module FFI

Public Class Methods

raise_windows_error(function, err = FFI.errno) click to toggle source

Raises a Windows specific error using SystemCallError that is based on the err provided, with the message prepended with the function name.

# File lib/ffi/win32/extensions.rb, line 100
def raise_windows_error(function, err = FFI.errno)
  raise SystemCallError.new(windows_error_message(function, err), err)
end

windows_error_message(function, err = FFI.errno) click to toggle source

Returns a Windows specific error message based on err prepended with the function name. Note that this does not actually raise an error, it only returns the message.

The message will always be English regardless of your locale.

# File lib/ffi/win32/extensions.rb, line 80
def windows_error_message(function, err = FFI.errno)
  error_message = ""

  # ARGUMENT_ARRAY + SYSTEM + MAX_WIDTH_MASK
  flags = 0x00001000 | 0x00000200 | 0x000000FF

  # 0x0409 = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US)
  # We use English for errors because Ruby uses English for errors.

  FFI::MemoryPointer.new(:char, 1024) do |buf|
    length = FormatMessage(flags, nil, err , 0x0409, buf, buf.size, nil)
    error_message = function + ": " + buf.read_string(length).strip
  end

  error_message
end

Private Instance Methods

raise_windows_error(function, err = FFI.errno) click to toggle source

Raises a Windows specific error using SystemCallError that is based on the err provided, with the message prepended with the function name.

# File lib/ffi/win32/extensions.rb, line 100
def raise_windows_error(function, err = FFI.errno)
  raise SystemCallError.new(windows_error_message(function, err), err)
end

windows_error_message(function, err = FFI.errno) click to toggle source

Returns a Windows specific error message based on err prepended with the function name. Note that this does not actually raise an error, it only returns the message.

The message will always be English regardless of your locale.

# File lib/ffi/win32/extensions.rb, line 80
def windows_error_message(function, err = FFI.errno)
  error_message = ""

  # ARGUMENT_ARRAY + SYSTEM + MAX_WIDTH_MASK
  flags = 0x00001000 | 0x00000200 | 0x000000FF

  # 0x0409 = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US)
  # We use English for errors because Ruby uses English for errors.

  FFI::MemoryPointer.new(:char, 1024) do |buf|
    length = FormatMessage(flags, nil, err , 0x0409, buf, buf.size, nil)
    error_message = function + ": " + buf.read_string(length).strip
  end

  error_message
end