static HashMap<Set<S>, Class> loadFunctions_cache = new HashMap;
static Lock loadFunctions_cached_lock = lock();

sbool loadFunctions_preferDiskCache; // Note: This may use outdated versions of standard functions

static Class loadFunctions_cached(S... functions) {
  ret loadFunctions_cached(asList(functions));
}

static Class loadFunctions_cached(Collection<S> functions) {
  TreeSet<S> functionSet = new TreeSet<S>(functions);
  lock loadFunctions_cached_lock;
  Class c = loadFunctions_cache.get(functionSet);
  if (c != null) ret c;
  S transpilation = null;
  
  // new mode for slow machines (Raspberry Pi): get server transpilation
  if (l(functions) == 1 && isSlowMachine()) {
    S snippetID = stdFunctions_cached().get(first(functions));
    if (nempty(snippetID)) {
      if (!isMD5(getUpToDateSnippetTranspilationMD5(snippetID)))
        print("Slow machine mode: " + snippetID + " transpilation not up to date");
      else {
        transpilation = getServerTranspiledWithoutLibs(snippetID); // TODO: libs?
        print("Loaded server transpilation: " + snippetID);
      }
    }
  }
  
  if (transpilation == null) {
    S cached = getTranspiledStandardFunctionsIfCached(functionSet);
    // TODO: make sure we're using an up-to-date transpiler too
    if (cached != null && (loadFunctions_preferDiskCache || standardFunctionsCacheUpToDate(functionSet)))
      transpilation = cached;
  }
  if (transpilation != null) {
    // TODO: LIBS
    print("Loading " + joinWithPlus(functionSet));
    c = veryQuickJava_finish(transpilation, emptyList());
  }
  
  if (c == null) c = loadFunctions(functionSet);
  
  loadFunctions_cache.put(functionSet, c);
  assertNotNull(loadFunctions_cache.get(functionSet));
  ret c;
}

svoid loadFunctions_cached_clearCache() {
  lock loadFunctions_cached_lock;
  loadFunctions_cache.clear();
}

svoid _onLoad_loadFunctions_cached {
  ownResource(vmBus_onMessage('refreshedTranspiler, r loadFunctions_clearCache));
}

Began life as a copy of #1007852