Package org.aoju.bus.core.io.buffer

Class CircularBuffer

java.lang.Object

org.aoju.bus.core.io.buffer.CircularBuffer

public class CircularBuffer
extends Object

循环缓冲区

Constructor Summary

Constructors

Constructor	Description
CircularBuffer()	默认缓冲大小的构造
CircularBuffer(int pSize)	构造

Method Summary

Modifier and Type	Method	Description
void	add(byte value)	增加byte到buffer中
void	add(byte[] targetBuffer, int offset, int length)	Adds the given bytes to the buffer.
void	clear()	Removes all bytes from the buffer.
int	getCurrentNumberOfBytes()	Returns the number of bytes, that are currently present in the buffer.
int	getSpace()	Returns the number of bytes, that can currently be added to the buffer.
boolean	hasBytes()	Returns, whether the buffer is currently holding, at least, a single byte.
boolean	hasSpace()	Returns, whether there is currently room for a single byte in the buffer.
boolean	hasSpace(int count)	Returns, whether there is currently room for the given number of bytes in the buffer.
boolean	peek(byte[] sourceBuffer, int offset, int length)	Returns, whether the next bytes in the buffer are exactly those, given by sourceBuffer, offset, and length.
byte	read()	从buffer中读取下一个byte，同时移除这个bytes。
void	read(byte[] targetBuffer, int targetOffset, int length)	Returns the given number of bytes from the buffer by storing them in the given byte array at the given offset.

Methods inherited from class java.lang.Object

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

Constructor Details

CircularBuffer

public CircularBuffer()

默认缓冲大小的构造

CircularBuffer

public CircularBuffer(int pSize)

构造

Parameters:

pSize - 缓冲大小

Method Details

read

public byte read()

从buffer中读取下一个byte，同时移除这个bytes。

Returns:

The byte

Throws:

IllegalStateException - buffer为空抛出，使用hasBytes(),或 getCurrentNumberOfBytes()判断

read

public void read(byte[] targetBuffer,
 int targetOffset,
 int length)

Returns the given number of bytes from the buffer by storing them in the given byte array at the given offset. 从buffer中获取指定长度的bytes，从给定的targetBuffer的targetOffset位置写出

Parameters:

targetBuffer - 目标bytes

targetOffset - 目标数组开始位置

length - 读取长度

Throws:

NullPointerException - 提供的数组为null

IllegalArgumentException - targetOffset或length 为负数或targetBuffer太小

IllegalStateException - buffer中的byte不足，使用getCurrentNumberOfBytes()判断。

add

public void add(byte value)

增加byte到buffer中

Parameters:

value - The byte

Throws:

IllegalStateException - buffer已满. 用hasSpace()或getSpace()判断。

peek

public boolean peek(byte[] sourceBuffer,
 int offset,
 int length)

Returns, whether the next bytes in the buffer are exactly those, given by sourceBuffer, offset, and length. No bytes are being removed from the buffer. If the result is true, then the following invocations of read() are guaranteed to return exactly those bytes.

Parameters:

sourceBuffer - the buffer to compare against

offset - start offset

length - length to compare

Returns:

True, if the next invocations of read() will return the bytes at offsets pOffset+0, pOffset+1, ..., pOffset+pLength-1 of byte array pBuffer.

Throws:

IllegalArgumentException - Either of pOffset, or pLength is negative.

NullPointerException - The byte array pBuffer is null.

add

public void add(byte[] targetBuffer,
 int offset,
 int length)

Adds the given bytes to the buffer. This is the same as invoking add(byte) for the bytes at offsets offset+0, offset+1, ..., offset+length-1 of byte array targetBuffer.

Parameters:

targetBuffer - the buffer to copy

offset - start offset

length - length to copy

Throws:

IllegalStateException - The buffer doesn't have sufficient space. Use getSpace() to prevent this exception.

IllegalArgumentException - Either of pOffset, or pLength is negative.

NullPointerException - The byte array pBuffer is null.

hasSpace

public boolean hasSpace()

Returns, whether there is currently room for a single byte in the buffer. Same as hasSpace(1).

Returns:

true if there is space for a byte

See Also:

• hasSpace(int)
• getSpace()

hasSpace

public boolean hasSpace(int count)

Returns, whether there is currently room for the given number of bytes in the buffer.

Parameters:

count - the byte count

Returns:

true if there is space for the given number of bytes

See Also:

• hasSpace()
• getSpace()

hasBytes

public boolean hasBytes()

Returns, whether the buffer is currently holding, at least, a single byte.

Returns:

true if the buffer is not empty

getSpace

public int getSpace()

Returns the number of bytes, that can currently be added to the buffer.

Returns:

the number of bytes that can be added

getCurrentNumberOfBytes

public int getCurrentNumberOfBytes()

Returns the number of bytes, that are currently present in the buffer.

Returns:

the number of bytes

clear

public void clear()

Removes all bytes from the buffer.