RubyのMemoryView入門（５）

前

要素数を176000で固定してハードコードしているから動的な、というのはちょっと変だけど、ファイルから読み込むことで予め値が分からないという意味で動的。

code:ext/learning_memory_view/learning_memory_view.c

VALUE cShortArray;

static VALUE

short_array_initialize(VALUE self, VALUE audio_path)

{

rb_iv_set(self, "audio_path", audio_path);

return Qnil;

}

static bool

short_array_get_memory_view(const VALUE obj, rb_memory_view_t *view, int flags)

{

VALUE rb_audio_path = rb_iv_get(obj, "audio_path");

const char *audio_path = StringValueCStr(rb_audio_path);

const int n_samples = 176000;

FILE *fp = fopen(audio_path, "rb");

if (fp == NULL) {

rb_raise(rb_eRuntimeError, "failed to open file");

}

fseek(fp, 0, SEEK_SET);

const unsigned long read_size = fread(samples, sizeof(short), n_samples, fp);

if (read_size != n_samples) {

fclose(fp);

rb_raise(rb_eRuntimeError, "failed to read file");

}

fclose(fp);

view->obj = obj;

view->data = samples;

view->byte_size = sizeof(samples);

view->readonly = true;

view->format = "s";

view->item_size = sizeof(short);

view->item_desc.components = NULL;

view->item_desc.length = 0;

view->ndim = 1;

view->shape = NULL;

view->sub_offsets = NULL;

view->private_data = NULL;

return true;

}

static bool

short_array_release_memory_view(const VALUE obj, rb_memory_view_t *view)

{

return true;

}

static bool

short_array_memory_view_available_p(const VALUE obj)

{

return true;

}

static const rb_memory_view_entry_t short_array_view_entry = {

short_array_get_memory_view,

short_array_release_memory_view,

short_array_memory_view_available_p

};

void

Init_learning_memory_view(void)

{

VALUE mod = rb_define_module("LearningMemoryView");

cShortArray = rb_define_class_under(mod, "ShortArray", rb_cObject);

rb_memory_view_register(cShortArray, &short_array_view_entry);

rb_define_method(cShortArray, "initialize", short_array_initialize, 1);

}

code:test/test_learning_memory_view.rb

require "test/unit"

require "fiddle"

require "learning_memory_view"

require "tempfile"

class TestLearningMemoryView < Test::Unit::TestCase

include LearningMemoryView

class TestShortArray < self

def test_short_array

size = 176000

Tempfile.create do |tempfile|

tempfile.write Array.new(size, 3).pack("s*")

short_array = ShortArray.new(tempfile.path)

Fiddle::MemoryView.export short_array do |memory_view|

assert_equal 2, memory_view.item_size

assert_equal 2 * size, memory_view.byte_size

assert_equal "s", memory_view.format

rb_unpacked = File.read(tempfile.to_path).unpack("s*")

assert_equal size, rb_unpacked.length

mv_unpacked = memory_view.to_s.unpack("#{memory_view.format}*")

assert_equal size, mv_unpacked.length

diffs = []

rb_unpacked.zip(mv_unpacked).each_with_index do |(a, b), i|

diffs << i if a != b

end

end

assert_equal [].length, diffs.length

end

end

end

end

end

が、これはうまく行かない。

テストするとこんな感じにのエラーになってしまう：

code:shell

% rake test

Loaded suite /Users/kitaitimakoto/.gem/ruby/3.3.6/gems/rake-13.2.1/lib/rake/rake_test_loader

Started

found 175020: 3 != -31376

found 175021: 3 != 28066

found 175022: 3 != 1

found 175023: 3 != 0

found 175024: 3 != 27044

found 175025: 3 != 698

found 175026: 3 != 1

found 175027: 3 != 0

found 175032: 3 != 150

found 175033: 3 != -15122

found 175034: 3 != -29510

F

=====================================================================================================================================================================================================

Failure: test_short_array(TestLearningMemoryView::TestShortArray)

/Users/kitaitimakoto/src/gitlab.com/KitaitiMakoto/learning-memory-view/test/test_learning_memory_view.rb:54:in `block (2 levels) in test_short_array'

53: end

=> 54: assert_equal [].length, diffs.length

55: end

56: end

57: end

/Users/kitaitimakoto/src/gitlab.com/KitaitiMakoto/learning-memory-view/test/test_learning_memory_view.rb:38:in `export'

/Users/kitaitimakoto/src/gitlab.com/KitaitiMakoto/learning-memory-view/test/test_learning_memory_view.rb:38:in `block in test_short_array'

/Users/kitaitimakoto/.gem/ruby/3.3.6/gems/tempfile-0.3.1/lib/tempfile.rb:576:in `create_with_filename'

/Users/kitaitimakoto/.gem/ruby/3.3.6/gems/tempfile-0.3.1/lib/tempfile.rb:562:in `create'

/Users/kitaitimakoto/src/gitlab.com/KitaitiMakoto/learning-memory-view/test/test_learning_memory_view.rb:34:in `test_short_array'

<0> expected but was

<965>

=====================================================================================================================================================================================================

Finished in 0.045941 seconds.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

4 tests, 12 assertions, 1 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications

75% passed

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

87.07 tests/s, 261.20 assertions/s

rake aborted!

Command failed with status (1)

/Users/kitaitimakoto/.gem/ruby/3.3.6/gems/rake-13.2.1/exe/rake:27:in `<top (required)>'

Tasks: TOP => test

(See full trace by running task with --trace)

175020バイト目以降がおかしなことになってしまう。

十年以上プログラミングしてきたけど、どうやったらスタックオーバーフローになるか知らなくて初めて仕込んだ。

記録のため、この問題のある実装を載せておく。

分かったこと

ちゃんとAPIを整理する時まで、一旦置いておこう。

次