Allow user to specify start time

lib/opentelemetry/trace/recording_span.lua

@@ -21,15 +21,16 @@ local mt = {
 -- @config              optional config
 --                          config.kind: span kind
 --                          config.attributes: span attributes
+-- @start_time          optional start time
 -- @return              span
 ------------------------------------------------------------------
-function _M.new(tracer, parent_ctx, ctx, name, config)
+function _M.new(tracer, parent_ctx, ctx, name, config, start_time)
     local self = {
         tracer = tracer,
         parent_ctx = parent_ctx,
         ctx = ctx,
         name = name,
-        start_time = util.time_nano(),
+        start_time = start_time or util.time_nano(),
         end_time = 0,
         kind = span_kind.validate(config.kind),
         attributes = config.attributes or {},

lib/opentelemetry/trace/tracer.lua

@@ -19,7 +19,7 @@ function _M.new(provider, il)
     return setmetatable(self, mt)
 end
 
-local function new_span(self, context, name, config)
+local function new_span(self, context, name, config, start_time)
     local span_context = context:span_context()
     if not config then
         config = {}
@@ -52,7 +52,7 @@ local function new_span(self, context, name, config)
     if not sampling_result:is_recording() then
         span = non_recording_span_new(self, new_span_context)
     else
-        span = recording_span_new(self, span_context, new_span_context, name, config)
+        span = recording_span_new(self, span_context, new_span_context, name, config, start_time)
     end
 
     return context:with_span(span), span
@@ -66,12 +66,13 @@ end
 -- @span_start_config   [optional]
 --                          span_start_config.kind: opentelemetry.trace.span_kind.*
 --                          span_start_config.attributes: a list of attribute
+-- @start_time          [optional] start time: nanoseconds
 -- @return
 --                      context: new context with span
 --                      span
 ------------------------------------------------------------------
-function _M.start(self, context, span_name, span_start_config)
-    return new_span(self, context, span_name, span_start_config)
+function _M.start(self, context, span_name, span_start_config, start_time)
+    return new_span(self, context, span_name, span_start_config, start_time)
 end
 
 return _M

spec/trace/exporter/otlp_spec.lua

@@ -25,8 +25,8 @@ describe("encode_spans", function()
         local ctx = context.new()
         local spans = {}
         for i=10,1,-1 do
-            ctx, span = tracer:start(ctx, "test span" .. i)
-            span:finish()
+            ctx, span = tracer:start(ctx, "test span" .. i, {}, 123456788)
+            span:finish(123456789)
             table.insert(spans, span)
         end
         local cb = exporter.new(nil)
@@ -36,6 +36,8 @@ describe("encode_spans", function()
         local resource = encoded.resource_spans[1]
         assert(#resource.instrumentation_library_spans == 1)
         assert(#resource.instrumentation_library_spans[1].spans == 10)
+        assert(resource.instrumentation_library_spans[1].spans[1].start_time_unix_nano == "123456788")
+        assert(resource.instrumentation_library_spans[1].spans[1].end_time_unix_nano == "123456789")
     end)
 
     it("one resource span and two ils for spans from distinct tracers", function()

t/trace/span_finish_timestamp.t → t/trace/span_timestamps.t

@@ -8,7 +8,7 @@ run_tests();
 
 __DATA__
 
-=== TEST 1: span end timestamp can be set explicitly
+=== TEST 1: span start and end timestamps can be set explicitly
 --- config
 location = /t {
     content_by_lua_block {
@@ -19,8 +19,11 @@ location = /t {
         local attr = require("opentelemetry.attribute")
         local tracer = tracer_provider:tracer("unit_test")
         local context, recording_span = tracer:start(context, "recording",
-            {kind = span_kind.producer, attributes = {attr.string("key", "value")}})
+            {kind = span_kind.producer, attributes = {attr.string("key", "value")}}, 123456788)
         context.sp:finish(123456789)
+        if context.sp.start_time ~= 123456788 then
+            ngx.log(ngx.ERR, "start time should have been 123456788, was " .. context.sp.start_time)
+        end
         if context.sp.end_time ~= 123456789 then
             ngx.log(ngx.ERR, "end time should have been 123456789, was " .. context.sp.end_time)
         end