jp.go.aist.rtm.RTC.buffer
Class RingBuffer<DataType>

java.lang.Object
  jp.go.aist.rtm.RTC.buffer.RingBuffer<DataType>

Type Parameters:

DataType - Data type to store in the buffer

All Implemented Interfaces:

BufferBase<DataType>

public class RingBuffer<DataType>
extends java.lang.Object
implements BufferBase<DataType>

Ring buffer implementation class

[@.ja 指定した長さのリング状バッファを持つバッファ実装クラス。 バッファ全体にデータが格納された場合、以降のデータは古いデータから 順次上書きされる。 従って、バッファ内には直近のバッファ長分のデータのみ保持される。 注)現在の実装では、一番最後に格納したデータのみバッファから読み出し可能} This is the buffer implementation class with ring shaped buffer of specified length. If data is stored in the entire buffer, data from now on will be overwritten from old data one by one. Therefore, only the length of latest data is stored in the buffer. Note: In the current implementation, only last stored data can be read from the buffer.

Nested Class Summary

protected class

RingBuffer.condition class for condition variable

Field Summary

(package private) int

m_wcount Counter for writing

Constructor Summary

RingBuffer()
Constructor

RingBuffer(int length)
Constructor

Method Summary

ReturnCode	advanceRptr() advances the reading pointer.
ReturnCode	advanceRptr(int n) advances the reading pointer.
ReturnCode	advanceWptr() advances the writing pointer.
ReturnCode	advanceWptr(int n) Get the buffer length
boolean	empty() Check on whether the buffer is empty.
boolean	full() Check on whether the buffer is full.
DataType	get() Reading data from the buffer
ReturnCode	get(DataRef<DataType> value) Write data into the buffer
void	init(Properties prop) Sets the buffer.
boolean	isFull() Check on whether the buffer is full.
int	length() Get the buffer length
ReturnCode	length(int n) Get the buffer length
ReturnCode	put(DataType data) Write data into the buffer
ReturnCode	read(DataRef<DataType> valueRef) Readout data from the buffer
ReturnCode	read(DataRef<DataType> valueRef, int sec) Readout data from the buffer
ReturnCode	read(DataRef<DataType> valueRef, int sec, int nsec) Readout data from the buffer
int	readable() returns the number of elements that can be read.
ReturnCode	reset() Get the buffer length
DataType	rptr() returns the pointer of a present reading element.
DataType	rptr(int n) returns the pointer of a present reading element.
DataType	wptr() Returns the pointer of a present writing element.
DataType	wptr(int n) Returns the pointer of a present writing element.
int	writable() Write data into the buffer
ReturnCode	write(DataType value) Write data into the buffer
ReturnCode	write(DataType value, int sec) Write data into the buffer
ReturnCode	write(DataType value, int sec, int nsec) Write data into the buffer

Methods inherited from class java.lang.Object

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

Field Detail

m_wcount

int m_wcount

Counter for writing

Constructor Detail

RingBuffer

public RingBuffer()

Constructor

RingBuffer

public RingBuffer(int length)

Constructor

Initialize the buffer by specified buffer length. However, if the specified length is less than two, the buffer should be initialized by two in length.

Parameters:

length - Buffer length

Method Detail

length

public int length()

Get the buffer length

Specified by:

length in interface BufferBase<DataType>

Returns:

Buffer length

length

public ReturnCode length(int n)

Get the buffer length

Pure virtual function to get the buffer length.

Specified by:

length in interface BufferBase<DataType>

Returns:

BUFFER_OK

write

public ReturnCode write(DataType value)

Write data into the buffer

Write data which is given argument into the buffer.

Specified by:

write in interface BufferBase<DataType>

Parameters:

value - Target data for writing

Returns:

BUFFER_OK Normal return BUFFER_FULL Buffer full TIMEOUT Timeout PRECONDITION_NOT_MET Unknown condition

write

public ReturnCode write(DataType value,
                        int sec)

Write data into the buffer

Write data which is given argument into the buffer.

Parameters:

value - Target data for writing

sec - Timeout sec

Returns:

BUFFER_OK Normal return BUFFER_FULL Buffer full TIMEOUT Timeout PRECONDITION_NOT_MET Unknown condition

write

public ReturnCode write(DataType value,
                        int sec,
                        int nsec)

Write data into the buffer

Write data which is given argument into the buffer.

Specified by:

write in interface BufferBase<DataType>

Parameters:

value - Target data for writing

sec - Timeout sec

nsec - Timeout nsec

Returns:

BUFFER_OK Normal return BUFFER_FULL Buffer full TIMEOUT Timeout PRECONDITION_NOT_MET Unknown condition

read

public ReturnCode read(DataRef<DataType> valueRef)

Readout data from the buffer

Readout data stored into the buffer.

Specified by:

read in interface BufferBase<DataType>

Parameters:

valueRef - Readout data

Returns:

BUFFER_OK BUFFER_EMPTY TIMEOUT PRECONDITION_NOT_MET

read

public ReturnCode read(DataRef<DataType> valueRef,
                       int sec)

Readout data from the buffer

Readout data stored into the buffer.

Parameters:

valueRef - Readout data

sec - TimeOut sec order

Returns:

BUFFER_OK BUFFER_EMPTY TIMEOUT PRECONDITION_NOT_MET

read

public ReturnCode read(DataRef<DataType> valueRef,
                       int sec,
                       int nsec)

Readout data from the buffer

Readout data stored into the buffer.

Specified by:

read in interface BufferBase<DataType>

Parameters:

valueRef - Readout data

sec - TimeOut sec order

nsec - TimeOut nsec order

Returns:

BUFFER_OK BUFFER_EMPTY TIMEOUT PRECONDITION_NOT_MET

isFull

public boolean isFull()

Check on whether the buffer is full.

This is not implemented.

Returns:

True if the buffer is full, else false.

put

public ReturnCode put(DataType data)

Write data into the buffer

Pure virtual function to write data into the buffer. Always BUFFER_OK will be returned in this implementation.

Specified by:

put in interface BufferBase<DataType>

Parameters:

data - Target data to write.

Returns:

BUFFER_ERROR: 異常終了} BUFFER_OK: Successful BUFFER_ERROR: Failed

get

public DataType get()

Reading data from the buffer

The position of the pointer for reading is not changed.

Specified by:

get in interface BufferBase<DataType>

Returns:

Read data

get

public ReturnCode get(DataRef<DataType> value)

Write data into the buffer

The position of the pointer for reading is not changed.

Specified by:

get in interface BufferBase<DataType>

Parameters:

value - Target data to write.

Returns:

Result of having written in data (true:Successful, false:Failed)

init

public void init(Properties prop)

Sets the buffer.

Initializes the setting of the buffer according to the property given by Properties.

buffer.length: Length of buffer

buffer.write.full_policy: Policy whether overwrite.Default is overwrite.

buffer.write.timeout: The timeout period is specified every second. Default is 1.0 seconds.

buffer.read.empty_policy: Reading policy when buffer is empty.Default is readback.

buffer.read.timeout: The timeout period is specified every second. Default is 1.0 seconds.

Specified by:

init in interface BufferBase<DataType>

Parameters:

prop - Property to set buffer

reset

public ReturnCode reset()

Get the buffer length

Pure virtual function to get the buffer length.

Specified by:

reset in interface BufferBase<DataType>

Returns:

BUFFER_OK: Normal termination NOT_SUPPORTED:Reset failure BUFFER_ERROR:Abnormal termination

wptr

public DataType wptr(int n)

Returns the pointer of a present writing element.

This function returns the object of a present writing element of the buffer.

Specified by:

wptr in interface BufferBase<DataType>

Parameters:

n - Pointer for writing

Returns:

Object at writing position

wptr

public DataType wptr()

Returns the pointer of a present writing element.

This function returns the pointer of a present writing element of the buffer.

Specified by:

wptr in interface BufferBase<DataType>

Returns:

Object at writing position

advanceWptr

public ReturnCode advanceWptr(int n)

Get the buffer length

This function advances the writing pointer.

Specified by:

advanceWptr in interface BufferBase<DataType>

Parameters:

n - write pinter + n pointer

Returns:

BUFFER_OK:Normal termination PRECONDITION_NOT_MET: n > writable()

advanceWptr

public ReturnCode advanceWptr()

advances the writing pointer.

This function advances the writing pointer.

Specified by:

advanceWptr in interface BufferBase<DataType>

Returns:

BUFFER_OK: Normal termination PRECONDITION_NOT_MET: n > writable()

writable

public int writable()

Write data into the buffer

This function returns the number of elements that can be written in the buffer.

Specified by:

writable in interface BufferBase<DataType>

Returns:

Recordable number of elements

full

public boolean full()

Check on whether the buffer is full.

Pure virtual function to check on whether the buffer is full.

Specified by:

full in interface BufferBase<DataType>

Returns:

True if the buffer is full, else false.

rptr

public DataType rptr(int n)

returns the pointer of a present reading element.

This function returns the pointer of a present reading element of the buffer.

Specified by:

rptr in interface BufferBase<DataType>

Parameters:

n - reading position

Returns:

Object at reading position

rptr

public DataType rptr()

returns the pointer of a present reading element.

This function returns the pointer of a present reading element of the buffer.

Specified by:

rptr in interface BufferBase<DataType>

Returns:

Object at reading position

advanceRptr

public ReturnCode advanceRptr(int n)

advances the reading pointer.

This function advances the reading pointer.

Specified by:

advanceRptr in interface BufferBase<DataType>

Parameters:

n - Advanced number of points

Returns:

BUFFER_OK: Normal termination BUFFER_ERROR: Abnormal termination

advanceRptr

public ReturnCode advanceRptr()

advances the reading pointer.

This function advances the reading pointer.

Specified by:

advanceRptr in interface BufferBase<DataType>

Returns:

BUFFER_OK: Normal termination BUFFER_ERROR: Abnormal termination

readable

public int readable()

returns the number of elements that can be read.

This function returns the number of elements that can be read from the buffer.

Specified by:

readable in interface BufferBase<DataType>

Returns:

Number of elements that can be read

empty

public boolean empty()

Check on whether the buffer is empty.

Pure virtual function to check on whether the buffer is empty.

Specified by:

empty in interface BufferBase<DataType>

Returns:

True if the buffer is empty, else false.