Class: HaveAPI::Fs::Components::RemoteControlFile

Inherits:
File show all
Defined in:
lib/haveapi/fs/components/remote_control_file.rb

Overview

This file serves as an IPC between the file system and outer processes, mainly executables from the file system itself.

It does not behave like a regular file, it's more like a local socket. The process opens the file, writes a message with a command and then reads a message with a response.

Messages are formatted in YAML and separated by MSG_DELIMITER.

Defined Under Namespace

Classes: FileHandle

Constant Summary collapse

MSG_DELIMITER = 
"\nMSG_OVER\n"

Instance Attribute Summary

Attributes inherited from HaveAPI::Fs::Component

#atime, #context, #ctime, #mtime

Instance Method Summary collapse

Methods inherited from File

#file?, #read, #write

Methods inherited from HaveAPI::Fs::Component

#abspath, #bound=, #bound?, children_reader, component, #contents, #directory?, #executable?, #file?, #find, inherited, #initialize, #invalid?, #invalidate, #parent, #path, #readable?, #reset, #setup, #times, #title, #unsaved?, #use

Constructor Details

This class inherits a constructor from HaveAPI::Fs::Component

Instance Method Details

#raw_close(path, handle = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 88

def raw_close(path, handle = nil)
  nil
end

#raw_open(path, mode, rfusefs = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 52

def raw_open(path, mode, rfusefs = nil)
  FileHandle.new
end

#raw_read(path, offset, size, handle = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 56

def raw_read(path, offset, size, handle = nil)
  handle.read(offset, size)
end

#raw_sync(path, datasync, handle = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 80

def raw_sync(path, datasync, handle = nil)
  nil
end

#raw_truncate(path, offset, handle = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 84

def raw_truncate(path, offset, handle = nil)
  true
end

#raw_write(path, offset, size, buf, handle = nil) ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 60

def raw_write(path, offset, size, buf, handle = nil)
  handle.write(offset, size, buf)

  if handle.complete?
    cmd = handle.parse

    case cmd[:action]
    when :execute
      ret = HaveAPI::Fs::RemoteControl.execute(context, cmd[:path])

    else
      raise Errno::EIO, "unsupported action '#{cmd[:action]}'"
    end

    handle.read_buf = YAML.dump(ret)
  end

  size
end

#size ⇒ Object 



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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 47

def size
  # The size limits the maximum amount of data that can be read from this file
  4096
end

#writable? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/haveapi/fs/components/remote_control_file.rb', line 43

def writable?
  true
end