From 8ffe3ad6dd299c234f1ef07467bcbbfdcc465b42 Mon Sep 17 00:00:00 2001
From: dvic <info@dvic.io>
Date: Tue, 3 Aug 2021 23:13:49 +0200
Subject: [PATCH 1/3] Introduce otel_sampler:new/3 and fix behavior typespec

---
 apps/opentelemetry/src/otel_sampler.erl    | 32 ++++++++++++++--------
 apps/opentelemetry/test/static_sampler.erl |  7 +++--
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/apps/opentelemetry/src/otel_sampler.erl b/apps/opentelemetry/src/otel_sampler.erl
index bbae7d5e..9f7d5afb 100644
--- a/apps/opentelemetry/src/otel_sampler.erl
+++ b/apps/opentelemetry/src/otel_sampler.erl
@@ -19,7 +19,8 @@
 %%%-------------------------------------------------------------------------
 -module(otel_sampler).
 
--export([setup/1,
+-export([new/3,
+         setup/1,
          get_description/1,
          always_on/7,
          always_off/7,
@@ -31,26 +32,35 @@
 -include("otel_sampler.hrl").
 -include("otel_span.hrl").
 
--callback setup(module(), map()) -> t().
+-callback setup(sampler_opts()) -> t().
 
 -type sampling_decision() :: ?DROP | ?RECORD_ONLY | ?RECORD_AND_SAMPLE.
 -type sampling_result() :: {sampling_decision(), opentelemetry:attributes(), opentelemetry:tracestate()}.
 -type description() :: unicode:unicode_binary().
--type sampler() :: {fun((otel_ctx:t(),
-                         opentelemetry:trace_id(),
-                         opentelemetry:links(),
-                         opentelemetry:span_name(),
-                         opentelemetry:span_kind(),
-                         opentelemetry:attributes(),
-                         term()) -> sampling_result()), description(), term()}.
+-type decider() :: fun((otel_ctx:t(),
+                        opentelemetry:trace_id(),
+                        opentelemetry:links(),
+                        opentelemetry:span_name(),
+                        opentelemetry:span_kind(),
+                        opentelemetry:attributes(),
+                        term()) -> sampling_result()).
+-type sampler() :: {decider(), description(), sampler_opts()}.
+-type sampler_opts() :: term().
 -opaque t() :: sampler().
--export_type([sampling_result/0,
+-export_type([decider/0,
+              description/0,
+              sampling_result/0,
               sampling_decision/0,
+              sampler_opts/0,
               t/0]).
 
 -define(MAX_VALUE, 9223372036854775807). %% 2^63 - 1
 
--spec setup(atom() | {atom() | module(), term()}) -> t().
+-spec new(decider(), description(), sampler_opts()) -> t().
+new(DecisionFunction, Description, SamplerOpts) ->
+    {DecisionFunction, Description, SamplerOpts}.
+
+-spec setup(atom() | {atom() | module(), sampler_opts()}) -> t().
 setup({Sampler, Opts}) ->
     setup(Sampler, Opts);
 setup(Sampler) when is_atom(Sampler) ->
diff --git a/apps/opentelemetry/test/static_sampler.erl b/apps/opentelemetry/test/static_sampler.erl
index 6d3cca55..6db0a2d3 100644
--- a/apps/opentelemetry/test/static_sampler.erl
+++ b/apps/opentelemetry/test/static_sampler.erl
@@ -6,6 +6,7 @@
 
 %% sampler returns the value from the Opts map based on the SpanName or `NOT_RECORD'
 setup(Opts) ->
-    {fun(_, _, _, SpanName, _, _, Opts1) ->
-             {maps:get(SpanName, Opts1, ?DROP), [], []}
-     end, <<"StaticSampler">>, Opts}.
+    otel_sampler:new(
+        fun(_, _, _, SpanName, _, _, Opts1) -> {maps:get(SpanName, Opts1, ?DROP), [], []} end, <<"StaticSamplerr">>,
+        Opts
+    ).

From 055afa2cb341d63fa1e89c8054195e59f639c2ba Mon Sep 17 00:00:00 2001
From: dvic <info@dvic.io>
Date: Tue, 3 Aug 2021 23:31:02 +0200
Subject: [PATCH 2/3] Rename decider() to sampler_fun()

---
 apps/opentelemetry/src/otel_sampler.erl | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/apps/opentelemetry/src/otel_sampler.erl b/apps/opentelemetry/src/otel_sampler.erl
index 9f7d5afb..3e4e649b 100644
--- a/apps/opentelemetry/src/otel_sampler.erl
+++ b/apps/opentelemetry/src/otel_sampler.erl
@@ -37,17 +37,17 @@
 -type sampling_decision() :: ?DROP | ?RECORD_ONLY | ?RECORD_AND_SAMPLE.
 -type sampling_result() :: {sampling_decision(), opentelemetry:attributes(), opentelemetry:tracestate()}.
 -type description() :: unicode:unicode_binary().
--type decider() :: fun((otel_ctx:t(),
-                        opentelemetry:trace_id(),
-                        opentelemetry:links(),
-                        opentelemetry:span_name(),
-                        opentelemetry:span_kind(),
-                        opentelemetry:attributes(),
-                        term()) -> sampling_result()).
--type sampler() :: {decider(), description(), sampler_opts()}.
+-type sampler_fun() :: fun((otel_ctx:t(),
+                            opentelemetry:trace_id(),
+                            opentelemetry:links(),
+                            opentelemetry:span_name(),
+                            opentelemetry:span_kind(),
+                            opentelemetry:attributes(),
+                            term()) -> sampling_result()).
+-type sampler() :: {sampler_fun(), description(), sampler_opts()}.
 -type sampler_opts() :: term().
 -opaque t() :: sampler().
--export_type([decider/0,
+-export_type([sampler_fun/0,
               description/0,
               sampling_result/0,
               sampling_decision/0,
@@ -56,7 +56,7 @@
 
 -define(MAX_VALUE, 9223372036854775807). %% 2^63 - 1
 
--spec new(decider(), description(), sampler_opts()) -> t().
+-spec new(sampler_fun(), description(), sampler_opts()) -> t().
 new(DecisionFunction, Description, SamplerOpts) ->
     {DecisionFunction, Description, SamplerOpts}.
 

From 99633d7719c8a94932615a518536c67fd6f870cc Mon Sep 17 00:00:00 2001
From: dvic <info@dvic.io>
Date: Tue, 3 Aug 2021 23:37:13 +0200
Subject: [PATCH 3/3] Fix formatting

---
 apps/opentelemetry/test/static_sampler.erl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/apps/opentelemetry/test/static_sampler.erl b/apps/opentelemetry/test/static_sampler.erl
index 6db0a2d3..19bb292d 100644
--- a/apps/opentelemetry/test/static_sampler.erl
+++ b/apps/opentelemetry/test/static_sampler.erl
@@ -7,6 +7,7 @@
 %% sampler returns the value from the Opts map based on the SpanName or `NOT_RECORD'
 setup(Opts) ->
     otel_sampler:new(
-        fun(_, _, _, SpanName, _, _, Opts1) -> {maps:get(SpanName, Opts1, ?DROP), [], []} end, <<"StaticSamplerr">>,
+        fun(_, _, _, SpanName, _, _, Opts1) -> {maps:get(SpanName, Opts1, ?DROP), [], []} end,
+        <<"StaticSampler">>,
         Opts
     ).