First Commit of Voltha-Go-Controller from Radisys
Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go b/vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go
new file mode 100644
index 0000000..376e0ca
--- /dev/null
+++ b/vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go
@@ -0,0 +1,57 @@
+// +build !appengine
+
+// This file encapsulates usage of unsafe.
+// xxhash_safe.go contains the safe implementations.
+
+package xxhash
+
+import (
+ "unsafe"
+)
+
+// In the future it's possible that compiler optimizations will make these
+// XxxString functions unnecessary by realizing that calls such as
+// Sum64([]byte(s)) don't need to copy s. See https://golang.org/issue/2205.
+// If that happens, even if we keep these functions they can be replaced with
+// the trivial safe code.
+
+// NOTE: The usual way of doing an unsafe string-to-[]byte conversion is:
+//
+// var b []byte
+// bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+// bh.Data = (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+// bh.Len = len(s)
+// bh.Cap = len(s)
+//
+// Unfortunately, as of Go 1.15.3 the inliner's cost model assigns a high enough
+// weight to this sequence of expressions that any function that uses it will
+// not be inlined. Instead, the functions below use a different unsafe
+// conversion designed to minimize the inliner weight and allow both to be
+// inlined. There is also a test (TestInlining) which verifies that these are
+// inlined.
+//
+// See https://github.com/golang/go/issues/42739 for discussion.
+
+// Sum64String computes the 64-bit xxHash digest of s.
+// It may be faster than Sum64([]byte(s)) by avoiding a copy.
+func Sum64String(s string) uint64 {
+ b := *(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)}))
+ return Sum64(b)
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+// It may be faster than Write([]byte(s)) by avoiding a copy.
+func (d *Digest) WriteString(s string) (n int, err error) {
+ d.Write(*(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)})))
+ // d.Write always returns len(s), nil.
+ // Ignoring the return output and returning these fixed values buys a
+ // savings of 6 in the inliner's cost model.
+ return len(s), nil
+}
+
+// sliceHeader is similar to reflect.SliceHeader, but it assumes that the layout
+// of the first two words is the same as the layout of a string.
+type sliceHeader struct {
+ s string
+ cap int
+}