NAME
Bencher::Backend - Backend for Bencher
VERSION
This document describes version 1.052 of Bencher::Backend (from Perl
distribution Bencher-Backend), released on 2020-09-21.
FUNCTIONS
bencher
Usage:
bencher(%args) -> [status, msg, payload, meta]
A benchmark framework.
Bencher is a benchmark framework. You specify a *scenario* (either in a
"Bencher::Scenario::*" Perl module, or a Perl script, or over the
command-line) containing list of *participants* and *datasets*.
Participants are codes or commands to run, and datasets are arguments
for the codes/commands. Bencher will permute the participants and
datasets into benchmark items, ready to run.
You can choose to include only some participants, datasets, or items.
And there are options to view your scenario's
participants/datasets/items/mentioned modules, run benchmark against
multiple perls and module versions, and so on. Bencher comes as a CLI
script as well as Perl module. See the Bencher::Backend documentation
for more information.
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
* action => *str* (default: "bench")
* capture_stderr => *bool*
Trap output to stderr.
* capture_stdout => *bool*
Trap output to stdout.
* code_startup => *bool*
Benchmark code startup overhead instead of normal benchmark.
* cpanmodules_module => *perl::modname*
Load a scenario from an Acme::CPANModules:: Perl module.
An Acme::CPANModules module can also contain benchmarking
information, e.g. Acme::CPANModules::TextTable.
* datasets => *array[hash]*
Add datasets.
* detail => *bool*
Show detailed information for each result.
* env_hashes => *array[hash]*
Add environment hashes.
* exclude_dataset_names => *array[str]*
Exclude datasets whose name matches this.
* exclude_dataset_pattern => *re*
Exclude datasets matching this regex pattern.
* exclude_dataset_seqs => *array[int]*
Exclude datasets whose sequence number matches this.
* exclude_dataset_tags => *array[str]*
Exclude datasets whose tag matches this.
You can specify "A & B" to exclude datasets that have *both* tags A
and B.
* exclude_datasets => *array[str]*
Exclude datasets whose seq/name matches this.
* exclude_function_pattern => *re*
Exclude function(s) matching this regex pattern.
* exclude_functions => *array[str]*
Exclude functions specified in this list.
* exclude_item_names => *array[str]*
Exclude items whose name matches this.
* exclude_item_pattern => *re*
Exclude items matching this regex pattern.
* exclude_item_seqs => *array[int]*
Exclude items whose sequence number matches this.
* exclude_items => *array[str]*
Exclude items whose seq/name matches this.
* exclude_module_pattern => *re*
Exclude module(s) matching this regex pattern.
* exclude_modules => *array[str]*
Exclude modules specified in this list.
* exclude_participant_names => *array[str]*
Exclude participants whose name matches this.
* exclude_participant_pattern => *re*
Exclude participants matching this regex pattern.
* exclude_participant_seqs => *array[int]*
Exclude participants whose sequence number matches this.
* exclude_participant_tags => *array[str]*
Exclude participants whose tag matches this.
You can specify "A & B" to exclude participants that have *both*
tags A and B.
* exclude_participants => *array[str]*
Exclude participants whose seq/name matches this.
* exclude_perls => *array[str]*
Exclude some perls.
* exclude_pp_modules => *bool*
Exclude PP (pure-Perl) modules.
* exclude_xs_modules => *bool*
Exclude XS modules.
* include_dataset_names => *array[str]*
Only include datasets whose name matches this.
* include_dataset_pattern => *re*
Only include datasets matching this regex pattern.
* include_dataset_seqs => *array[int]*
Only include datasets whose sequence number matches this.
* include_dataset_tags => *array[str]*
Only include datasets whose tag matches this.
You can specify "A & B" to include datasets that have *both* tags A
and B.
* include_datasets => *array[str]*
Only include datasets whose seq/name matches this.
* include_function_pattern => *re*
Only include functions matching this regex pattern.
* include_functions => *array[str]*
Only include functions specified in this list.
* include_item_names => *array[str]*
Only include items whose name matches this.
* include_item_pattern => *re*
Only include items matching this regex pattern.
* include_item_seqs => *array[int]*
Only include items whose sequence number matches this.
* include_items => *array[str]*
Only include items whose seq/name matches this.
* include_module_pattern => *re*
Only include modules matching this regex pattern.
* include_modules => *array[str]*
Only include modules specified in this list.
* include_participant_names => *array[str]*
Only include participants whose name matches this.
* include_participant_pattern => *re*
Only include participants matching this regex pattern.
* include_participant_seqs => *array[int]*
Only include participants whose sequence number matches this.
* include_participant_tags => *array[str]*
Only include participants whose tag matches this.
You can specify "A & B" to include participants that have *both*
tags A and B.
* include_participants => *array[str]*
Only include participants whose seq/name matches this.
* include_path => *array[str]*
Additional module search paths.
Used when searching for scenario module, or when in multimodver
mode.
* include_perls => *array[str]*
Only include some perls.
* keep_tempdir => *bool*
Do not cleanup temporary directory when bencher ends.
* module_startup => *bool*
Benchmark module startup overhead instead of normal benchmark.
* multimodver => *perl::modname*
Benchmark multiple module versions.
If set to a module name, will search for all (instead of the first
occurrence) of the module in @INC. Then will generate items for each
version.
Currently only one module can be multi version.
* multiperl => *bool* (default: 0)
Benchmark against multiple perls.
Requires App::perlbrew to be installed. Will use installed perls
from the perlbrew installation. Each installed perl must have
Bencher::Backend module installed (in addition to having all modules
that you want to benchmark, obviously).
By default, only perls having Bencher::Backend will be included. Use
"--include-perl" and "--exclude-perl" to include and exclude which
perls you want.
Also note that due to the way this is currently implemented,
benchmark code that contains closures (references to variables
outside the code) won't work.
* note => *str*
Put additional note in the result.
* on_failure => *str*
What to do when there is a failure.
For a command participant, failure means non-zero exit code. For a
Perl-code participant, failure means Perl code dies or (if expected
result is specified) the result is not equal to the expected result.
The default is "die". When set to "skip", will first run the code of
each item before benchmarking and trap command failure/Perl
exception and if that happens, will "skip" the item.
* on_result_failure => *str*
What to do when there is a result failure.
This is like "on_failure" except that it specifically refer to the
failure of item's result not being equal to expected result.
There is an extra choice of "warn" for this type of failure, which
is to print a warning to STDERR and continue.
* participants => *array[hash]*
Add participants.
* precision => *float*
Precision.
When benchmarking with the default Benchmark::Dumb runner, will pass
the precision to it. The value is a fraction, e.g. 0.5 (for 5%
precision), 0.01 (for 1% precision), and so on. Or, it can also be a
positive integer to speciify minimum number of iterations, usually
need to be at least 6 to avoid the "Number of initial runs is very
small (<6)" warning. The default precision is 0, which is to let
Benchmark::Dumb determine the precision, which is good enough for
most cases.
When benchmarking with Benchmark runner, will pass this value as the
$count argument. Which can be a positive integer to mean the number
of iterations to do (e.g. 10, or 100). Or, can also be set to a
negative number (e.g. -0.5 or -2) to mean minimum number of CPU
seconds. The default is -0.5.
When benchmarking with Benchmark::Dumb::SimpleTime, this value is a
positive integer which means the number of iterations to perform.
When profiling, a number greater than 1 will set a repetition loop
(e.g. "for(1..100){ ... }").
This setting overrides "default_precision" property in the scenario.
* precision_limit => *float*
Set precision limit.
Instead of setting "precision" which forces a single value, you can
also set this "precision_limit" setting. If the precision in the
scenario is higher (=number is smaller) than this limit, then this
limit is used. For example, if the scenario specifies
"default_precision" 0.001 and "precision_limit" is set to 0.005 then
0.005 is used.
This setting is useful on slower computers which might not be able
to reach the required precision before hitting maximum number of
iterations.
* raw => *bool*
Show "raw" data.
When action=show-items-result, will print result as-is instead of
dumping as Perl.
* result_dir => *dirname*
Directory to use when saving benchmark result.
Default is from "BENCHER_RESULT_DIR" environment variable, or the
home directory.
* result_filename => *filename*
Filename to use when saving benchmark result.
Default is:
<NAME>.<yyyy-dd-dd-"T"HH-MM-SS>.json
or, when running in module startup mode:
<NAME>.module_startup.<yyyy-dd-dd-"T"HH-MM-SS>.json
or, when running in code startup mode:
<NAME>.code_startup.<yyyy-dd-dd-"T"HH-MM-SS>.json
where <NAME> is scenario module name, or "NO_MODULE" if scenario is
not from a module. The "::" (double colon in the module name will be
replaced with "-" (dash).
* return_meta => *bool*
Whether to return extra metadata.
When set to true, will return extra metadata such as platform
information, CPU information, system load before & after the
benchmark, system time, and so on. This is put in result metadata
under "func.*" keys.
The default is to true (return extra metadata) unless when run as
CLI and format is text (where the extra metadata is not shown).
* runner => *str*
Runner module to use.
The default is "Benchmark::Dumb" which should be good enough for
most cases.
You can use "Benchmark" runner ("Benchmark.pm") if you are
accustomed to it and want to see its output format.
You can use "Benchmark::Dumb::SimpleTime" if your participant code
runs for at least a few to many seconds and you want to use very few
iterations (like 1 or 2) because you don't want to wait for too
long.
* save_result => *bool*
Whether to save benchmark result to file.
Will also be turned on automatically if "BENCHER_RESULT_DIR"
environment variabl is defined.
When this is turned on, will save a JSON file after benchmark,
containing the result along with metadata. The directory of the JSON
file will be determined from the "results_dir" option, while the
filename from the "results_filename" option.
* scenario => *hash*
Load a scenario from data structure.
* scenario_file => *str*
Load a scenario from a Perl file.
Perl file will be do()'ed and the last expression should be a hash
containing the scenario specification.
* scenario_module => *perl::modname*
Load a scenario from a Bencher::Scenario:: Perl module.
Will try to load module "Bencher::Scenario::<NAME>" and expect to
find a package variable in the module called $scenario which should
be a hashref containing the scenario specification.
* scientific_notation => *bool*
* sorts => *array[str]* (default: ["-time"])
* test => *bool*
Whether to test participant code once first before benchmarking.
By default, participant code is run once first for testing (e.g.
whether it dies or return the correct result) before benchmarking.
If your code runs for many seconds, you might want to skip this test
and set this to 0.
* tidy => *bool*
Run perltidy over generated scripts.
* with_args_size => *bool*
Also return memory usage of item's arguments.
Memory size is measured using Devel::Size.
* with_process_size => *bool*
Also return process size information for each item.
This is done by dumping each item's code into a temporary file and
running the file with a new perl interpreter process and measuring
the process size at the end (so it does not need to load Bencher
itself or the other items). Currently only works on Linux because
process size information is retrieved from "/proc/PID/smaps". Not
all code can work, e.g. if the code tries to access a closure or
outside data or extra modules (modules not specified in the
participant or loaded by the code itself). Usually does not make
sense to use this on external command participants.
* with_result_size => *bool*
Also return memory usage of each item code's result (return value).
Memory size is measured using Devel::Size.
Returns an enveloped result (an array).
First element (status) is an integer containing HTTP status code (200
means OK, 4xx caller error, 5xx function error). Second element (msg) is
a string containing error message, or 'OK' if status is 200. Third
element (payload) is optional, the actual result. Fourth element (meta)
is called result metadata and is optional, a hash that contains extra
information.
Return value: (any)
chart_result
Usage:
chart_result(%args) -> [status, msg, payload, meta]
Generate chart from the result.
Will use gnuplot (via Chart::Gnuplot) to generate the chart. Will
produce ".png" files in the specified directory.
Currently only results with one or two permutations of different items
will be chartable.
Options to customize the look/style of the chart will be added in the
future.
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
* envres* => *array*
Enveloped result from bencher.
* output_file* => *str*
.
* overwrite => *bool*
* title => *str*
Returns an enveloped result (an array).
First element (status) is an integer containing HTTP status code (200
means OK, 4xx caller error, 5xx function error). Second element (msg) is
a string containing error message, or 'OK' if status is 200. Third
element (payload) is optional, the actual result. Fourth element (meta)
is called result metadata and is optional, a hash that contains extra
information.
Return value: (any)
format_result
Usage:
format_result($envres, $formatters, $options, $exclude_formatters) -> [status, msg, payload, meta]
Format bencher result.
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
* $envres* => *array*
Enveloped result from bencher.
* $exclude_formatters => *any*
Exclude Formatters specification.
* $formatters* => *array[str|array]*
Formatters specification.
* $options => *hash*
Returns an enveloped result (an array).
First element (status) is an integer containing HTTP status code (200
means OK, 4xx caller error, 5xx function error). Second element (msg) is
a string containing error message, or 'OK' if status is 200. Third
element (payload) is optional, the actual result. Fourth element (meta)
is called result metadata and is optional, a hash that contains extra
information.
Return value: (any)
parse_scenario
Usage:
parse_scenario(%args) -> [status, msg, payload, meta]
Parse scenario (fill in default values, etc).
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
* scenario => *hash*
Unparsed scenario.
Returns an enveloped result (an array).
First element (status) is an integer containing HTTP status code (200
means OK, 4xx caller error, 5xx function error). Second element (msg) is
a string containing error message, or 'OK' if status is 200. Third
element (payload) is optional, the actual result. Fourth element (meta)
is called result metadata and is optional, a hash that contains extra
information.
Return value: (any)
split_result
Usage:
split_result($envres, $fields, $options) -> any
Split results based on one or more fields.
This routine splits a table into multiple table based on one or more
fields. If you want to split a result, you should do it before
"format_result()" and then format the split results individually.
A common use-case is to produce separate tables for each participant or
dataset, to make the benchmark results more readable (this is an
alternative to having to perform separate benchmark run per participant
or dataset).
Each split result clones all the result metadata (like
"func.module_version", "func.platform_info", "table.fields", and so on).
But the result items are only a subset of the original result.
Return an array where each element is "[\%field_values, $split_result]".
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
* $envres* => *array*
Enveloped result from bencher.
* $fields* => *array[str]*
Fields to split the results on.
* $options => *hash*
Return value: (any)
ENVIRONMENT
BENCHER_RESULT_DIR => str
Set default for "--results-dir".
HOMEPAGE
Please visit the project's homepage at
<
https://metacpan.org/release/Bencher-Backend>.
SOURCE
Source repository is at
<
https://github.com/perlancar/perl-Bencher-Backend>.
BUGS
Please report any bugs or feature requests on the bugtracker website
<
https://rt.cpan.org/Public/Dist/Display.html?Name=Bencher-Backend>
When submitting a bug or request, please include a test-file or a patch
to an existing test-file that illustrates the bug or desired feature.
SEE ALSO
bencher
Bencher
"Bencher::Manual::*"
AUTHOR
perlancar <
[email protected]>
COPYRIGHT AND LICENSE
This software is copyright (c) 2020, 2019, 2018, 2017, 2016, 2015 by
[email protected].
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.