io.questdb.griffin.engine.functions.rnd.RndVarcharFunctionFactory Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of questdb Show documentation
QuestDB is high performance SQL time series database
The newest version!
/*******************************************************************************
 *     ___                  _   ____  ____
 *    / _ \ _   _  ___  ___| |_|  _ \| __ )
 *   | | | | | | |/ _ \/ __| __| | | |  _ \
 *   | |_| | |_| |  __/\__ \ |_| |_| | |_) |
 *    \__\_\\__,_|\___||___/\__|____/|____/
 *
 *  Copyright (c) 2014-2019 Appsicle
 *  Copyright (c) 2019-2024 QuestDB
 *
 *  Licensed 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 io.questdb.griffin.engine.functions.rnd;

import io.questdb.cairo.CairoConfiguration;
import io.questdb.cairo.sql.Function;
import io.questdb.cairo.sql.Record;
import io.questdb.cairo.sql.SymbolTableSource;
import io.questdb.griffin.FunctionFactory;
import io.questdb.griffin.PlanSink;
import io.questdb.griffin.SqlException;
import io.questdb.griffin.SqlExecutionContext;
import io.questdb.griffin.engine.functions.VarcharFunction;
import io.questdb.std.IntList;
import io.questdb.std.ObjList;
import io.questdb.std.Rnd;
import io.questdb.std.str.Utf8Sequence;
import io.questdb.std.str.Utf8Sink;
import io.questdb.std.str.Utf8StringSink;

public class RndVarcharFunctionFactory implements FunctionFactory {

    @Override
    public String getSignature() {
        return "rnd_varchar(iii)";
    }

    @Override
    public Function newInstance(
            int position,
            ObjList args,
            IntList argPositions,
            CairoConfiguration configuration,
            SqlExecutionContext sqlExecutionContext
    ) throws SqlException {
        int lo = args.getQuick(0).getInt(null);
        int hi = args.getQuick(1).getInt(null);
        int nullRate = args.getQuick(2).getInt(null);

        if (nullRate < 0) {
            throw SqlException.position(argPositions.getQuick(2)).put("null rate must be positive");
        }

        if (lo < hi && lo > 0) {
            return new RndVarcharFunction(lo, hi, nullRate + 1);
        } else if (lo == hi) {
            return new RndFixedVarcharFunction(lo, nullRate + 1);
        }

        throw SqlException.position(position).put("invalid range");
    }

    private static class RndFixedVarcharFunction extends VarcharFunction implements Function {
        private final int len;
        private final int nullRate;

        private final Utf8StringSink utf8SinkA = new Utf8StringSink();
        private final Utf8StringSink utf8SinkB = new Utf8StringSink();

        private Rnd rnd;

        public RndFixedVarcharFunction(int len, int nullRate) {
            this.len = len;
            this.nullRate = nullRate;
        }

        @Override
        public Utf8Sequence getVarcharA(Record rec) {
            if ((rnd.nextInt() % nullRate) == 1) {
                return null;
            }
            utf8SinkA.clear();
            sinkRnd(utf8SinkA);
            return utf8SinkA;
        }

        @Override
        public Utf8Sequence getVarcharB(Record rec) {
            if ((rnd.nextInt() % nullRate) == 1) {
                return null;
            }
            utf8SinkB.clear();
            sinkRnd(utf8SinkB);
            return utf8SinkB;
        }

        @Override
        public void init(SymbolTableSource symbolTableSource, SqlExecutionContext executionContext) {
            this.rnd = executionContext.getRandom();
        }

        @Override
        public boolean isNonDeterministic() {
            return true;
        }

        @Override
        public void toPlan(PlanSink sink) {
            sink.val("rnd_str(").val(len).val(',').val(len).val(',').val(nullRate - 1).val(')');
        }

        private void sinkRnd(Utf8Sink utf8Sink) {
            rnd.nextUtf8Str(len, utf8Sink);
        }
    }
}