flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/functions/SqlFunctionUtils.java

/*
 * 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.runtime.functions;

import org.apache.flink.table.data.DecimalData;
import org.apache.flink.table.data.DecimalDataUtils;
import org.apache.flink.table.data.binary.BinaryStringData;
import org.apache.flink.table.data.binary.BinaryStringDataUtil;
import org.apache.flink.table.utils.EncodingUtils;
import org.apache.flink.table.utils.ThreadLocalCache;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.RoundingMode;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static org.apache.flink.table.data.DecimalDataUtils.castFrom;
import static org.apache.flink.table.data.DecimalDataUtils.doubleValue;

/**
 * Built-in scalar runtime functions.
 *
 * <p>NOTE: Before you add functions here, check if Calcite provides it in {@code
 * org.apache.calcite.runtime.SqlFunctions}. Furthermore, make sure to implement the function
 * efficiently. Sometimes it makes sense to create a {@code
 * org.apache.flink.table.codegen.calls.CallGenerator} instead to avoid massive object creation and
 * reuse instances.
 */
public class SqlFunctionUtils {

    private static final Logger LOG = LoggerFactory.getLogger(SqlFunctionUtils.class);

    private static final ThreadLocalCache<String, Pattern> REGEXP_PATTERN_CACHE =
            new ThreadLocalCache<String, Pattern>() {
                @Override
                public Pattern getNewInstance(String regex) {
                    return Pattern.compile(regex);
                }
            };

    private static final ThreadLocalCache<String, URL> URL_CACHE =
            new ThreadLocalCache<String, URL>() {
                public URL getNewInstance(String url) {
                    try {
                        return new URL(url);
                    } catch (MalformedURLException e) {
                        throw new RuntimeException(e);
                    }
                }
            };

    private static final Map<String, String> EMPTY_MAP = new HashMap<>(0);

    public static double exp(DecimalData d) {
        return Math.exp(doubleValue(d));
    }

    public static double power(double base, DecimalData exponent) {
        return Math.pow(base, doubleValue(exponent));
    }

    public static double power(DecimalData base, DecimalData exponent) {
        return Math.pow(doubleValue(base), doubleValue(exponent));
    }

    public static double power(DecimalData base, double exponent) {
        return Math.pow(doubleValue(base), exponent);
    }

    public static double cosh(DecimalData x) {
        return Math.cosh(doubleValue(x));
    }

    public static double acos(DecimalData a) {
        return Math.acos(doubleValue(a));
    }

    public static double asin(DecimalData a) {
        return Math.asin(doubleValue(a));
    }

    public static double atan(DecimalData a) {
        return Math.atan(doubleValue(a));
    }

    public static double atan2(DecimalData y, DecimalData x) {
        return Math.atan2(doubleValue(y), doubleValue(x));
    }

    public static double sin(DecimalData a) {
        return Math.sin(doubleValue(a));
    }

    public static double sinh(DecimalData a) {
        return Math.sinh(doubleValue(a));
    }

    public static double cos(DecimalData a) {
        return Math.cos(doubleValue(a));
    }

    public static double tan(DecimalData a) {
        return Math.tan(doubleValue(a));
    }

    /** Calculates the hyperbolic tangent of a big decimal number. */
    public static double tanh(DecimalData a) {
        return Math.tanh(doubleValue(a));
    }

    public static double cot(DecimalData a) {
        return 1.0d / Math.tan(doubleValue(a));
    }

    public static double degrees(DecimalData angrad) {
        return Math.toDegrees(doubleValue(angrad));
    }

    public static double radians(DecimalData angdeg) {
        return Math.toRadians(doubleValue(angdeg));
    }

    public static DecimalData abs(DecimalData a) {
        return DecimalDataUtils.abs(a);
    }

    public static DecimalData floor(DecimalData a) {
        return DecimalDataUtils.floor(a);
    }

    public static DecimalData ceil(DecimalData a) {
        return DecimalDataUtils.ceil(a);
    }

    // -------------------------- natural logarithm ------------------------

    /** Returns the natural logarithm of "x". */
    public static double log(double x) {
        return Math.log(x);
    }

    public static double log(DecimalData x) {
        return Math.log(doubleValue(x));
    }

    /** Returns the logarithm of "x" with base "base". */
    public static double log(double base, double x) {
        return Math.log(x) / Math.log(base);
    }

    public static double log(double base, DecimalData x) {
        return log(base, doubleValue(x));
    }

    public static double log(DecimalData base, double x) {
        return log(doubleValue(base), x);
    }

    public static double log(DecimalData base, DecimalData x) {
        return log(doubleValue(base), doubleValue(x));
    }

    /** Returns the logarithm of "a" with base 2. */
    public static double log2(double x) {
        return Math.log(x) / Math.log(2);
    }

    public static double log2(DecimalData x) {
        return log2(doubleValue(x));
    }

    public static double log10(double x) {
        return Math.log10(x);
    }

    public static double log10(DecimalData x) {
        return log10(doubleValue(x));
    }

    // -------------------------- string functions ------------------------

    /**
     * Returns the string str left-padded with the string pad to a length of len characters. If str
     * is longer than len, the return value is shortened to len characters.
     */
    public static String lpad(String base, int len, String pad) {
        if (len < 0 || "".equals(pad)) {
            return null;
        } else if (len == 0) {
            return "";
        }

        char[] data = new char[len];
        char[] baseChars = base.toCharArray();
        char[] padChars = pad.toCharArray();

        // the length of the padding needed
        int pos = Math.max(len - base.length(), 0);

        // copy the padding
        for (int i = 0; i < pos; i += pad.length()) {
            for (int j = 0; j < pad.length() && j < pos - i; j++) {
                data[i + j] = padChars[j];
            }
        }

        // copy the base
        int i = 0;
        while (pos + i < len && i < base.length()) {
            data[pos + i] = baseChars[i];
            i += 1;
        }

        return new String(data);
    }

    /**
     * Returns the string str right-padded with the string pad to a length of len characters. If str
     * is longer than len, the return value is shortened to len characters.
     */
    public static String rpad(String base, int len, String pad) {
        if (len < 0 || "".equals(pad)) {
            return null;
        } else if (len == 0) {
            return "";
        }

        char[] data = new char[len];
        char[] baseChars = base.toCharArray();
        char[] padChars = pad.toCharArray();

        int pos = 0;

        // copy the base
        while (pos < base.length() && pos < len) {
            data[pos] = baseChars[pos];
            pos += 1;
        }

        // copy the padding
        while (pos < len) {
            int i = 0;
            while (i < pad.length() && i < len - pos) {
                data[pos + i] = padChars[i];
                i += 1;
            }
            pos += pad.length();
        }

        return new String(data);
    }

    /** Returns a string that repeats the base string n times. */
    public static String repeat(String str, int repeat) {
        return EncodingUtils.repeat(str, repeat);
    }

    /** Replaces all the old strings with the replacement string. */
    public static String replace(String str, String oldStr, String replacement) {
        return str.replace(oldStr, replacement);
    }

    /**
     * Split target string with custom separator and pick the index-th(start with 0) result.
     *
     * @param str target string.
     * @param separator custom separator.
     * @param index index of the result which you want.
     * @return the string at the index of split results.
     */
    public static String splitIndex(String str, String separator, int index) {
        if (index < 0) {
            return null;
        }
        String[] values = StringUtils.splitByWholeSeparatorPreserveAllTokens(str, separator);
        if (index >= values.length) {
            return null;
        } else {
            return values[index];
        }
    }

    /**
     * Split target string with custom separator and pick the index-th(start with 0) result.
     *
     * @param str target string.
     * @param character int value of the separator character
     * @param index index of the result which you want.
     * @return the string at the index of split results.
     */
    public static String splitIndex(String str, int character, int index) {
        if (character > 255 || character < 1 || index < 0) {
            return null;
        }
        String[] values = StringUtils.splitPreserveAllTokens(str, (char) character);
        if (index >= values.length) {
            return null;
        } else {
            return values[index];
        }
    }

    /**
     * Returns a string resulting from replacing all substrings that match the regular expression
     * with replacement.
     */
    public static String regexpReplace(String str, String regex, String replacement) {
        if (str == null || regex == null || replacement == null) {
            return null;
        }
        try {
            return str.replaceAll(regex, Matcher.quoteReplacement(replacement));
        } catch (Exception e) {
            LOG.error(
                    String.format(
                            "Exception in regexpReplace('%s', '%s', '%s')",
                            str, regex, replacement),
                    e);
            // return null if exception in regex replace
            return null;
        }
    }

    /**
     * Returns a string extracted with a specified regular expression and a regex match group index.
     */
    public static String regexpExtract(String str, String regex, int extractIndex) {
        if (str == null || regex == null) {
            return null;
        }

        try {
            Matcher m = Pattern.compile(regex).matcher(str);
            if (m.find()) {
                MatchResult mr = m.toMatchResult();
                return mr.group(extractIndex);
            }
        } catch (Exception e) {
            LOG.error(
                    String.format(
                            "Exception in regexpExtract('%s', '%s', '%d')",
                            str, regex, extractIndex),
                    e);
        }

        return null;
    }

    public static String regexpExtract(String str, String regex, long extractIndex) {
        return regexpExtract(str, regex, (int) extractIndex);
    }

    /** Returns the first string extracted with a specified regular expression. */
    public static String regexpExtract(String str, String regex) {
        return regexpExtract(str, regex, 0);
    }

    /**
     * Parse string as key-value string and return the value matches key name. example:
     * keyvalue('k1=v1;k2=v2', ';', '=', 'k2') = 'v2' keyvalue('k1:v1,k2:v2', ',', ':', 'k3') = NULL
     *
     * @param str target string.
     * @param pairSeparator separator between key-value tuple.
     * @param kvSeparator separator between key and value.
     * @param keyName name of the key whose value you want return.
     * @return target value.
     */
    public static BinaryStringData keyValue(
            BinaryStringData str,
            BinaryStringData pairSeparator,
            BinaryStringData kvSeparator,
            BinaryStringData keyName) {
        if (str == null || str.getSizeInBytes() == 0) {
            return null;
        }
        if (pairSeparator != null
                && pairSeparator.getSizeInBytes() == 1
                && kvSeparator != null
                && kvSeparator.getSizeInBytes() == 1) {
            return BinaryStringDataUtil.keyValue(
                    str, pairSeparator.byteAt(0), kvSeparator.byteAt(0), keyName);
        } else {
            return BinaryStringData.fromString(
                    keyValue(
                            BinaryStringDataUtil.safeToString(str),
                            BinaryStringDataUtil.safeToString(pairSeparator),
                            BinaryStringDataUtil.safeToString(kvSeparator),
                            BinaryStringDataUtil.safeToString(keyName)));
        }
    }

    private static String keyValue(
            String str, String pairSeparator, String kvSeparator, String keyName) {
        try {
            if (StringUtils.isEmpty(str)) {
                return null;
            }
            String[] values = StringUtils.split(str, pairSeparator);
            for (String value : values) {
                if (!StringUtils.isEmpty(value)) {
                    String[] kv = StringUtils.split(kvSeparator);
                    if (kv != null && kv.length == 2 && kv[0].equals(keyName)) {
                        return kv[1];
                    }
                }
            }
            return null;
        } catch (Exception e) {
            LOG.error("Exception when parse key-value", e);
            return null;
        }
    }

    /**
     * Calculate the hash value of a given string.
     *
     * @param algorithm message digest algorithm.
     * @param str string to hash.
     * @return hash value of string.
     */
    public static String hash(String algorithm, String str) {
        return hash(algorithm, str, "");
    }

    /**
     * Calculate the hash value of a given string.
     *
     * @param algorithm message digest algorithm.
     * @param str string to hash.
     * @param charsetName charset of string.
     * @return hash value of string.
     */
    public static String hash(String algorithm, String str, String charsetName) {
        try {
            byte[] digest =
                    MessageDigest.getInstance(algorithm)
                            .digest(strToBytesWithCharset(str, charsetName));
            return EncodingUtils.hex(digest);
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalArgumentException("Unsupported algorithm: " + algorithm, e);
        }
    }

    private static byte[] strToBytesWithCharset(String str, String charsetName) {
        byte[] byteArray = null;
        if (!StringUtils.isEmpty(charsetName)) {
            try {
                byteArray = str.getBytes(charsetName);
            } catch (UnsupportedEncodingException e) {
                LOG.warn(
                        "Unsupported encoding: " + charsetName + ", fallback to system charset", e);
                byteArray = null;
            }
        }
        if (byteArray == null) {
            byteArray = str.getBytes(StandardCharsets.UTF_8);
        }
        return byteArray;
    }

    /**
     * Parse url and return various components of the URL. If accept any null arguments, return
     * null.
     *
     * @param urlStr URL string.
     * @param partToExtract determines which components would return. accept values:
     *     HOST,PATH,QUERY,REF, PROTOCOL,FILE,AUTHORITY,USERINFO
     * @return target value.
     */
    public static String parseUrl(String urlStr, String partToExtract) {
        URL url;
        try {
            url = URL_CACHE.get(urlStr);
        } catch (Exception e) {
            LOG.error("Parse URL error: " + urlStr, e);
            return null;
        }
        if ("HOST".equals(partToExtract)) {
            return url.getHost();
        }
        if ("PATH".equals(partToExtract)) {
            return url.getPath();
        }
        if ("QUERY".equals(partToExtract)) {
            return url.getQuery();
        }
        if ("REF".equals(partToExtract)) {
            return url.getRef();
        }
        if ("PROTOCOL".equals(partToExtract)) {
            return url.getProtocol();
        }
        if ("FILE".equals(partToExtract)) {
            return url.getFile();
        }
        if ("AUTHORITY".equals(partToExtract)) {
            return url.getAuthority();
        }
        if ("USERINFO".equals(partToExtract)) {
            return url.getUserInfo();
        }

        return null;
    }

    /**
     * Parse url and return various parameter of the URL. If accept any null arguments, return null.
     *
     * @param urlStr URL string.
     * @param partToExtract must be QUERY, or return null.
     * @param key parameter name.
     * @return target value.
     */
    public static String parseUrl(String urlStr, String partToExtract, String key) {
        if (!"QUERY".equals(partToExtract)) {
            return null;
        }

        String query = parseUrl(urlStr, partToExtract);
        if (query == null) {
            return null;
        }

        Pattern p = Pattern.compile("(&|^)" + Pattern.quote(key) + "=([^&]*)");
        Matcher m = p.matcher(query);
        if (m.find()) {
            return m.group(2);
        }
        return null;
    }

    public static int divideInt(int a, int b) {
        return a / b;
    }

    public static String subString(String str, long start, long len) {
        if (len < 0) {
            LOG.error(
                    "len of 'substring(str, start, len)' must be >= 0 and Int type, but len = {}",
                    len);
            return null;
        }
        if (len > Integer.MAX_VALUE || start > Integer.MAX_VALUE) {
            LOG.error(
                    "len or start of 'substring(str, start, len)' must be Int type, but len = {}, start = {}",
                    len,
                    start);
            return null;
        }
        int length = (int) len;
        int pos = (int) start;
        if (str.isEmpty()) {
            return "";
        }

        int startPos;
        int endPos;

        if (pos > 0) {
            startPos = pos - 1;
            if (startPos >= str.length()) {
                return "";
            }
        } else if (pos < 0) {
            startPos = str.length() + pos;
            if (startPos < 0) {
                return "";
            }
        } else {
            startPos = 0;
        }

        if ((str.length() - startPos) < length) {
            endPos = str.length();
        } else {
            endPos = startPos + length;
        }
        return str.substring(startPos, endPos);
    }

    public static String subString(String str, long start) {
        return subString(str, start, Integer.MAX_VALUE);
    }

    public static String chr(long chr) {
        if (chr < 0) {
            return "";
        } else if ((chr & 0xFF) == 0) {
            return String.valueOf(Character.MIN_VALUE);
        } else {
            return String.valueOf((char) (chr & 0xFF));
        }
    }

    public static String overlay(String s, String r, long start, long length) {
        if (start <= 0 || start > s.length()) {
            return s;
        } else {
            StringBuilder sb = new StringBuilder();
            int startPos = (int) start;
            int len = (int) length;
            sb.append(s, 0, startPos - 1);
            sb.append(r);
            if ((startPos + len) <= s.length() && len > 0) {
                sb.append(s.substring(startPos - 1 + len));
            }
            return sb.toString();
        }
    }

    public static String overlay(String s, String r, long start) {
        return overlay(s, r, start, r.length());
    }

    public static int position(BinaryStringData seek, BinaryStringData s) {
        return position(seek, s, 1);
    }

    public static int position(BinaryStringData seek, BinaryStringData s, int from) {
        return s.indexOf(seek, from - 1) + 1;
    }

    public static int instr(
            BinaryStringData str,
            BinaryStringData subString,
            int startPosition,
            int nthAppearance) {
        if (nthAppearance <= 0) {
            throw new IllegalArgumentException("nthAppearance must be positive!");
        }
        if (startPosition == 0) {
            return 0;
        } else if (startPosition > 0) {
            int startIndex = startPosition;
            int index = 0;
            for (int i = 0; i < nthAppearance; i++) {
                index = str.indexOf(subString, startIndex - 1) + 1;
                if (index == 0) {
                    return 0;
                }
                startIndex = index + 1;
            }
            return index;
        } else {
            int pos =
                    instr(
                            BinaryStringDataUtil.reverse(str),
                            BinaryStringDataUtil.reverse(subString),
                            -startPosition,
                            nthAppearance);
            if (pos == 0) {
                return 0;
            } else {
                return str.numChars() + 2 - pos - subString.numChars();
            }
        }
    }

    /** Returns the hex string of a long argument. */
    public static String hex(long x) {
        return Long.toHexString(x).toUpperCase();
    }

    /** Returns the hex string of a string argument. */
    public static String hex(String x) {
        return EncodingUtils.hex(x.getBytes(StandardCharsets.UTF_8)).toUpperCase();
    }

    /**
     * Creates a map by parsing text. Split text into key-value pairs using two delimiters. The
     * first delimiter separates pairs, and the second delimiter separates key and value. If only
     * one parameter is given, default delimiters are used: ',' as delimiter1 and '=' as delimiter2.
     *
     * @param text the input text
     * @return the map
     */
    public static Map<String, String> strToMap(String text) {
        return strToMap(text, ",", "=");
    }

    /**
     * Creates a map by parsing text. Split text into key-value pairs using two delimiters. The
     * first delimiter separates pairs, and the second delimiter separates key and value.
     *
     * @param text the input text
     * @param listDelimiter the delimiter to separates pairs
     * @param keyValueDelimiter the delimiter to separates key and value
     * @return the map
     */
    public static Map<String, String> strToMap(
            String text, String listDelimiter, String keyValueDelimiter) {
        if (StringUtils.isEmpty(text)) {
            return EMPTY_MAP;
        }

        String[] keyValuePairs = text.split(listDelimiter);
        Map<String, String> ret = new HashMap<>(keyValuePairs.length);
        for (String keyValuePair : keyValuePairs) {
            String[] keyValue = keyValuePair.split(keyValueDelimiter, 2);
            if (keyValue.length < 2) {
                ret.put(keyValuePair, null);
            } else {
                ret.put(keyValue[0], keyValue[1]);
            }
        }
        return ret;
    }

    // SQL ROUND
    /** SQL <code>ROUND</code> operator applied to byte values. */
    public static byte sround(byte b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to byte values. */
    public static byte sround(byte b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).byteValue();
    }

    /** SQL <code>ROUND</code> operator applied to short values. */
    public static short sround(short b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to short values. */
    public static short sround(short b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).shortValue();
    }

    /** SQL <code>ROUND</code> operator applied to int values. */
    public static int sround(int b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to int values. */
    public static int sround(int b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).intValue();
    }

    /** SQL <code>ROUND</code> operator applied to long values. */
    public static long sround(long b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to long values. */
    public static long sround(long b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).longValue();
    }

    /** SQL <code>ROUND</code> operator applied to BigDecimal values. */
    public static BigDecimal sround(BigDecimal b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to BigDecimal values. */
    public static BigDecimal sround(BigDecimal b0, int b1) {
        return b0.movePointRight(b1).setScale(0, RoundingMode.HALF_UP).movePointLeft(b1);
    }

    /** SQL <code>ROUND</code> operator applied to float values. */
    public static float sround(float b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to float values. */
    public static float sround(float b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).floatValue();
    }

    /** SQL <code>ROUND</code> operator applied to double values. */
    public static double sround(double b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to double values. */
    public static double sround(double b0, int b1) {
        return sround(BigDecimal.valueOf(b0), b1).doubleValue();
    }

    /** SQL <code>ROUND</code> operator applied to DecimalData values. */
    public static DecimalData sround(DecimalData b0) {
        return sround(b0, 0);
    }

    /** SQL <code>ROUND</code> operator applied to DecimalData values. */
    public static DecimalData sround(DecimalData b0, int b1) {
        return DecimalDataUtils.sround(b0, b1);
    }

    public static DecimalData sign(DecimalData b0) {
        return DecimalDataUtils.sign(b0);
    }

    public static boolean isDecimal(Object obj) {
        if ((obj instanceof Long)
                || (obj instanceof Integer)
                || (obj instanceof Short)
                || (obj instanceof Byte)
                || (obj instanceof Float)
                || (obj instanceof Double)
                || (obj instanceof BigDecimal)
                || (obj instanceof BigInteger)) {
            return true;
        }
        if (obj instanceof String || obj instanceof Character) {
            String s = obj.toString();
            if (s.isEmpty()) {
                return false;
            }
            return isInteger(s) || isLong(s) || isDouble(s);
        } else {
            return false;
        }
    }

    private static boolean isInteger(String s) {
        boolean flag = true;
        try {
            Integer.parseInt(s);
        } catch (NumberFormatException e) {
            flag = false;
        }
        return flag;
    }

    private static boolean isLong(String s) {
        boolean flag = true;
        try {
            Long.parseLong(s);
        } catch (NumberFormatException e) {
            flag = false;
        }
        return flag;
    }

    private static boolean isDouble(String s) {
        boolean flag = true;
        try {
            Double.parseDouble(s);
        } catch (NumberFormatException e) {
            flag = false;
        }
        return flag;
    }

    public static boolean isDigit(Object obj) {
        if ((obj instanceof Long)
                || (obj instanceof Integer)
                || (obj instanceof Short)
                || (obj instanceof Byte)) {
            return true;
        }
        if (obj instanceof String) {
            String s = obj.toString();
            if (s.isEmpty()) {
                return false;
            }
            return StringUtils.isNumeric(s);
        } else {
            return false;
        }
    }

    public static boolean isAlpha(Object obj) {
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof String)) {
            return false;
        }
        String s = obj.toString();
        if ("".equals(s)) {
            return false;
        }
        return StringUtils.isAlpha(s);
    }

    public static Integer hashCode(String str) {
        if (str == null) {
            return Integer.MIN_VALUE;
        }
        return Math.abs(str.hashCode());
    }

    public static Boolean regExp(String s, String regex) {
        if (regex.length() == 0) {
            return false;
        }
        try {
            return (REGEXP_PATTERN_CACHE.get(regex)).matcher(s).find(0);
        } catch (Exception e) {
            LOG.error("Exception when compile and match regex:" + regex + " on: " + s, e);
            return false;
        }
    }

    public static Byte bitAnd(Byte a, Byte b) {
        if (a == null || b == null) {
            return 0;
        }
        return (byte) (a & b);
    }

    public static Short bitAnd(Short a, Short b) {
        if (a == null || b == null) {
            return 0;
        }
        return (short) (a & b);
    }

    public static Integer bitAnd(Integer a, Integer b) {
        if (a == null || b == null) {
            return 0;
        }

        return a & b;
    }

    public static Long bitAnd(Long a, Long b) {
        if (a == null || b == null) {
            return 0L;
        }
        return a & b;
    }

    public static Byte bitNot(Byte a) {
        if (a == null) {
            a = 0;
        }
        return (byte) (~a);
    }

    public static Short bitNot(Short a) {
        if (a == null) {
            a = 0;
        }
        return (short) (~a);
    }

    public static Integer bitNot(Integer a) {
        if (a == null) {
            a = 0;
        }
        return ~a;
    }

    public static Long bitNot(Long a) {
        if (a == null) {
            a = 0L;
        }
        return ~a;
    }

    public static Byte bitOr(Byte a, Byte b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return (byte) (a | b);
    }

    public static Short bitOr(Short a, Short b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return (short) (a | b);
    }

    public static Integer bitOr(Integer a, Integer b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return a | b;
    }

    public static Long bitOr(Long a, Long b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0L;
            }
            if (b == null) {
                b = 0L;
            }
        }
        return a | b;
    }

    public static Byte bitXor(Byte a, Byte b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return (byte) (a ^ b);
    }

    public static Short bitXor(Short a, Short b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return (short) (a ^ b);
    }

    public static Integer bitXor(Integer a, Integer b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0;
            }
            if (b == null) {
                b = 0;
            }
        }
        return a ^ b;
    }

    public static Long bitXor(Long a, Long b) {
        if (a == null || b == null) {
            if (a == null) {
                a = 0L;
            }
            if (b == null) {
                b = 0L;
            }
        }
        return a ^ b;
    }

    public static String toBase64(BinaryStringData bs) {
        return toBase64(bs.toBytes());
    }

    public static String toBase64(byte[] bytes) {
        return Base64.getEncoder().encodeToString(bytes);
    }

    public static BinaryStringData fromBase64(BinaryStringData bs) {
        return BinaryStringData.fromBytes(Base64.getDecoder().decode(bs.toBytes()));
    }

    public static BinaryStringData fromBase64(byte[] bytes) {
        return BinaryStringData.fromBytes(Base64.getDecoder().decode(bytes));
    }

    public static String uuid() {
        return UUID.randomUUID().toString();
    }

    public static String uuid(byte[] b) {
        return UUID.nameUUIDFromBytes(b).toString();
    }

    /** SQL <code>TRUNCATE</code> operator applied to BigDecimal values. */
    public static DecimalData struncate(DecimalData b0) {
        return struncate(b0, 0);
    }

    public static DecimalData struncate(DecimalData b0, int b1) {
        if (b1 >= b0.scale()) {
            return b0;
        }

        BigDecimal b2 =
                b0.toBigDecimal()
                        .movePointRight(b1)
                        .setScale(0, RoundingMode.DOWN)
                        .movePointLeft(b1);
        int p = b0.precision();
        int s = b0.scale();

        if (b1 < 0) {
            return DecimalData.fromBigDecimal(b2, Math.min(38, 1 + p - s), 0);
        } else {
            return DecimalData.fromBigDecimal(b2, 1 + p - s + b1, b1);
        }
    }

    /** SQL <code>TRUNCATE</code> operator applied to double values. */
    public static float struncate(float b0) {
        return struncate(b0, 0);
    }

    public static float struncate(float b0, int b1) {
        return (float) doubleValue(struncate(castFrom((double) b0, 38, 18), b1));
    }

    /**
     * Compares two byte arrays in lexicographical order.
     *
     * <p>The result is positive if {@code array1} is great than {@code array2}, negative if {@code
     * array1} is less than {@code array2} and 0 if {@code array1} is equal to {@code array2}.
     *
     * <p>Note: Currently, this is used in {@code ScalarOperatorGens} for comparing two fields of
     * binary or varbinary type.
     *
     * @param array1 byte array to compare.
     * @param array2 byte array to compare.
     * @return an Integer indicating which one is bigger
     */
    public static int byteArrayCompare(byte[] array1, byte[] array2) {
        for (int i = 0, j = 0; i < array1.length && j < array2.length; i++, j++) {
            int a = (array1[i] & 0xff);
            int b = (array2[j] & 0xff);
            if (a != b) {
                return a - b;
            }
        }
        return array1.length - array2.length;
    }
}