%%%------------------------------------------------------------------------ %% 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 %% ETS backed interface for working with spans. %% @end %%%------------------------------------------------------------------------- -module(otel_span_ets). -behaviour(gen_server). -export([start_link/1, init/1, handle_call/3, handle_cast/2]). -export([start_span/7, end_span/1, end_span/2, get_ctx/1, set_attribute/3, set_attributes/2, add_event/3, add_events/2, set_status/2, update_name/2]). %% since `span_ctx' and `span' are in the API the `span_sdk' has to be term() -eqwalizer({nowarn_function, get_ctx/1}). -include_lib("opentelemetry_api/include/opentelemetry.hrl"). -include("otel_span.hrl"). -include("otel_span_ets.hrl"). -include_lib("stdlib/include/ms_transform.hrl"). -include_lib("opentelemetry_api/include/gradualizer.hrl"). -record(state, {}). start_link(Opts) -> gen_server:start_link(?MODULE, Opts, []). %% @doc Start a span and insert into the active span ets table. -spec start_span(otel_ctx:t(), opentelemetry:span_name(), otel_sampler:t(), otel_id_generator:t(), otel_span:start_config(), fun(), otel_tracer_server:instrumentation_scope() | undefined) -> opentelemetry:span_ctx(). start_span(Ctx, Name, Sampler, IdGeneratorModule, Opts, Processors, InstrumentationScope) -> case otel_span_utils:start_span(Ctx, Name, Sampler, IdGeneratorModule, Opts) of {SpanCtx=#span_ctx{is_recording=true}, Span=#span{}} -> Span1 = Span#span{instrumentation_scope=InstrumentationScope}, Span2 = Processors(Ctx, Span1), case storage_insert(Span2) of true -> SpanCtx; _ -> %% adding the span to storage failed, this means there %% is no span backing the spanctx and we must return %% a noop span instead otel_tracer_noop:noop_span_ctx() end; {SpanCtx, #span{}} -> %% span isn't recorded so don't run processors or insert into ets table SpanCtx end. end_span(SpanCtx=#span_ctx{span_sdk={_, OnEndProcessors}}) -> end_span(SpanCtx, undefined, OnEndProcessors). end_span(SpanCtx=#span_ctx{span_sdk={_, OnEndProcessors}}, Timestamp) -> end_span(SpanCtx, Timestamp, OnEndProcessors). %% @doc End a span based on its context and send to exporter. -spec end_span(opentelemetry:span_ctx(), integer() | undefined, fun()) -> boolean() | {error, term()}. end_span(#span_ctx{span_id=SpanId, is_recording=true, tracestate=Tracestate}, Timestamp, Processors) -> case ets:take(?SPAN_TAB, SpanId) of [Span] -> Span1 = otel_span_utils:end_span((?assert_type(Span, #span{}))#span{tracestate=Tracestate, is_recording=false}, Timestamp), Processors(Span1); _ -> false end; end_span(_, _, _) -> true. -spec get_ctx(opentelemetry:span()) -> opentelemetry:span_ctx(). get_ctx(#span{trace_id=TraceId, span_id=SpanId, tracestate=TraceState, is_recording=IsRecording}) -> #span_ctx{trace_id=TraceId, hex_trace_id=otel_utils:encode_hex(<>), span_id=SpanId, hex_span_id=otel_utils:encode_hex(<>), tracestate=TraceState, is_recording=IsRecording}. -spec set_attribute(opentelemetry:span_ctx() | undefined, opentelemetry:attribute_key(), opentelemetry:attribute_value()) -> boolean(). set_attribute(#span_ctx{span_id=SpanId}, Key, Value) -> try ets:lookup_element(?SPAN_TAB, SpanId, #span.attributes) of Attributes -> ets:update_element(?SPAN_TAB, SpanId, {#span.attributes, otel_attributes:set(Key, Value, Attributes)}) catch error:badarg -> false end; set_attribute(_, _, _) -> false. %% Note: Spans are referenced through the current active span context in a process %% and thus modified only by a single process, so concurrent updates of the same field %% are not a real concern. This allows `add_events' and `set_attributes' to lookup and %% update only the specific element of the `span' without worrying about it having been %% changed by another process between the lookup and update. -spec set_attributes(opentelemetry:span_ctx() | undefined, opentelemetry:attributes_map()) -> boolean(). set_attributes(#span_ctx{span_id=SpanId}, NewAttributes) -> try ets:lookup_element(?SPAN_TAB, SpanId, #span.attributes) of Attributes -> ets:update_element(?SPAN_TAB, SpanId, {#span.attributes, otel_attributes:set(NewAttributes, Attributes)}) catch error:badarg -> false end. -spec add_event(opentelemetry:span_ctx() | undefined, unicode:unicode_binary(), opentelemetry:attributes_map()) -> boolean(). add_event(SpanCtx, Name, Attributes) -> Events = opentelemetry:events([{Name, Attributes}]), add_events(SpanCtx, Events). -spec add_events(opentelemetry:span_ctx() | undefined, [opentelemetry:event()]) -> boolean(). add_events(#span_ctx{span_id=SpanId}, NewEvents) -> try ets:lookup_element(?SPAN_TAB, SpanId, #span.events) of Events -> ets:update_element(?SPAN_TAB, SpanId, {#span.events, otel_events:add(NewEvents, Events)}) catch error:badarg -> false end. -spec set_status(opentelemetry:span_ctx() | undefined, opentelemetry:status()) -> boolean(). set_status(#span_ctx{span_id=SpanId}, Status=#status{code=NewCode}) -> try ets:lookup_element(?SPAN_TAB, SpanId, #span.status) of #status{code=?OTEL_STATUS_ERROR} when NewCode =:= ?OTEL_STATUS_OK -> %% can only set status to OK if it has been set to ERROR before ets:update_element(?SPAN_TAB, SpanId, {#span.status, Status}); #status{code=?OTEL_STATUS_UNSET} -> %% if UNSET then the status can be updated to OK or ERROR ets:update_element(?SPAN_TAB, SpanId, {#span.status, Status}); undefined -> %% if undefined then the status can be updated to anything ets:update_element(?SPAN_TAB, SpanId, {#span.status, Status}); _ -> %% nothing to do since status code is either %% OK or ERROR but NewCode is not OK false catch error:badarg -> false end; set_status(_, _) -> false. -spec update_name(opentelemetry:span_ctx() | undefined, opentelemetry:span_name()) -> boolean(). update_name(#span_ctx{span_id=SpanId}, Name) -> ets:update_element(?SPAN_TAB, SpanId, {#span.name, Name}); update_name(_, _) -> false. %% storage_insert(undefined) -> true; storage_insert(Span) -> try ets:insert(?SPAN_TAB, Span) catch error:badarg -> false end. init(_Opts) -> %% ets table is required for other parts to not crash so we create %% it in init and not in a handle_continue or whatever else case ets:info(?SPAN_TAB, name) of undefined -> ets:new(?SPAN_TAB, [named_table, public, {write_concurrency, true}, {keypos, #span.span_id}]); _ -> ok end, {ok, #state{}}. handle_call(_Msg, _From, State) -> {noreply, State}. handle_cast(_Msg, State) -> {noreply, State}.