Module: Hook

Included in:
Fastdfs::Client::Storage, Fastdfs::Client::Tracker
Defined in:
lib/fastdfs-client/hook.rb

Instance Method Summary collapse

Instance Method Details

#add_hook(where, meth_name, &callback) ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 16

def add_hook(where, meth_name, &callback)
  hooks[meth_name][where] << callback
  ensure_hijacked meth_name
end

#after(*meth_names, &callback) ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 6

def after(*meth_names, &callback)
  meth_names.each{|meth_name| add_hook :after, meth_name, &callback }
end

#before(*meth_names, &callback) ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 2

def before(*meth_names, &callback)
  meth_names.each{|meth_name| add_hook :before, meth_name, &callback }
end

#ensure_hijacked(meth_name) ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 25

def ensure_hijacked(meth_name)
  return if hooks[meth_name][:hijacked] || !instance_methods.include?(meth_name)
  meth = instance_method meth_name
  _hooks = hooks
  _hooks[meth_name][:hijacked] = true
  define_method meth_name do |*args, &block|
    _hooks[meth_name][:before].each do |callback|
      self.instance_exec(&callback)
    end
    return_value = meth.bind(self).call *args, &block
    _hooks[meth_name][:after].each do |callback|
      self.instance_exec(&callback)
    end
    return_value
  end
end

#hooks ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 10

def hooks
  @hooks ||= Hash.new do |hash, method_name|
    hash[method_name] = { before: [], after: [], hijacked: false }
  end
end

#method_added(meth_name) ⇒ Object 



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# File 'lib/fastdfs-client/hook.rb', line 21

def method_added(meth_name)
  ensure_hijacked meth_name if hooks.has_key? meth_name
end