[
https://issues.apache.org/jira/browse/FLINK-3599?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15473636#comment-15473636
]
ASF GitHub Bot commented on FLINK-3599:
---------------------------------------
Github user ggevay commented on a diff in the pull request:
https://github.com/apache/flink/pull/2211#discussion_r77990262
--- Diff:
flink-core/src/main/java/org/apache/flink/api/java/typeutils/runtime/PojoComparatorGenerator.java
---
@@ -0,0 +1,207 @@
+/*
+ * 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.api.java.typeutils.runtime;
+
+import org.apache.flink.api.common.ExecutionConfig;
+import org.apache.flink.api.common.typeutils.TypeComparator;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.util.InstantiationUtil;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.util.HashMap;
+import java.util.Map;
+
+import static
org.apache.flink.api.java.typeutils.PojoTypeInfo.accessStringForField;
+
+public final class PojoComparatorGenerator<T> {
+ private static final String packageName =
"org.apache.flink.api.java.typeutils.runtime.generated";
+
+ private transient Field[] keyFields;
+ private transient Integer[] keyFieldIds;
+ private final TypeComparator<Object>[] comparators;
+ private final TypeSerializer<T> serializer;
+ private final Class<T> type;
+ private final ExecutionConfig config;
+ private String code;
+
+ public PojoComparatorGenerator(Field[] keyFields, TypeComparator<?>[]
comparators, TypeSerializer<T> serializer,
+
Class<T> type, Integer[] keyFieldIds, ExecutionConfig config) {
+ this.keyFields = keyFields;
+ this.comparators = (TypeComparator<Object>[]) comparators;
+
+ this.type = type;
+ this.serializer = serializer;
+ this.keyFieldIds = keyFieldIds;
+ this.config = config;
+ }
+
+ public TypeComparator<T> createComparator() {
+ // Multiple comparators can be generated for each type based on
a list of keys. The list of keys and the type
+ // name should determine the generated comparator. This
information is used for caching (avoiding
+ // recompilation). Note that, the name of the field is not
sufficient because nested POJOs might have a field
+ // with the name.
+ StringBuilder keyBuilder = new StringBuilder();
+ for(Integer i : keyFieldIds) {
+ keyBuilder.append(i);
+ keyBuilder.append("_");
+ }
+ final String className = type.getCanonicalName().replace('.',
'_') + "_GeneratedComparator" +
+ keyBuilder.toString();
+ final String fullClassName = packageName + "." + className;
+ Class<?> comparatorClazz;
+ code = InstantiationUtil.getCodeForCachedClass(fullClassName);
+ if (code == null) {
+ generateCode(className);
+ }
+ if (config.isWrapGeneratedClassesEnabled()) {
+ return new GenTypeComparatorProxy<>(type,
fullClassName, code, comparators, serializer);
+ }
+ try {
+ comparatorClazz =
InstantiationUtil.compile(type.getClassLoader(), fullClassName, code);
+ } catch (Exception e) {
+ throw new RuntimeException("Unable to generate
comparator: " + className, e);
+ }
+ Constructor<?>[] ctors = comparatorClazz.getConstructors();
+ assert ctors.length == 1;
+ try {
+ return (TypeComparator<T>) ctors[0].newInstance(new
Object[]{comparators, serializer, type});
--- End diff --
varargs
> GSoC: Code Generation in Serializers
> ------------------------------------
>
> Key: FLINK-3599
> URL: https://issues.apache.org/jira/browse/FLINK-3599
> Project: Flink
> Issue Type: Improvement
> Components: Type Serialization System
> Reporter: Márton Balassi
> Assignee: Gabor Horvath
> Labels: gsoc2016, mentor
>
> The current implementation of the serializers can be a
> performance bottleneck in some scenarios. These performance problems were
> also reported on the mailing list recently [1].
> E.g. the PojoSerializer uses reflection for accessing the fields, which is
> slow [2].
> For the complete proposal see [3].
> [1]
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/Tuple-performance-and-the-curious-JIT-compiler-td10666.html
> [2]
> https://github.com/apache/flink/blob/master/flink-core/src/main/java/org/apache/flink/api/java/typeutils/runtime/PojoSerializer.java#L369
> [3]
> https://docs.google.com/document/d/1VC8lCeErx9kI5lCMPiUn625PO0rxR-iKlVqtt3hkVnk
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