Update otel tracer caching implementation

Author: shikokuchuo

R/otel.R

@@ -1,53 +1,48 @@
 otel_tracer_name <- "org.r-lib.testthat"
-otel_is_tracing <- FALSE
-otel_tracer <- NULL
 
 # generic otel helpers ---------------------------------------------------------
 
-# nocov start
-
-otel_cache_tracer <- function() {
-  requireNamespace("otel", quietly = TRUE) || return()
-  otel_tracer <<- otel::get_tracer(otel_tracer_name)
-  otel_is_tracing <<- tracer_enabled(otel_tracer)
-}
-
-# nocov end
+otel_cache_tracer <- NULL
+otel_local_active_span <- NULL
+
+local({
+  otel_is_tracing <- FALSE
+  otel_tracer <- NULL
+
+  otel_cache_tracer <<- function() {
+    requireNamespace("otel", quietly = TRUE) || return()
+    otel_tracer <<- otel::get_tracer(otel_tracer_name)
+    otel_is_tracing <<- tracer_enabled(otel_tracer)
+  }
+
+  otel_local_active_span <<- function(
+    name,
+    label,
+    attributes = list(),
+    links = NULL,
+    options = NULL,
+    scope = parent.frame()
+  ) {
+    otel_is_tracing || return()
+    spn <- otel::start_local_active_span(
+      sprintf("%s %s", name, label),
+      attributes = otel::as_attributes(attributes),
+      links = links,
+      options = options,
+      tracer = otel_tracer,
+      activation_scope = scope
+    )
+  }
+})
 
 tracer_enabled <- function(tracer) {
   .subset2(tracer, "is_enabled")()
 }
 
-otel_refresh_tracer <- function() {
-  requireNamespace("otel", quietly = TRUE) || return()
-  tracer <- otel::get_tracer()
-  modify_binding(
-    topenv(),
-    list(otel_tracer = tracer, otel_is_tracing = tracer_enabled(tracer))
-  )
-}
-
-modify_binding <- function(env, lst) {
-  lapply(names(lst), unlockBinding, env)
-  list2env(lst, envir = env)
-  lapply(names(lst), lockBinding, env)
-}
-
-otel_local_active_span <- function(
-  name,
-  label,
-  attributes = list(),
-  links = NULL,
-  options = NULL,
-  scope = parent.frame()
-) {
-  otel_is_tracing || return()
-  spn <- otel::start_local_active_span(
-    sprintf("%s %s", name, label),
-    attributes = otel::as_attributes(attributes),
-    links = links,
-    options = options,
-    tracer = otel_tracer,
-    activation_scope = scope
-  )
+with_otel_record <- function(expr) {
+  on.exit(otel_cache_tracer())
+  otelsdk::with_otel_record({
+    otel_cache_tracer()
+    expr
+  })
 }

tests/testthat/test-otel.R

@@ -1,15 +1,12 @@
 test_that("otel instrumentation works", {
   skip_if_not_installed("otelsdk")
 
-  record <- otelsdk::with_otel_record({
-    otel_refresh_tracer()
+  record <- with_otel_record({
     test_that("otel testing", {
       expect_equal(1, 1)
       expect_error(stop("otel error"))
     })
   })
-  # reset tracer after tests
-  otel_refresh_tracer()
 
   traces <- record$traces
   expect_length(traces, 1L)