From: normalperson@...
Date: 2014-12-12T10:48:22+00:00
Subject: [ruby-core:66807] [ruby-trunk - Feature #10585] struct: speedup struct.attr = v for first 10 attributes and struct[:attr] for big structs

Issue #10585 has been updated by Eric Wong.


 funny.falcon:
 
   I tried using khash fstring for Feature #10096 but benefits seemed
   minor.  I also worry about executable size getting bigger every
   release...  Maybe using Array storage + open address hash can save
   space (both runtime memory and execuatable size).
 
 ko1:
 
   Feature #10575 was inspired by a private (crazy) project many years
   ago.  As a C programmer learning Ruby, I expected Ruby Struct to be
   similar to C struct and offer performance characteristics of an array.
   I had 200-500 member (auto-generated) Ruby Structs and noticed speed
   problems.  It was easier to rewrite Ruby code at the time (to use
   hashes or attr), so I rewrote my code and forgot about struct.c
   However, I still hope to spare others from having to learn VM
   internals or rewrite any Ruby code for consistent performance.

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Feature #10585: struct: speedup struct.attr = v for first 10 attributes and struct[:attr] for big structs
https://bugs.ruby-lang.org/issues/10585#change-50379

* Author: Yura Sokolov
* Status: Open
* Priority: Normal
* Assignee: 
* Category: core
* Target version: current: 2.2.0
----------------------------------------
0001 - Define optimized setters for first 10 attributes.

0002 - Cache members definition in an subclasses - it is safe cause it could be modified/overloaded.
And use `rb_attr_get` to lookup definition - it is safe cause result is checked later and `Qnil` is treated as error.

0003,0004 - Use custom hash structure (on top of Array) to lookup members index in a big structure.
Well, I doubt that big structures are useful, so I will not grieve if 0004 is not accepted.

---Files--------------------------------
0001-struct.c-speedup-struct.name-v-for-small-structs.patch (2.33 KB)
0002-struct.c-cache-member-definition-in-a-subclass.patch (1.09 KB)
0003-benchmark-struct-name.patch (2.42 KB)
0004-struct.c-speedup-for-big-structs.patch (5.47 KB)


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