# ChronologicalEvictionStrategy Methods

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.chronologicalevictionstrategy/)

## OnBlockAllocated(FixedSizeBuffer) {#onblockallocated-orleans-providers-streams-common-fixedsizebuffer-8795d866}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.chronologicalevictionstrategy/methods/onblockallocated-orleans-providers-streams-common-fixedsizebuffer-8795d866/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Common/PooledCache/ChronologicalEvictionStrategy.cs#L64-L68)

```csharp
public void OnBlockAllocated(FixedSizeBuffer newBlock)
```

Method which should be called when data adapter allocated a new block

### Parameters

- `newBlock` (`FixedSizeBuffer`): The new block.

## PerformPurge(DateTime) {#performpurge-system-datetime-1ca01dde}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.chronologicalevictionstrategy/methods/performpurge-system-datetime-1ca01dde/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Common/PooledCache/ChronologicalEvictionStrategy.cs#L73-L75)

```csharp
public void PerformPurge(DateTime nowUtc)
```

Method which should be called when pulling agent try to do a purge on the cache

### Parameters

- `nowUtc` (`DateTime`): The current time (UTC)