TimeoutError is raised.

:timeout is the only checked entry in options and is preferred over the timeout argument (which will be removed in a future release). Other options may be used by subclasses that extend TimedStack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 63
def pop(timeout = 0.5, options = {})
  options, timeout = timeout, 0.5 if Hash === timeout
  timeout = options.fetch :timeout, timeout

  deadline = current_time + timeout
  @mutex.synchronize do
    loop do
      raise Bundler::ConnectionPool::PoolShuttingDownError if @shutdown_block
      return fetch_connection(options) if connection_stored?(options)

      connection = try_create(options)
      return connection if connection

      to_wait = deadline - current_time
      raise Bundler::ConnectionPool::TimeoutError, "Waited #{timeout} sec, #{length}/#{@max} available" if to_wait <= 0
      @resource.wait(@mutex, to_wait)
    end
  end
end
push(obj, options = {}) click to toggle source

Returns obj to the stack. options is ignored in TimedStack but may be used by subclasses that extend TimedStack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 41
def push(obj, options = {})
  @mutex.synchronize do
    if @shutdown_block
      @shutdown_block.call(obj)
    else
      store_connection obj, options
    end

    @resource.broadcast
  end
end
Also aliased as: <<
shutdown(reload: false, &block) click to toggle source

Shuts down the TimedStack by passing each connection to block and then removing it from the pool. Attempting to checkout a connection after shutdown will raise Bundler::ConnectionPool::PoolShuttingDownError unless :reload is true.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 89
def shutdown(reload: false, &block)
  raise ArgumentError, "shutdown must receive a block" unless block

  @mutex.synchronize do
    @shutdown_block = block
    @resource.broadcast

    shutdown_connections
    @shutdown_block = nil if reload
  end
end

Private Instance Methods

connection_stored?(options = nil) click to toggle source

This is an extension point for TimedStack and is called with a mutex.

This method must returns true if a connection is available on the stack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 126
def connection_stored?(options = nil)
  !@que.empty?
end
current_time() click to toggle source
# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 117
def current_time
  Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
fetch_connection(options = nil) click to toggle source

This is an extension point for TimedStack and is called with a mutex.

This method must return a connection from the stack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 135
def fetch_connection(options = nil)
  @que.pop
end
shutdown_connections(options = nil) click to toggle source

This is an extension point for TimedStack and is called with a mutex.

This method must shut down all connections on the stack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 144
def shutdown_connections(options = nil)
  while connection_stored?(options)
    conn = fetch_connection(options)
    @shutdown_block.call(conn)
  end
  @created = 0
end
store_connection(obj, options = nil) click to toggle source

This is an extension point for TimedStack and is called with a mutex.

This method must return obj to the stack.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 157
def store_connection(obj, options = nil)
  @que.push obj
end
try_create(options = nil) click to toggle source

This is an extension point for TimedStack and is called with a mutex.

This method must create a connection if and only if the total number of connections allowed has not been met.

# File bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb, line 167
def try_create(options = nil)
  unless @created == @max
    object = @create_block.call
    @created += 1
    object
  end
end