63 lines
1.8 KiB
Java
63 lines
1.8 KiB
Java
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package cpw.mods.fml.common.network;
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import org.apache.commons.lang3.Validate;
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import com.google.common.base.Charsets;
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import io.netty.buffer.ByteBuf;
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public class ByteBufUtils {
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public static int varIntByteCount(int toCount)
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{
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return (toCount & -128) == 0 ? 1 : ((toCount & -16384) == 0 ? 2 : ((toCount & -2097152) == 0 ? 3 : ((toCount & -268435456) == 0 ? 4 : 5)));
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}
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public static int readVarInt(ByteBuf buf, int maxSize)
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{
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Validate.isTrue(maxSize < 6 && maxSize > 0, "Varint length is between 1 and 5, not %d", maxSize);
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int i = 0;
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int j = 0;
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byte b0;
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do
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{
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b0 = buf.readByte();
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i |= (b0 & 127) << j++ * 7;
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if (j > maxSize)
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{
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throw new RuntimeException("VarInt too big");
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}
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}
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while ((b0 & 128) == 128);
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return i;
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}
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public static void writeVarInt(ByteBuf to, int toWrite, int maxSize)
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{
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Validate.isTrue(varIntByteCount(toWrite) < maxSize, "Integer is too big for %d bytes", maxSize);
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while ((toWrite & -128) != 0)
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{
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to.writeByte(toWrite & 127 | 128);
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toWrite >>>= 7;
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}
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to.writeByte(toWrite);
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}
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public static String readUTF8String(ByteBuf from)
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{
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int len = readVarInt(from,2);
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String str = from.toString(from.readerIndex(), len, Charsets.UTF_8);
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from.readerIndex(from.readerIndex() + len);
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return str;
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}
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public static void writeUTF8String(ByteBuf to, String string)
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{
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byte[] utf8Bytes = string.getBytes(Charsets.UTF_8);
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Validate.isTrue(varIntByteCount(utf8Bytes.length) < 3, "The string is too long for this encoding.");
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writeVarInt(to, utf8Bytes.length, 2);
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to.writeBytes(utf8Bytes);
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}
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}
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