com.oracle.truffle.polyglot.PolyglotIterator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of truffle-api Show documentation
Show all versions of truffle-api Show documentation
Truffle is a multi-language framework for executing dynamic languages
that achieves high performance when combined with Graal.
/*
* Copyright (c) 2020, 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 com.oracle.truffle.polyglot;
import com.oracle.truffle.api.CallTarget;
import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.interop.InteropLibrary;
import com.oracle.truffle.api.interop.StopIterationException;
import com.oracle.truffle.api.interop.TruffleObject;
import com.oracle.truffle.api.interop.UnsupportedMessageException;
import com.oracle.truffle.api.library.CachedLibrary;
import com.oracle.truffle.api.profiles.BranchProfile;
import com.oracle.truffle.api.utilities.TriState;
import com.oracle.truffle.polyglot.PolyglotIteratorFactory.CacheFactory.HasNextNodeGen;
import com.oracle.truffle.polyglot.PolyglotIteratorFactory.CacheFactory.NextNodeGen;
import java.lang.reflect.Type;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Objects;
class PolyglotIterator implements Iterator, PolyglotWrapper {
final Object guestObject;
final PolyglotLanguageContext languageContext;
final Cache cache;
/**
* Caches value returned from the {@link #hasNext()}. The {@link PolyglotIterator} needs to
* preserve the Java {@link Iterator} contract requiring that when the
* {@link Iterator#hasNext()} returns {@code true} the {@link Iterator#next()} does not throw
* {@link NoSuchElementException}. The interop contract is weaker when the underlying data
* structure is modified. We emulate the Java iterator behaviour by throwing a
* {@link ConcurrentModificationException} when we detect an inconsistency among
* {@link InteropLibrary#hasIteratorNextElement(Object)} and
* {@link InteropLibrary#getIteratorNextElement(Object)} calls. The {@link #lastHasNext} field
* is used to detect such an inconsistency.
*/
private TriState lastHasNext;
/**
* A flag marking the iterator as concurrently modified. When the {@link #next()} throws a
* {@link ConcurrentModificationException} any other call to the {@link #next()} has to throw
* {@link ConcurrentModificationException}.
*/
private boolean concurrentlyModified;
PolyglotIterator(Class elementClass, Type elementType, Object array, PolyglotLanguageContext languageContext) {
this.guestObject = array;
this.languageContext = languageContext;
this.cache = Cache.lookup(languageContext, array.getClass(), elementClass, elementType);
lastHasNext = TriState.UNDEFINED;
}
@Override
public Object getGuestObject() {
return guestObject;
}
@Override
public PolyglotLanguageContext getLanguageContext() {
return languageContext;
}
@Override
public PolyglotContextImpl getContext() {
return languageContext.context;
}
@Override
public boolean hasNext() {
if (lastHasNext == TriState.UNDEFINED) {
lastHasNext = TriState.valueOf((Boolean) cache.hasNext.call(languageContext, guestObject));
}
return lastHasNext == TriState.TRUE ? true : false;
}
@Override
@SuppressWarnings("unchecked")
public T next() {
if (concurrentlyModified) {
throw new ConcurrentModificationException();
}
try {
TriState prevHasNext = lastHasNext;
if (lastHasNext == TriState.TRUE) {
lastHasNext = TriState.UNDEFINED;
}
return (T) cache.next.call(languageContext, guestObject, prevHasNext);
} catch (NoSuchElementException noSuchElementException) {
lastHasNext = TriState.FALSE;
throw noSuchElementException;
} catch (ConcurrentModificationException concurrentModificationException) {
concurrentlyModified = true;
throw concurrentModificationException;
}
}
@Override
public String toString() {
return PolyglotWrapper.toString(this);
}
@Override
public int hashCode() {
return PolyglotWrapper.hashCode(languageContext, guestObject);
}
@Override
public boolean equals(Object o) {
if (o instanceof PolyglotIterator) {
return PolyglotWrapper.equals(languageContext, guestObject, ((PolyglotIterator) o).guestObject);
} else {
return false;
}
}
static final class Cache {
final Class receiverClass;
final Class valueClass;
final Type valueType;
final CallTarget hasNext;
final CallTarget next;
final CallTarget apply;
private Cache(Class receiverClass, Class valueClass, Type valueType) {
this.receiverClass = receiverClass;
this.valueClass = valueClass;
this.valueType = valueType;
this.hasNext = HostToGuestRootNode.createTarget(HasNextNodeGen.create(this));
this.next = HostToGuestRootNode.createTarget(NextNodeGen.create(this));
this.apply = HostToGuestRootNode.createTarget(new Apply(this));
}
static Cache lookup(PolyglotLanguageContext languageContext, Class receiverClass, Class valueClass, Type valueType) {
Key cacheKey = new Key(receiverClass, valueClass, valueType);
Cache cache = HostToGuestRootNode.lookupHostCodeCache(languageContext, cacheKey, Cache.class);
if (cache == null) {
cache = HostToGuestRootNode.installHostCodeCache(languageContext, cacheKey, new Cache(receiverClass, valueClass, valueType), Cache.class);
}
assert cache.receiverClass == receiverClass;
assert cache.valueClass == valueClass;
assert Objects.equals(cache.valueType, valueType);
return cache;
}
private static final class Key {
private final Class receiverClass;
private final Class valueClass;
private final Type valueType;
Key(Class receiverClass, Class valueClass, Type valueType) {
this.receiverClass = Objects.requireNonNull(receiverClass);
this.valueClass = Objects.requireNonNull(valueClass);
this.valueType = valueType;
}
@Override
public int hashCode() {
int res = receiverClass.hashCode();
res = res * 31 + valueClass.hashCode();
res = res * 31 + (valueType == null ? 0 : valueType.hashCode());
return res;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
} else if (obj == null || getClass() != obj.getClass()) {
return false;
}
Key other = (Key) obj;
return receiverClass == other.receiverClass && valueClass == other.valueClass && Objects.equals(valueType, other.valueType);
}
}
abstract static class PolyglotIteratorNode extends HostToGuestRootNode {
static final int LIMIT = 5;
final Cache cache;
PolyglotIteratorNode(Cache cache) {
this.cache = cache;
}
@SuppressWarnings("unchecked")
@Override
protected Class getReceiverType() {
return (Class) cache.receiverClass;
}
@Override
public final String getName() {
return "PolyglotIterator<" + cache.receiverClass + ", " + cache.valueType + ">." + getOperationName();
}
protected abstract String getOperationName();
}
abstract static class HasNextNode extends PolyglotIteratorNode {
HasNextNode(Cache cache) {
super(cache);
}
@Override
protected String getOperationName() {
return "hasNext";
}
@Specialization(limit = "LIMIT")
@SuppressWarnings("unused")
Object doCached(PolyglotLanguageContext languageContext, Object receiver, Object[] args,
@CachedLibrary("receiver") InteropLibrary iterators,
@Cached BranchProfile error) {
try {
return iterators.hasIteratorNextElement(receiver);
} catch (UnsupportedMessageException e) {
error.enter();
throw PolyglotInteropErrors.iteratorUnsupported(languageContext, receiver, cache.valueType, "hasNext");
}
}
}
abstract static class NextNode extends PolyglotIteratorNode {
NextNode(Cache cache) {
super(cache);
}
@Override
protected String getOperationName() {
return "next";
}
@Specialization(limit = "LIMIT")
@SuppressWarnings("unused")
Object doCached(PolyglotLanguageContext languageContext, Object receiver, Object[] args,
@CachedLibrary("receiver") InteropLibrary iterators,
@Cached PolyglotToHostNode toHost,
@Cached BranchProfile error,
@Cached BranchProfile stop) {
TriState lastHasNext = (TriState) args[ARGUMENT_OFFSET];
try {
Object next = iterators.getIteratorNextElement(receiver);
if (lastHasNext == TriState.FALSE) {
error.enter();
throw PolyglotInteropErrors.iteratorConcurrentlyModified(languageContext, receiver, cache.valueType);
}
return toHost.execute(languageContext, next, cache.valueClass, cache.valueType);
} catch (StopIterationException e) {
stop.enter();
if (lastHasNext == TriState.TRUE) {
throw PolyglotInteropErrors.iteratorConcurrentlyModified(languageContext, receiver, cache.valueType);
} else {
throw PolyglotInteropErrors.stopIteration(languageContext, receiver, cache.valueType);
}
} catch (UnsupportedMessageException e) {
error.enter();
throw PolyglotInteropErrors.iteratorElementUnreadable(languageContext, receiver, cache.valueType);
}
}
}
private static class Apply extends PolyglotIteratorNode {
@Child private PolyglotExecuteNode apply = PolyglotExecuteNodeGen.create();
Apply(Cache cache) {
super(cache);
}
@Override
protected String getOperationName() {
return "apply";
}
@Override
protected Object executeImpl(PolyglotLanguageContext languageContext, Object receiver, Object[] args) {
return apply.execute(languageContext, receiver, args[ARGUMENT_OFFSET]);
}
}
}
@CompilerDirectives.TruffleBoundary
static PolyglotIterator create(PolyglotLanguageContext languageContext, Object iterable, boolean implementFunction, Class elementClass, Type elementType) {
if (implementFunction) {
return new PolyglotIteratorAndFunction<>(elementClass, elementType, iterable, languageContext);
} else {
return new PolyglotIterator<>(elementClass, elementType, iterable, languageContext);
}
}
}