Compare Exchange: How to Get Compare Exchange Values

• Use GetCompareExchangeValuesOperation to return the saved compare-exchange Values for the specified Keys.

• For an overview of the 'Compare Exchange' feature click: Compare Exchange Overview

• In this page:

  • Syntax
  • Example I - Get Value for Specified Keys
  • Example II - Get Values for Keys with Common Prefix

Syntax

Methods:

public GetCompareExchangeValuesOperation(string startWith, int? start = null, int? pageSize = null)

Parameters	Type	Description
startWith	string	A common prefix for those keys whose values should be returned
start	int	The number of items that should be skipped
pageSize	int	The maximum number of values that will be retrieved

Returned object:

public class CompareExchangeValue<T>
{
  public readonly string Key;
  public readonly T Value;
  public readonly long Index;
}

Return Value	Description
Dictionary<string, CompareExchangeValue<T>>	A Dictionary containing 'Key' to 'CompareExchangeValue' associations

Session Interface and Lazy Get

You can also get compare exchange values through the session cluster transactions at session.Advanced.ClusterTransaction.

This method also exposes methods getting compare exchange lazily.

Example II - Get Values for Keys with Common Prefix

// Get values for keys that have the common prefix 'users'
// Retrieve maximum 20 entries
Dictionary<string, CompareExchangeValue<User>> compareExchangeValues
  = store.Operations.Send(new GetCompareExchangeValuesOperation<User>("users", 0, 20));