abstract¶

Speedup block.call where block is passed block parameter with a special object named "proxyblock" which responds to call and invoke passed block.

background¶

Ruby 2.5 improved performance of passing a passed block parameter by lazy Proc creation ([Feature #14045]).
However, block.call (block is a passed block parameter) is not optimized and need to create a Proc object immediately.

proposal¶

We need to make Proc creation lazily for performance. There are several way to achieve it, but I propose to use special object named "blockproxy" object.

This is a pseudo code to use it:

# block is given block parameter block.call(1, 2, 3) #=> translate at compile time if block is not modified and block is ISeq/IFunc block tmp = blockproxy else tmp = block # create Proc and so on end tmp.call(1, 2, 3) 

blockproxy.call invoke given block if Proc#call is not redefined, otherwise make a Proc and call Proc#call as usual.

Advantage of this method is we can also use this technique with the safe navigation operator (block&.call).
If block is not given, then tmp will be nil, and no method dispatched with &..

Note that this technique depends on the assumption "we can't access to the evaluated receiver just before method dispatch". We don't/can't access blockproxy object at method dispatch, and no compatibility issue.

evaluation¶

Using https://github.com/k0kubun/benchmark_driver

prelude: | def block_yield yield end def bp_yield &b yield end def bp_call &b b.call end def bp_safe_call &b b&.call end benchmark: - block_yield{} - bp_yield{} - bp_call{} - bp_safe_call{} - bp_safe_call 

Result:

Warming up -------------------------------------- block_yield{} 1.298M i/100ms bp_yield{} 1.177M i/100ms bp_call{} 447.723k i/100ms bp_safe_call{} 413.261k i/100ms bp_safe_call 2.955M i/100ms Calculating ------------------------------------- trunk modified block_yield{} 20.672M 20.808M i/s - 51.933M in 2.512265s 2.495806s bp_yield{} 16.294M 16.220M i/s - 47.099M in 2.890459s 2.903797s bp_call{} 5.626M 14.752M i/s - 17.909M in 3.182966s 1.213976s # x2.62 bp_safe_call{} 5.555M 14.557M i/s - 16.530M in 2.975892s 1.135586s # x2.62 bp_safe_call 31.339M 23.561M i/s - 118.184M in 3.771157s 5.016200s 

The patch is here:
https://gist.github.com/ko1/d8a1a9d92075b27a8e95ca528cc57fd2