io.activej.common.Checks Maven / Gradle / Ivy
/*
* Copyright (C) 2020 ActiveJ LLC.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.activej.common;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;
/**
* This class is used for determining whether {@link Checks} should be enabled or not.
* It is sometimes useful to disable preconditions checks at runtime environment
* to squeeze out more performance in a tight loop.
*
* The common pattern is having a
*
* {@code private static final boolean CHECK = Check.isEnabled(MyClass.class);}
*
* constant in your class. When using {@link Checks} just wrap the call in if-statement like so:
*
* {@code if (CHECK) Preconditions.checkNotNull(value);}
*
*
* By default, all checks are disabled (like java asserts).
* To enable all checks you can run application with system property {@code -Dchk=on}
* You can enable or disable checks for the whole package (with its subpackages) or for individual classes
* like so: {@code -Dchk:io.activej.eventloop=on -Dchk:io.activej.promise.Promise=off}.
*/
public final class Checks {
private static final boolean ENABLED_BY_DEFAULT;
private static final String ENV_PREFIX = "chk:";
static {
String enabled = System.getProperty("chk");
if (enabled == null || enabled.equals("off")) ENABLED_BY_DEFAULT = false;
else if (enabled.equals("on")) ENABLED_BY_DEFAULT = true;
else throw new RuntimeException(getErrorMessage(enabled));
}
/**
* Indicates whether checks are enabled or disabled for the specified class
*
* @param cls class to be checked
* @return {@code true} if checks are enabled for the given class, {@code false} otherwise
*/
public static boolean isEnabled(Class cls) {
checkState(!cls.isAnonymousClass(), "Anonymous classes cannot be used for checks");
String property;
String path = cls.getName();
if ((property = System.getProperty(ENV_PREFIX + path)) == null) {
property = System.getProperty(ENV_PREFIX + cls.getSimpleName());
while (property == null) {
int idx = path.lastIndexOf('.');
if (idx == -1) break;
path = path.substring(0, idx);
property = System.getProperty(ENV_PREFIX + path);
}
}
boolean enabled = ENABLED_BY_DEFAULT;
if (property != null) {
if (property.equals("on")) enabled = true;
else if (property.equals("off")) enabled = false;
else throw new RuntimeException(getErrorMessage(property));
}
return enabled;
}
public static boolean isEnabledByDefault() {
return ENABLED_BY_DEFAULT;
}
@NotNull
public static T checkNotNull(@Nullable T reference) {
if (reference != null) {
return reference;
}
throw new NullPointerException();
}
@NotNull
public static T checkNotNull(@Nullable T reference, Object message) {
if (reference != null) {
return reference;
}
throw new NullPointerException(String.valueOf(message));
}
@NotNull
public static T checkNotNull(@Nullable T reference, Supplier message) {
if (reference != null) {
return reference;
}
throw new NullPointerException(message.get());
}
@NotNull
public static T checkNotNull(@Nullable T reference, String template, Object... args) {
if (reference != null) {
return reference;
}
throw new NullPointerException(String.format(template, args));
}
public static void checkState(boolean expression) {
if (!expression) {
throw new IllegalStateException();
}
}
public static void checkState(boolean expression, Object message) {
if (!expression) {
throw new IllegalStateException(String.valueOf(message));
}
}
public static void checkState(boolean expression, Supplier message) {
if (!expression) {
throw new IllegalStateException(message.get());
}
}
public static void checkState(boolean expression, String template, Object... args) {
if (!expression) {
throw new IllegalStateException(String.format(template, args));
}
}
public static void checkArgument(boolean expression) {
if (!expression) {
throw new IllegalArgumentException();
}
}
public static void checkArgument(boolean expression, Object message) {
if (!expression) {
throw new IllegalArgumentException(String.valueOf(message));
}
}
public static void checkArgument(boolean expression, Supplier message) {
if (!expression) {
throw new IllegalArgumentException(message.get());
}
}
public static void checkArgument(boolean expression, String template, Object... args) {
if (!expression) {
throw new IllegalArgumentException(String.format(template, args));
}
}
public static T checkArgument(T argument, Predicate predicate) {
if (predicate.test(argument)) {
return argument;
}
throw new IllegalArgumentException();
}
public static T checkArgument(T argument, Predicate predicate, Object message) {
if (predicate.test(argument)) {
return argument;
}
throw new IllegalArgumentException(String.valueOf(message));
}
public static T checkArgument(T argument, Predicate predicate, Supplier message) {
if (predicate.test(argument)) {
return argument;
}
throw new IllegalArgumentException(message.get());
}
public static T checkArgument(T argument, Predicate predicate, Function message) {
if (predicate.test(argument)) {
return argument;
}
throw new IllegalArgumentException(message.apply(argument));
}
public static T checkArgument(T argument, Predicate predicate, String template, Object... args) {
if (predicate.test(argument)) {
return argument;
}
throw new IllegalArgumentException(String.format(template, args));
}
private static String getErrorMessage(String value) {
return "Only 'on' and 'off' values are allowed for 'chk' system properties, was '" + value + '\'';
}
}