Class CacheBase
Base class for caches.
Inheritance
Inherited Members
Namespace: SuperOffice.Data.Cache
Assembly: SoDataBase.dll
Syntax
public abstract class CacheBase : IDisposable, IFlushableRemarks
Implement this class if you want to implement a cache within NetServer. Classes implementing this class should always be instantiated with the GetCache(Type) method.
The OnFlush() and OnRefresh() methods needs to be implemented by all classes implementing the cache.
Constructors
CacheBase(String, CacheType, Int32)
Default constructor for CacheBase
Declaration
protected CacheBase(string name, CacheType cacheType, int timeout)Parameters
| Type | Name | Description |
|---|---|---|
| String | name | Name of the cache. |
| CacheType | cacheType | Type of cache. |
| Int32 | timeout | Timeout in [s] for the cache to expire. |
Remarks
Classes inheriting this class should only be instantiated through the
Exceptions
| Type | Condition |
|---|---|
| SecurityException | This exception will be thrown if not above elements in the call stack is saved with the SuperOffice strong name. |
Fields
_cacheState
Current state of the cache.
Declaration
protected CacheBase.CacheState _cacheStateField Value
| Type | Description |
|---|---|
| CacheBase.CacheState |
_lastUpdated
Time when the cache was last updated.
Declaration
protected DateTime _lastUpdatedField Value
| Type | Description |
|---|---|
| DateTime |
Properties
CacheType
Type of cache
Declaration
public CacheType CacheType { get; }Property Value
| Type | Description |
|---|---|
| CacheType |
IsValid
Check if the data in the cache is valid.
Declaration
public virtual bool IsValid { get; }Property Value
| Type | Description |
|---|---|
| Boolean |
Remarks
Default behavior is to verify that the time has not expired. If the time-out is 0, false will always be returned. if time-out is less than 0, true will always be returned.
When overriding this property, false should always be returned if _cacheState is different from Normal. If the cache is not valid, the _cacheState should be set to Expired prior to returning false.
Lock
Declaration
protected ReaderWriterLock Lock { get; }Property Value
| Type | Description |
|---|---|
| ReaderWriterLock |
Name
Name of the cache
Declaration
public string Name { get; }Property Value
| Type | Description |
|---|---|
| String |
State
State of the cache.
Declaration
public CacheBase.CacheState State { get; }Property Value
| Type | Description |
|---|---|
| CacheBase.CacheState |
Timeout
Timeout in [ms] for the cache to expire.
Declaration
public int Timeout { get; }Property Value
| Type | Description |
|---|---|
| Int32 |
Methods
Dispose()
Dispose of the cache
Declaration
public void Dispose()Remarks
A call to this method will cause a consequent call to Flush().
Flush()
Force the cache to be emptied.
Declaration
public void Flush()Remarks
All memory used for caching should be "freed", by the consequent call to OnFlush().
GetCachedTableNumbers()
Implement in derived classes to declare what tables the cache is covering.
Declaration
public abstract int[] GetCachedTableNumbers()Returns
| Type | Description |
|---|---|
| Int32[] | List of tables covered by the cache. |
IsCacheInvalidated(Int32, SqlType, Int32)
Determine if the change made the cache invalid.
Declaration
protected virtual bool IsCacheInvalidated(int tableNumber, SqlType sqlType, int primaryKey)Parameters
| Type | Name | Description |
|---|---|---|
| Int32 | tableNumber | Number of Table that is modified. |
| SqlType | sqlType | Type of change (i.e. Insert, Update or Delete) |
| Int32 | primaryKey | Primary key of the record being changed. |
Returns
| Type | Description |
|---|---|
| Boolean |
OnDisposed()
Method called when the cache is disposed.
Declaration
protected void OnDisposed()OnExpired()
Method called when the cache has expired.
Declaration
protected void OnExpired()OnFlush()
Flush data in the cache.
Declaration
protected abstract void OnFlush()Remarks
Removing reference to all the data in the cache so the garbage collector can free up the memory.
OnFlushed()
Method called when the cache is flushed.
Declaration
protected void OnFlushed()OnRefresh()
Refresh data in the cache.
Declaration
protected abstract void OnRefresh()OnRefreshed()
Method called when the cache is refreshed.
Declaration
protected void OnRefreshed()Refresh()
Force the cache to be refreshed
Declaration
public void Refresh()Remarks
All invalid data in the cache should be removed, by the consequent call to OnRefresh().
Validate()
Validate the cache.
Declaration
public void Validate()Remarks
Properties and methods returning data from the cache should call this method prior to accessing any of the data in the cache.
The implementation of the method forces a Refresh() if the data is not valid (e.g. not IsValid).
Events
Disposed
Event fired when the cache has been disposed;
Declaration
public event CacheEventHandler DisposedEvent Type
| Type | Description |
|---|---|
| CacheEventHandler |
Expired
Event fired when the flush has expired.
Declaration
public event CacheEventHandler ExpiredEvent Type
| Type | Description |
|---|---|
| CacheEventHandler |
Flushed
Event fired when the cache has been flushed (e.g. emptied);
Declaration
public event CacheEventHandler FlushedEvent Type
| Type | Description |
|---|---|
| CacheEventHandler |
Refreshed
Event fired when the cache has been refreshed.
Declaration
public event CacheEventHandler RefreshedEvent Type
| Type | Description |
|---|---|
| CacheEventHandler |
Remarks
Refreshing the cache does not necesearly mean that all the data is loaded back in the cache.