Class LDAPCache
- All Implemented Interfaces:
Serializable
LDAPCache
represents an in-memory cache that you can use
to reduce the number of search requests sent to the LDAP server.
Each item in the cache represents a search request and its results. Each item is uniquely identified by the search criteria, which includes:
- the host name and port number of the LDAP server
- the base DN of the search
- the search filter
- the scope of the search
- the attributes to be returned in the search results
- the DN used to authenticate the client when binding to the server
- the LDAP v3 controls specified in the search request
After a search request is cached, the results of any subsequent search requests using the same criteria are read from the cache. Note that if any part of the criteria differs (for example, if a different DN is used when binding to the server or if a different set of attributes to be returned is specified), the search request is sent to the server.
When you create the cache, you specify the maximum amount of time that an item can be kept in the cache. When an item's age exceeds that time limit, the item is removed from the cache.
The cache also has a maximum size that you specify when creating the cache. If adding a new item exceeds the maximum size of the cache, the first entries in the cache are removed to make enough space for the new item.
Finally, when creating the cache, you can specify a list
of the base DNs in search requests that you want to cache.
For example, if you specify o=Airius.com
as
a base DN to cache, your client caches search requests
where the base DN is o=Airius.com
.
To specify that you want to use a cache for a particular
LDAP session, call the setCache
method of
the LDAPConnection
object that you are
working with.
All clones of an LDAPConnection
object share
the same LDAPCache
object.
Note that LDAPCache
does not maintain consistency
with the directory, so that cached search results may no longer be
valid after a directory update. If the same application is performing
both cached searches and directory updates, then the
application should flush the corresponding cache entries after an update.
To do this use the flushEntries
method.
Also, note that search requests that return referrals are not cached.
The LDAPCache
class includes methods for
getting statistics (such as hit rates) from the cache and
for flushing entries from the cache.
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Field Summary
Fields -
Constructor Summary
ConstructorsConstructorDescriptionLDAPCache
(long ttl, long size) Constructs a newLDAPCache
object, using the specified maximum size of the cache (in bytes) and the maximum age of cached items (in seconds).Constructs a newLDAPCache
object, using the specified maximum size of the cache (in bytes), and the maximum age of cached items (in seconds), and an array of the base DNs of searches that you want to cache. -
Method Summary
Modifier and TypeMethodDescriptionboolean
flushEntries
(String dn, int scope) Flush the entries identified by DN and scope from the cache.long
Gets the amount of available space (in bytes) left in the cache.String[]
Gets the array of base DNs of searches to be cached.int
Gets the number of entries being cached.long
Gets the total number of entries that are flushed when timer expires andflushEntries
is called.long
Gets the total number of requests which successfully found and retrieved an item from the cache.long
Gets the total number of requests which failed to find and retrieve an item from the cache.long
getSize()
Gets the maximum size of the cache (in bytes).long
Gets the maximum age allowed for cached items (in seconds).long
Gets the total number of requests for retrieving items from the cache.
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Field Details
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DELIM
Delimiter used internally when creating keys for the cache.- See Also:
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Constructor Details
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LDAPCache
public LDAPCache(long ttl, long size) Constructs a newLDAPCache
object, using the specified maximum size of the cache (in bytes) and the maximum age of cached items (in seconds). When items in the cache exceed this age, they are removed from the cache.- Parameters:
ttl
- the maximum amount of time that an item can be cached (in seconds)size
- the maximum size of the cache (in bytes)
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LDAPCache
Constructs a newLDAPCache
object, using the specified maximum size of the cache (in bytes), and the maximum age of cached items (in seconds), and an array of the base DNs of searches that you want to cache. (For example, if the array of base DNs includeso=Airius.com
, the cache stores search results if the base DN in the search request iso=Airius.com
.)- Parameters:
ttl
- the maximum amount of time that an item can be cached (in seconds)size
- the maximum size of the cache (in bytes)dns
- the list of base DNs of searches that you want to cache.
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Method Details
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getSize
public long getSize()Gets the maximum size of the cache (in bytes).- Returns:
- the maximum size of the cache (in bytes).
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getTimeToLive
public long getTimeToLive()Gets the maximum age allowed for cached items (in seconds). (Items that exceed this age are removed from the cache.)- Returns:
- the maximum age of items in the cache (in seconds).
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getBaseDNs
Gets the array of base DNs of searches to be cached. (Search requests with these base DNs are cached.)- Returns:
- the array of base DNs.
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flushEntries
Flush the entries identified by DN and scope from the cache.- Parameters:
dn
- the distinguished name (or base DN) of the entries to be removed from the cache. Use this parameter in conjunction withscope
to identify the entries that you want removed from the cache. If this parameter isnull
, the entire cache is flushed.scope
- the scope identifying the entries that you want removed from the cache. The value of this parameter can be one of the following:LDAPv2.SCOPE_BASE
(to remove the entry identified bydn
)LDAPv2.SCOPE_ONE
(to remove the entries that havedn
as their parent entry)LDAPv2.SCOPE_SUB
(to remove the entries in the subtree underdn
in the directory)
- Returns:
true
if the entry is removed from the cache;false
if the entry is not removed.
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getAvailableSize
public long getAvailableSize()Gets the amount of available space (in bytes) left in the cache.- Returns:
- the available space (in bytes) in the cache.
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getTotalOperations
public long getTotalOperations()Gets the total number of requests for retrieving items from the cache. This includes both items successfully found in the cache and items not found in the cache.- Returns:
- the total number of requests for retrieving items from the cache.
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getNumMisses
public long getNumMisses()Gets the total number of requests which failed to find and retrieve an item from the cache.- Returns:
- the number of requests that did not find and retrieve an item in the cache.
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getNumHits
public long getNumHits()Gets the total number of requests which successfully found and retrieved an item from the cache.- Returns:
- the number of requests that successfully found and retrieved an item from the cache.
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getNumFlushes
public long getNumFlushes()Gets the total number of entries that are flushed when timer expires andflushEntries
is called.- Returns:
- the total number of entries that are flushed when timer expires.
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getNumEntries
public int getNumEntries()Gets the number of entries being cached.- Returns:
- the number of entries being cached.
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