de.caff.util

Class TextLineRingBuffer

java.lang.Object

de.caff.util.TextLineRingBuffer

All Implemented Interfaces:

ByteCollector

public class TextLineRingBuffer
extends java.lang.Object
implements ByteCollector

A text line ring buffer working as a byte collector.

This is especially useful for collecting text output.

If the buffer overflows you can only retrieve the latest getLimit() lines.

Since:

August 10, 2022

Author:

Rammi

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int	INITIAL_LIMIT Initial limit: 64 Mi-lines.

Constructor Summary

Constructors

Constructor and Description
TextLineRingBuffer(int limit, java.nio.charset.Charset charset) Create a ring buffer with the given size.
TextLineRingBuffer(int limit, java.nio.charset.Charset charset, int initialLimit) Create a ring buffer with the given size.

Method Summary

Modifier and Type	Method and Description
void	append(byte[] bytes, int offset, int length) Append the given byte array part to this buffer.
void	append(int value) Append one byte
void	clear() Clear all data.
int	getLimit() Get the limit of this ring buffer.
long	getNumberOfCollectedBytes() Get the total number of bytes appended to this buffer.
boolean	isEmpty() Is the text line ring buffer empty.
int	size() Get the number of valid lines cached in this buffer.
java.lang.String[]	toLineArray() Get the lines of this ring buffer as an array of strings.
Indexable<java.lang.String>	toLineIndexable() Get the lines of this ring buffer as an indexable of strings.
java.util.List<java.lang.String>	toLineList() Get the lines of this ring buffer as a list of strings.
java.lang.String	toString() Get the lines of this line buffer as a concatenated string.
Indexable<java.lang.String>	viewLines() Get a temporary view of the lines in this ring buffer.

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.caff.util.ByteCollector

append

Field Detail

INITIAL_LIMIT

static final int INITIAL_LIMIT

Initial limit: 64 Mi-lines.

See Also:

Constant Field Values

Constructor Detail

TextLineRingBuffer

public TextLineRingBuffer(int limit,
                          @NotNull
                          java.nio.charset.Charset charset)

Create a ring buffer with the given size.

Parameters:

limit - size limit of this text line buffer

charset - charset used to convert bytes into strings

TextLineRingBuffer

TextLineRingBuffer(int limit,
                   @NotNull
                   java.nio.charset.Charset charset,
                   int initialLimit)

Create a ring buffer with the given size. This allows to set the initial limit for testing.

Parameters:

limit - size limit of this buffer

charset - charset for decoding text from bytes

initialLimit - initial limit

Method Detail

getLimit

public int getLimit()

Get the limit of this ring buffer.

Returns:

buffer limit

size

public int size()

Get the number of valid lines cached in this buffer. Due to implementation the returned number might be 1 more than the cache limit.

Returns:

number of text lines cached, possibly 1 more than the limit if the last line added is not ending with an eol mark

isEmpty

public boolean isEmpty()

Is the text line ring buffer empty.

Returns:

if there are no cached lines

append

public void append(int value)

Append one byte

Specified by:

append in interface ByteCollector

Parameters:

value - byte value. Accepts integer for convenience, but will cast the given value to byte.

append

public void append(@NotNull
                   byte[] bytes,
                   int offset,
                   int length)

Append the given byte array part to this buffer.

Specified by:

append in interface ByteCollector

Parameters:

bytes - basic byte array

offset - start offset of the bytes to append

length - number of bytes to append

Throws:

java.lang.IndexOutOfBoundsException - if the parameters define a part which is at least partially outside the bytes

clear

public void clear()

Clear all data. This will clear everything but the total number of bytes handled by this buffer.

Specified by:

clear in interface ByteCollector

viewLines

@NotNull
public Indexable<java.lang.String> viewLines()

Get a temporary view of the lines in this ring buffer. Use only on finished buffer: the returned view will become invalid if any data is appended to this ring buffer. The advantage compared to toLineIndexable(), toLineList(), and toString() is that no data is copied.

Returns:

lines view

toLineIndexable

@NotNull
public Indexable<java.lang.String> toLineIndexable()

Get the lines of this ring buffer as an indexable of strings. This is safe, the returned indexable is independent of this buffer with the price of copying the data.

Returns:

indexable of size size() with the lines of this ring buffer

toLineList

@NotNull
public java.util.List<java.lang.String> toLineList()

Get the lines of this ring buffer as a list of strings. This is safe, the returned list is independent of this buffer with the price of copying the data.

Returns:

list with the lines of this ring buffer

toLineArray

@NotNull
public java.lang.String[] toLineArray()

Get the lines of this ring buffer as an array of strings. This is safe, the returned array is independent of this buffer with the price of copying the data.

Returns:

array with the lines of this ring buffer

toString

@NotNull
public java.lang.String toString()

Get the lines of this line buffer as a concatenated string.

Overrides:

toString in class java.lang.Object

Returns:

string representation of the lines, connected with the local end-of-line sequence

getNumberOfCollectedBytes

public long getNumberOfCollectedBytes()

Get the total number of bytes appended to this buffer.

Specified by:

getNumberOfCollectedBytes in interface ByteCollector

Returns:

total number of appended bytes