VOL-1868 move simulated onu from voltha-go to voltha-simonu-adapter
Sourced from voltha-go commit 251a11c0ffe60512318a644cd6ce0dc4e12f4018
Change-Id: Iab179bc2f3dd772ed7f488d1c03d1a84ba75e874
diff --git a/vendor/github.com/eapache/go-xerial-snappy/snappy.go b/vendor/github.com/eapache/go-xerial-snappy/snappy.go
new file mode 100644
index 0000000..ea8f7af
--- /dev/null
+++ b/vendor/github.com/eapache/go-xerial-snappy/snappy.go
@@ -0,0 +1,131 @@
+package snappy
+
+import (
+ "bytes"
+ "encoding/binary"
+ "errors"
+
+ master "github.com/golang/snappy"
+)
+
+const (
+ sizeOffset = 16
+ sizeBytes = 4
+)
+
+var (
+ xerialHeader = []byte{130, 83, 78, 65, 80, 80, 89, 0}
+
+ // This is xerial version 1 and minimally compatible with version 1
+ xerialVersionInfo = []byte{0, 0, 0, 1, 0, 0, 0, 1}
+
+ // ErrMalformed is returned by the decoder when the xerial framing
+ // is malformed
+ ErrMalformed = errors.New("malformed xerial framing")
+)
+
+func min(x, y int) int {
+ if x < y {
+ return x
+ }
+ return y
+}
+
+// Encode encodes data as snappy with no framing header.
+func Encode(src []byte) []byte {
+ return master.Encode(nil, src)
+}
+
+// EncodeStream *appends* to the specified 'dst' the compressed
+// 'src' in xerial framing format. If 'dst' does not have enough
+// capacity, then a new slice will be allocated. If 'dst' has
+// non-zero length, then if *must* have been built using this function.
+func EncodeStream(dst, src []byte) []byte {
+ if len(dst) == 0 {
+ dst = append(dst, xerialHeader...)
+ dst = append(dst, xerialVersionInfo...)
+ }
+
+ // Snappy encode in blocks of maximum 32KB
+ var (
+ max = len(src)
+ blockSize = 32 * 1024
+ pos = 0
+ chunk []byte
+ )
+
+ for pos < max {
+ newPos := min(pos + blockSize, max)
+ chunk = master.Encode(chunk[:cap(chunk)], src[pos:newPos])
+
+ // First encode the compressed size (big-endian)
+ // Put* panics if the buffer is too small, so pad 4 bytes first
+ origLen := len(dst)
+ dst = append(dst, dst[0:4]...)
+ binary.BigEndian.PutUint32(dst[origLen:], uint32(len(chunk)))
+
+ // And now the compressed data
+ dst = append(dst, chunk...)
+ pos = newPos
+ }
+ return dst
+}
+
+// Decode decodes snappy data whether it is traditional unframed
+// or includes the xerial framing format.
+func Decode(src []byte) ([]byte, error) {
+ return DecodeInto(nil, src)
+}
+
+// DecodeInto decodes snappy data whether it is traditional unframed
+// or includes the xerial framing format into the specified `dst`.
+// It is assumed that the entirety of `dst` including all capacity is available
+// for use by this function. If `dst` is nil *or* insufficiently large to hold
+// the decoded `src`, new space will be allocated.
+func DecodeInto(dst, src []byte) ([]byte, error) {
+ var max = len(src)
+ if max < len(xerialHeader) {
+ return nil, ErrMalformed
+ }
+
+ if !bytes.Equal(src[:8], xerialHeader) {
+ return master.Decode(dst[:cap(dst)], src)
+ }
+
+ if max < sizeOffset+sizeBytes {
+ return nil, ErrMalformed
+ }
+
+ if dst == nil {
+ dst = make([]byte, 0, len(src))
+ }
+
+ dst = dst[:0]
+ var (
+ pos = sizeOffset
+ chunk []byte
+ err error
+ )
+
+ for pos+sizeBytes <= max {
+ size := int(binary.BigEndian.Uint32(src[pos : pos+sizeBytes]))
+ pos += sizeBytes
+
+ nextPos := pos + size
+ // On architectures where int is 32-bytes wide size + pos could
+ // overflow so we need to check the low bound as well as the
+ // high
+ if nextPos < pos || nextPos > max {
+ return nil, ErrMalformed
+ }
+
+ chunk, err = master.Decode(chunk[:cap(chunk)], src[pos:nextPos])
+
+ if err != nil {
+ return nil, err
+ }
+ pos = nextPos
+ dst = append(dst, chunk...)
+ }
+ return dst, nil
+}