Class: VirtFS::VIO

Inherits:
Object
  • Object
show all
Includes:
IOInstanceDelegate
Defined in:
lib/virtfs/v_io.rb

Overview

VirtFS IO representation - implements the core Ruby IO methods, dispatching to underlying mounted VirtFS filesystems

Direct Known Subclasses

VFile

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io_obj) ⇒ VIO

VFile initializer

Parameters:

  • io_obj (VirtFS::FS::IO) —

    handle to filesystem specific io obj



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# File 'lib/virtfs/v_io.rb', line 14

def initialize(io_obj)
  __setobj__(io_obj)
end

Class Method Details

.binread(f, length = nil, offset = 0) ⇒ Array<Byte>

Read specified number of bytes from file

Parameters:

  • f (String) —

    file to ready

  • length (Integer) (defaults to: nil) —

    number of bytes to read

  • offset (Integer) (defaults to: 0) —

    position to start reading at

Returns:

  • (Array<Byte>) —

    bytes read from file (up to length size)



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# File 'lib/virtfs/v_io.rb', line 56

def binread(f, length = nil, offset = 0)
  VFile.open(f, "rb") do |fobj|
    fobj.pos = offset
    return fobj.read unless length
    return fobj.read(length)
  end
end

.copy_stream(from, to, max_length = nil, offset = 0) ⇒ Object

Copy stream from source to destination

Parameters:

  • from (String) —

    file stream to copy

  • to (String) —

    file stream to copy to

  • max_length (Integer) (defaults to: nil) —

    max number of bytes to copy

  • offset (Integer) (defaults to: 0) —

    position to start coying from



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# File 'lib/virtfs/v_io.rb', line 72

def copy_stream(from, to, max_length = nil, offset = 0) # rubocop:disable CyclomaticComplexity
  from_file = from.is_a?(VIO) ? from : VFile.open(from, "rb")
  to_file   = to.is_a?(VIO)   ? to   : VFile.open(to, "wb") # rubocop:disable SpaceAroundOperators
  return copy_from_to(from_file, to_file, max_length, offset)
ensure
  from_file.close unless from_file.nil? || from.is_a?(VIO)
  to_file.close   unless to_file.nil?   || to.is_a?(VIO)    # rubocop:disable SpaceAroundOperators
end

.foreach(portname, *args, &block) ⇒ Object

Invoke block for each file matching pattern

IO.foreach( portname, separator=$/ <, options> ) { | line | . . . } -> nil IO.foreach( portname, limit <, options> ) { | line | . . . } -> nil IO.foreach( portname, separator, limit <, options> ) { | line | . . . } -> nil



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# File 'lib/virtfs/v_io.rb', line 87

def foreach(portname, *args, &block)
  return VfsRealIO.foreach(portname, *args) unless filename?(portname)
  return to_enum(__method__, portname, *args) unless block_given?

  separator, limit, options = parse_args(args)

  VFile.open(portname, "r", options) do |fobj|
    fobj.each(separator, limit, &block)
  end
  nil
end

.new(integer_fd, mode = "r", hash_options = {}) ⇒ Object Also known as: for_fd

Instantiate IO instance.

Parameters:

  • integer_fd (Integer) —

    file descriptor

  • mode (String) (defaults to: "r") —

    mode to open IO instance

  • hash_options (defaults to: {}) —

    options to forward to IO initialiezr



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# File 'lib/virtfs/v_io.rb', line 145

def new(integer_fd, mode = "r", hash_options = {})
  #
  # Directly instantiating an IO instance (not through File)
  # will return a standard IO object.
  #
  fs_obj = VfsRealIO.new(integer_fd, mode, hash_options)
  obj = allocate
  obj.send(:initialize, fs_obj)
  obj
end

.open(*args) ⇒ Object

Open IO Instance and invoke block w/ it before closing

See Also:

  • #new


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# File 'lib/virtfs/v_io.rb', line 160

def open(*args)
  io_obj = new(*args) # IO.new or File.new
  return io_obj unless block_given?
  begin
    return yield(io_obj)
  ensure
    io_obj.close
  end
end

.pipe(*args, &block) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 99

def pipe(*args, &block)
  # XXX - should wrap VfsRealIO objects in common delegator class
  # so is_a? and kind_of? will work with all IO objects.
  VfsRealIO.pipe(*args, &block) # TODO: wrap returned read and write IO
end

.popen(*args, &block) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 105

def popen(*args, &block)
  VfsRealIO.popen(*args, &block) # TODO: wrap returned IO
end

.read(portname, *args) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 109

def read(portname, *args)
  return VfsRealIO.read(portname, *args) unless filename?(portname)

  length, offset, options = length_offset_options(args)

  VFile.open(portname, "r", options) do |fobj|
    fobj.pos = offset
    return fobj.read unless length
    return fobj.read(length)
  end
end

.readlines(portname, *args) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 121

def readlines(portname, *args)
  return VfsRealIO.readlines(portname, *args) unless filename?(portname)
  foreach(portname, *args).to_a
end

.select(*args) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 126

def select(*args)
  VfsRealIO.select(*args)
end

.sysopen(*args) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 130

def sysopen(*args)
  VfsRealIO.sysopen(*args)
end

.try_convert(obj) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 134

def try_convert(obj)
  return nil unless obj.respond_to?(:to_io)
  obj.to_io # TODO: wrap?
end

Instance Method Details

#<<(obj) ⇒ Object

Some methods need to return the IO object. Methods in the delegator object can’t do that, so we intercept them and do it here.



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# File 'lib/virtfs/v_io.rb', line 23

def <<(obj)
  super
  self
end

#binmode ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 28

def binmode
  super
  self
end

#reopen(*args) ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 33

def reopen(*args)
  __setobj__(super)
  self
end

#set_encoding(*args) ⇒ Object

rubocop:disable Style/AccessorMethodName



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# File 'lib/virtfs/v_io.rb', line 38

def set_encoding(*args) # rubocop:disable Style/AccessorMethodName
  super
  self
end

#to_io ⇒ Object 



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# File 'lib/virtfs/v_io.rb', line 43

def to_io
  self
end