Feature #5937: Zlib::Inflate#add_dictionary to pre-supply dictionaries for inflate streams

• Status: Closed
• Assignee: -
• Target version: 2.0.0

[drbrain (Eric Hodel)]

The attached patch allows Zlib::Inflate users to supply dictionaries ahead of time in order to avoid handling the Zlib::NeedDict exception.

Multiple dictionaries may be provided. Zlib::Inflate will choose a matching dictionary based on the adler32 checksum of the provided dictionaries.

[drbrain (Eric Hodel)]

• File zlib.c.add_dictionary.patch zlib.c.add_dictionary.patch added

Oops, forgot patch

[drbrain (Eric Hodel)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r34553.
Eric, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• ext/zlib/zlib.c (rb_inflate_add_dictionary): Added
  Zlib::Inflate#add_dictionary to allow users to pre-specify
  for using during #inflate. [ruby-trunk - Feature #5937]

[igrigorik (Ilya Grigorik)]

What are the odds of having this be backported to 1.9.x? We need custom dictionary support to support SPDY without relying on FFI or other native extensions.

ex: https://github.com/igrigorik/spdy/blob/master/lib/spdy/compressor.rb

[naruse (Yui NARUSE)]

igrigorik (Ilya Grigorik) wrote:

What are the odds of having this be backported to 1.9.x? We need custom dictionary support to support SPDY without relying on FFI or other native extensions.

ex: https://github.com/igrigorik/spdy/blob/master/lib/spdy/compressor.rb

You may know, in principle backporting is for bug fixes.
And even if 1.9.3 backport this, 1.9.2 and 1.8.x still needs ffi.
This means your pain won't decrease, will it?

[drbrain (Eric Hodel)]

I think #5929 should be backported instead. While #5937 makes working with custom dictionaries easier, #5929 fixes the current API (#set_dictionary) to be fully usable.

[igrigorik (Ilya Grigorik)]

@naruse (Yui NARUSE): as Eric pointed out in his original ticket (#5929), I do believe this is a bug, as the current API advertises that it can set and use the dictionary, but that is not the case.

I've opened a different / new ticket: http://bugs.ruby-lang.org/issues/6516