com.hazelcast.org.apache.calcite.sql.advise.SqlAdvisorGetHintsFunction Maven / Gradle / Ivy
/*
* 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.advise;
import com.hazelcast.org.apache.calcite.DataContext;
import com.hazelcast.org.apache.calcite.adapter.enumerable.CallImplementor;
import com.hazelcast.org.apache.calcite.adapter.enumerable.NullPolicy;
import com.hazelcast.org.apache.calcite.adapter.enumerable.RexImpTable;
import com.hazelcast.org.apache.calcite.linq4j.Enumerable;
import com.hazelcast.org.apache.calcite.linq4j.Linq4j;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expression;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expressions;
import com.hazelcast.org.apache.calcite.linq4j.tree.Types;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.schema.FunctionParameter;
import com.hazelcast.org.apache.calcite.schema.ImplementableFunction;
import com.hazelcast.org.apache.calcite.schema.TableFunction;
import com.hazelcast.org.apache.calcite.schema.impl.ReflectiveFunctionBase;
import com.hazelcast.org.apache.calcite.sql.validate.SqlMoniker;
import com.hazelcast.org.apache.calcite.util.BuiltInMethod;
import com.hazelcast.com.google.common.collect.Iterables;
import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Table function that returns completion hints for a given SQL statement.
*/
public class SqlAdvisorGetHintsFunction
implements TableFunction, ImplementableFunction {
private static final Expression ADVISOR =
Expressions.convert_(
Expressions.call(DataContext.ROOT,
BuiltInMethod.DATA_CONTEXT_GET.method,
Expressions.constant(DataContext.Variable.SQL_ADVISOR.camelName)),
SqlAdvisor.class);
private static final Method GET_COMPLETION_HINTS =
Types.lookupMethod(SqlAdvisorGetHintsFunction.class, "getCompletionHints",
SqlAdvisor.class, String.class, int.class);
private static final CallImplementor IMPLEMENTOR =
RexImpTable.createImplementor(
(translator, call, operands) ->
Expressions.call(GET_COMPLETION_HINTS,
Iterables.concat(Collections.singleton(ADVISOR), operands)),
NullPolicy.ANY, false);
private static final List PARAMETERS =
ReflectiveFunctionBase.builder()
.add(String.class, "sql")
.add(int.class, "pos")
.build();
@Override public CallImplementor getImplementor() {
return IMPLEMENTOR;
}
@Override public RelDataType getRowType(RelDataTypeFactory typeFactory,
List arguments) {
return typeFactory.createJavaType(SqlAdvisorHint.class);
}
@Override public Type getElementType(List arguments) {
return SqlAdvisorHint.class;
}
@Override public List getParameters() {
return PARAMETERS;
}
/**
* Returns completion hints for a given SQL statement.
*
* Typically this is called from generated code
* (via {@link SqlAdvisorGetHintsFunction#IMPLEMENTOR}).
*
* @param advisor Advisor to produce completion hints
* @param sql SQL to complete
* @param pos Cursor position in SQL
* @return the table that contains completion hints for a given SQL statement
*/
public static Enumerable getCompletionHints(
final SqlAdvisor advisor, final String sql, final int pos) {
final String[] replaced = new String[1];
final List hints = advisor.getCompletionHints(sql,
pos, replaced);
final List res = new ArrayList<>(hints.size() + 1);
res.add(new SqlAdvisorHint(replaced[0], null, "MATCH"));
for (SqlMoniker hint : hints) {
res.add(new SqlAdvisorHint(hint));
}
return Linq4j.asEnumerable(res).asQueryable();
}
}