vkGetValidationCacheDataEXT
Data can be retrieved from a validation cache object using the command:
VkResult vkGetValidationCacheDataEXT(
VkDevice device,
VkValidationCacheEXT validationCache,
size_t* pDataSize,
void* pData);
device
is the logical device that owns the validation cache.validationCache
is the validation cache to retrieve data from.pDataSize
is a pointer to a value related to the amount of data in the validation cache, as described below.pData
is eitherNULL
or a pointer to a buffer.
If pData
is NULL
, then the maximum size of the data that can be
retrieved from the validation cache, in bytes, is returned in
pDataSize
.
Otherwise, pDataSize
must point to a variable set by the application
to the size of the buffer, in bytes, pointed to by pData
, and on
return the variable is overwritten with the amount of data actually written
to pData
.
If pDataSize
is less than the maximum size that can be retrieved by
the validation cache, at most pDataSize
bytes will be written to
pData
, and vkGetValidationCacheDataEXT
will return
VK_INCOMPLETE
instead of VK_SUCCESS
, to indicate that not all of
the validation cache was returned.
Any data written to pData
is valid and can be provided as the
pInitialData
member of the VkValidationCacheCreateInfoEXT
structure passed to vkCreateValidationCacheEXT
.
Two calls to vkGetValidationCacheDataEXT
with the same parameters
must retrieve the same data unless a command that modifies the contents of
the cache is called between them.
Applications can store the data retrieved from the validation cache, and
use these data, possibly in a future run of the application, to populate new
validation cache objects.
The results of validation, however, may depend on the vendor ID, device ID,
driver version, and other details of the device.
To enable applications to detect when previously retrieved data is
incompatible with the device, the initial bytes written to pData
must
be a header consisting of the following members:
Offset | Size | Meaning |
---|---|---|
0 | 4 | length in bytes of the entire validation cache header written as a stream of bytes, with the least significant byte first |
4 | 4 | a VkValidationCacheHeaderVersionEXT value written as a stream of bytes, with the least significant byte first |
8 | a layer commit ID expressed as a UUID, which uniquely identifies the version of the validation layers used to generate these validation results |
The first four bytes encode the length of the entire validation cache header, in bytes. This value includes all fields in the header including the validation cache version field and the size of the length field.
The next four bytes encode the validation cache version, as described for VkValidationCacheHeaderVersionEXT. A consumer of the validation cache should use the cache version to interpret the remainder of the cache header.
If pDataSize
is less than what is necessary to store this header,
nothing will be written to pData
and zero will be written to
pDataSize
.
Valid Usage (Implicit)
VUID-vkGetValidationCacheDataEXT-device-parameter
device
must be a valid VkDevice handle
VUID-vkGetValidationCacheDataEXT-validationCache-parameter
validationCache
must be a valid VkValidationCacheEXT handle
VUID-vkGetValidationCacheDataEXT-pDataSize-parameter
pDataSize
must be a valid pointer to a size_t
value
VUID-vkGetValidationCacheDataEXT-pData-parameter
If the value referenced by pDataSize
is not 0
, and pData
is not NULL
, pData
must be a valid pointer to an array of pDataSize
bytes
VUID-vkGetValidationCacheDataEXT-validationCache-parent
validationCache
must have been created, allocated, or retrieved from device