This PR is to add comments to patchDatasetStatus in pkg\ddc\alluxio\cache.go. (#4578)

* Add Notation to patchDatasetStatus in pkg\ddc\alluxio\cache.go

Signed-off-by: Volta234 <3313467495@qq.com>

* Add Notation to patchDatasetStatus in pkg\ddc\alluxio\cache.go

Signed-off-by: Volta234 <3313467495@qq.com>

---------

Signed-off-by: Volta234 <3313467495@qq.com>

Author: Volta233

pkg/ddc/alluxio/cache.go

@@ -63,6 +63,21 @@ func (e *AlluxioEngine) queryCacheStatus() (states cacheStates, err error) {
 
 }
 
+// PatchDatasetStatus updates the Dataset status with cached percentage based on the provided cache states.
+// It skips updating under the following conditions:
+// - When the Dataset's UfsTotal field is empty
+// - When the Dataset's UfsTotal field contains the metadata sync pending message
+// The cached percentage is calculated as (cached bytes / UfsTotal bytes) * 100.
+// 
+// Parameters:
+//   - dataset (v1alpha1.Dataset): Pointer to the Dataset object containing UFS metadata.
+//     The Status.UfsTotal field must be a valid human-readable size string (e.g. "10GiB")
+//   - states (cacheStates): Pointer to the cache state structure that will be modified in-place.
+//     The cached field must be a valid human-readable size string (e.g. "5GiB")
+// 
+// Returns:
+//   - None: Modifies the states.cachedPercentage field directly with formatted percentage string.
+//     The percentage is stored as a string using cachedPercentageFormat (e.g. "45.60%")
 func (e AlluxioEngine) patchDatasetStatus(dataset *v1alpha1.Dataset, states *cacheStates) {
 	// skip when `dataset.Status.UfsTotal` is empty
 	if dataset.Status.UfsTotal == "" {