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authorMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
committerMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
commite9c24f4af7ed56760f6db7941827d09f6db9020b (patch)
tree62128c43b883ce5e3148113350978755779bb5de /teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go
parent58d5e7cfda4781d8a57ec52aefd02983835c301a (diff)
add matterbridge
Diffstat (limited to 'teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go')
-rw-r--r--teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go35
1 files changed, 35 insertions, 0 deletions
diff --git a/teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go b/teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go
new file mode 100644
index 0000000..5d73c21
--- /dev/null
+++ b/teleirc/matterbridge/vendor/github.com/klauspost/compress/zstd/hash.go
@@ -0,0 +1,35 @@
+// 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)
+ }
+}