Class: Ruby_process::Cproxy

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby_process_cproxy.rb

Overview

This class is used to seamlessly use leaky classes without working through ‘Ruby_process’.

Examples

Ruby_process::Cproxy.run do |data|
  data[:subproc].static(:Object, :require, "rubygems")
  data[:subproc].static(:Object, :require, "rexml/document")

  doc = Ruby_process::Cproxy::REXML::Document.new("test")
  strio = StringIO.new
  doc.write(strio)
  puts strio.string #=> "<test/>"
  raise "REXML shouldnt be defined?" if Kernel.const_defined?(:REXML)

Constant Summary collapse

@@lock =

Lock is used to to create new Ruby-process-instances and not doing double-counts.

Mutex.new
@@instances =

Counts how many instances are using the Cproxy-module. This way it can be safely unset once no-body is using it again.

0
@@subproc =

This variable will hold the ‘Ruby_process’-object where sub-objects will be created.

nil

Class Method Summary collapse

Class Method Details

.const_missing(name) ⇒ Object

Creates the new constant under the ‘Ruby_process::Cproxy’-namespace.



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# File 'lib/ruby_process_cproxy.rb', line 76

def self.const_missing(name)
  Ruby_process::Cproxy.load_class(self, name) if !self.const_defined?(name)
  raise "Still not created on const: '#{name}'." if !self.const_defined?(name)
  return self.const_get(name)
end

.destroy_loaded_constants ⇒ Object

Destroy all loaded sub-process-constants.



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# File 'lib/ruby_process_cproxy.rb', line 69

def self.destroy_loaded_constants
  self.constants.each do |constant|
    self.__send__(:remove_const, constant)
  end
end

.load_class(const, name) ⇒ Object

Loads a new class to the given constants namespace for recursive creating of missing classes.



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# File 'lib/ruby_process_cproxy.rb', line 83

def self.load_class(const, name)
  const.const_set(name, Class.new{
    #Use 'const_missing' to auto-create missing sub-constants recursivly.
    def self.const_missing(name)
      Ruby_process::Cproxy.load_class(self, name) if !self.const_defined?(name)
      raise "Still not created on const: '#{name}'." if !self.const_defined?(name)
      return self.const_get(name)
    end
    
    #Manipulate 'new'-method return proxy-objects instead of real objects.
    def self.new(*args, &blk)
      name_match = self.name.to_s.match(/^Ruby_process::Cproxy::(.+)$/)
      class_name = name_match[1]
      return Ruby_process::Cproxy.subproc.new(class_name, *args, &blk)
    end
    
    def self.method_missing(method_name, *args, &blk)
      name_match = self.name.to_s.match(/^Ruby_process::Cproxy::(.+)$/)
      class_name = name_match[1]
      return Ruby_process::Cproxy.subproc.static(class_name, method_name, *args, &blk)
    end
  })
end

.run ⇒ Object

All use should go through this method to automatically destroy sub-processes and keep track of ressources.



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# File 'lib/ruby_process_cproxy.rb', line 23

def self.run
  #Increase count of instances that are using Cproxy and set the subproc-object if not already set.
  @@lock.synchronize do
    #Check if the sub-process is alive.
    if @@subproc and (!@@subproc.alive? or @@subproc.destroyed?)
      raise "Cant destroy sub-process because instances are running: '#{@@instances}'." if @@instances > 0
      @@subproc.destroy
      @@subproc = nil
    end
    
    #Start a new subprocess if none is defined and active.
    if !@@subproc
      subproc = Ruby_process.new(:title => "ruby_process_cproxy", :debug => false)
      subproc.spawn_process
      @@subproc = subproc
    end
    
    @@instances += 1
  end
  
  begin
    yield(:subproc => @@subproc)
    raise "'run'-caller destroyed sub-process. This shouldn't happen." if @@subproc.destroyed?
  ensure
    @@lock.synchronize do
      @@instances -= 1
      
      if @@instances <= 0
        begin
          @@subproc.destroy
        ensure
          @@subproc = nil
          self.destroy_loaded_constants
        end
      end
    end
  end
end

.subproc ⇒ Object

Returns the ‘Ruby_process’-object or raises an error if it has not been set.



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# File 'lib/ruby_process_cproxy.rb', line 63

def self.subproc
  raise "CProxy process not set for some reason?" if !@@subproc
  return @@subproc
end