petrov-mg commented on code in PR #12429: URL: https://github.com/apache/ignite/pull/12429#discussion_r2770854794
########## modules/commons/src/main/java/org/apache/ignite/internal/thread/context/Context.java: ########## @@ -0,0 +1,331 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 org.apache.ignite.internal.thread.context; + +import java.util.ArrayList; +import java.util.List; +import org.apache.ignite.internal.util.typedef.F; +import org.jetbrains.annotations.Nullable; + +import static org.apache.ignite.internal.thread.context.Scope.NOOP_SCOPE; + +/** + * Represents a storage of {@link ContextAttribute}s and their corresponding values bound to the thread. + * The state of Context is determined by a sequence of {@link Update}s applied to it. Each Update stores the + * updated or newly added {@link ContextAttribute} values and link to the previous Update. + * <pre> + * +-----------+ +-----------+ + * | | | A1 -> V2 | + * null <--| A1 -> V1 |<--| | + * | | | A2 -> V3 | + * +-----------+ +-----------+ + *</pre> + * Context Updates can be undone in the same order they were applied by closing the {@link Scope} associated with each + * update (see {@link #set(ContextAttribute, Object)} and related methods). + */ +public class Context { + /** */ + private static final ThreadLocal<Context> INSTANCE = ThreadLocal.withInitial(Context::new); + + /** + * Sequence of updated applied to the Context. Each update holds a link to the previous Update, so we store only + * the reference to the last one. + */ + @Nullable private Update lastUpd; + + /** */ + private Context() { + // No-op. + } + + /** + * Retrieves value associated with specified attribute by accessing Context bound to the thread this method is + * called from. If no value is explicitly associated with specified attribute, {@link ContextAttribute#initialValue()} + * is returned. + * + * @param attr Context Attribute. + * @return Context Attribute Value. + */ + @Nullable public static <T> T get(ContextAttribute<T> attr) { + return INSTANCE.get().getInternal(attr); + } + + /** + * Updates the value of the specified attribute for the Context bound to the thread this method is called from. + * + * @param attr Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T> Scope set(ContextAttribute<T> attr, T val) { + Context ctx = INSTANCE.get(); + + return ctx.getInternal(attr) == val ? NOOP_SCOPE : ctx.applyAttributeUpdates(new AttributeValueHolder<>(attr, val)); + } + + /** + * Updates the values of the specified attributes for the Context bound to the thread this method is called from. + * + * @param attr1 First Context Attribute. + * @param val1 Values associated with first Context Attribute. + * @param attr2 Second Context Attribute. + * @param val2 Values associated with second Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T1, T2> Scope set( + ContextAttribute<T1> attr1, T1 val1, + ContextAttribute<T2> attr2, T2 val2 + ) { + return ContextUpdater.create().set(attr1, val1).set(attr2, val2).apply(); + } + + /** + * Updates the values of the specified attributes for the Context bound to the thread this method is called from. + * + * @param attr1 First Context Attribute. + * @param val1 Values associated with first Context Attribute. + * @param attr2 Second Context Attribute. + * @param val2 Values associated with second Context Attribute. + * @param attr3 Third Context Attribute. + * @param val3 Values associated with third Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T1, T2, T3> Scope set( + ContextAttribute<T1> attr1, T1 val1, + ContextAttribute<T2> attr2, T2 val2, + ContextAttribute<T3> attr3, T3 val3 + ) { + return ContextUpdater.create().set(attr1, val1).set(attr2, val2).set(attr3, val3).apply(); + } + + /** + * Creates Snapshot of all attributes and their corresponding values stored in the Context bound to the thread this + * method is called from. + * + * @return Context Snapshot. + */ + public static ContextSnapshot createSnapshot() { + return INSTANCE.get().createSnapshotInternal(); + } + + /** + * Restores values of all attributes for Context bound to the thread this method is called from. + * + * @param snp Context Snapshot. + * @return Scope instance that, when closed, undoes the applied operation. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static Scope restoreSnapshot(ContextSnapshot snp) { + return INSTANCE.get().restoreSnapshotInternal(snp); + } + + /** + * Retrieves value for the specified attribute from the current Context. If no value is explicitly associated with + * specified attribute, {@link ContextAttribute#initialValue()} is returned. + */ + @Nullable private <T> T getInternal(ContextAttribute<T> attr) { + if (lastUpd == null || (lastUpd.storedAttrBits & attr.bitmask()) == 0) + return attr.initialValue(); // Context does not store value for the specified attribute. + + AttributeValueHolder<T> valHolder = findAttributeValue(attr); + + assert valHolder != null; + assert valHolder.attribute().equals(attr); + + return valHolder.value(); + } + + /** Updates the current context with the specified attributes and their corresponding values. */ + private Scope applyAttributeUpdates(AttributeValueHolder<?>... atrVals) { + lastUpd = new Update(atrVals, lastUpd); + + return lastUpd; + } + + /** Undoes the latest updated. */ + private void undo(Update upd) { + assert lastUpd == upd; + + lastUpd = lastUpd.prev; + } + + /** Iterates over the currently applied context updates and finds the latest value associated with the specified attribute. */ + private <T> AttributeValueHolder<T> findAttributeValue(ContextAttribute<T> attr) { + for (Update upd = lastUpd; upd != null; upd = upd.prev) { + if (!upd.holdsValueFor(attr)) + continue; + + return upd.value(attr); + } + + return null; + } + + /** */ + private ContextSnapshot createSnapshotInternal() { + // The sequence of updates defines the state of the Context. Each update is linked to the previous one and immutable. + // Therefore, to restore the context state elsewhere, we only need to share a reference to the most recent update. + return lastUpd; + } + + /** */ + private Scope restoreSnapshotInternal(ContextSnapshot newSnp) { + ContextSnapshot prevSnp = createSnapshotInternal(); + + if (newSnp == prevSnp) + return NOOP_SCOPE; + + changeState(prevSnp, newSnp); + + return () -> INSTANCE.get().changeState(newSnp, prevSnp); Review Comment: Done. ########## modules/commons/src/main/java/org/apache/ignite/internal/thread/context/Context.java: ########## @@ -0,0 +1,331 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 org.apache.ignite.internal.thread.context; + +import java.util.ArrayList; +import java.util.List; +import org.apache.ignite.internal.util.typedef.F; +import org.jetbrains.annotations.Nullable; + +import static org.apache.ignite.internal.thread.context.Scope.NOOP_SCOPE; + +/** + * Represents a storage of {@link ContextAttribute}s and their corresponding values bound to the thread. + * The state of Context is determined by a sequence of {@link Update}s applied to it. Each Update stores the + * updated or newly added {@link ContextAttribute} values and link to the previous Update. + * <pre> + * +-----------+ +-----------+ + * | | | A1 -> V2 | + * null <--| A1 -> V1 |<--| | + * | | | A2 -> V3 | + * +-----------+ +-----------+ + *</pre> + * Context Updates can be undone in the same order they were applied by closing the {@link Scope} associated with each + * update (see {@link #set(ContextAttribute, Object)} and related methods). + */ +public class Context { + /** */ + private static final ThreadLocal<Context> INSTANCE = ThreadLocal.withInitial(Context::new); + + /** + * Sequence of updated applied to the Context. Each update holds a link to the previous Update, so we store only + * the reference to the last one. + */ + @Nullable private Update lastUpd; + + /** */ + private Context() { + // No-op. + } + + /** + * Retrieves value associated with specified attribute by accessing Context bound to the thread this method is + * called from. If no value is explicitly associated with specified attribute, {@link ContextAttribute#initialValue()} + * is returned. + * + * @param attr Context Attribute. + * @return Context Attribute Value. + */ + @Nullable public static <T> T get(ContextAttribute<T> attr) { + return INSTANCE.get().getInternal(attr); + } + + /** + * Updates the value of the specified attribute for the Context bound to the thread this method is called from. + * + * @param attr Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T> Scope set(ContextAttribute<T> attr, T val) { + Context ctx = INSTANCE.get(); + + return ctx.getInternal(attr) == val ? NOOP_SCOPE : ctx.applyAttributeUpdates(new AttributeValueHolder<>(attr, val)); + } + + /** + * Updates the values of the specified attributes for the Context bound to the thread this method is called from. + * + * @param attr1 First Context Attribute. + * @param val1 Values associated with first Context Attribute. + * @param attr2 Second Context Attribute. + * @param val2 Values associated with second Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T1, T2> Scope set( + ContextAttribute<T1> attr1, T1 val1, + ContextAttribute<T2> attr2, T2 val2 + ) { + return ContextUpdater.create().set(attr1, val1).set(attr2, val2).apply(); + } + + /** + * Updates the values of the specified attributes for the Context bound to the thread this method is called from. + * + * @param attr1 First Context Attribute. + * @param val1 Values associated with first Context Attribute. + * @param attr2 Second Context Attribute. + * @param val2 Values associated with second Context Attribute. + * @param attr3 Third Context Attribute. + * @param val3 Values associated with third Context Attribute. + * @return Scope instance that, when closed, undoes the applied update. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static <T1, T2, T3> Scope set( + ContextAttribute<T1> attr1, T1 val1, + ContextAttribute<T2> attr2, T2 val2, + ContextAttribute<T3> attr3, T3 val3 + ) { + return ContextUpdater.create().set(attr1, val1).set(attr2, val2).set(attr3, val3).apply(); + } + + /** + * Creates Snapshot of all attributes and their corresponding values stored in the Context bound to the thread this + * method is called from. + * + * @return Context Snapshot. + */ + public static ContextSnapshot createSnapshot() { + return INSTANCE.get().createSnapshotInternal(); + } + + /** + * Restores values of all attributes for Context bound to the thread this method is called from. + * + * @param snp Context Snapshot. + * @return Scope instance that, when closed, undoes the applied operation. It is crucial to undo all applied Context + * updates to free up thread-bound resources and avoid memory leaks, so it is highly encouraged to use a + * try-with-resource block to close the returned Scope. Note, updates must be undone in the same order they were applied. + */ + public static Scope restoreSnapshot(ContextSnapshot snp) { + return INSTANCE.get().restoreSnapshotInternal(snp); + } + + /** + * Retrieves value for the specified attribute from the current Context. If no value is explicitly associated with + * specified attribute, {@link ContextAttribute#initialValue()} is returned. + */ + @Nullable private <T> T getInternal(ContextAttribute<T> attr) { + if (lastUpd == null || (lastUpd.storedAttrBits & attr.bitmask()) == 0) + return attr.initialValue(); // Context does not store value for the specified attribute. + + AttributeValueHolder<T> valHolder = findAttributeValue(attr); + + assert valHolder != null; + assert valHolder.attribute().equals(attr); + + return valHolder.value(); + } + + /** Updates the current context with the specified attributes and their corresponding values. */ + private Scope applyAttributeUpdates(AttributeValueHolder<?>... atrVals) { Review Comment: Done. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. 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