Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Copyright (c) 2019, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* The Universal Permissive License (UPL), Version 1.0
*
* Subject to the condition set forth below, permission is hereby granted to any
* person obtaining a copy of this software, associated documentation and/or
* data (collectively the "Software"), free of charge and under any and all
* copyright rights in the Software, and any and all patent rights owned or
* freely licensable by each licensor hereunder covering either (i) the
* unmodified Software as contributed to or provided by such licensor, or (ii)
* the Larger Works (as defined below), to deal in both
*
* (a) the Software, and
*
* (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
* one is included with the Software each a "Larger Work" to which the Software
* is contributed by such licensors),
*
* without restriction, including without limitation the rights to copy, create
* derivative works of, display, perform, and distribute the Software and make,
* use, sell, offer for sale, import, export, have made, and have sold the
* Software and the Larger Work(s), and to sublicense the foregoing rights on
* either these or other terms.
*
* This license is subject to the following condition:
*
* The above copyright notice and either this complete permission notice or at a
* minimum a reference to the UPL must be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package org.graalvm.polyglot;
import java.util.function.Consumer;
import java.util.function.Predicate;
/**
* Represents resource limits configuration that is used to configure contexts. Resource limit
* instances are created using the {@link #newBuilder() builder} and activated by
* {@link Context.Builder#resourceLimits(ResourceLimits) enabling} them for a {@link Context
* context}. All configured limits are applied per context instance. Resource limits may be
* {@link Context#resetLimits() reset}. If a resource limit is triggered the context that triggered
* the limit will automatically be {@link Context#close(boolean) closed} and can no longer be used
* to evaluate code.
*
* The following resource limits are supported:
*
*
{@link Builder#statementLimit(long, Predicate) Statement count} limit per context. Allows to
* limit the amount of statements executed per context.
*
*
*
Statement Limit Example
*
* ResourceLimits limits = ResourceLimits.newBuilder()
* .statementLimit(500, null)
* .build();
* try (Context context = Context.newBuilder("js")
* .resourceLimits(limits)
* .build();) {
* try {
* context.eval("js", "while(true);");
* assert false;
* } catch (PolyglotException e) {
* // triggered after 500 iterations of while(true);
* // context is closed and can no longer be used
* assert e.isCancelled();
* }
* }
*
*
*
* @see #newBuilder()
* @since 19.3
*/
public final class ResourceLimits {
private static final ResourceLimits EMPTY = new ResourceLimits(null);
final Object receiver;
ResourceLimits(Object receiver) {
this.receiver = receiver;
}
/**
* Creates a new builder to construct {@link ResourceLimits} instances.
*
* @since 19.3
*/
public static Builder newBuilder() {
return EMPTY.new Builder();
}
/**
* A builder used to construct resource limits. Builder instances are not thread-safe and may
* not be used from multiple threads at the same time.
*
* @since 19.3
*/
public final class Builder {
long statementLimit;
Predicate statementLimitSourceFilter;
Consumer onLimit;
Builder() {
}
/**
* Specifies the maximum number of statements a context may execute until the onLimit event
* is notified and the context will be {@link Context#close() closed}. After the statement
* limit was triggered for a context, it is no longer usable and every use of the context
* will throw a {@link PolyglotException} that returns true for
* {@link PolyglotException#isCancelled()}. The statement limit is independent of the number
* of threads executing and is applied per context. Invoking this method multiple times
* overwrites previous statement limit configurations. If the statement limit is exceeded
* then the {@link #onLimit(Consumer) onLimit} listener is notified.
*
* By default there is no statement limit applied. The limit may be set to 0 to disable it.
* In addition to the limit a source filter may be set to indicate for which sources the
* limit should be applied. If the source filter is null then it will be
* applied to all {@link Source#isInternal() internal} and public sources. The provided
* limit must not be negative otherwise an {@link IllegalArgumentException} is thrown. If a
* {@link Context.Builder#engine(Engine) shared engine} is used then the same source filter
* instance must be used for all contexts of an engine. Otherwise an
* {@link IllegalArgumentException} is thrown when the context is
* {@link Context.Builder#build() built}. The limit itself may vary between contexts.
*
* The statement limit is applied to the context and all inner contexts it spawns.
* Therefore, new inner contexts cannot be used to exceed the statement limit.
*
* Note that attaching a statement limit to a context reduces the throughput of all guest
* applications with the same engine. The statement counter needs to be updated with every
* statement that is executed. It is recommended to benchmark the use of the statement limit
* before it is used in production.
*
* Note that the complexity of a single statement may not be constant time depending on the
* guest language. For example, statements that execute JavaScript builtins, like
* Array.sort, may account for a single statement, but its execution time is
* dependent on the size of the array. The statement count limit is therefore not suitable
* to perform time boxing and must be combined with other more reliable measures.
*
* @see ResourceLimits Example Usage
* @since 19.3
*/
@SuppressWarnings("hiding")
public Builder statementLimit(long limit, Predicate sourceFilter) {
if (limit < 0) {
throw new IllegalArgumentException("The statement limit must not be negative.");
}
this.statementLimit = limit;
this.statementLimitSourceFilter = sourceFilter;
return this;
}
/**
* Notified when a resource limit is reached. Default is null. May be set to
* null to disable events.
*
* @since 19.3
*/
public Builder onLimit(@SuppressWarnings("hiding") Consumer onLimit) {
this.onLimit = onLimit;
return this;
}
/**
* Builds the limit configuration object.
*
* @see ResourceLimits Example Usage
* @since 19.3
*/
public ResourceLimits build() {
return new ResourceLimits(Engine.getImpl().buildLimits(statementLimit, statementLimitSourceFilter, onLimit));
}
}
}
