Package org.xbill.DNS.dnssec

Class KeyCache

java.lang.Object

org.xbill.DNS.dnssec.KeyCache

final class KeyCache
extends Object

Cache for DNSKEY RRsets or corresponding null/bad key entries with a limited size and respect for TTL values.

Since:

3.5

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	KeyCache.CacheEntry	Utility class to cache key entries with an expiration date.

Field Summary

Fields

Modifier and Type	Field	Description
private final Map<String,KeyCache.CacheEntry>	cache	This is the main caching data structure.
private final Clock	clock
private static final int	DEFAULT_MAX_CACHE_SIZE
private static final int	DEFAULT_MAX_TTL
static final String	MAX_CACHE_SIZE_CONFIG	Name of the property that configures the maximum cache size.
static final String	MAX_TTL_CONFIG	Name of the property that configures the maximum cache TTL.
private int	maxCacheSize	This is the maximum number of entries that the key cache will hold.
private long	maxTtl	This is the maximum TTL [s] that all key cache entries will have.

Constructor Summary

Constructors

Constructor	Description
KeyCache()	Creates a new instance of this class.
KeyCache(Clock clock)	Creates a new instance of this class.

Method Summary

Modifier and Type	Method	Description
KeyEntry	find(Name n, int dclass)	Find the 'closest' trusted DNSKEY rrset to the given name.
void	init(Properties config)	Initialize the cache.
private String	key(Name n, int dclass)
private KeyEntry	lookupEntry(String key)
void	store(KeyEntry ke)	Store a KeyEntry in the cache.

Methods inherited from class java.lang.Object

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

Field Details

MAX_TTL_CONFIG

public static final String MAX_TTL_CONFIG

Name of the property that configures the maximum cache TTL.

See Also:

• Constant Field Values

MAX_CACHE_SIZE_CONFIG

public static final String MAX_CACHE_SIZE_CONFIG

Name of the property that configures the maximum cache size.

See Also:

• Constant Field Values

DEFAULT_MAX_TTL

private static final int DEFAULT_MAX_TTL

See Also:

• Constant Field Values

DEFAULT_MAX_CACHE_SIZE

private static final int DEFAULT_MAX_CACHE_SIZE

See Also:

• Constant Field Values

cache

private final Map<String,KeyCache.CacheEntry> cache

This is the main caching data structure.

clock

private final Clock clock

maxTtl

private long maxTtl

This is the maximum TTL [s] that all key cache entries will have.

maxCacheSize

private int maxCacheSize

This is the maximum number of entries that the key cache will hold.

Constructor Details

KeyCache

public KeyCache()

Creates a new instance of this class. Uses the default system clock for cache eviction.

KeyCache

public KeyCache(Clock clock)

Creates a new instance of this class.

Parameters:

clock - The clock to use for cache eviction.

Method Details

init

public void init(Properties config)

Initialize the cache. This implementation recognizes the following configuration parameters:

"dnsjava.dnssec.keycache.max_ttl"

The maximum TTL to apply to any cache entry.

"dnsjava.dnssec.keycache.max_size"

The maximum number of entries that the cache will hold.

Parameters:

config - The configuration information.

find

public KeyEntry find(Name n,
 int dclass)

Find the 'closest' trusted DNSKEY rrset to the given name.

Parameters:

n - The name to start the search.

dclass - The class this DNSKEY rrset should be in.

Returns:

The 'closest' entry to 'n' in the same class as 'dclass'.

store

public void store(KeyEntry ke)

Store a KeyEntry in the cache. The entry will be ignored if it isn't a DNSKEY rrset, if it doesn't have the SECURE security status, or if it isn't a null-Key.

Parameters:

ke - The key entry to cache.

key

private String key(Name n,
 int dclass)

lookupEntry

private KeyEntry lookupEntry(String key)