com.allanbank.mongodb.bson.io

Class StringEncoderCache

java.lang.Object

com.allanbank.mongodb.bson.io.AbstractStringCache

com.allanbank.mongodb.bson.io.StringEncoderCache

public class StringEncoderCache
extends AbstractStringCache

StringEncoderCache provides the ability to cache the encoding of a string to speed the writing of strings.

This class is thread safe. Thread safety is achieved by maintaining two data structures. The first is a map of seen strings to the number of times the string has been seen. The map is maintained by the base class: AbstractStringCache. The second structure is a simple map of the cached String to the encoded byte[]. The map has no locking or synchronization since it is read-only after construction.

API Warning:

This class is NOT part of the drivers API. This class may be mutated in incompatible ways between any two releases of the driver.

Copyright ©:

2014, Allanbank Consulting, Inc., All Rights Reserved

Nested Class Summary

Nested classes/interfaces inherited from class com.allanbank.mongodb.bson.io.AbstractStringCache

AbstractStringCache.ReverseIntegerComparator

Field Summary

Fields inherited from class com.allanbank.mongodb.bson.io.AbstractStringCache

DEFAULT_MAX_CACHE_ENTRIES, DEFAULT_MAX_CACHE_LENGTH, MAX_MULTIPLIER, myMaxCacheLength, myMaxCachEntries, myMaxCachEntriesMultiplier, mySeen, myUseCount

Constructor Summary

Constructors

Constructor and Description
StringEncoderCache() Creates a new StringEncoder.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	clear() Clears the cache.
byte[]	find(String string) Looks in the cache for encoded bytes for the specified string.
protected void	rebuildCache() Rebuilds the cache from the current collection of seen entries.

Methods inherited from class com.allanbank.mongodb.bson.io.AbstractStringCache

buildCacheGroups, getMaxCacheEntries, getMaxCacheLength, setMaxCacheEntries, setMaxCacheLength, used

Methods inherited from class java.lang.Object

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

Constructor Detail

StringEncoderCache

public StringEncoderCache()

Creates a new StringEncoder.

Method Detail

find

public byte[] find(String string)

Looks in the cache for encoded bytes for the specified string.

Parameters:

string - The string value to find the cached bytes for.

Returns:

The cached bytes for the string. May be null.

clear

protected void clear()

Clears the cache.

Overrides:

clear in class AbstractStringCache

rebuildCache

protected void rebuildCache()

Rebuilds the cache from the current collection of seen entries.

Specified by:

rebuildCache in class AbstractStringCache