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# CGDataProviderSequentialCallbacks

Defines a structure containing pointers to client-defined callback functions that manage the sending of data for a sequential-access data provider.

```
struct CGDataProviderSequentialCallbacks
```

## Overview

The functions specified by the `CGDataProviderSequentialCallbacks` structure are responsible for sequentially copying data to a memory buffer for Core Graphics to use. The functions are also responsible for handling the data provider’s basic memory management. You supply a `CGDataProviderSequentialCallbacks` structure to the function [`init(sequentialInfo:callbacks:)`](/documentation/CoreGraphics/CGDataProvider/init(sequentialInfo:callbacks:)) to create a sequential-access data provider.

## Topics

### Initializers

[`init()`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/init())

[`init(version:getBytes:skipForward:rewind:releaseInfo:)`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/init(version:getBytes:skipForward:rewind:releaseInfo:))

### Instance Properties

[`getBytes`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/getBytes)

A pointer to a function that copies data from the provider. For more information, see [`CGDataProviderGetBytesCallback`](/documentation/CoreGraphics/CGDataProviderGetBytesCallback).

[`releaseInfo`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/releaseInfo)

A pointer to a function that handles clean-up for the data provider, or `NULL`. For more information, see [`CGDataProviderReleaseInfoCallback`](/documentation/CoreGraphics/CGDataProviderReleaseInfoCallback).

[`rewind`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/rewind)

A pointer to a function Core Graphics calls to return the provider to the beginning of the data stream. For more information, see [`CGDataProviderRewindCallback`](/documentation/CoreGraphics/CGDataProviderRewindCallback).

[`skipForward`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/skipForward)

A pointer to a function that Core Graphics calls to advance the stream of data supplied by the provider.

[`version`](/documentation/CoreGraphics/CGDataProviderSequentialCallbacks/version)

The version of this structure. It should be set to 0.


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