vendor: Add dependencies for discosrv

vendor/github.com/cznic/zappy/decode_nocgo.go

@@ -0,0 +1,89 @@
+// Copyright 2014 The zappy Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the SNAPPY-GO-LICENSE file.
+
+// +build !cgo purego
+
+package zappy
+
+import (
+	"encoding/binary"
+)
+
+func puregoDecode() bool { return true }
+
+// Decode returns the decoded form of src. The returned slice may be a sub-
+// slice of buf if buf was large enough to hold the entire decoded block.
+// Otherwise, a newly allocated slice will be returned.
+// It is valid to pass a nil buf.
+func Decode(buf, src []byte) ([]byte, error) {
+	dLen, s, err := decodedLen(src)
+	if err != nil {
+		return nil, err
+	}
+
+	if dLen == 0 {
+		if len(src) == 1 {
+			return nil, nil
+		}
+
+		return nil, ErrCorrupt
+	}
+
+	if len(buf) < dLen {
+		buf = make([]byte, dLen)
+	}
+
+	var d, offset, length int
+	for s < len(src) {
+		n, i := binary.Varint(src[s:])
+		if i <= 0 {
+			return nil, ErrCorrupt
+		}
+
+		s += i
+		if n >= 0 {
+			length = int(n + 1)
+			if length > len(buf)-d || length > len(src)-s {
+				return nil, ErrCorrupt
+			}
+
+			copy(buf[d:], src[s:s+length])
+			d += length
+			s += length
+			continue
+		}
+
+		length = int(-n)
+		off64, i := binary.Uvarint(src[s:])
+		if i <= 0 {
+			return nil, ErrCorrupt
+		}
+
+		offset = int(off64)
+		s += i
+		if s > len(src) {
+			return nil, ErrCorrupt
+		}
+
+		end := d + length
+		if offset > d || end > len(buf) {
+			return nil, ErrCorrupt
+		}
+
+		for s, v := range buf[d-offset : end-offset] {
+			buf[d+s] = v
+		}
+		d = end
+
+	}
+	if d != dLen {
+		return nil, ErrCorrupt
+	}
+
+	return buf[:d], nil
+}