Class: Session::AbstractSession

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

Overview

class Command

Direct Known Subclasses

IDL, Sh

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ AbstractSession

instance methods

Raises:

  • (ArgumentError) 


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# File 'lib/session.rb', line 139

def initialize(*args)
  @opts = hashify(*args)

  @prog = getopt('prog', opts, getopt('program', opts, self.class::default_prog))

  raise(ArgumentError, "no program specified") unless @prog

  @track_history = nil
  @track_history = Session::track_history unless Session::track_history.nil?
  @track_history = self.class::track_history unless self.class::track_history.nil?
  @track_history = getopt('history', opts) if hasopt('history', opts) 
  @track_history = getopt('track_history', opts) if hasopt('track_history', opts) 

  @use_spawn = nil
  @use_spawn = Session::use_spawn unless Session::use_spawn.nil?
  @use_spawn = self.class::use_spawn unless self.class::use_spawn.nil?
  @use_spawn = getopt('use_spawn', opts) if hasopt('use_spawn', opts)

  if defined? JRUBY_VERSION
    @use_open3 = true
  else
    @use_open3 = nil
    @use_open3 = Session::use_open3 unless Session::use_open3.nil?
    @use_open3 = self.class::use_open3 unless self.class::use_open3.nil?
    @use_open3 = getopt('use_open3', opts) if hasopt('use_open3', opts)
  end

  @debug = nil
  @debug = Session::debug unless Session::debug.nil?
  @debug = self.class::debug unless self.class::debug.nil?
  @debug = getopt('debug', opts) if hasopt('debug', opts) 

  @history = nil
  @history = History::new if @track_history 

  @outproc = nil
  @errproc = nil

  @stdin, @stdout, @stderr =
    if @use_spawn
      Spawn::spawn @prog
    elsif @use_open3
      Open3::popen3 @prog
    else
      __popen3 @prog
    end

  @threads = []

  clear

  if block_given?
    ret = nil
    begin
      ret = yield self
    ensure
      self.close!
    end
    return ret
  end

  return self
end

Class Attribute Details

.debug ⇒ Object

Returns the value of attribute debug.



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# File 'lib/session.rb', line 106

def debug
  @debug
end

.track_history ⇒ Object

Returns the value of attribute track_history.



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# File 'lib/session.rb', line 103

def track_history
  @track_history
end

.use_open3 ⇒ Object

Returns the value of attribute use_open3.



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# File 'lib/session.rb', line 105

def use_open3
  @use_open3
end

.use_spawn ⇒ Object

Returns the value of attribute use_spawn.



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# File 'lib/session.rb', line 104

def use_spawn
  @use_spawn
end

Instance Attribute Details

#debug ⇒ Object Also known as: debug?

Returns the value of attribute debug.



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# File 'lib/session.rb', line 134

def debug
  @debug
end

#errproc ⇒ Object

Returns the value of attribute errproc.



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# File 'lib/session.rb', line 131

def errproc
  @errproc
end

#history ⇒ Object (readonly)

Returns the value of attribute history.



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# File 'lib/session.rb', line 128

def history
  @history
end

#opts ⇒ Object (readonly)

attributes



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# File 'lib/session.rb', line 120

def opts
  @opts
end

#outproc ⇒ Object

Returns the value of attribute outproc.



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# File 'lib/session.rb', line 130

def outproc
  @outproc
end

#prog ⇒ Object (readonly)

Returns the value of attribute prog.



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# File 'lib/session.rb', line 121

def prog
  @prog
end

#stderr ⇒ Object (readonly) Also known as: e

Returns the value of attribute stderr.



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# File 'lib/session.rb', line 126

def stderr
  @stderr
end

#stdin ⇒ Object (readonly) Also known as: i

Returns the value of attribute stdin.



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

def stdin
  @stdin
end

#stdout ⇒ Object (readonly) Also known as: o

Returns the value of attribute stdout.



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# File 'lib/session.rb', line 124

def stdout
  @stdout
end

#threads ⇒ Object (readonly)

Returns the value of attribute threads.



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# File 'lib/session.rb', line 136

def threads
  @threads
end

#track_history ⇒ Object

Returns the value of attribute track_history.



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# File 'lib/session.rb', line 129

def track_history
  @track_history
end

#use_open3 ⇒ Object (readonly)

Returns the value of attribute use_open3.



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# File 'lib/session.rb', line 133

def use_open3
  @use_open3
end

#use_spawn ⇒ Object (readonly)

Returns the value of attribute use_spawn.



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# File 'lib/session.rb', line 132

def use_spawn
  @use_spawn
end

Class Method Details

.default_prog ⇒ Object 



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# File 'lib/session.rb', line 91

def default_prog
  return @default_prog if defined? @default_prog and @default_prog
  if defined? self::DEFAULT_PROG
    return @default_prog = self::DEFAULT_PROG 
  else
    @default_prog = ENV["SESSION_#{ self }_PROG"]
  end
  nil
end

.default_prog=(prog) ⇒ Object 



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# File 'lib/session.rb', line 100

def default_prog= prog
  @default_prog = prog 
end

.init ⇒ Object 



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# File 'lib/session.rb', line 107

def init
  @track_history = nil
  @use_spawn = nil
  @use_open3 = nil
  @debug = nil
end

Instance Method Details

#__fork(*a, &b) ⇒ Object 



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# File 'lib/session.rb', line 259

def __fork(*a, &b)
  verbose = $VERBOSE
  begin
    $VERBOSE = nil 
    Kernel::fork(*a, &b)
  ensure
    $VERBOSE = verbose
  end
end

#__popen3(*cmd) ⇒ Object 



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# File 'lib/session.rb', line 220

def __popen3(*cmd)
  pw = IO::pipe   # pipe[0] for read, pipe[1] for write
  pr = IO::pipe
  pe = IO::pipe

  pid =
    __fork{
      # child
      pw[1].close
      STDIN.reopen(pw[0])
      pw[0].close

      pr[0].close
      STDOUT.reopen(pr[1])
      pr[1].close

      pe[0].close
      STDERR.reopen(pe[1])
      pe[1].close

      exec(*cmd)
    }

  Process::detach pid   # avoid zombies

  pw[0].close
  pr[1].close
  pe[1].close
  pi = [pw[1], pr[0], pe[0]]
  pw[1].sync = true
  if defined? yield
    begin
      return yield(*pi)
    ensure
      pi.each{|p| p.close unless p.closed?}
    end
  end
  pi
end

#clear ⇒ Object Also known as: flush

abstract methods

Raises:

  • (NotImplementedError) 


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# File 'lib/session.rb', line 270

def clear
  raise NotImplementedError
end

#close! ⇒ Object Also known as: close 



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# File 'lib/session.rb', line 294

def close!
  [stdin, stdout, stderr].each{|pipe| pipe.close}
  stdin, stdout, stderr = nil, nil, nil
  true
end

#execute(command, redirects = {}) ⇒ Object

Raises:



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# File 'lib/session.rb', line 304

def execute(command, redirects = {})
  $session_command = command if @debug

  raise(PipeError, command) unless ready? 

# clear buffers
  clear

# setup redirects
  rerr = redirects[:e] || redirects[:err] || redirects[:stderr] || 
         redirects['stderr'] || redirects['e'] || redirects['err'] ||
         redirects[2] || redirects['2']

  rout = redirects[:o] || redirects[:out] || redirects[:stdout] || 
         redirects['stdout'] || redirects['o'] || redirects['out'] ||
         redirects[1] || redirects['1']

# create cmd object and add to history
  cmd = Command::new command.to_s

# store cmd if tracking history
  history << cmd if track_history

# mutex for accessing shared data
  mutex = Mutex::new

# io data for stderr and stdout 
  err = {
    :io        => stderr,
    :cmd       => cmd.err,
    :name      => 'stderr',
    :begin     => false,
    :end       => false,
    :begin_pat => cmd.begin_err_pat,
    :end_pat   => cmd.end_err_pat,
    :redirect  => rerr,
    :proc      => errproc,
    :yield     => lambda{|buf| yield(nil, buf)},
    :mutex     => mutex,
  }
  out = {
    :io        => stdout,
    :cmd       => cmd.out,
    :name      => 'stdout',
    :begin     => false,
    :end       => false,
    :begin_pat => cmd.begin_out_pat,
    :end_pat   => cmd.end_out_pat,
    :redirect  => rout,
    :proc      => outproc,
    :yield     => lambda{|buf| yield(buf, nil)},
    :mutex     => mutex,
  }

begin
  # send command in the background so we can begin processing output
  # immediately - thanks to tanaka akira for this suggestion
    threads << Thread::new { send_command cmd }

  # init 
    main       = Thread::current
    exceptions = []

  # fire off reader threads
    [err, out].each do |iodat|
      threads <<
        Thread::new(iodat, main) do |iodat, main|

          loop do
            main.raise(PipeError, command) unless ready? 
            main.raise ExecutionError, iodat[:name] if iodat[:end] and not iodat[:begin]

            break if iodat[:end] or iodat[:io].eof?

            line = iodat[:io].gets

            # In case their are weird chars, this will avoid a "invalid byte sequence in US-ASCII" error
            line.force_encoding("binary") if line.respond_to? :force_encoding

            buf = nil

            case line
              when iodat[:end_pat]
                iodat[:end] = true
              # handle the special case of non-newline terminated output
                if((m = %r/(.+)__CMD/o.match(line)) and (pre = m[1]))
                  buf = pre
                end
              when iodat[:begin_pat]
                iodat[:begin] = true
              else
                next unless iodat[:begin] and not iodat[:end] # ignore chaff
                buf = line
            end

            if buf
              iodat[:mutex].synchronize do
                iodat[:cmd] << buf
                iodat[:redirect] << buf if iodat[:redirect]
                iodat[:proc].call buf  if iodat[:proc]
                iodat[:yield].call buf  if block_given?
              end
            end
          end

          true
      end
    end
  ensure
  # reap all threads - accumulating and rethrowing any exceptions
    begin
      while((t = threads.shift))
        t.join
        raise ExecutionError, 'iodat thread failure' unless t.value
      end
    rescue => e
      exceptions << e
      retry unless threads.empty?
    ensure
      unless exceptions.empty?
        meta_message = '<' << exceptions.map{|e| "#{ e.message } - (#{ e.class })"}.join('|') << '>'
        meta_backtrace = exceptions.map{|e| e.backtrace}.flatten
        raise ExecutionError, meta_message, meta_backtrace 
      end
    end
  end

# this should only happen if eof was reached before end pat
  [err, out].each do |iodat|
    raise ExecutionError, iodat[:name] unless iodat[:begin] and iodat[:end]
  end


# get the exit status
  get_status if respond_to? :get_status

  out = err = iodat = nil

  return [cmd.out, cmd.err]
end

#getopt(opt, hash, default = nil) ⇒ Object 



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# File 'lib/session.rb', line 202

def getopt opt, hash, default = nil
  key = opt
  return hash[key] if hash.has_key? key
  key = "#{ key }"
  return hash[key] if hash.has_key? key
  key = key.intern
  return hash[key] if hash.has_key? key
  return default
end

#hasopt(opt, hash) ⇒ Object 



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# File 'lib/session.rb', line 211

def hasopt opt, hash
  key = opt
  return key if hash.has_key? key
  key = "#{ key }"
  return key if hash.has_key? key
  key = key.intern
  return key if hash.has_key? key
  return false 
end

#path ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/session.rb', line 274

def path 
  raise NotImplementedError
end

#path= ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/session.rb', line 277

def path= 
  raise NotImplementedError
end

#ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/session.rb', line 289

def ready?
  (stdin and stdout and stderr) and
  (IO === stdin and IO === stdout and IO === stderr) and
  (not (stdin.closed? or stdout.closed? or stderr.closed?))
end

#send_command(cmd) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/session.rb', line 280

def send_command cmd
  raise NotImplementedError
end