io.asyncer.r2dbc.mysql.internal.util

Class VarIntUtils

java.lang.Object

io.asyncer.r2dbc.mysql.internal.util.VarIntUtils

public final class VarIntUtils
extends Object

An utility for encoding/decoding var integer.

TODO: add more unit tests.

Method Summary

Modifier and Type	Method and Description
static int	checkNextVarInt(io.netty.buffer.ByteBuf buf) Checks the next variable-length integer position/index.
static long	crossReadVarInt(io.netty.buffer.ByteBuf firstPart, io.netty.buffer.ByteBuf secondPart)
static long	readVarInt(io.netty.buffer.ByteBuf buf) Note: it will change buf readerIndex.
static void	reserveVarInt(io.netty.buffer.ByteBuf buf) Reserve a seat of an unknown var integer in buf header.
static io.netty.buffer.ByteBuf	setReservedVarInt(io.netty.buffer.ByteBuf buf, int value) Set a var integer to the buf header from 32-bits integer, the buf header should be reserved by reserveVarInt(io.netty.buffer.ByteBuf).
static void	setReservedVarInt(io.netty.buffer.ByteBuf buf, long value) Set a var integer to the buf header from 64-bits integer, the buf header should be reserved by reserveVarInt(io.netty.buffer.ByteBuf).
static int	varIntBytes(int value) Calculate encoded bytes of a var integer.
static void	writeVarInt(io.netty.buffer.ByteBuf buf, int value) Write MySQL var integer to buf from 32-bits integer.
static void	writeVarInt(io.netty.buffer.ByteBuf buf, long value) Write MySQL var integer to buf from 64-bits integer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

crossReadVarInt

public static long crossReadVarInt(io.netty.buffer.ByteBuf firstPart,
                                   io.netty.buffer.ByteBuf secondPart)

readVarInt

public static long readVarInt(io.netty.buffer.ByteBuf buf)

Note: it will change buf readerIndex.

Parameters:

buf - a readable buffer include a var integer.

Returns:

A var integer read from buffer.

checkNextVarInt

public static int checkNextVarInt(io.netty.buffer.ByteBuf buf)

Checks the next variable-length integer position/index. If the index is a negative integer means the buf has not a var integer. If the index is 0, means buf looks like has only a var integer which buffer has no other data. If the index is a positive integer means how much buffer size after read a var integer.

Parameters:

buf - a readable buffer for check it has next a var integer or not.

Returns:

the index.

varIntBytes

public static int varIntBytes(int value)

Calculate encoded bytes of a var integer.

Note: it will NOT check value validation.

Parameters:

value - a integer to calculate encoded bytes.

Returns:

encoded bytes length.

reserveVarInt

public static void reserveVarInt(io.netty.buffer.ByteBuf buf)

Reserve a seat of an unknown var integer in buf header.

Note: make sure the var integer will be set into the buf header, can not use it when you want write a var integer into a buf which has data before the var integer. i.e. the buf should be a new ByteBuf.

Parameters:

buf - that want reserve to this ByteBuf.

setReservedVarInt

public static io.netty.buffer.ByteBuf setReservedVarInt(io.netty.buffer.ByteBuf buf,
                                                        int value)

Set a var integer to the buf header from 32-bits integer, the buf header should be reserved by reserveVarInt(io.netty.buffer.ByteBuf).

Parameters:

buf - that want set to this ByteBuf, which is reserved a var integer.

value - integer that want to set.

Returns:

the buf which is set a var integer to the reserved seat.

setReservedVarInt

public static void setReservedVarInt(io.netty.buffer.ByteBuf buf,
                                     long value)

Set a var integer to the buf header from 64-bits integer, the buf header should be reserved by reserveVarInt(io.netty.buffer.ByteBuf).

Parameters:

buf - that want set to this ByteBuf, which is reserved a var integer.

value - integer that want to set.

writeVarInt

public static void writeVarInt(io.netty.buffer.ByteBuf buf,
                               int value)

Write MySQL var integer to buf from 32-bits integer.

Parameters:

buf - that want write to this ByteBuf

value - integer that want write

writeVarInt

public static void writeVarInt(io.netty.buffer.ByteBuf buf,
                               long value)

Write MySQL var integer to buf from 64-bits integer.

Parameters:

buf - that want write to this ByteBuf

value - integer that want write