ceph-csi/e2e/vendor/github.com/klauspost/compress/zstd/hash.go
Niels de Vos bec6090996 build: move e2e dependencies into e2e/go.mod
Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>
2025-03-07 16:05:04 +00:00

36 lines
1.1 KiB
Go

// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
const (
prime3bytes = 506832829
prime4bytes = 2654435761
prime5bytes = 889523592379
prime6bytes = 227718039650203
prime7bytes = 58295818150454627
prime8bytes = 0xcf1bbcdcb7a56463
)
// hashLen returns a hash of the lowest mls bytes of with length output bits.
// mls must be >=3 and <=8. Any other value will return hash for 4 bytes.
// length should always be < 32.
// Preferably length and mls should be a constant for inlining.
func hashLen(u uint64, length, mls uint8) uint32 {
switch mls {
case 3:
return (uint32(u<<8) * prime3bytes) >> (32 - length)
case 5:
return uint32(((u << (64 - 40)) * prime5bytes) >> (64 - length))
case 6:
return uint32(((u << (64 - 48)) * prime6bytes) >> (64 - length))
case 7:
return uint32(((u << (64 - 56)) * prime7bytes) >> (64 - length))
case 8:
return uint32((u * prime8bytes) >> (64 - length))
default:
return (uint32(u) * prime4bytes) >> (32 - length)
}
}