ICubeCacheSaver.GetGlobalWriteLock

Syntax

GetGlobalWriteLock(

DestKey: Integer;

ParamValues: IMetabaseObjectParamValues;

Selections: IDimSelectionSet): ILock;

Parameters

DestKey. The key of the required cube display version.

ParamValues. The set of parameter values, for which caching object is saved.

Selections. The collection of selections in the specified cube display version.

Description

The GetGlobalWriteLock method returns the object that controls write lock of cached data for the specified cube parameters.

Comments

Write lock is required to prevent a situation when several users modify same data simultaneously. It is probable if working with cube cache is performed in the code, which is executed via web services of the BI server of Foresight Analytics Platform.

Example

Executing the example requires that the repository contains a cube with the STD_CUBE identifier. Data caching is available for the cube.

Sub UserProc;
Var
    MB: IMetabase;
    MDesc, CacheDesc: IMetabaseObjectDescriptor;
    Cache: ICubeCacheSaver;
    CubeInst: ICubeInstance;
    Dest: ICubeInstanceDestination;
    Sels: IDimSelectionSet;
    Sel: IDimSelection;
    Matr: IMatrix;
    Lock: ILock;
Begin
    MB := MetabaseClass.Active;
    MDesc := MB.ItemById("STD_CUBE");
    CacheDesc := GetCache(MDesc);
    If CacheDesc <> Null Then
        Cache := CacheDesc.Edit As ICubeCacheSaver;
        CubeInst := MDesc.Open(Null) As ICubeInstance;
        Dest := CubeInst.Destinations.DefaultDestination;
        Sels := Dest.CreateDimSelectionSet;
        For Each Sel In Sels Do
            Sel.SelectAll;
        End For;
        //Get cached matrix with data
        Matr := Cache.GetGlobalCache(Dest.Key, Null, Sels);
        If Matr <> Null Then
            Lock := Cache.GetGlobalWriteLock(Dest.Key, Null, Sels);
            //...
            //Further working with data matrix
            //...
            //Save updated matrix to cache
            Cache.SaveCache(Dest.Key, Null, Sels, Matr);
            Lock.Unlock;
            Lock := Null;
        End If;
    End If;
End Sub UserProc;

Function GetCache(MObj: IMetabaseObjectDescriptor): IMetabaseObjectDescriptor;
Var
    Desc: IMetabaseObjectDescriptor;
Begin
    For Each Desc In MObj.Children Do
        If Desc.ClassId = MetabaseObjectClass.KE_CLASS_CUBE_CACHE_SAVER Then
            Return Desc;
        End If;
    End For;
    Return Null;
End Function GetCache;

On executing the example the matrix of cached data will be obtained for the specified cube parameters. Data is locked for modification. After data is updated in cache, the data is unlocked.