VkPipelineCache

VkPipelineCache is a Vulkan object that caches VkPipeline objects. It allows applications to store and retrieve pre-compiled pipeline state objects, which can significantly reduce application startup times and improve performance, especially when creating many pipelines.

A VkPipelineCache is created using vkCreatePipelineCache and destroyed with vkDestroyPipelineCache. It can be created empty, or initialized with data from a previous VkPipelineCache using vkGetPipelineCacheData to retrieve its contents, which can then be passed to vkCreatePipelineCache to create a new, pre-populated cache.

When creating a VkPipeline object using vkCreateGraphicsPipelines or vkCreateComputePipelines, an application can provide a VkPipelineCache object. If the pipeline is found in the cache, the pre-compiled version is returned, avoiding the cost of recompilation. If not found, the pipeline is compiled and stored in the cache for future use.

The cache can be serialized to a binary format, allowing it to be saved to disk and reloaded later. This persistence is crucial for applications that need to maintain pipeline compilations across different runs. Vulkan implementations are responsible for managing the internal format and content of the pipeline cache.

Using VkPipelineCache effectively requires careful consideration of when and how to create, load, and save caches. Incorrect usage or frequent re-creation of caches can negate the performance benefits.