io.permazen.kv.caching

Interface CachingConfig

All Known Implementing Classes:

AbstractCachingConfig, CachingKVDatabase, CachingKVStore, CachingKVTransaction

public interface CachingConfig

API for configuring caching behavior.

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_MAX_RANGE_BYTES Default maximum number of bytes to cache in a single contiguous range of key/value pairs (10485760L).
static int	DEFAULT_MAX_RANGES Default maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones (256).
static long	DEFAULT_MAX_TOTAL_BYTES Default maximum total number of bytes to cache including all ranges (104857600L).
static boolean	DEFAULT_READ_AHEAD Default for whether read-ahead is enabled.
static double	DEFAULT_WAIT_FACTOR Default wait factor (1.5).

Method Summary

Modifier and Type	Method and Description
default void	copyCachingConfigTo(CachingConfig dest) Copy config parameters.
long	getMaxRangeBytes() Get the maximum number of bytes to cache in a single contiguous range of key/value pairs.
int	getMaxRanges() Get the maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones.
long	getMaxTotalBytes() Get the total number of bytes to cache.
double	getWaitFactor() Get the wait factor.
boolean	isReadAhead() Get whether this instance is configured to perform read-ahead.
void	setMaxRangeBytes(long maxRangeBytes) Configure the maximum number of bytes to cache in a single contiguous range of key/value pairs.
void	setMaxRanges(int maxRanges) Configure the maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones.
void	setMaxTotalBytes(long maxTotalBytes) Configure the total number of bytes to cache.
void	setReadAhead(boolean readAhead) Configure whether read-ahead is enabled.
void	setWaitFactor(double waitFactor) Set the wait factor.

Field Detail

DEFAULT_MAX_RANGES

static final int DEFAULT_MAX_RANGES

Default maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones (256).

See Also:

getMaxRanges(), Constant Field Values

DEFAULT_MAX_RANGE_BYTES

static final long DEFAULT_MAX_RANGE_BYTES

Default maximum number of bytes to cache in a single contiguous range of key/value pairs (10485760L).

See Also:

getMaxRangeBytes(), Constant Field Values

DEFAULT_MAX_TOTAL_BYTES

static final long DEFAULT_MAX_TOTAL_BYTES

Default maximum total number of bytes to cache including all ranges (104857600L).

See Also:

getMaxTotalBytes(), Constant Field Values

DEFAULT_WAIT_FACTOR

static final double DEFAULT_WAIT_FACTOR

Default wait factor (1.5).

See Also:

getWaitFactor(), Constant Field Values

DEFAULT_READ_AHEAD

static final boolean DEFAULT_READ_AHEAD

Default for whether read-ahead is enabled.

See Also:

isReadAhead(), Constant Field Values

Method Detail

getMaxRangeBytes

long getMaxRangeBytes()

Get the maximum number of bytes to cache in a single contiguous range of key/value pairs.

Default is 10485760L.

Returns:

maximum bytes in any one range

setMaxRangeBytes

void setMaxRangeBytes(long maxRangeBytes)

Configure the maximum number of bytes to cache in a single contiguous range of key/value pairs.

Default is 10485760L.

Parameters:

maxRangeBytes - maximum bytes in any one range

Throws:

IllegalArgumentException - if maxRangeBytes <= 0

getMaxTotalBytes

long getMaxTotalBytes()

Get the total number of bytes to cache. This is an overal maximum incluging all ranges.

Default is 104857600L.

Returns:

maximum cached ranges

setMaxTotalBytes

void setMaxTotalBytes(long maxTotalBytes)

Configure the total number of bytes to cache. This is an overal maximum incluging all ranges.

Default is 104857600L.

Parameters:

maxTotalBytes - maximum cached ranges

Throws:

IllegalArgumentException - if maxTotalBytes <= 0

getMaxRanges

int getMaxRanges()

Get the maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones.

Default is 256.

Returns:

maximum cached ranges

setMaxRanges

void setMaxRanges(int maxRanges)

Configure the maximum number of contiguous ranges of key/value pairs to allow before we start purging the least recently used ones.

Default is 256.

Parameters:

maxRanges - maximum cached ranges

Throws:

IllegalArgumentException - if maxRanges <= 0

getWaitFactor

double getWaitFactor()

Get the wait factor.

The wait factor, when multiplied by the estimated amount of time we expect to have to wait for incoming data that's already on its way, is how long we will actually wait for that data before initiating a new query. A value of zero means never wait, i.e., always start a new query immediately; a value of 1.0 would mean to wait up to the estimated amount of time; a very high value would mean wait until the outstanding query either produces the data or completes.

Default is 1.5.

Returns:

wait factor

setWaitFactor

void setWaitFactor(double waitFactor)

Set the wait factor.

Default is 1.5.

Parameters:

waitFactor - wait factor

Throws:

IllegalArgumentException - if waitFactor is negative or not finite

isReadAhead

boolean isReadAhead()

Get whether this instance is configured to perform read-ahead.

Default is true.

Returns:

true if read-ahead is enabled, otherwise false

setReadAhead

void setReadAhead(boolean readAhead)

Configure whether read-ahead is enabled.

Default is true.

Parameters:

readAhead - true to enable read-ahead, false to disable

copyCachingConfigTo

default void copyCachingConfigTo(CachingConfig dest)

Copy config parameters.

Parameters:

dest - destination for copied caching parameters

Throws:

IllegalArgumentException - if dest is null