private Map<String, Object> mergeBindings(
final Context context, final Bindings request, final Bindings... scopes) {
Set<String> safeAttributes = null != request ? request.keySet() : Collections.EMPTY_SET;
Map<String, Object> scope = new HashMap<String, Object>();
for (Map<String, Object> next : scopes) {
if (null == next) {
continue;
}
for (Map.Entry<String, Object> entry : next.entrySet()) {
if (scope.containsKey(entry.getKey()) || safeAttributes.contains(entry.getKey())) {
continue;
}
scope.put(entry.getKey(), entry.getValue());
}
}
// Make lazy deep copy
if (!scope.isEmpty()) {
scope =
new LazyMap<String, Object>(
new InnerMapFactory(
scope,
new OperationParameter(context, "DEFAULT", engine.getPersistenceConfig())));
}
if (null == request || request.isEmpty()) {
return scope;
} else if (scope.isEmpty()) {
return request;
} else {
request.putAll(scope);
return request;
}
}
/**
* Выполняет скрипт
*
* @param script Тело скрипта / код
* @param language Язык скрипта (JavaScript)
* @param bindings Переменные для привязки/передачи данных
* @return Результат выполнения
* @throws ScriptException Ошибка исполнения скрипта
*/
public static Object eval(
String script, String language, Map<? extends String, ? extends Object> bindings)
throws ScriptException {
if (script == null) throw new IllegalArgumentException("script==null");
if (language == null) throw new IllegalArgumentException("language==null");
// if( bindings==null )throw new IllegalArgumentException("bindings==null");
ScriptEngine se = null;
Map<String, ScriptEngine> map = getMapScriptEngines();
if (map.containsKey(language)) {
se = map.get(language);
} else {
se = getScriptEngineManager().getEngineByName(language);
if (se == null)
throw new IllegalArgumentException(Text.template("language ({0}) not supported", language));
map.put(language, se);
}
Bindings seBindings = se.getBindings(javax.script.ScriptContext.ENGINE_SCOPE);
if (bindings != null) seBindings.putAll(bindings);
return se.eval(script);
}
private ScriptEngines createScriptEngines() {
// plugins already on the path - ones static to the classpath
final List<GremlinPlugin> globalPlugins = new ArrayList<>();
ServiceLoader.load(GremlinPlugin.class).forEach(globalPlugins::add);
return new ScriptEngines(
se -> {
// this first part initializes the scriptengines Map
for (Map.Entry<String, EngineSettings> config : settings.entrySet()) {
final String language = config.getKey();
se.reload(
language,
new HashSet<>(config.getValue().getImports()),
new HashSet<>(config.getValue().getStaticImports()),
config.getValue().getConfig());
}
// use grabs dependencies and returns plugins to load
final List<GremlinPlugin> pluginsToLoad = new ArrayList<>(globalPlugins);
use.forEach(
u -> {
if (u.size() != 3)
logger.warn(
"Could not resolve dependencies for [{}]. Each entry for the 'use' configuration must include [groupId, artifactId, version]",
u);
else {
logger.info("Getting dependencies for [{}]", u);
pluginsToLoad.addAll(se.use(u.get(0), u.get(1), u.get(2)));
}
});
// now that all dependencies are in place, the imports can't get messed up if a plugin
// tries to execute
// a script (as the script engine appends the import list to the top of all scripts passed
// to the engine).
// only enable those plugins that are configured to be enabled.
se.loadPlugins(
pluginsToLoad
.stream()
.filter(plugin -> enabledPlugins.contains(plugin.getName()))
.collect(Collectors.toList()));
// initialization script eval can now be performed now that dependencies are present with
// "use"
for (Map.Entry<String, EngineSettings> config : settings.entrySet()) {
final String language = config.getKey();
// script engine initialization files that fail will only log warnings - not fail server
// initialization
final AtomicBoolean hasErrors = new AtomicBoolean(false);
config
.getValue()
.getScripts()
.stream()
.map(File::new)
.filter(
f -> {
if (!f.exists()) {
logger.warn(
"Could not initialize {} ScriptEngine with {} as file does not exist",
language,
f);
hasErrors.set(true);
}
return f.exists();
})
.map(
f -> {
try {
return Pair.with(f, Optional.of(new FileReader(f)));
} catch (IOException ioe) {
logger.warn(
"Could not initialize {} ScriptEngine with {} as file could not be read - {}",
language,
f,
ioe.getMessage());
hasErrors.set(true);
return Pair.with(f, Optional.<FileReader>empty());
}
})
.filter(p -> p.getValue1().isPresent())
.map(p -> Pair.with(p.getValue0(), p.getValue1().get()))
.forEachOrdered(
p -> {
try {
final Bindings bindings = new SimpleBindings();
bindings.putAll(this.globalBindings);
// evaluate init scripts with hard reference so as to ensure it doesn't get
// garbage collected
bindings.put(
GremlinGroovyScriptEngine.KEY_REFERENCE_TYPE,
GremlinGroovyScriptEngine.REFERENCE_TYPE_HARD);
se.eval(p.getValue1(), bindings, language);
// re-assign graph bindings back to global bindings and grab TraversalSource
// creations.
// prevent assignment of non-graph implementations just in case someone
// tries to overwrite
// them in the init
bindings
.entrySet()
.stream()
.filter(promoteBinding)
.forEach(kv -> this.globalBindings.put(kv.getKey(), kv.getValue()));
logger.info("Initialized {} ScriptEngine with {}", language, p.getValue0());
} catch (ScriptException sx) {
hasErrors.set(true);
logger.warn(
"Could not initialize {} ScriptEngine with {} as script could not be evaluated - {}",
language,
p.getValue0(),
sx.getMessage());
}
});
}
});
}
/**
* Evaluate a script and allow for the submission of both a transform {@link Function} and {@link
* Consumer}. The {@link Function} will transform the result after script evaluates but before
* transaction commit and before the returned {@link CompletableFuture} is completed. The {@link
* Consumer} will take the result for additional processing after the script evaluates and after
* the {@link CompletableFuture} is completed, but before the transaction is committed.
*
* @param script the script to evaluate
* @param language the language to evaluate it in
* @param boundVars the bindings to evaluate in the context of the script
* @param transformResult a {@link Function} that transforms the result - can be {@code null}
* @param withResult a {@link Consumer} that accepts the result - can be {@code null}
*/
public CompletableFuture<Object> eval(
final String script,
final String language,
final Bindings boundVars,
final Function<Object, Object> transformResult,
final Consumer<Object> withResult) {
final String lang = Optional.ofNullable(language).orElse("gremlin-groovy");
logger.debug(
"Preparing to evaluate script - {} - in thread [{}]",
script,
Thread.currentThread().getName());
final Bindings bindings = new SimpleBindings();
bindings.putAll(this.globalBindings);
bindings.putAll(boundVars);
beforeEval.accept(bindings);
final CompletableFuture<Object> evaluationFuture = new CompletableFuture<>();
final FutureTask<Void> f =
new FutureTask<>(
() -> {
try {
logger.debug(
"Evaluating script - {} - in thread [{}]",
script,
Thread.currentThread().getName());
final Object o = scriptEngines.eval(script, bindings, lang);
// apply a transformation before sending back the result - useful when trying to
// force serialization
// in the same thread that the eval took place given ThreadLocal nature of graphs as
// well as some
// transactional constraints
final Object result = null == transformResult ? o : transformResult.apply(o);
evaluationFuture.complete(result);
// a mechanism for taking the final result and doing something with it in the same
// thread, but
// AFTER the eval and transform are done and that future completed. this provides a
// final means
// for working with the result in the same thread as it was eval'd
if (withResult != null) withResult.accept(result);
afterSuccess.accept(bindings);
} catch (Exception ex) {
final Throwable root = null == ex.getCause() ? ex : ExceptionUtils.getRootCause(ex);
// thread interruptions will typically come as the result of a timeout, so in those
// cases,
// check for that situation and convert to TimeoutException
if (root instanceof InterruptedException)
evaluationFuture.completeExceptionally(
new TimeoutException(
String.format(
"Script evaluation exceeded the configured threshold of %s ms for request [%s]: %s",
scriptEvaluationTimeout, script, root.getMessage())));
else {
afterFailure.accept(bindings, root);
evaluationFuture.completeExceptionally(root);
}
}
return null;
});
executorService.execute(f);
if (scriptEvaluationTimeout > 0) {
// Schedule a timeout in the thread pool for future execution
final ScheduledFuture<?> sf =
scheduledExecutorService.schedule(
() -> {
logger.info(
"Timing out script - {} - in thread [{}]",
script,
Thread.currentThread().getName());
if (!f.isDone()) {
afterTimeout.accept(bindings);
f.cancel(true);
}
},
scriptEvaluationTimeout,
TimeUnit.MILLISECONDS);
// Cancel the scheduled timeout if the eval future is complete or the script evaluation failed
// with exception
evaluationFuture.handleAsync(
(v, t) -> {
logger.debug(
"Killing scheduled timeout on script evaluation as the eval completed (possibly with exception).");
return sf.cancel(true);
});
}
return evaluationFuture;
}
