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/*
 * 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 com.hazelcast.org.apache.calcite.sql;

import com.hazelcast.org.apache.calcite.linq4j.Ord;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeField;
import com.hazelcast.org.apache.calcite.sql.type.ReturnTypes;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandCountRanges;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandMetadata;
import com.hazelcast.org.apache.calcite.sql.type.SqlReturnTypeInference;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeName;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeUtil;
import com.hazelcast.org.apache.calcite.sql.validate.SqlNameMatcher;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidator;

import com.hazelcast.com.google.common.base.Preconditions;
import com.hazelcast.com.google.common.collect.ImmutableList;

import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;

import java.util.Collections;
import java.util.List;

import static com.hazelcast.org.apache.calcite.util.Static.RESOURCE;

/**
 * Base class for a table-valued function that computes windows. Examples
 * include {@code TUMBLE}, {@code HOP} and {@code SESSION}.
 */
public class SqlWindowTableFunction extends SqlFunction
    implements SqlTableFunction {

  /** The data source which the table function computes with. */
  protected static final String PARAM_DATA = "DATA";

  /** The time attribute column. Also known as the event time. */
  protected static final String PARAM_TIMECOL = "TIMECOL";

  /** The window duration INTERVAL. */
  protected static final String PARAM_SIZE = "SIZE";

  /** The optional align offset for each window. */
  protected static final String PARAM_OFFSET = "OFFSET";

  /** The session key(s), only used for SESSION window. */
  protected static final String PARAM_KEY = "KEY";

  /** The slide interval, only used for HOP window. */
  protected static final String PARAM_SLIDE = "SLIDE";

  /**
   * Type-inference strategy whereby the row type of a table function call is a
   * ROW, which is combined from the row type of operand #0 (which is a TABLE)
   * and two additional fields. The fields are as follows:
   *
   * 
    *
  1. {@code window_start}: TIMESTAMP type to indicate a window's start *
  2. {@code window_end}: TIMESTAMP type to indicate a window's end *
*/ public static final SqlReturnTypeInference ARG0_TABLE_FUNCTION_WINDOWING = SqlWindowTableFunction::inferRowType; /** Creates a window table function with a given name. */ public SqlWindowTableFunction(String name, SqlOperandMetadata operandMetadata) { super(name, SqlKind.OTHER_FUNCTION, ReturnTypes.CURSOR, null, operandMetadata, SqlFunctionCategory.SYSTEM); } @Override public @Nullable SqlOperandMetadata getOperandTypeChecker() { return (@Nullable SqlOperandMetadata) super.getOperandTypeChecker(); } @Override public SqlReturnTypeInference getRowTypeInference() { return ARG0_TABLE_FUNCTION_WINDOWING; } /** * {@inheritDoc} * *

Overrides because the first parameter of * table-value function windowing is an explicit TABLE parameter, * which is not scalar. */ @Override public boolean argumentMustBeScalar(int ordinal) { return ordinal != 0; } /** Helper for {@link #ARG0_TABLE_FUNCTION_WINDOWING}. */ private static RelDataType inferRowType(SqlOperatorBinding opBinding) { final RelDataType inputRowType = opBinding.getOperandType(0); final RelDataTypeFactory typeFactory = opBinding.getTypeFactory(); return typeFactory.builder() .kind(inputRowType.getStructKind()) .addAll(inputRowType.getFieldList()) .add("window_start", SqlTypeName.TIMESTAMP, 3) .add("window_end", SqlTypeName.TIMESTAMP, 3) .build(); } /** Partial implementation of operand type checker. */ protected abstract static class AbstractOperandMetadata implements SqlOperandMetadata { final List paramNames; final int mandatoryParamCount; AbstractOperandMetadata(List paramNames, int mandatoryParamCount) { this.paramNames = ImmutableList.copyOf(paramNames); this.mandatoryParamCount = mandatoryParamCount; Preconditions.checkArgument(mandatoryParamCount >= 0 && mandatoryParamCount <= paramNames.size()); } @Override public SqlOperandCountRange getOperandCountRange() { return SqlOperandCountRanges.between(mandatoryParamCount, paramNames.size()); } @Override public List paramTypes(RelDataTypeFactory typeFactory) { return Collections.nCopies(paramNames.size(), typeFactory.createSqlType(SqlTypeName.ANY)); } @Override public List paramNames() { return paramNames; } @Override public Consistency getConsistency() { return Consistency.NONE; } @Override public boolean isOptional(int i) { return i > getOperandCountRange().getMin() && i <= getOperandCountRange().getMax(); } boolean throwValidationSignatureErrorOrReturnFalse(SqlCallBinding callBinding, boolean throwOnFailure) { if (throwOnFailure) { throw callBinding.newValidationSignatureError(); } else { return false; } } /** * Checks whether the heading operands are in the form * {@code (ROW, DESCRIPTOR, DESCRIPTOR ..., other params)}, * returning whether successful, and throwing if any columns are not found. * * @param callBinding The call binding * @param descriptorCount The number of descriptors following the first * operand (e.g. the table) * * @return true if validation passes; throws if any columns are not found */ boolean checkTableAndDescriptorOperands(SqlCallBinding callBinding, int descriptorCount) { final SqlNode operand0 = callBinding.operand(0); final SqlValidator validator = callBinding.getValidator(); final RelDataType type = validator.getValidatedNodeType(operand0); if (type.getSqlTypeName() != SqlTypeName.ROW) { return false; } for (int i = 1; i < descriptorCount + 1; i++) { final SqlNode operand = callBinding.operand(i); if (operand.getKind() != SqlKind.DESCRIPTOR) { return false; } validateColumnNames(validator, type.getFieldNames(), ((SqlCall) operand).getOperandList()); } return true; } /** * Checks whether the type that the operand of time col descriptor refers to is valid. * * @param callBinding The call binding * @param pos The position of the descriptor at the operands of the call * @return true if validation passes, false otherwise */ boolean checkTimeColumnDescriptorOperand(SqlCallBinding callBinding, int pos) { SqlValidator validator = callBinding.getValidator(); SqlNode operand0 = callBinding.operand(0); RelDataType type = validator.getValidatedNodeType(operand0); List operands = ((SqlCall) callBinding.operand(pos)).getOperandList(); SqlIdentifier identifier = (SqlIdentifier) operands.get(0); String columnName = identifier.getSimple(); SqlNameMatcher matcher = validator.getCatalogReader().nameMatcher(); for (RelDataTypeField field : type.getFieldList()) { if (matcher.matches(field.getName(), columnName)) { return SqlTypeUtil.isTimestamp(field.getType()); } } return false; } /** * Checks whether the operands starting from position {@code startPos} are * all of type {@code INTERVAL}, returning whether successful. * * @param callBinding The call binding * @param startPos The start position to validate (starting index is 0) * * @return true if validation passes */ boolean checkIntervalOperands(SqlCallBinding callBinding, int startPos) { final SqlValidator validator = callBinding.getValidator(); for (int i = startPos; i < callBinding.getOperandCount(); i++) { final RelDataType type = validator.getValidatedNodeType(callBinding.operand(i)); if (!SqlTypeUtil.isInterval(type)) { return false; } } return true; } void validateColumnNames(SqlValidator validator, List fieldNames, List columnNames) { final SqlNameMatcher matcher = validator.getCatalogReader().nameMatcher(); Ord.forEach(SqlIdentifier.simpleNames(columnNames), (name, i) -> { if (matcher.indexOf(fieldNames, name) < 0) { final SqlIdentifier columnName = (SqlIdentifier) columnNames.get(i); throw SqlUtil.newContextException(columnName.getParserPosition(), RESOURCE.unknownIdentifier(name)); } }); } } }





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