ch.qos.logback.ext.loggly.io

Class DiscardingRollingOutputStream

java.lang.Object

java.io.OutputStream

ch.qos.logback.ext.loggly.io.DiscardingRollingOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class DiscardingRollingOutputStream
extends OutputStream

Capped in-memory OutputStream composed of a chain of ByteArrayOutputStream called 'buckets'.

Each 'bucket' is limited in size (see maxBucketSizeInBytes) and the total size of the OutputStream is bounded thanks to a discarding policy. An external component is expected to consume the filled buckets thanks to getFilledBuckets().

Implementation decisions:

• Why in-memory without offload on disk: offload on disk was possible with Google Guava's FileBackedOutputStream but had the drawback to introduce a dependency. Loggly batch appender use case should be OK with a pure in-memory approach.

Author:

Cyrille Le Clerc

Field Summary

Fields

Modifier and Type	Field and Description
static String	LINE_SEPARATOR

Constructor Summary

Constructors

Constructor and Description
DiscardingRollingOutputStream(int maxBucketSizeInBytes, int maxBucketCount)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close all the underlying buckets (current bucket, filled buckets and buckets from the recycled buckets pool).
void	flush()
long	getCurrentOutputStreamSize()
int	getDiscardedBucketCount() Number of discarded buckets.
BlockingDeque<ByteArrayOutputStream>	getFilledBuckets() Return the filled buckets
protected ByteArrayOutputStream	newBucket() Get a new bucket from the recycledBucketPool or instantiate a new one if none available in the free bucket pool.
protected void	onBucketDiscard(ByteArrayOutputStream discardedBucket) Designed for extension.
protected void	onBucketRoll(ByteArrayOutputStream rolledBucket) The rolled bucket.
void	recycleBucket(ByteArrayOutputStream bucket) Returns the given bucket to the pool of free buckets.
void	rollCurrentBucket() Moves the current active bucket to the list of filled buckets and defines a new one.
void	rollCurrentBucketIfNotEmpty() Roll current bucket if size threshold has been reached.
String	toString()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.lang.Object

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

Field Detail

LINE_SEPARATOR

public static final String LINE_SEPARATOR

Constructor Detail

DiscardingRollingOutputStream

public DiscardingRollingOutputStream(int maxBucketSizeInBytes,
                             int maxBucketCount)

Parameters:

maxBucketSizeInBytes -

maxBucketCount -

Method Detail

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b,
         int off,
         int len)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

close

public void close()

Close all the underlying buckets (current bucket, filled buckets and buckets from the recycled buckets pool).

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

rollCurrentBucketIfNotEmpty

public void rollCurrentBucketIfNotEmpty()

Roll current bucket if size threshold has been reached.

rollCurrentBucket

public void rollCurrentBucket()

Moves the current active bucket to the list of filled buckets and defines a new one.

The new active bucket is reused from the recycledBucketPool pool if one is available or recreated.

onBucketDiscard

protected void onBucketDiscard(ByteArrayOutputStream discardedBucket)

Designed for extension.

Parameters:

discardedBucket - the discarded bucket

onBucketRoll

protected void onBucketRoll(ByteArrayOutputStream rolledBucket)

The rolled bucket. Designed for extension.

Parameters:

rolledBucket - the discarded bucket

newBucket

protected ByteArrayOutputStream newBucket()

Get a new bucket from the recycledBucketPool or instantiate a new one if none available in the free bucket pool.

Returns:

the bucket ready to use

recycleBucket

public void recycleBucket(ByteArrayOutputStream bucket)

Returns the given bucket to the pool of free buckets.

Parameters:

bucket - the bucket to recycle

getFilledBuckets

public BlockingDeque<ByteArrayOutputStream> getFilledBuckets()

Return the filled buckets

getDiscardedBucketCount

public int getDiscardedBucketCount()

Number of discarded buckets. Monitoring oriented metric.

getCurrentOutputStreamSize

public long getCurrentOutputStreamSize()

toString

public String toString()

Overrides:

toString in class Object