# This file is syntactic sugar for accessing the Ruby comedilib
# extension library generated by SWIG. The syntactic sugar is in
-# three forms:
+# four forms:
#
# (1) Method names without the 'comedi_' prefix. The Comedi module
# disambiguates the namespace.
# (3) A pre-defined IO object and an accessor method to simplify
# reading from the file descriptor associated with the comedi device.
# Data from comedi device dev can be accessed with dev.ios.read.
+#
+# (4) A ComediError exception class. If the underlying comedi
+# function returns an error indication, the ruby method will raise
+# ComediError.
require 'comedi.so'
include Comedi
-include SWIG
-
-module SWIG
-# TYPE_p_comedi_t is returned by Comedi::open
+# SWIG::TYPE_p_comedi_t is returned by Comedi::open
-class TYPE_p_comedi_t
+class SWIG::TYPE_p_comedi_t
# create an IO object to access the comedi_t fileno
def ios
- @ios = IO.new(fileno, 'r') if @ios.nil?
- @ios
+ def self.ios
+ @ios
+ end
+ @ios = IO.new(fileno, 'r')
end
end
+# ComediError is raised by methods whose underlying comedi functions return
+# indication of an error.
+
+class ComediError < SystemCallError
+
+ def initialize
+ @comedi_errno = Comedi::errno
+ end
+
+ attr_reader :comedi_errno
end
module Comedi
private
- # wrap_module_method defines Comedi module methods without the
- # unnecessary comedi_ prefix.
+ # wrap_method is the basis for wrap_module_method and
+ # wrap_instance_method.
- def wrap_module_method(mod, name)
- mod.module_eval <<-EOF
+ def wrap_method(mod, name, err, arglist)
+ wrap_def = %Q{
def #{name}(*args)
- comedi_#{name}(*args)
+ ret = comedi_#{name}(#{arglist})
+ }
+ unless err == :none
+ wrap_def << %Q{ raise ComediError.new if }
+ case err
+ when :neg
+ wrap_def << %Q{ ret < 0 }
+ when nil
+ wrap_def << %Q{ ret.nil? }
+ else
+ wrap_def << %Q{ ret == #{err} }
+ end
+ end
+ wrap_def << %Q{
+ ret
end
- EOF
+ }
+ mod.module_eval wrap_def
+ end
+
+ # wrap_module_method defines Comedi module methods without the
+ # unnecessary comedi_ prefix. The wrapped method raises
+ # ComediError if the return value equals a specified value.
+
+ def wrap_module_method(mod, name, err)
+ wrap_method(mod, name, err, '*args')
end
# wrap_instance_method defines instance methods for any of several
# classes. It removes the comedi_ prefix and allows use of an
- # explicit receiver.
+ # explicit receiver. The wrapped method raises ComediError
+ # if the return value equals a specified value.
- def wrap_instance_method(mod, name)
- mod.module_eval <<-EOF
- def #{name}(*args)
- comedi_#{name}(self, *args)
- end
- EOF
+ def wrap_instance_method(mod, name, err)
+ wrap_method(mod, name, err, 'self, *args')
end
- # Comedi module methods
+ # This struct holds information for methods with return class and
+ # error indication.
- %w{ open loglevel perror strerrno errno to_phys from_phys
- set_global_oor_behavior parse_calibration_file
- }.each do |name|
- wrap_module_method(Comedi, name)
- end
+ Method_group = Struct.new(:class, :err, :names)
- # Comedi_t_struct instance methods
-
- %w{ close fileno get_n_subdevices get_version_code
- get_driver_name get_board_name get_subdevice_type
- find_subdevice_by_type get_read_subdevice get_write_device
- get_subdevice_flags get_n_channels range_is_chan_specific
- maxdata_is_chan_specific get_maxdata get_n_ranges
- get_range find_range get_buffer size
- get_max_buffer_size set_buffer_size trigger
- do_insnlist do_insn lock unlock data_read
- data_read_delayed data_read_hint data_write dio_config
- dio_read dio_write dio_bitfield get_cmd_src_mask
- get_cmd_generic_timed cancel command command_test poll
- set_max_buffer_size get_buffer_contents
- mark_buffer_read get_buffer_offset apply_calibration
- apply_parsed_calibration get_default_calibration_path
- }.each do |name|
- wrap_instance_method(SWIG::TYPE_p_comedi_t, name)
- end
+ # Wrap Comedi module methods
- # Comedi_sv_t instance methods
+ [
+ # Comedi module methods that return nil on error.
- %w{ sv_init sv_update sv_measure
- }.each do |name|
- wrap_instance_method(Comedi_sv_t, name)
- end
+ Method_group.new(Comedi, nil, %w{
+ open
+ parse_calibration_file
+ }),
- # Comedi_calibration_t instance methods
+ # Comedi module methods that do not indicate errors.
+
+ Method_group.new(Comedi, :none, %w{
+ loglevel
+ perror
+ strerrno
+ errno
+ to_phys
+ from_phys
+ set_global_oor_behavior
+ }),
+ ].each do |d|
+ d.names.each do |n|
+ wrap_module_method(d.class, n, d.err)
+ end
+ end
- %w{ cleanup_calibration_file
- }.each do |name|
- wrap_instance_method(Comedi_calibration_t, name)
+ # Wrap Instance methods
+
+ [
+ # SWIG::TYPE_p_comedi_t methods that return -1 on error.
+
+ Method_group.new(SWIG::TYPE_p_comedi_t, -1, %w{
+ close
+ fileno
+ get_subdevice_type
+ find_subdevice_by_type
+ get_read_subdevice
+ get_write_device
+ get_subdevice_flags
+ get_n_channels
+ range_is_chan_specific
+ maxdata_is_chan_specific
+ get_n_ranges
+ find_range
+ get_buffer_size
+ get_max_buffer_size
+ set_buffer_size
+ trigger
+ do_insnlist
+ do_insn
+ lock
+ unlock
+ data_read
+ data_read_delayed
+ data_write
+ dio_config
+ dio_read
+ dio_write
+ dio_bitfield
+ get_cmd_src_mask
+ get_cmd_generic_timed
+ cancel
+ command
+ command_test
+ poll
+ set_max_buffer_size
+ get_buffer_contents
+ mark_buffer_read
+ get_buffer_offset
+ }),
+
+ # SWIG::TYPE_p_comedi_t methods that return 0 on error.
+
+ Method_group.new(SWIG::TYPE_p_comedi_t, 0, %w{
+ get_maxdata
+ }),
+
+ # SWIG::TYPE_p_comedi_t methods that return <0 on error.
+
+ Method_group.new(SWIG::TYPE_p_comedi_t, :neg, %w{
+ apply_calibration
+ apply_parsed_calibration
+ }),
+
+ # SWIG::TYPE_p_comedi_t methods that return nil on error.
+
+ Method_group.new(SWIG::TYPE_p_comedi_t, nil, %w{
+ get_driver_name
+ get_board_name
+ get_range
+ get_default_calibration_path
+ }),
+
+ # SWIG::TYPE_p_comedi_t methods that do not indicate errors.
+
+ Method_group.new(SWIG::TYPE_p_comedi_t, :none, %w{
+ get_n_subdevices
+ get_version_code
+ data_read_hint
+ }),
+
+ # Comedi_sv_t methods that return -1 on errors.
+
+ Method_group.new(Comedi_sv_t, -1, %w{
+ sv_init
+ sv_update
+ sv_measure
+ }),
+
+ # Comedi_calibration_t methods that do not indicate errors.
+
+ Method_group.new(Comedi_calibration_t, :none, %w{
+ cleanup_calibration_file
+ })
+ ].each do |d|
+ d.names.each do |n|
+ wrap_instance_method(d.class, n, d.err)
+ end
end
end
projects / comedilib.git / commitdiff