org.helidb.backend.cache.lru
Class LruCacheBackendFactory<K,V,P>

java.lang.Object
  org.helidb.backend.cache.lru.LruCacheBackendFactory<K,V,P>

Type Parameters:

K - The type of keys in the database.

V - The type of values in the database.

P - The type used to represent positions in the proxied backend.

All Implemented Interfaces:

DatabaseBackendFactory<K,V,P>

public class LruCacheBackendFactory<K,V,P>
extends Object
implements DatabaseBackendFactory<K,V,P>

This is a DatabaseBackendFactory for building LruCacheBackend objects.

Since:

1.0

Author:

Karl Gustafsson

In_jar:

helidb-core

Field Summary

static int	DEFAULT_CACHE_SIZE The default cache size is 128 records.
static int	DEFAULT_NEGATIVE_CACHE_SIZE The default negative cache size is 32 keys.

Constructor Summary

LruCacheBackendFactory()

Method Summary

DatabaseBackend<K,V,P>	create(DatabaseFiles files, boolean readOnly) Create a new backend for the supplied file.
LruCacheBackendFactory<K,V,P>	setMaxCacheSize(int cacheSize) Set the maximum size for the database record cache.
LruCacheBackendFactory<K,V,P>	setMaxNegativeCacheSize(int negativeCacheSize) Set the maximum size for the cache for failed search results.
LruCacheBackendFactory<K,V,P>	setProxiedBackendFactory(DatabaseBackendFactory<K,V,P> factory) Set the factory for the proxied backend.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CACHE_SIZE

public static final int DEFAULT_CACHE_SIZE

The default cache size is 128 records.

See Also:

Constant Field Values

DEFAULT_NEGATIVE_CACHE_SIZE

public static final int DEFAULT_NEGATIVE_CACHE_SIZE

The default negative cache size is 32 keys.

See Also:

Constant Field Values

Constructor Detail

LruCacheBackendFactory

public LruCacheBackendFactory()

Method Detail

setProxiedBackendFactory

public LruCacheBackendFactory<K,V,P> setProxiedBackendFactory(DatabaseBackendFactory<K,V,P> factory)

Set the factory for the proxied backend. This property must be set.

Parameters:

factory - The factory for the proxied backend.

Returns:

this.

setMaxCacheSize

public LruCacheBackendFactory<K,V,P> setMaxCacheSize(int cacheSize)
                                              throws IllegalArgumentException

Set the maximum size for the database record cache. The default value of this property is 128 records.

Parameters:

cacheSize - The maximum record cache size.

Returns:

this

Throws:

IllegalArgumentException - If the cache size is < 0.

setMaxNegativeCacheSize

public LruCacheBackendFactory<K,V,P> setMaxNegativeCacheSize(int negativeCacheSize)
                                                      throws IllegalArgumentException

Set the maximum size for the cache for failed search results. The default value of this property is 32 keys.

Parameters:

negativeCacheSize - The maximum size for the negative cache.

Returns:

this

Throws:

IllegalArgumentException - If the cache size is < 0.

create

public DatabaseBackend<K,V,P> create(DatabaseFiles files,
                                     boolean readOnly)

Description copied from interface: DatabaseBackendFactory

Create a new backend for the supplied file.

Specified by:

create in interface DatabaseBackendFactory<K,V,P>

Parameters:

files - The file(s) containing the database data. The implementation of this method should be able to assume a specific DatabaseFiles implementation. Which depends on the implementation of the database backend to create.

readOnly - Should the backend object be created read only?

Returns:

A new database backend object.