PRLogModuleInfo replacement

gistfile1.md

An attempt to get rid of lazy log instantiation boilerplate

#define LAZY_LOG_GETTER(fnx, name) \
    LogModule* fnx() { static LogModule* module = LogModule::CreateModule(name); return module; }

LAZY_LOG_GETTER(GetFooLog, "foo");

// ...

MOZ_LOG(GetFooLog(), LogLevel::Debug, ("Debugging the foo!"));

Or perhaps a nice way w/o macros (I'm not sure how we'd get name in there though)

struct LazyLogModule<name> {
   operator LogModule*() {
       static LogModule* module = LogModule::CreateModule(name); return module;
   }
};

LazyLogModule<"Foo"> gFooLog;

// ...

MOZ_LOG(gFooLog, LogLevel::Debug, ("Debugging the foo!"));

Rough draft of LogModule and LogManager

class LogModule {
public:
  static LogModule* CreateModule(const nsAString& name, LogLevel level = LogLevel::Disabled);
  bool ShouldLog(LogLevel aLevel);

  PRLogModule* GetPRModule();
  LogLevel GetLevel();

private:
  LogModule(PRLogModule aModule, LogLevel level);

  LogModule(LogModule&) = delete;
  LogModule& operator=(const LogModule&) = delete;

  LogLevel mLevel;      // mozilla log level
  PRLogModule* mModule; // non-owning
}

// Handles registration, pref updates
class LogManager
{
public:
  static LogManager& GetManager();

  
private:
  Lock tableLock;
  Table moduleTable;
};

LogModule* CreateModule(const nsAString& name, LogLevel level = LogLevel::Disabled)
{
  AutoLock guard(tableLock);
  
  // check our table
  LogModule* module = table.find(name);
  
  if (!module) {
    PRLogModuleInfo* pr = PR_NewLogModule(name);
    module = new Module(pr, std::max(level, pr->level));
    table.insert(name, module);
  }
  
  return module;
}