NamedMapTKey, TValueAddOrUpdate Method (TKey, FuncTKey, TValue, FuncTKey, TValue, TValue)

ScaleOut Software NamedCache API

Adds a key/value pair to NamedMapTKey, TValue if the key does not already exist, or updates a key/value pair in the NamedMapTKey, TValue if the key already exists.

Namespace: Soss.Client.Concurrent
Assembly: soss_namedcache (in soss_namedcache.dll) Version: 6.2.0.0

Syntax

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public TValue AddOrUpdate(
	TKey key,
	Func<TKey, TValue> addValueFactory,
	Func<TKey, TValue, TValue> updateValueFactory
)

Public Function AddOrUpdate ( 
	key As TKey,
	addValueFactory As Func(Of TKey, TValue),
	updateValueFactory As Func(Of TKey, TValue, TValue)
) As TValue

Parameters

key: Type: TKey
The key to be added or whose value should be updated.
addValueFactory: Type: SystemFuncTKey, TValue
The function used to generate a value for an absent key.
updateValueFactory: Type: SystemFuncTKey, TValue, TValue
The function used to generate a new value for an existing key based on the key's existing value

Return Value

Type: TValue
A new value for the key. This will be either the result of addValueFactory (if the key was absent) or the result of updateValueFactory (if the key was present).

Exceptions

Exception	Condition
ArgumentNullException	Thrown if key is a null reference or addValueFactory is a null reference or updateValueFactory is a null reference.
TimeoutException	Thrown when the maximum number of internal retries reached.

Examples

The following example illustrates how to use the AddOrUpdate method

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using System;
using System.Diagnostics;
using Soss.Client;
using Soss.Client.Concurrent;

class AddOrUpdateUsage
{
    static void Main(string[] args)
    {
        NamedMap<int, string> map = new NamedMap<int, string>("myMap");

        // Both calls below should add new elements to the 
        // map since these keys are not yet present there
        for (int key = 6; key <= 7; key++)
        {
            map.AddOrUpdate(key, 
                (k) => {
                    switch (k)
                    {
                        case 6: 
                            return "F";
                        case 7: 
                            return "G";
                        default:
                            return "Unexpected";
                    }
                }, 

                (k, oldValue) => "this 'update' arg will not be used"
            );
        }

        // Verify one of the elements that was inserted above
        string value = map.GetOrAdd(7, "this 'add' arg will not be used");
        Debug.Assert("G" == value);

        // Repeat the AddOrUpdate calls, resulting in an update to each element
        for (int key = 6; key <= 7; key++)
        {
            map.AddOrUpdate(key, "this 'add' arg will not be used", 
                (k, oldValue) => {
                    switch (oldValue)
                    {
                        case "F": 
                            return "FF";
                        case "G":
                            return "GG";
                        default:
                            return "Unexpected";
                    }
                }
            );
        }

        // Verify one of the elements that was inserted above
        value = map.GetOrAdd(7, "this 'add' arg will not be used");
        Debug.Assert("GG" == value);

        // Clean up
        map.Clear();
    }
}

Reference

NamedMapTKey, TValue Class

AddOrUpdate Overload

Soss.Client.Concurrent Namespace