Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/5688#discussion_r190136859
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/sinks/QueryableTableSink.scala
---
@@ -0,0 +1,223 @@
+/*
+ * 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.sinks
+
+import java.lang.{Boolean => JBool}
+
+import org.apache.flink.api.common.state.{ValueState, ValueStateDescriptor}
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.api.java.functions.KeySelector
+import org.apache.flink.api.java.tuple.{Tuple2 => JTuple2}
+import org.apache.flink.api.java.typeutils.{ResultTypeQueryable,
RowTypeInfo}
+import org.apache.flink.configuration.Configuration
+import org.apache.flink.streaming.api.datastream.DataStream
+import org.apache.flink.streaming.api.functions.KeyedProcessFunction
+import org.apache.flink.streaming.api.{TimeCharacteristic, TimeDomain}
+import org.apache.flink.table.api.StreamQueryConfig
+import
org.apache.flink.table.runtime.aggregate.KeyedProcessFunctionWithCleanupState
+import org.apache.flink.types.Row
+import org.apache.flink.util.Collector
+
+/**
+ * A QueryableTableSink stores table in queryable state.
+ *
+ * This class stores table in queryable state so that users can access
table data without
+ * dependency on external storage.
+ *
+ * Since this is only a kv storage, currently user can only do point
query against it.
+ *
+ * Example:
+ * {{{
+ * val env = ExecutionEnvironment.getExecutionEnvironment
+ * val tEnv = TableEnvironment.getTableEnvironment(env)
+ *
+ * val table: Table = ...
+ *
+ * val queryableTableSink: QueryableTableSink = new QueryableTableSink(
+ * "prefix",
+ * queryConfig,
+ * None)
+ *
+ * tEnv.writeToSink(table, queryableTableSink, config)
+ * }}}
+ *
+ * When program starts to run, user can access state with
QueryableStateClient.
+ * {{{
+ * val client = new QueryableStateClient(tmHostname, proxyPort)
+ * val data = client.getKvState(
+ * jobId,
+ * "prefix-column1",
+ * Row.of(1),
+ * new RowTypeInfo(Array(TypeInfoformation.of(classOf[Int]),
Array("id"))
+ * stateDescriptor)
+ * .get();
+ *
+ * }}}
+ *
+ *
+ * @param namePrefix
+ * @param queryConfig
+ * @param cleanupTimeDomain
+ */
+class QueryableTableSink(
+ private val namePrefix: String,
+ private val queryConfig: StreamQueryConfig,
+ private val cleanupTimeDomain: Option[TimeDomain])
+ extends UpsertStreamTableSink[Row]
+ with TableSinkBase[JTuple2[JBool, Row]] {
+ private var keys: Array[String] = _
+
+ override def setKeyFields(keys: Array[String]): Unit = {
+ if (keys == null) {
+ throw new IllegalArgumentException("keys can't be null!")
+ }
+ this.keys = keys
+ }
+
+ override def setIsAppendOnly(isAppendOnly: JBool): Unit = {
+ if (isAppendOnly) {
+ throw new IllegalArgumentException("A QueryableTableSink can not be
used with append-only " +
+ "tables as the table would grow infinitely")
+ }
+ }
+
+ override def getRecordType: TypeInformation[Row] = new
RowTypeInfo(getFieldTypes, getFieldNames)
+
+ override def emitDataStream(dataStream: DataStream[JTuple2[JBool,
Row]]): Unit = {
+ val keyIndices = keys.map(getFieldNames.indexOf(_))
+ val keyTypes = keyIndices.map(getFieldTypes(_))
+
+ val keySelectorType = new RowTypeInfo(keyTypes, keys)
+
+ val processFunction = new QueryableStateProcessFunction(
+ namePrefix,
+ queryConfig,
+ keys,
+ getFieldNames,
+ getFieldTypes,
+
calculateCleanupTimeDomain(dataStream.getExecutionEnvironment.getStreamTimeCharacteristic))
--- End diff --
We should make this configurable through the constructor parameters instead
and I think it makes sense to allow specifying a retention time as well. Use
the `StreamQueryConfig` values as default.
---
