snuyanzin commented on code in PR #29070: URL: https://github.com/apache/flink/pull/29070#discussion_r3925981266
########## flink-table/flink-table-api-java/src/main/java/org/apache/flink/table/operations/WindowTableFunctionQueryOperation.java: ########## @@ -0,0 +1,183 @@ +/* + * 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.operations; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.api.DataTypes; +import org.apache.flink.table.api.ValidationException; +import org.apache.flink.table.catalog.Column; +import org.apache.flink.table.catalog.ResolvedSchema; +import org.apache.flink.table.expressions.ApiExpressionUtils; +import org.apache.flink.table.expressions.SqlFactory; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.utils.EncodingUtils; + +import java.time.Duration; +import java.util.ArrayList; +import java.util.Collections; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; + +import static org.apache.flink.table.types.logical.utils.LogicalTypeChecks.canBeTimeAttributeType; + +/** + * Relational operation that assigns rows to windows using a windowing table-valued function + * (TUMBLE/HOP/CUMULATE/SESSION). Appends {@code window_start}, {@code window_end} and {@code + * window_time} to the input and returns the enriched relation. + */ +@Internal +public class WindowTableFunctionQueryOperation implements QueryOperation { + + private static final String INPUT_ALIAS = "$$T_WIN"; + + /** Window kind; the name maps to the SQL window operator. */ + @Internal + public enum WindowKind { + TUMBLE(1), + HOP(2), + CUMULATE(2), + SESSION(1); + + private final int expectedIntervalCount; + + WindowKind(int expectedIntervalCount) { + this.expectedIntervalCount = expectedIntervalCount; + } + + /** Number of interval operands this window kind requires. */ + public int expectedIntervalCount() { + return expectedIntervalCount; + } + } + + private final WindowKind windowKind; + private final String timeColumn; + private final List<Duration> intervals; + private final QueryOperation child; + private final ResolvedSchema resolvedSchema; + + public WindowTableFunctionQueryOperation( + WindowKind windowKind, + String timeColumn, + List<Duration> intervals, + QueryOperation child) { + if (intervals.size() != windowKind.expectedIntervalCount()) { + throw new ValidationException( + String.format( + "Window kind %s requires %d interval(s), but got %d.", + windowKind, windowKind.expectedIntervalCount(), intervals.size())); + } + final ResolvedSchema inputSchema = child.getResolvedSchema(); + final int timeIndex = inputSchema.getColumnNames().indexOf(timeColumn); + if (timeIndex < 0) { + throw new ValidationException( + String.format( + "Window time column '%s' does not exist. Available columns: %s", + timeColumn, inputSchema.getColumnNames())); + } + final DataType timeType = inputSchema.getColumnDataTypes().get(timeIndex); + if (!canBeTimeAttributeType(timeType.getLogicalType())) { + throw new ValidationException( + String.format( + "Window time column '%s' must be a TIMESTAMP or TIMESTAMP_LTZ column, " + + "but was %s.", + timeColumn, timeType.getLogicalType())); + } + this.windowKind = windowKind; + this.timeColumn = timeColumn; + this.intervals = intervals; + this.child = child; + this.resolvedSchema = deriveResolvedSchema(inputSchema, timeType); + } + + private static ResolvedSchema deriveResolvedSchema( + ResolvedSchema inputSchema, DataType timeColumnType) { + final List<Column> columns = new ArrayList<>(inputSchema.getColumns()); + columns.add(Column.physical("window_start", DataTypes.TIMESTAMP(3).notNull())); + columns.add(Column.physical("window_end", DataTypes.TIMESTAMP(3).notNull())); + columns.add(Column.physical("window_time", timeColumnType.notNull())); + return ResolvedSchema.of(columns); + } + + public WindowKind getWindowKind() { + return windowKind; + } + + public String getTimeColumn() { + return timeColumn; + } + + public List<Duration> getIntervals() { + return intervals; + } + + public QueryOperation getChild() { + return child; + } + + @Override + public ResolvedSchema getResolvedSchema() { + return resolvedSchema; + } + + @Override + public String asSummaryString() { + final Map<String, Object> args = new LinkedHashMap<>(); + args.put("window", windowKind); + args.put("timeCol", timeColumn); + args.put("intervals", intervals); + return OperationUtils.formatWithChildren( + "WindowTableFunction", args, getChildren(), Operation::asSummaryString); + } + + @Override + public String asSerializableString(SqlFactory sqlFactory) { + return String.format( + "SELECT %s FROM TABLE(%s\n) %s", + OperationUtils.formatSelectColumns(getResolvedSchema(), INPUT_ALIAS), + OperationUtils.indent(serializeWindowCall(sqlFactory)), + INPUT_ALIAS); + } + + private String serializeWindowCall(SqlFactory sqlFactory) { + final String childSql = OperationUtils.indent(child.asSerializableString(sqlFactory)); + final String descriptor = "DESCRIPTOR(" + EncodingUtils.escapeIdentifier(timeColumn) + ")"; + final String serializedIntervals = + intervals.stream() + .map( + d -> + ApiExpressionUtils.intervalOfMillis(d.toMillis()) + .asSerializableString(sqlFactory)) + .collect(Collectors.joining(", ")); + return String.format( + "%s((%s\n), %s, %s)", windowKind, childSql, descriptor, serializedIntervals); + } + + @Override + public List<QueryOperation> getChildren() { + return Collections.singletonList(child); Review Comment: ```suggestion return List.of(child); ``` -- This is an automated message from the Apache Git Service. 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