shunping commented on code in PR #30317: URL: https://github.com/apache/beam/pull/30317#discussion_r1635356930
########## sdks/java/harness/src/main/java/org/apache/beam/fn/harness/state/OrderedListUserState.java: ########## @@ -0,0 +1,314 @@ +/* + * 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.beam.fn.harness.state; + +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkArgument; +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkNotNull; +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkState; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; +import java.util.Map.Entry; +import java.util.NavigableMap; +import java.util.concurrent.CompletableFuture; +import org.apache.beam.fn.harness.Cache; +import org.apache.beam.fn.harness.Caches; +import org.apache.beam.fn.harness.state.StateFetchingIterators.CachingStateIterable; +import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateClearRequest; +import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateKey; +import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateRequest; +import org.apache.beam.model.fnexecution.v1.BeamFnApi.StateResponse; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.coders.KvCoder; +import org.apache.beam.sdk.coders.LengthPrefixCoder; +import org.apache.beam.sdk.coders.StructuredCoder; +import org.apache.beam.sdk.coders.VarLongCoder; +import org.apache.beam.sdk.fn.stream.PrefetchableIterable; +import org.apache.beam.sdk.fn.stream.PrefetchableIterables; +import org.apache.beam.sdk.util.ByteStringOutputStream; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.TimestampedValue; +import org.apache.beam.sdk.values.TypeDescriptor; +import org.apache.beam.sdk.values.TypeParameter; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.BoundType; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Iterables; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Maps; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Range; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.TreeRangeSet; +import org.joda.time.Instant; + +/** + * An implementation of an ordered list user state that utilizes the Beam Fn State API to fetch, + * clear and persist values. + * + * <p>Calling {@link #asyncClose()} schedules any required persistence changes. This object should + * no longer be used after it is closed. + * + * <p>TODO: Move to an async persist model where persistence is signalled based upon cache memory + * pressure and its need to flush. + */ +public class OrderedListUserState<T> { + private final BeamFnStateClient beamFnStateClient; + private final StateRequest request; + private final TimestampedValueCoder<T> timestampedValueCoder; + // Pending updates to persistent storage + private NavigableMap<Instant, Collection<T>> pendingAdds = Maps.newTreeMap(); + private TreeRangeSet<Instant> pendingRemoves = TreeRangeSet.create(); + + private boolean isCleared = false; + private boolean isClosed = false; + + public static class TimestampedValueCoder<T> extends StructuredCoder<TimestampedValue<T>> { + + private final Coder<T> valueCoder; + + // Internally, a TimestampedValue is encoded with a KvCoder, where the key is encoded with + // a VarLongCoder and the value is encoded with a LengthPrefixCoder. + // Refer to the comment in StateAppendRequest + // (org/apache/beam/model/fn_execution/v1/beam_fn_api.proto) for more detail. + private final KvCoder<Long, T> internalKvCoder; + + public static <T> OrderedListUserState.TimestampedValueCoder<T> of(Coder<T> valueCoder) { + return new OrderedListUserState.TimestampedValueCoder<>(valueCoder); + } + + @Override + public Object structuralValue(TimestampedValue<T> value) { + Object structuralValue = valueCoder.structuralValue(value.getValue()); + return TimestampedValue.of(structuralValue, value.getTimestamp()); + } + + @SuppressWarnings("unchecked") + TimestampedValueCoder(Coder<T> valueCoder) { + this.valueCoder = checkNotNull(valueCoder); + this.internalKvCoder = KvCoder.of(VarLongCoder.of(), LengthPrefixCoder.of(valueCoder)); + } + + @Override + public void encode(TimestampedValue<T> windowedElem, OutputStream outStream) + throws IOException { + internalKvCoder.encode( + KV.of(windowedElem.getTimestamp().getMillis(), windowedElem.getValue()), outStream); + } + + @Override + public TimestampedValue<T> decode(InputStream inStream) throws IOException { + KV<Long, T> kv = internalKvCoder.decode(inStream); + return TimestampedValue.of(kv.getValue(), Instant.ofEpochMilli(kv.getKey())); + } + + @Override + public void verifyDeterministic() throws NonDeterministicException { + verifyDeterministic( + this, "TimestampedValueCoder requires a deterministic valueCoder", valueCoder); + } + + @Override + public List<? extends Coder<?>> getCoderArguments() { + return Arrays.<Coder<?>>asList(valueCoder); + } + + public Coder<T> getValueCoder() { + return valueCoder; + } + + @Override + public TypeDescriptor<TimestampedValue<T>> getEncodedTypeDescriptor() { + return new TypeDescriptor<TimestampedValue<T>>() {}.where( + new TypeParameter<T>() {}, valueCoder.getEncodedTypeDescriptor()); + } + + @Override + public List<? extends Coder<?>> getComponents() { + return Collections.singletonList(valueCoder); + } + } + + public OrderedListUserState( + Cache<?, ?> cache, + BeamFnStateClient beamFnStateClient, + String instructionId, + StateKey stateKey, + Coder<T> valueCoder) { + checkArgument( + stateKey.hasOrderedListUserState(), + "Expected OrderedListUserState StateKey but received %s.", + stateKey); + this.beamFnStateClient = beamFnStateClient; + this.timestampedValueCoder = TimestampedValueCoder.of(valueCoder); + this.request = + StateRequest.newBuilder().setInstructionId(instructionId).setStateKey(stateKey).build(); + } + + public void add(TimestampedValue<T> value) { + checkState( + !isClosed, + "OrderedList user state is no longer usable because it is closed for %s", + request.getStateKey()); + Instant timestamp = value.getTimestamp(); + pendingAdds.putIfAbsent(timestamp, new ArrayList<>()); + pendingAdds.get(timestamp).add(value.getValue()); + } + + public Iterable<TimestampedValue<T>> readRange(Instant minTimestamp, Instant limitTimestamp) { + checkState( + !isClosed, + "OrderedList user state is no longer usable because it is closed for %s", + request.getStateKey()); + + // Store pendingAdds whose sort key is in the query range and values are truncated by the + // current size. The values (collections) of pendingAdds are kept, so that they will still be + // accessible in pre-existing iterables even after: + // (1) a sort key is added to or removed from pendingAdds, or + // (2) a new value is added to an existing sort key + ArrayList<PrefetchableIterable<TimestampedValue<T>>> pendingAddsInRange = new ArrayList<>(); + for (Entry<Instant, Collection<T>> kv : + pendingAdds.subMap(minTimestamp, limitTimestamp).entrySet()) { + pendingAddsInRange.add( + PrefetchableIterables.limit( + Iterables.transform(kv.getValue(), (v) -> TimestampedValue.of(v, kv.getKey())), + kv.getValue().size())); + } + Iterable<TimestampedValue<T>> valuesInRange = Iterables.concat(pendingAddsInRange); + + if (!isCleared) { + StateRequest.Builder getRequestBuilder = this.request.toBuilder(); + getRequestBuilder + .getStateKeyBuilder() + .getOrderedListUserStateBuilder() + .getRangeBuilder() + .setStart(minTimestamp.getMillis()) + .setEnd(limitTimestamp.getMillis()); + + // TODO: consider use cache here + CachingStateIterable<TimestampedValue<T>> persistentValues = + StateFetchingIterators.readAllAndDecodeStartingFrom( + Caches.noop(), + this.beamFnStateClient, + getRequestBuilder.build(), + this.timestampedValueCoder); + + // Make a snapshot of the current pendingRemoves and use them to filter persistent values. + // The values of pendingRemoves are kept, so that they will still be accessible in + // pre-existing iterables even after a sort key is removed. + TreeRangeSet<Instant> pendingRemovesSnapshot = TreeRangeSet.create(pendingRemoves); + Iterable<TimestampedValue<T>> persistentValuesAfterRemoval = + Iterables.filter( + persistentValues, v -> !pendingRemovesSnapshot.contains(v.getTimestamp())); + + return Iterables.mergeSorted( + ImmutableList.of(persistentValuesAfterRemoval, valuesInRange), + Comparator.comparing(TimestampedValue::getTimestamp)); + } + + return valuesInRange; + } + + public Iterable<TimestampedValue<T>> read() { + checkState( + !isClosed, + "OrderedList user state is no longer usable because it is closed for %s", + request.getStateKey()); + + return readRange(Instant.ofEpochMilli(Long.MIN_VALUE), Instant.ofEpochMilli(Long.MAX_VALUE)); + } + + public void clearRange(Instant minTimestamp, Instant limitTimestamp) { + checkState( + !isClosed, + "OrderedList user state is no longer usable because it is closed for %s", + request.getStateKey()); + + // Remove items (in a collection) in the specific range from pendingAdds. + // The old values of the removed sub map are kept, so that they will still be accessible in + // pre-existing iterables even after the sort key is cleared. + pendingAdds.subMap(minTimestamp, limitTimestamp).clear(); + if (!isCleared) { Review Comment: I think there may be some confusion of what pendingRemoves actually is. In this implementation, it contains the items we need to remove **from the persisted storage.** Let's look at your use case. After we call clear(), all pendingAdds and pendingRemoves are reset to empty, which means that we expect the persisted storage to restart from scratch. Then if you call add() and then clearRange(), the operations will only be done on pendingAdds() (i.e. we do a subMap() on pendingAdds on Line 248). We have the condition on Line 249, because we don't need to remove anything from that empty persisted storage. This use case has been covered by `testAddAndClearRangeAfterClear` in OrderedListUserStateTest.java. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
