Class CacheParallelLoadStoreAdapter<TK, TV, TData>

Cache storage adapter with parallel loading in LoadAll method.

Inheritance

System.Object

CacheParallelLoadStoreAdapter<TK, TV, TData>

Implements

ICacheStore<TK, TV>

ICacheStore

Namespace: Apache.Ignite.Core.Cache.Store

Assembly: Apache.Ignite.Core.dll

Syntax

public abstract class CacheParallelLoadStoreAdapter<TK, TV, TData> : object, ICacheStore<TK, TV>, ICacheStore

Type Parameters

Name	Description
TK	Key type.
TV	Value type.
TData	Custom data entry type.

Remarks

LoadCache calls GetInputData() and iterates over it in parallel. GetInputData().GetEnumerator() result will be disposed if it implements IDisposable. Any additional post-LoadCache steps can be performed by overriding LoadCache method.

Constructors

CacheParallelLoadStoreAdapter()

Constructor.

Declaration

protected CacheParallelLoadStoreAdapter()

Properties

MaxDegreeOfParallelism

Gets or sets the maximum degree of parallelism to use in LoadCache. Must be either positive or -1 for unlimited amount of threads.

Defaults to .

Declaration

public int MaxDegreeOfParallelism { get; set; }

Property Value

Type	Description
System.Int32

Methods

Delete(TK)

Delete the cache entry from the external resource.

Expiry of a cache entry is not a delete hence will not cause this method to be invoked.

This method is invoked even if no mapping for the key exists.

Declaration

public virtual void Delete(TK key)

Parameters

Type	Name	Description
TK	key	The key that is used for the delete operation.

DeleteAll(IEnumerable<TK>)

Remove data and keys from the external resource for the given collection of keys, if present.

The order that individual deletes occur is undefined.

If this operation fails (by throwing an exception) after a partial success, the writer must remove any successfully written entries from the entries collection so that the caching implementation knows what succeeded and can mutate the cache.

Expiry of a cache entry is not a delete hence will not cause this method to be invoked.

This method may include keys even if there is no mapping for that key, in which case the data represented by that key should be removed from the underlying resource.

Declaration

public virtual void DeleteAll(IEnumerable<TK> keys)

Parameters

Type	Name	Description
IEnumerable<TK>	keys	a mutable collection of keys for entries to delete. Upon invocation, it contains the keys to delete for write-through. Upon return the collection must only contain the keys that were not successfully deleted.

GetInputData()

Gets the input data sequence to be used in LoadCache.

Declaration

protected abstract IEnumerable<TData> GetInputData()

Returns

Type	Description
IEnumerable<TData>

Load(TK)

Loads an object. Application developers should implement this method to customize the loading of a value for a cache entry. This method is called by a cache when a requested entry is not in the cache. If the object can't be loaded null should be returned.

Declaration

public virtual TV Load(TK key)

Parameters

Type	Name	Description
TK	key	The key identifying the object being loaded.

Returns

Type	Description
TV	The value for the entry that is to be stored in the cache or `null` if the object can't be loaded

LoadAll(IEnumerable<TK>)

Loads multiple objects. Application developers should implement this method to customize the loading of cache entries. This method is called when the requested object is not in the cache. If an object can't be loaded, it is not returned in the resulting map.

Declaration

public virtual IEnumerable<KeyValuePair<TK, TV>> LoadAll(IEnumerable<TK> keys)

Parameters

Type	Name	Description
IEnumerable<TK>	keys	Keys identifying the values to be loaded.

Returns

Type	Description
IEnumerable<KeyValuePair<TK, TV>>	A map of key, values to be stored in the cache.

LoadCache(Action<TK, TV>, Object[])

Loads all values from underlying persistent storage. Note that keys are not passed, so it is up to implementation to figure out what to load. This method is called whenever LocalLoadCache(ICacheEntryFilter<TK, TV>, Object[]) method is invoked which is usually to preload the cache from persistent storage.

This method is optional, and cache implementation does not depend on this method to do anything.

For every loaded value method provided action should be called. The action will then make sure that the loaded value is stored in cache.

Declaration

public virtual void LoadCache(Action<TK, TV> act, params object[] args)

Parameters

Type	Name	Description
Action<TK, TV>	act	Action for loaded values.
System.Object[]	args	Optional arguemnts passed to LocalLoadCache(ICacheEntryFilter<TK, TV>, Object[]) method.

Exceptions

Type	Condition
CacheStoreException

Parse(TData, Object[])

This method should transform raw data records from GetInputData into valid key-value pairs to be stored into cache.

Declaration

protected abstract KeyValuePair<TK, TV>? Parse(TData inputRecord, params object[] args)

Parameters

Type	Name	Description
TData	inputRecord
System.Object[]	args

Returns

Type	Description
System.Nullable<KeyValuePair<TK, TV>>

SessionEnd(Boolean)

Tells store to commit or rollback a transaction depending on the value of the commit parameter.

Declaration

public virtual void SessionEnd(bool commit)

Parameters

Type	Name	Description
System.Boolean	commit	`True` if transaction should commit, `false` for rollback.

Write(TK, TV)

Write the specified value under the specified key to the external resource.

This method is intended to support both key/value creation and value update.

Declaration

public virtual void Write(TK key, TV val)

Parameters

Type	Name	Description
TK	key	Key to write.
TV	val	Value to write.

WriteAll(IEnumerable<KeyValuePair<TK, TV>>)

Write the specified entries to the external resource. This method is intended to support both insert and update.

The order that individual writes occur is undefined.

Declaration

public virtual void WriteAll(IEnumerable<KeyValuePair<TK, TV>> entries)

Parameters

Type	Name	Description
IEnumerable<KeyValuePair<TK, TV>>	entries	a mutable collection to write. Upon invocation, it contains the entries to write for write-through. Upon return the collection must only contain entries that were not successfully written. (see partial success above).

Implements

ICacheStore<TK, TV>

ICacheStore