Merge pull request #6 from tsloughter/benchmarker

add benchmarking example

README.md

@@ -7,5 +7,21 @@ Requires OTP 21.3 of above.
 
 ## Design
 
+## Benchmarks
+
+Running benchmarks is done with [benchee](https://github.com/bencheeorg/benchee). Benchmark functions are in modules under `samples/`. To run them open a rebar3 shell in the `bench` profile:
+
+``` shell
+$ rebar3 as bench compile
+
+> ot_benchmarks:run().
+```
+
+If an Elixir script is wanted for the benchmarks they could be run like:
+
+``` shell
+$ ERL_LIBS=_build/bench/lib/ mix run --no-mix-exs samples/run.exs
+```
+
 ## Contributing
 

rebar.config

@@ -7,7 +7,12 @@
 
 {profiles,
  [{test, [{erl_opts, [nowarn_export_all]},
-          {ct_opts, [{ct_hooks, [cth_surefire]}]}]}]}.
+          {ct_opts, [{ct_hooks, [cth_surefire]}]}]},
+
+  {bench, [{deps, [benchee]},
+           {extra_src_dirs, ["samples"]},
+           {plugins, [rebar_mix]},
+           {provider_hooks, [{pre,  [{compile, {mix, find_elixir_libs}}]}]}]}]}.
 
 {xref_checks, [undefined_function_calls, undefined_functions,
                deprecated_function_calls, deprecated_functions]}.

samples/ot_benchmarks.erl

@@ -0,0 +1,29 @@
+%%%------------------------------------------------------------------------
+%% Copyright 2019, OpenTelemetry Authors
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% @doc
+%% @end
+%%%-------------------------------------------------------------------------
+-module(ot_benchmarks).
+
+-export([run/0]).
+
+run() ->
+    Iterations = 100,
+    PDictCtxFun = fun() ->
+                      [ot_tracer:start_span(<<"span-", (integer_to_binary(X))/binary>>)
+                       || X <- lists:seq(1, 100)]
+                  end,
+    benchee:run(#{<<"pdict_ctx">> => PDictCtxFun}),
+    ok.