From: ko1@... Date: 2014-05-14T08:17:58+00:00 Subject: [ruby-core:62579] [ruby-trunk - Feature #9614] ordering of non-Hash items which use st_ internally Issue #9614 has been updated by Koichi Sasada. > ko1: adding flag for ordering might complicate the st code even more. > I think st should only be for implementing Hash. I agree that st.c is already complicated. But I think Hash class should use original one. Adding similar data structure can also increase complexity. At least, I like same interfaces for such similar data structures. > My primary goals for ihash are to reduce pointer chasing and malloc use. > ihash uses container_of, like ccan/list: It makes sense. I think open addressing is better for such internal, small tables such as method table. It doesn't need chain buckets. So I wanted to extend st to introduce open addressing mode. ---------------------------------------- Feature #9614: ordering of non-Hash items which use st_ internally https://bugs.ruby-lang.org/issues/9614#change-46723 * Author: Eric Wong * Status: Open * Priority: Normal * Assignee: Yukihiro Matsumoto * Category: core * Target version: current: 2.2.0 ---------------------------------------- Hi matz, I would like your permission to remove the order preservation from any or all of the following currently implemented using `st_table`: * method tables * global symbols (`Symbol.all_symbols`) * constant tables * instance variable tables * `global_variables` method * `Thread#keys` * anything besides the `Hash` class I am currently working on a patch series to reduce internal memory usage, so far I have only converted three pieces: 1. method tables (~200K reduction) 2. symbol table (`global_symbols.`{`id_str`,`sym_id`}) (~200K) 3. `frozen_strings` (~100K) n.b. `frozen_strings` ordering is never exposed to users, so I expect it to be OK. Memory reduction is just based on "`ruby -e exit`" (which loads RubyGems); bigger programs with more methods/symbols will save more memory. Work-in-progress patches attached (0002 describes implementation details) ---Files-------------------------------- 0001-adjust-tests-to-account-for-unsorted-methods.patch (1.87 KB) 0002-ihash-initial-implementation-method-table-conversion.patch (32.8 KB) 0004-ihash-implement-rb_ihash_update-to-support-rb_fstrin.patch (7.84 KB) 0003-parse.y-switch-to-ihash-saves-200K-out-of-the-box.patch (9.51 KB) -- https://bugs.ruby-lang.org/