CGDataProviderCreateWithData

CGDataProviderCreateWithData is a function in the Core Graphics framework for macOS and iOS. It is used to create a data provider object that can be used to supply image data for Core Graphics image objects. This function allows developers to directly provide a block of memory containing image data.

The function takes three arguments: a pointer to the data, the size of the data in bytes, and a release callback function. The release callback function is an optional function that Core Graphics will call when the data provider is no longer needed. This allows the developer to manage the memory associated with the provided data. If the data is allocated from a temporary buffer that should be freed after use, a release callback is essential.

When creating an image using a CGDataProvider created with this function, Core Graphics will access the provided data block to render the image. The data must remain valid and accessible for the entire lifetime of the CGImage object that uses it. If the data is not owned by the application after the CGImage is created, a release callback should be provided to ensure proper memory management. This is a common way to load images from memory, such as when decoding image data received over a network or extracted from a custom file format.