Class: Rust::RubyWrapperGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/rust_require/ruby_wrapper_generator.rb

Overview

This class generates Ruby wrappers for a dylib with information from an info.json file and a ruby Module (or Class) Object

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#rust_lib=(value) ⇒ Object (writeonly)

@rust_lib: path to the rust lib to be included (String)



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 12

def rust_lib=(value)
  @rust_lib = value
end

Instance Method Details

#attach_fns(fn_headers, mod, mod_string) ⇒ Object

attaches fns via FFI to mod



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 35

def attach_fns(fn_headers, mod, mod_string)
  # add ffi and the rust lib to mod
  mod.extend FFI::Library
  mod.ffi_lib @rust_lib

  fn_headers.each do |fn|
    rust_fn_name = fn['name']

    # fn mod::fn() => fn _mod_fn_wrapper
    wrapper_name = "_#{mod_string+fn['name']}_wrapper".to_sym

    input_types = fn['inputs'].map { |t| Rust::Types.find_type(t) }
    ffi_input_types = input_types.map { |t| t.ffi_input_type }


    output_type = Rust::Types.find_type(fn['output'])
    ffi_output_type = output_type.ffi_output_type

    # attach fn and define ruby wrapper
    mod.attach_function wrapper_name, ffi_input_types, ffi_output_type
    mod.instance_eval do
      define_method(rust_fn_name) do |*args|
        # check input parameter count
        raise ArgumentError, "wrong number of arguments (#{args.count} for #{input_types.count})" unless args.count == input_types.count

        # check & convert ruby objects before handling them to FFI
        args.map!.with_index do |arg,i|
          input_types[i].ruby_input_conversion(arg)
        end

        # call FFI function and convert output
        raw_output = send wrapper_name, *args
        output_type.ruby_output_conversion raw_output
      end
    end
  end
end

#attach_items(rust_module, mod, mod_string) ⇒ Object

attaches items to mod, mod_string is the mod’s prefix eg ‘mod_submod_’



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 23

def attach_items(rust_module, mod, mod_string)
  rust_module['submodules'].each do |x|
    rust_mod = Module.new
    attach_items(x, rust_mod, mod_string+x['name']+'_')
    mod.const_set(x['name'].camelize, rust_mod)
  end

  attach_fns(rust_module['fn_headers'], mod, mod_string)
  attach_structs(rust_module['structs'], mod)
end

#attach_structs(struct_defs, mod) ⇒ Object

attaches structs via FFI to mod



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 74

def attach_structs(struct_defs, mod)
  struct_defs.each do |s|
    fields = s['fields'].map do |name, type|
      type = Rust::Types.find_type(type)
      [name.to_sym, type.ffi_output_type]
    end.flatten

    struct = Class.new(FFI::Struct)
    struct.layout *fields

    mod.const_set(s['name'], struct)
  end
end

#include_lib(mod) ⇒ Object

makes items from lib available in mod mod: Module/Class into which the wrappers should get included (Module || Class)



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 16

def include_lib(mod)
  # attach items according to @info_file
  attach_items(@info_file, mod, '')
end

#info_file=(info_file) ⇒ Object

@info_file: info.json file, parsed with JSON



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# File 'lib/rust_require/ruby_wrapper_generator.rb', line 7

def info_file=(info_file)
  @info_file = info_file
end