Myasuka commented on a change in pull request #9231: [FLINK-13252] Common CachedLookupFunction for All connector URL: https://github.com/apache/flink/pull/9231#discussion_r307451707
########## File path: flink-table/flink-table-common/src/main/java/org/apache/flink/table/sources/decorator/CachedLookupFunctionDecorator.java ########## @@ -0,0 +1,172 @@ +/* + * 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.flink.table.sources.decorator; + +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.table.functions.FunctionContext; +import org.apache.flink.table.functions.TableFunction; +import org.apache.flink.types.Row; +import org.apache.flink.util.Collector; + +import org.apache.flink.shaded.guava18.com.google.common.cache.Cache; +import org.apache.flink.shaded.guava18.com.google.common.cache.CacheBuilder; + +import java.lang.reflect.Method; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; + +/** + * CachedLookupableTableSource. + * LIMITATION: now the function eval of the lookupTableSource implementation only supports parameter as Object or Object... + * TODO: in the future, to extract the parameter type from the Method, but I think it's not much urgent. + */ +public class CachedLookupFunctionDecorator<T> extends TableFunction<T> { + //default 1day. + private static final long EXPIRED_TIME_MS_DEFAULT = 24 * 60 * 60 * 1000; + private final TableFunction<T> lookupTableSource; + private transient Cache<Row, List<T>> cache; + private transient LookupFunctionInvoker.Evaluation realEval; + private CollectorProxy collectorProxy; + private final long expireTimeMS; + private final long maximumSize; + private final boolean recordStat; + private final boolean isVariable; + + public CachedLookupFunctionDecorator(TableFunction<T> lookupTableSource, long maximumSize) { + this(lookupTableSource, maximumSize, EXPIRED_TIME_MS_DEFAULT); + } + + public CachedLookupFunctionDecorator(TableFunction<T> lookupTableSource, long maximumSize, long expireTimeMs) { + this(lookupTableSource, maximumSize, expireTimeMs, true); + } + + public CachedLookupFunctionDecorator( + TableFunction<T> lookupTableSource, long maximumSize, long expireTimeMs, boolean recordStat) { + this.lookupTableSource = lookupTableSource; + this.maximumSize = maximumSize; + this.expireTimeMS = expireTimeMs; + this.recordStat = recordStat; + this.isVariable = checkMethodVariable("eval", lookupTableSource.getClass()); + } + + @Override + public void open(FunctionContext context) throws Exception { + lookupTableSource.open(context); + collectorProxy = new CollectorProxy(); + lookupTableSource.setCollector(collectorProxy); + LookupFunctionInvoker lookupFunctionInvoker = new LookupFunctionInvoker(lookupTableSource); + realEval = lookupFunctionInvoker.getProxy(); + CacheBuilder cacheBuilder = CacheBuilder.newBuilder().expireAfterWrite(expireTimeMS, + TimeUnit.MILLISECONDS).maximumSize(maximumSize); + if (this.recordStat) { + cacheBuilder.recordStats(); + } + this.cache = cacheBuilder.build(); + } + + @Override + public void close() throws Exception { + if (cache != null) { + cache.cleanUp(); + cache = null; + } + lookupTableSource.close(); + } + + @Override + public TypeInformation<T> getResultType() { + return lookupTableSource.getResultType(); + } + + @Override + public TypeInformation<?>[] getParameterTypes(Class<?>[] signature) { + return lookupTableSource.getParameterTypes(signature); + } + + @VisibleForTesting + Cache<Row, List<T>> getCache() { + return cache; + } + + public void eval(Object... keys) { + try { + Row keyRow = Row.of(keys); + List<T> cachedRows = cache.getIfPresent(keyRow); + if (cachedRows != null) { + for (T cachedRow : cachedRows) { + collect(cachedRow); + } + } else { + collectorProxy.setCurrentKey(keyRow); + if (isVariable) { + //TODO: we can extract the exactly parameter In the future. + realEval.eval(keys); + } else { + realEval.eval(keys[0]); + } + } + } catch (Exception e) { + throw new RuntimeException("CachedLookupTableSource exception:" + e.getCause(), e); + } + + } + + private class CollectorProxy implements Collector<T> { + + private volatile Row currentKey; + + public void setCurrentKey(Row currentKey) { + this.currentKey = currentKey; + } + + @Override + public void collect(T record) { + try { + List<T> cachedRows = cache.get(currentKey, ArrayList::new); + cachedRows.add(record); + CachedLookupFunctionDecorator.this.collect(record); + } catch (Exception e) { + throw new RuntimeException("CollectorProxy exception:" + e.getMessage(), e); + } + } + + @Override + public void close() { + + } + } + + private boolean checkMethodVariable(String methodName, Class clazz) { + Method result = null; + for (Method method : clazz.getMethods()) { + if (methodName.equals(method.getName())) { + if (result != null) { + throw new RuntimeException("TableFunction only can have one eval function."); Review comment: If we only check whether `eval` existed, why we need `methodName` as argument of this method? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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