From: duerst@... Date: 2020-06-07T00:54:49+00:00 Subject: [ruby-core:98668] [Ruby master Feature#16352] Modify Marshal to dump objects larger than 2 GiB Issue #16352 has been updated by duerst (Martin D�rst). marcandre (Marc-Andre Lafortune) wrote in #note-6: > Couldn't we dedicate a special "size" value to indicate "extended marshal size" (say `SIZEOF_LONG - 1`), such that compatibility with all current and future marshal dumps is maintained, with the exception of a marshal object that would actually happen to have exactly a size of `SIZEOF_LONG - 1`? This sounds like a good idea because the chance of old files with a value of exactly `SIZEOF_LONG - 1` is low. The problem is that, as far as I understand, it significantly increases the difficulties of diagnosing/debugging problems in the cases where `SIZEOF_LONG - 1` was actually used. ---------------------------------------- Feature #16352: Modify Marshal to dump objects larger than 2 GiB https://bugs.ruby-lang.org/issues/16352#change-86014 * Author: seoanezonjic (Pedro Seoane) * Status: Open * Priority: Normal ---------------------------------------- Using a gem called Numo-array to handle matrix operations, I found the following error while saving a large matrix: ``` in `dump': long too big to dump (TypeError) ``` Github thread is https://github.com/ruby-numo/numo-narray/issues/144. Digging with the authors, I found the following code that reproduces the error: ``` ruby -e 'Marshal.dump(" "*2**31)' ``` Executed in: ruby 2.7.0dev (2019-11-12T12:03:22Z master 3816622fbe) [x86_64-linux] The marshal library has a limit based on constant `SIZEOF_LONG`. This check is performed in [here](https://github.com/ruby/ruby/blob/e7ea6e078fecb70fbc91b04878b69f696749afac/marshal.c#L301L321). I don't understand the motivation of this limit. It has a great impact on libraries that need to serialize large objects such as numeric matrix. In this case, the limit >= 2 GiB is reached easily, and it blocks ruby development. I found another related bug report: #1560, but the Marshal problem was not addressed in it. -- https://bugs.ruby-lang.org/ Unsubscribe: