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authorgVisor bot <gvisor-bot@google.com>2019-06-02 06:44:55 +0000
committergVisor bot <gvisor-bot@google.com>2019-06-02 06:44:55 +0000
commitceb0d792f328d1fc0692197d8856a43c3936a571 (patch)
tree83155f302eff44a78bcc30a3a08f4efe59a79379 /pkg/tcpip/hash
parentdeb7ecf1e46862d54f4b102f2d163cfbcfc37f3b (diff)
parent216da0b733dbed9aad9b2ab92ac75bcb906fd7ee (diff)
Merge 216da0b7 (automated)
Diffstat (limited to 'pkg/tcpip/hash')
-rw-r--r--pkg/tcpip/hash/jenkins/jenkins.go80
-rwxr-xr-xpkg/tcpip/hash/jenkins/jenkins_state_autogen.go4
2 files changed, 84 insertions, 0 deletions
diff --git a/pkg/tcpip/hash/jenkins/jenkins.go b/pkg/tcpip/hash/jenkins/jenkins.go
new file mode 100644
index 000000000..52c22230e
--- /dev/null
+++ b/pkg/tcpip/hash/jenkins/jenkins.go
@@ -0,0 +1,80 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package jenkins implements Jenkins's one_at_a_time, non-cryptographic hash
+// functions created by by Bob Jenkins.
+//
+// See https://en.wikipedia.org/wiki/Jenkins_hash_function#cite_note-dobbsx-1
+//
+package jenkins
+
+import (
+ "hash"
+)
+
+// Sum32 represents Jenkins's one_at_a_time hash.
+//
+// Use the Sum32 type directly (as opposed to New32 below)
+// to avoid allocations.
+type Sum32 uint32
+
+// New32 returns a new 32-bit Jenkins's one_at_a_time hash.Hash.
+//
+// Its Sum method will lay the value out in big-endian byte order.
+func New32() hash.Hash32 {
+ var s Sum32
+ return &s
+}
+
+// Reset resets the hash to its initial state.
+func (s *Sum32) Reset() { *s = 0 }
+
+// Sum32 returns the hash value
+func (s *Sum32) Sum32() uint32 {
+ hash := *s
+
+ hash += (hash << 3)
+ hash ^= hash >> 11
+ hash += hash << 15
+
+ return uint32(hash)
+}
+
+// Write adds more data to the running hash.
+//
+// It never returns an error.
+func (s *Sum32) Write(data []byte) (int, error) {
+ hash := *s
+ for _, b := range data {
+ hash += Sum32(b)
+ hash += hash << 10
+ hash ^= hash >> 6
+ }
+ *s = hash
+ return len(data), nil
+}
+
+// Size returns the number of bytes Sum will return.
+func (s *Sum32) Size() int { return 4 }
+
+// BlockSize returns the hash's underlying block size.
+func (s *Sum32) BlockSize() int { return 1 }
+
+// Sum appends the current hash to in and returns the resulting slice.
+//
+// It does not change the underlying hash state.
+func (s *Sum32) Sum(in []byte) []byte {
+ v := s.Sum32()
+ return append(in, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
+}
diff --git a/pkg/tcpip/hash/jenkins/jenkins_state_autogen.go b/pkg/tcpip/hash/jenkins/jenkins_state_autogen.go
new file mode 100755
index 000000000..310f0ee6d
--- /dev/null
+++ b/pkg/tcpip/hash/jenkins/jenkins_state_autogen.go
@@ -0,0 +1,4 @@
+// automatically generated by stateify.
+
+package jenkins
+