443e2ec27d
[Bug #21170] st_table reserves -1 as a special hash value to indicate that an entry has been deleted. So that that's a valid value to be returned from the hash function, do_hash replaces -1 with 0 so that it is not mistaken for the sentinel. Previously, when upgrading an AR table to an ST table, rb_st_add_direct_with_hash was used which did not perform the same conversion, this could lead to a hash in a broken state where one if its entries which was supposed to exist being marked as a tombstone. The hash could then become further corrupted when the ST table required resizing as the falsely tombstoned entry would be skipped but it would be counted in num entries, leading to an uninitialized entry at index 15. In most cases this will be really rare, unless using a very poorly implemented custom hash function. This also adds two debug assertions, one that st_add_direct_with_hash does not receive the reserved hash value, and a second in rebuild_table_with, which ensures that after we rebuild/compact a table it contains the expected number of elements. Co-authored-by: Alan Wu <alanwu@ruby-lang.org>
What is Ruby?
Ruby is an interpreted object-oriented programming language often used for web development. It also offers many scripting features to process plain text and serialized files, or manage system tasks. It is simple, straightforward, and extensible.
Features of Ruby
- Simple Syntax
- Normal Object-oriented Features (e.g. class, method calls)
- Advanced Object-oriented Features (e.g. mix-in, singleton-method)
- Operator Overloading
- Exception Handling
- Iterators and Closures
- Garbage Collection
- Dynamic Loading of Object Files (on some architectures)
- Highly Portable (works on many Unix-like/POSIX compatible platforms as well as Windows, macOS, etc.) cf. https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
How to get Ruby
For a complete list of ways to install Ruby, including using third-party tools like rvm, see:
https://www.ruby-lang.org/en/downloads/
You can download release packages and the snapshot of the repository. If you want to download whole versions of Ruby, please visit https://www.ruby-lang.org/en/downloads/releases/.
Download with Git
The mirror of the Ruby source tree can be checked out with the following command:
$ git clone https://github.com/ruby/ruby.git
There are some other branches under development. Try the following command to see the list of branches:
$ git ls-remote https://github.com/ruby/ruby.git
You may also want to use https://git.ruby-lang.org/ruby.git (actual master of Ruby source) if you are a committer.
How to build
See Building Ruby
Ruby home page
Documentation
Mailing list
There is a mailing list to discuss Ruby. To subscribe to this list, please send the following phrase:
join
in the mail subject (not body) to the address ruby-talk-request@ml.ruby-lang.org.
Copying
See the file COPYING.
Feedback
Questions about the Ruby language can be asked on the Ruby-Talk mailing list or on websites like https://stackoverflow.com.
Bugs should be reported at https://bugs.ruby-lang.org. Read "Reporting Issues" for more information.
Contributing
See "Contributing to Ruby", which includes setup and build instructions.
The Author
Ruby was originally designed and developed by Yukihiro Matsumoto (Matz) in 1995.