vendor

vendor/github.com/cavaliercoder/go-cpio/hash.go

@@ -0,0 +1,45 @@
+package cpio
+
+import (
+	"encoding/binary"
+	"hash"
+)
+
+type digest struct {
+	sum uint32
+}
+
+// NewHash returns a new hash.Hash32 computing the SVR4 checksum.
+func NewHash() hash.Hash32 {
+	return &digest{}
+}
+
+func (d *digest) Write(p []byte) (n int, err error) {
+	for _, b := range p {
+		d.sum += uint32(b & 0xFF)
+	}
+
+	return len(p), nil
+}
+
+func (d *digest) Sum(b []byte) []byte {
+	out := [4]byte{}
+	binary.LittleEndian.PutUint32(out[:], d.sum)
+	return append(b, out[:]...)
+}
+
+func (d *digest) Sum32() uint32 {
+	return d.sum
+}
+
+func (d *digest) Reset() {
+	d.sum = 0
+}
+
+func (d *digest) Size() int {
+	return 4
+}
+
+func (d *digest) BlockSize() int {
+	return 1
+}