Class: Ernie

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

Defined Under Namespace

Classes: Mod, ServerError

Constant Summary collapse

VERSION = 
self.version

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.auto_start ⇒ Object

Returns the value of attribute auto_start.



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# File 'lib/ernie.rb', line 8

def auto_start
  @auto_start
end

.count ⇒ Object

Returns the value of attribute count.



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# File 'lib/ernie.rb', line 9

def count
  @count
end

.current_mod ⇒ Object

Returns the value of attribute current_mod.



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# File 'lib/ernie.rb', line 7

def current_mod
  @current_mod
end

.log ⇒ Object

Returns the value of attribute log.



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# File 'lib/ernie.rb', line 7

def log
  @log
end

.mods ⇒ Object

Returns the value of attribute mods.



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# File 'lib/ernie.rb', line 7

def mods
  @mods
end

.virgin_procline ⇒ Object

Returns the value of attribute virgin_procline.



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# File 'lib/ernie.rb', line 9

def virgin_procline
  @virgin_procline
end

Class Method Details

.dispatch(mod, fun, args) ⇒ Object

Dispatch the request to the proper mod:fun.

+mod+ is the module Symbol
+fun+ is the function Symbol
+args+ is the Array of arguments

Returns the Ruby object response



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# File 'lib/ernie.rb', line 79

def self.dispatch(mod, fun, args)
  self.mods[mod] || raise(ServerError.new("No such module '#{mod}'"))
  self.mods[mod].funs[fun] || raise(ServerError.new("No such function '#{mod}:#{fun}'"))
  self.mods[mod].funs[fun].call(*args)
end

.expose(name, mixin) ⇒ Object

Expose all public methods in a Ruby module:

+name+ is the ernie module Symbol
+mixin+ is the ruby module whose public methods are exposed

Returns nothing



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# File 'lib/ernie.rb', line 46

def self.expose(name, mixin)
  context = Object.new
  context.extend mixin
  mod(name, lambda {
    mixin.public_instance_methods.each do |meth|
      fun(meth.to_sym, context.method(meth))
    end
  })
  context
end

.fun(name, block) ⇒ Object

Record a function.

+name+ is the function Symbol
+block+ is the Block to associate

Returns nothing



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# File 'lib/ernie.rb', line 37

def self.fun(name, block)
  self.current_mod.fun(name, block)
end

.logfile(file) ⇒ Object

Set the logfile to given path.

+file+ is the String path to the logfile

Returns nothing



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# File 'lib/ernie.rb', line 61

def self.logfile(file)
  self.log = Logger.new(file)
end

.loglevel(level) ⇒ Object

Set the log level.

+level+ is the Logger level (Logger::WARN, etc)

Returns nothing



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

def self.loglevel(level)
  self.log.level = level
end

.mod(name, block) ⇒ Object

Record a module.

+name+ is the module Symbol
+block+ is the Block containing function definitions

Returns nothing



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# File 'lib/ernie.rb', line 25

def self.mod(name, block)
  m = Mod.new(name)
  self.current_mod = m
  self.mods[name] = m
  block.call
end

.procline(msg) ⇒ Object 



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# File 'lib/ernie.rb', line 183

def self.procline(msg)
  $0 = "ernie handler #{VERSION} (ruby) - #{self.virgin_procline} - [#{self.count}] #{msg}"[0..159]
end

.read_4(input) ⇒ Object

Read the length header from the wire.

+input+ is the IO from which to read

Returns the size Integer if one was read Returns nil otherwise



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# File 'lib/ernie.rb', line 90

def self.read_4(input)
  raw = input.read(4)
  return nil unless raw
  raw.unpack('N').first
end

.read_berp(input) ⇒ Object

Read a BERP from the wire and decode it to a Ruby object.

+input+ is the IO from which to read

Returns a Ruby object if one could be read Returns nil otherwise



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# File 'lib/ernie.rb', line 101

def self.read_berp(input)
  packet_size = self.read_4(input)
  return nil unless packet_size
  bert = input.read(packet_size)
  BERT.decode(bert)
end

.start ⇒ Object

Start the processing loop.

Loops forever



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# File 'lib/ernie.rb', line 122

def self.start
  self.procline('starting')
  self.log.info("(#{Process.pid}) Starting")
  self.log.debug(self.mods.inspect)

  input = IO.new(3)
  output = IO.new(4)
  input.sync = true
  output.sync = true

  loop do
    self.procline('waiting')
    iruby = self.read_berp(input)
    self.count += 1

    unless iruby
      puts "Could not read BERP length header. Ernie server may have gone away. Exiting now."
      self.log.info("(#{Process.pid}) Could not read BERP length header. Ernie server may have gone away. Exiting now.")
      exit!
    end

    if iruby.size == 4 && iruby[0] == :call
      mod, fun, args = iruby[1..3]
      self.procline("#{mod}:#{fun}(#{args})")
      self.log.info("-> " + iruby.inspect)
      begin
        res = self.dispatch(mod, fun, args)
        oruby = t[:reply, res]
        self.log.debug("<- " + oruby.inspect)
        write_berp(output, oruby)
      rescue ServerError => e
        oruby = t[:error, t[:server, 0, e.class.to_s, e.message, e.backtrace]]
        self.log.error("<- " + oruby.inspect)
        self.log.error(e.backtrace.join("\n"))
        write_berp(output, oruby)
      rescue Object => e
        oruby = t[:error, t[:user, 0, e.class.to_s, e.message, e.backtrace]]
        self.log.error("<- " + oruby.inspect)
        self.log.error(e.backtrace.join("\n"))
        write_berp(output, oruby)
      end
    elsif iruby.size == 4 && iruby[0] == :cast
      mod, fun, args = iruby[1..3]
      self.procline("#{mod}:#{fun}(#{args})")
      self.log.info("-> " + [:cast, mod, fun, args].inspect)
      begin
        self.dispatch(mod, fun, args)
      rescue Object => e
        # ignore
      end
      write_berp(output, t[:noreply])
    else
      self.procline("invalid request")
      self.log.error("-> " + iruby.inspect)
      oruby = t[:error, t[:server, 0, "Invalid request: #{iruby.inspect}"]]
      self.log.error("<- " + oruby.inspect)
      write_berp(output, oruby)
    end
  end
end

.version ⇒ Object 



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# File 'lib/ernie.rb', line 187

def self.version
  yml = YAML.load(File.read(File.join(File.dirname(__FILE__), *%w[.. VERSION.yml])))
  "#{yml[:major]}.#{yml[:minor]}.#{yml[:patch]}"
rescue
  'unknown'
end

.write_berp(output, ruby) ⇒ Object

Write the given Ruby object to the wire as a BERP.

+output+ is the IO on which to write
+ruby+ is the Ruby object to encode

Returns nothing



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# File 'lib/ernie.rb', line 113

def self.write_berp(output, ruby)
  data = BERT.encode(ruby)
  output.write([data.length].pack("N"))
  output.write(data)
end