A slight enhancement to the proposed IKeyedDataCache interface (overloading
the removeKeyedData method) :
public interface IKeyedDataCache {
/**
* Puts an keyed data to the cache.
* All key indexes will be updated.
*/
public void putKeyedData(IKeyedData data);
/**
* Gets an keyed data from the cache using the given key index.
*/
public IKeyedData getKeyedData(Serializable key, int idx);
/**
* Removes a keyed data from the cache using the given key index.
* All key indexes of the keyed data will be updated.
*/
public boolean removeKeyedData(Serializable key, int idx);
/**
* Removes a keyed data from the cache.
* All key indexes of the keyed data will be updated.
*/
public boolean removeKeyedData(IKeyedData data);
}
Hanson
> -----Original Message-----
> From: Hanson Char [mailto:[EMAIL PROTECTED]
> Sent: Saturday, July 19, 2003 6:16 AM
> To: 'Turbine JCS Users List'
> Subject: RE: composite keys and cache entries keys retrieval
>
>
> Imagine if one can have multiple-key supports for an object put to the
> cache, one can then have, say, a primary key of
> username+pageid, a secondary
> key of pageid+username. Now one can then invalidate all
> pageid of a given
> username via the primary composite key, and invalidate all
> user of a given
> pageid via the secondary composite key.
>
> Sometimes when we put a data value to the cache, such data
> value needs to be
> accessed via more than one key paths. Here is an idea for
> multi-key cached
> data support.
>
> Consider the interfaces:
> // Base interface for I2KeyData and INKeyData
> public interface IKeyedData extends Serializable {
> /** Returns the primary key used to access this cached data. */
> public Serializable getPrimaryKey();
> }
> // implemented by the multi-key data object for 2 key paths
> public interface I2KeyData extends IKeyedData {
> /** Returns the secondary key used to access this cached data. */
> public Serializable getSecondKey();
> }
> // implemented by the multi-key data object for 2+ key paths
> public interface INKeyData extends IKeyedData {
> /**
> * Returns all the keys used to access this cached data.
> * Note that key[0] must be the primary; and key[1], if
> any, must be the
> secondary key, etc.
> */
> public Serializable[] getKeyArray();
> }
>
> // implemented by the cache service provider (ie the cache system)
> public interface IKeyedDataCache {
> /**
> * Puts an keyed data to the cache.
> * All key indexes will be updated.
> */
> public void putKeyedData(IKeyedData data) throws IOException;
> /**
> * Gets an keyed data from the cache using the given key index.
> */
> public IKeyedData getKeyedData(Serializable key, int idx) throws
> IOException;
> /**
> * Removes a keyed data from the cache using the given key index.
> * All key indexes of the keyed data will be updated.
> */
> public boolean removeKeyedData(Serializable key, int idx) throws
> IOException;
> }
>
> Now to have multiple-key support, a data object can implement
> either the
> I2KeyData (for 2 keys) or INKeyData for 2+ keys. The
> important point is the
> implementation of the cache service provider should be done
> in such a way
> that putting or removing a multi-key data object to/from the
> cache via any
> key index will automatically update all keyed indexes (and in
> an atomic
> way).
>
> Hanson
>
> -----Original Message-----
> From: Hanson Char [mailto:[EMAIL PROTECTED]
> Sent: Friday, July 11, 2003 8:11 AM
> To: 'Turbine JCS Users List'
> Subject: RE: composite keys and cache entries keys retrieval
>
>
> >in memory
>
> should be in the cache system, not necessarily in memory.
>
> -----Original Message-----
> From: Hanson Char
> Sent: Friday, July 11, 2003 8:10 AM
> To: 'Turbine JCS Users List'
> Subject: RE: composite keys and cache entries keys retrieval
>
>
> This sounds like a cache as relational database feature to
> me, in that when
> a cache is created, the "schema" of the cache can be specified so that
> multiple "indexes" to each cache item can be automatically
> updated by the
> cache provider code when items are add/update/delete to the
> specific cache.
>
> If such feature is available, one can retrieve a cache item
> not only via 1
> key (composite or not) but via other "candidate keys" as
> well. Yet there
> will exist only 1 copy of cache item in memory at all time.
>
> Hanson
>
> -----Original Message-----
> From: Fulco Houkes [mailto:[EMAIL PROTECTED]
> Sent: Friday, July 11, 2003 5:28 AM
> To: JCS user mailinglist
> Subject: composite keys and cache entries keys retrieval
>
>
>
> Hi,
>
> (Sorry for this cross-posting, I noticed I send it to the
> wrong mailing
> list. My appologizes.)
>
> I'm try to use a composite key for all the cache entries; the
> composite key
> is combination of a pageID and a username. I need to be able
> to invalidate
> all the cache entries related to a specific pagesID as well
> as all the cache
> entries related to a username independently.
>
> I tried to use groups for this purpose, but it seems the entries are
> duplicated into the different groups, so it's not solving my
> problem. I've
> been looking for using the ":" hierarchy features, but the
> "very-light"
> documentation does present much on the subject, and I could not remove
> entries using the pattern ":"+ myKey +":". As far as I
> understood it, it's
> only possible to use this functionality with the myKey+":" pattern.
>
> Finally I opted to retrieve all the cache entries keys and
> filter myself the
> entries to be invalidated. But I could not found any method
> (from the JCS
> class) returning a Set/Enumeration/... of keys of all the the
> cache entries.
> The IMemoryCache interface has a getKeyArray() method, which
> does the job,
> but this method is not used within the inherited classes.
>
> Does anyone know how to retrieve the keys of all the entries
> present in the
> cache, without having to change the source code?
>
> Thanks a lot.
> Fulco Houkes
>
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