vendor: Add dependencies for discosrv

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

@@ -0,0 +1,121 @@
+// 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
+
+/*
+
+#include <stdint.h>
+#include <string.h>
+
+// supports only uint32 encoded values
+int uvarint(unsigned int* n, uint8_t* src, int len) {
+	int r = 0;
+	unsigned int v = 0;
+	unsigned int s = 0;
+	while ((len-- != 0) && (++r <= 5)) {
+		uint8_t b = *src++;
+		v = v | ((b&0x7f)<<s);
+		if (b < 0x80) {
+			*n = v;
+			return r;
+		}
+
+		s += 7;
+	}
+	return -1;
+}
+
+int varint(int* n, uint8_t* src, int len) {
+	unsigned int u;
+	int i = uvarint(&u, src, len);
+	int x = u>>1;
+	if ((u&1) != 0)
+		x = ~x;
+	*n = x;
+	return i;
+}
+
+int decode(int s, int len_src, uint8_t* src, int len_dst, uint8_t* dst) {
+	int d = 0;
+	int length;
+	while (s < len_src) {
+		int n, i = varint(&n, src+s, len_src-s);
+		if (i <= 0) {
+			return -1;
+		}
+
+		s += i;
+		if (n >= 0) {
+			length = n+1;
+			if ((length > len_dst-d) || (length > len_src-s))
+				return -1;
+
+			memcpy(dst+d, src+s, length);
+			d += length;
+			s += length;
+			continue;
+		}
+
+
+		length = -n;
+		int offset;
+		i = uvarint((unsigned int*)(&offset), src+s, len_src-s);
+		if (i <= 0)
+			return -1;
+
+		s += i;
+		if (s > len_src)
+			return -1;
+
+		int end = d+length;
+		if ((offset > d) || (end > len_dst))
+			return -1;
+
+		for( ; d < end; d++)
+			*(dst+d) = *(dst+d-offset);
+	}
+	return d;
+}
+
+*/
+import "C"
+
+func puregoDecode() bool { return false }
+
+// 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)
+	}
+
+	d := int(C.decode(C.int(s), C.int(len(src)), (*C.uint8_t)(&src[0]), C.int(len(buf)), (*C.uint8_t)(&buf[0])))
+	if d != dLen {
+		return nil, ErrCorrupt
+	}
+
+	return buf[:d], nil
+}