Class: WatchedProcess

Inherits:
Object
  • Object
show all
Defined in:
lib/stream2tracks/process.rb

Overview

A WatchedProcess is a process producing output which can be watched to indicate progress so far and validate output.

  • It supports these behaviours with the following callbacks:

    progress[@buffer] => [current,total]
validate[@buffer] => true when download is complete and successful
- validate may raise if an unrecoverable error occurs before the
  process is complete

Defined Under Namespace

Classes: Status

Constant Summary collapse

MAX_READ_LEN =

completely arbitrary

1024

Instance Method Summary collapse

Constructor Details

#initialize(cmd, env = {}) {|_self| ... } ⇒ WatchedProcess

Returns a new instance of WatchedProcess.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/stream2tracks/process.rb', line 60

def initialize cmd,env={}
	@out,out_write=IO.pipe
	@cmd=cmd
	@pid=spawn env,@cmd,:in=>:close,:out=>out_write,:err=>[:child,:out]
	out_write.close
	yield self if block_given?
end

Instance Method Details

#watch(options) ⇒ Object 



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# File 'lib/stream2tracks/process.rb', line 68

def watch options
	progress,validate=options.progress,options.validate
	@buffer||=''
	output=@out.readpartial MAX_READ_LEN rescue EOFError
	@buffer << output if output
	$stderr.print output if options.debug and output
	current,total=progress[@buffer] if progress
	eof=@out.eof?
	valid=validate[@buffer] if validate
	Status.new eof,valid,current,total
end