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author | Aaron Patterson <tenderlove@ruby-lang.org> | 2022-08-01 14:24:12 -0700 |
---|---|---|
committer | Aaron Patterson <aaron.patterson@gmail.com> | 2022-08-02 09:04:04 -0700 |
commit | e4e054e3ce409f1c1d04bf7cd75aa9238e205d52 (patch) | |
tree | 30bb1aa941ec81549a0ed448af24aa94f129dd7f /re.c | |
parent | da00243dfe745cba3b176112fe8245c23e6f1635 (diff) | |
download | ruby-e4e054e3ce409f1c1d04bf7cd75aa9238e205d52.tar.gz |
Speed up setting the backref match object
This patch speeds up setting the backref match object by avoiding some
memcopies. Take the following code for example:
```ruby
"hello world" =~ /hello/
p $~
```
When the RE matches the string, we have to set the Match object in the
backref global. So we would allocate a match object[^1] and use
`rb_reg_region_copy`[^2] to make a deep copy of the stack allocated
`re_registers` struct[^3] in to the newly created Ruby object. This
could possibly trigger GC[^4], and would allocate new memory.
This patch makes a shallow copy of the `re_registers` struct on to the
Match object allowing the match object to manage the `re_registers`
pointer and also avoiding some calls to `xmalloc` and some manual
memcopy.
Benchmark looks like this:
```ruby
require "benchmark/ips"
def test_re thing
thing =~ /hello/
end
Benchmark.ips do |x|
x.report("re hit") do
test_re "hello world"
end
x.report("re miss") do
test_re "world"
end
end
```
Before this patch:
```
$ ruby -v test.rb
ruby 3.2.0dev (2022-07-27T22:29:00Z master 4ad69899b7) [arm64-darwin21]
Ignoring bcrypt-3.1.16 because its extensions are not built. Try: gem pristine bcrypt --version 3.1.16
Warming up --------------------------------------
re hit 345.401k i/100ms
re miss 673.584k i/100ms
Calculating -------------------------------------
re hit 3.452M (± 0.5%) i/s - 17.270M in 5.002535s
re miss 6.736M (± 0.4%) i/s - 34.353M in 5.099593s
```
After this patch:
```
$ ./ruby -v test.rb
ruby 3.2.0dev (2022-08-01T21:24:12Z less-memcpy 0ff2a56606) [arm64-darwin21]
Warming up --------------------------------------
re hit 419.578k i/100ms
re miss 673.251k i/100ms
Calculating -------------------------------------
re hit 4.201M (± 0.7%) i/s - 21.398M in 5.093593s
re miss 6.716M (± 0.4%) i/s - 33.663M in 5.012756s
```
Matches get faster and misses maintain the same speed
[^1]: https://github.com/ruby/ruby/blob/24204d54ab730791bfbd0cd66b8e12f0bd62ca5d/re.c#L1737
[^2]: https://github.com/ruby/ruby/blob/24204d54ab730791bfbd0cd66b8e12f0bd62ca5d/re.c#L1738
[^3]: https://github.com/ruby/ruby/blob/24204d54ab730791bfbd0cd66b8e12f0bd62ca5d/re.c#L1686
[^4]: https://github.com/ruby/ruby/blob/24204d54ab730791bfbd0cd66b8e12f0bd62ca5d/re.c#L981
Diffstat (limited to 're.c')
-rw-r--r-- | re.c | 4 |
1 files changed, 1 insertions, 3 deletions
@@ -1735,9 +1735,7 @@ rb_reg_search_set_match(VALUE re, VALUE str, long pos, int reverse, int set_back } match = match_alloc(rb_cMatch); - int copy_err = rb_reg_region_copy(RMATCH_REGS(match), regs); - onig_region_free(regs, 0); - if (copy_err) rb_memerror(); + memcpy(RMATCH_REGS(match), regs, sizeof(struct re_registers)); if (set_backref_str) { RMATCH(match)->str = rb_str_new4(str); |