builtins: refactor shared console implementation (#432)

Author: Guy Bedford

c-dependencies/js-compute-runtime/builtins/shared/console.cpp

@@ -400,7 +400,7 @@ JS::Result<mozilla::Ok> ToSource(JSContext *cx, std::string &sourceOut, JS::Hand
 
 namespace builtins {
 
-template <const char *prefix, uint8_t prefix_len>
+template <Console::LogType log_ty>
 static bool console_out(JSContext *cx, unsigned argc, JS::Value *vp) {
   JS::CallArgs args = CallArgsFromVp(argc, vp);
   std::string fullLogLine = "";
@@ -425,25 +425,18 @@ static bool console_out(JSContext *cx, unsigned argc, JS::Value *vp) {
     }
   }
 
-  printf("%s: %s\n", prefix, fullLogLine.c_str());
-  fflush(stdout);
+  builtin_impl_console_log(log_ty, fullLogLine.c_str());
 
   args.rval().setUndefined();
   return true;
 }
 
-static constexpr char PREFIX_LOG[] = "Log";
-static constexpr char PREFIX_DEBUG[] = "Debug";
-static constexpr char PREFIX_INFO[] = "Info";
-static constexpr char PREFIX_WARN[] = "Warn";
-static constexpr char PREFIX_ERROR[] = "Error";
-
 const JSFunctionSpec Console::methods[] = {
-    JS_FN("log", (console_out<PREFIX_LOG, 3>), 1, JSPROP_ENUMERATE),
-    JS_FN("debug", (console_out<PREFIX_DEBUG, 5>), 1, JSPROP_ENUMERATE),
-    JS_FN("info", (console_out<PREFIX_INFO, 4>), 1, JSPROP_ENUMERATE),
-    JS_FN("warn", (console_out<PREFIX_WARN, 4>), 1, JSPROP_ENUMERATE),
-    JS_FN("error", (console_out<PREFIX_ERROR, 5>), 1, JSPROP_ENUMERATE),
+    JS_FN("log", (console_out<Console::LogType::Log>), 1, JSPROP_ENUMERATE),
+    JS_FN("debug", (console_out<Console::LogType::Debug>), 1, JSPROP_ENUMERATE),
+    JS_FN("info", (console_out<Console::LogType::Info>), 1, JSPROP_ENUMERATE),
+    JS_FN("warn", (console_out<Console::LogType::Warn>), 1, JSPROP_ENUMERATE),
+    JS_FN("error", (console_out<Console::LogType::Error>), 1, JSPROP_ENUMERATE),
     JS_FS_END};
 
 const JSPropertySpec Console::properties[] = {JS_PS_END};

c-dependencies/js-compute-runtime/builtins/shared/console.h

@@ -9,6 +9,13 @@ class Console : public BuiltinNoConstructor<Console> {
 private:
 public:
   static constexpr const char *class_name = "Console";
+  enum LogType {
+    Log,
+    Info,
+    Debug,
+    Warn,
+    Error,
+  };
   enum Slots { Count };
   static const JSFunctionSpec methods[];
   static const JSPropertySpec properties[];
@@ -18,4 +25,6 @@ class Console : public BuiltinNoConstructor<Console> {
 
 } // namespace builtins
 
+void builtin_impl_console_log(builtins::Console::LogType log_ty, const char *msg);
+
 #endif

c-dependencies/js-compute-runtime/js-compute-builtins.cpp

@@ -68,6 +68,8 @@ using std::chrono::ceil;
 using std::chrono::milliseconds;
 using std::chrono::system_clock;
 
+using builtins::Console;
+
 using JS::CallArgs;
 using JS::CallArgsFromVp;
 using JS::UniqueChars;
@@ -5318,6 +5320,29 @@ UniqueChars stringify_value(JSContext *cx, JS::HandleValue value) {
 
 bool debug_logging_enabled() { return builtins::Fastly::debug_logging_enabled; }
 
+void builtin_impl_console_log(Console::LogType log_ty, const char *msg) {
+  const char *prefix = "";
+  switch (log_ty) {
+  case Console::LogType::Log:
+    prefix = "Log";
+    break;
+  case Console::LogType::Debug:
+    prefix = "Debug";
+    break;
+  case Console::LogType::Info:
+    prefix = "Info";
+    break;
+  case Console::LogType::Warn:
+    prefix = "Warn";
+    break;
+  case Console::LogType::Error:
+    prefix = "Error";
+    break;
+  }
+  fprintf(stdout, "%s: %s\n", prefix, msg);
+  fflush(stdout);
+}
+
 bool dump_value(JSContext *cx, JS::Value val, FILE *fp) {
   RootedValue value(cx, val);
   UniqueChars utf8chars = stringify_value(cx, value);