Module: Aws::Crt::Native

Extended by:
FFI::Library
Defined in:
lib/aws-crt/native.rb

Overview

FFI Bindings to native CRT functions

Defined Under Namespace

Classes: CrtBuf, PropertyList

Class Method Summary collapse

Class Method Details

.array_to_native(array) ⇒ Object

Given a ruby array of strings, return a native array: char** and the FFI::MemoryPointers (these need to be pined for the length the native memory will be used to avoid GC)



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# File 'lib/aws-crt/native.rb', line 62

def self.array_to_native(array)
  native = FFI::MemoryPointer.new(:pointer, array.size)
  pointers = array.map do |s|
    FFI::MemoryPointer.from_string(s.to_s)
  end
  native.write_array_of_pointer(pointers)
  [native, pointers]
end

.attach_function(c_name, params, returns, options = {}) ⇒ Object

Extends FFI::attach_function

  1. Allows us to only supply the aws_crt C name and removes

    the aws_crt.

  2. Wraps the call in an error-raise checker (unless options

= false)

  1. Creates a bang method that does not do automatic error checking.



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# File 'lib/aws-crt/native.rb', line 78

def self.attach_function(c_name, params, returns, options = {})
  ruby_name = c_name.to_s.sub('aws_crt_', '').to_sym
  raise_errors = options.fetch(:raise, true)
  options.delete(:raise)
  unless raise_errors
    return super(ruby_name, c_name, params, returns, options)
  end

  bang_name = "#{ruby_name}!"
  no_raise_name = "#{ruby_name}_no_raise"

  super(no_raise_name, c_name, params, returns, options)
  alias_method(bang_name, no_raise_name)

  define_method(ruby_name) do |*args, &block|
    res = public_send(bang_name, *args, &block)
    # functions that return void cannot fail
    return unless res

    # for functions that return int, non-zero indicates failure
    Errors.raise_last_error if res.is_a?(Integer) && res != 0

    # for functions that return pointer, NULL indicates failure
    Errors.raise_last_error if res.is_a?(FFI::Pointer) && res.null?

    res
  end

  module_function ruby_name
  module_function bang_name
end

.hash_to_native_arrays(hash) ⇒ Object

Given a ruby hash (string -> string), return two native arrays: char** (:pointer) AND a list of all of the FFI::MemoryPointers that must be kept around to avoid GC



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# File 'lib/aws-crt/native.rb', line 53

def self.hash_to_native_arrays(hash)
  key_array, keys_p = array_to_native(hash.keys)
  value_array, values_p = array_to_native(hash.values)
  [key_array, value_array, keys_p + values_p]
end