RingBuffer

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

Nested Classes
Modifier and Type Class and Description

protected class RingBuffer.condition
class for condition variable

Nested Classes
Modifier and Type	Class and Description
`protected class`	`RingBuffer.condition` class for condition variable

Field Summary

Fields
Modifier and Type Field and Description

(package private) int m_wcount
Counter for writing

Fields
Modifier and Type	Field and Description
`(package private) int`	`m_wcount` Counter for writing

Constructor Summary

Constructors
Constructor and Description

RingBuffer()
Constructor

RingBuffer(int length)
Constructor

Constructors
Constructor and Description
`RingBuffer()` Constructor
`RingBuffer(int length)` Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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.

Class RingBuffer<DataType>

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

m_wcount

Constructor Detail

RingBuffer

RingBuffer

Method Detail

length

length

write

write

write

read

read

read

isFull

put

get

get

init

reset

wptr

wptr

advanceWptr

advanceWptr

writable

full

rptr

rptr

advanceRptr

advanceRptr

readable

empty