io.reactiverse.pgclient.impl.codec.util.Util.java Source code

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Here is the source code for io.reactiverse.pgclient.impl.codec.util.Util.java

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/*
 * Copyright (C) 2017 Julien Viet
 *
 * 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.reactiverse.pgclient.impl.codec.util;

import io.netty.buffer.ByteBuf;
import io.vertx.core.buffer.Buffer;

import java.nio.charset.Charset;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static java.nio.charset.StandardCharsets.*;

public class Util {

    private static final byte ZERO = 0;

    public static String readCString(ByteBuf src, Charset charset) {
        int len = src.bytesBefore(ZERO);
        String s = src.readCharSequence(len, charset).toString();
        src.readByte();
        return s;
    }

    public static String readCStringUTF8(ByteBuf src) {
        int len = src.bytesBefore(ZERO);
        String s = src.readCharSequence(len, UTF_8).toString();
        src.readByte();
        return s;
    }

    public static void writeCString(ByteBuf dst, String s, Charset charset) {
        dst.writeCharSequence(s, charset);
        dst.writeByte(0);
    }

    public static void writeCString(ByteBuf dst, ByteBuf buf) {
        // Important : won't not change data index
        dst.writeBytes(buf, buf.readerIndex(), buf.readableBytes());
        dst.writeByte(0);
    }

    public static void writeCStringUTF8(ByteBuf dst, String s) {
        dst.writeCharSequence(s, UTF_8);
        dst.writeByte(0);
    }

    public static void writeCString(ByteBuf dst, byte[] bytes) {
        dst.writeBytes(bytes, 0, bytes.length);
        dst.writeByte(0);
    }

    public static String buildInvalidArgsError(Stream<Object> values, Stream<Class> types) {
        return "Values [" + values.map(String::valueOf).collect(Collectors.joining(", "))
                + "] cannot be coerced to [" + types.map(Class::getSimpleName).collect(Collectors.joining(", "))
                + "]";
    }

    private static final int FIRST_HALF_BYTE_MASK = 0x0F;

    public static int writeHexString(Buffer buffer, ByteBuf to) {
        int len = buffer.length();
        for (int i = 0; i < len; i++) {
            final int b = Byte.toUnsignedInt(buffer.getByte(i));
            final int firstDigit = b >> 4;
            final byte firstHexDigit = (byte) bin2hex(firstDigit);
            final int secondDigit = b & FIRST_HALF_BYTE_MASK;
            final byte secondHexDigit = (byte) bin2hex(secondDigit);
            to.writeByte(firstHexDigit);
            to.writeByte(secondHexDigit);
        }
        return len;
    }

    private static int bin2hex(int digit) {
        final int isLessOrEqual9 = (digit - 10) >> 31;
        //isLessOrEqual9==0xff<->digit<=9
        //bin2hexAsciiDistance=digit<=9?48:87;
        final int bin2hexAsciiDistance = 48 + ((~isLessOrEqual9) & 39);
        return digit + bin2hexAsciiDistance;
    }
}