[VOL-1386] This commit add "dep" as the package management tool
for voltha-go.
Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/DataDog/zstd/zstd.go b/vendor/github.com/DataDog/zstd/zstd.go
new file mode 100644
index 0000000..e9953d6
--- /dev/null
+++ b/vendor/github.com/DataDog/zstd/zstd.go
@@ -0,0 +1,144 @@
+package zstd
+
+/*
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+#include "stdint.h" // for uintptr_t
+
+// The following *_wrapper function are used for removing superflouos
+// memory allocations when calling the wrapped functions from Go code.
+// See https://github.com/golang/go/issues/24450 for details.
+
+static size_t ZSTD_compress_wrapper(uintptr_t dst, size_t maxDstSize, const uintptr_t src, size_t srcSize, int compressionLevel) {
+ return ZSTD_compress((void*)dst, maxDstSize, (const void*)src, srcSize, compressionLevel);
+}
+
+static size_t ZSTD_decompress_wrapper(uintptr_t dst, size_t maxDstSize, uintptr_t src, size_t srcSize) {
+ return ZSTD_decompress((void*)dst, maxDstSize, (const void *)src, srcSize);
+}
+
+*/
+import "C"
+import (
+ "bytes"
+ "errors"
+ "io/ioutil"
+ "unsafe"
+)
+
+// Defines best and standard values for zstd cli
+const (
+ BestSpeed = 1
+ BestCompression = 20
+ DefaultCompression = 5
+)
+
+var (
+ // ErrEmptySlice is returned when there is nothing to compress
+ ErrEmptySlice = errors.New("Bytes slice is empty")
+)
+
+// CompressBound returns the worst case size needed for a destination buffer,
+// which can be used to preallocate a destination buffer or select a previously
+// allocated buffer from a pool.
+// See zstd.h to mirror implementation of ZSTD_COMPRESSBOUND
+func CompressBound(srcSize int) int {
+ lowLimit := 128 << 10 // 128 kB
+ var margin int
+ if srcSize < lowLimit {
+ margin = (lowLimit - srcSize) >> 11
+ }
+ return srcSize + (srcSize >> 8) + margin
+}
+
+// cCompressBound is a cgo call to check the go implementation above against the c code.
+func cCompressBound(srcSize int) int {
+ return int(C.ZSTD_compressBound(C.size_t(srcSize)))
+}
+
+// Compress src into dst. If you have a buffer to use, you can pass it to
+// prevent allocation. If it is too small, or if nil is passed, a new buffer
+// will be allocated and returned.
+func Compress(dst, src []byte) ([]byte, error) {
+ return CompressLevel(dst, src, DefaultCompression)
+}
+
+// CompressLevel is the same as Compress but you can pass a compression level
+func CompressLevel(dst, src []byte, level int) ([]byte, error) {
+ bound := CompressBound(len(src))
+ if cap(dst) >= bound {
+ dst = dst[0:bound] // Reuse dst buffer
+ } else {
+ dst = make([]byte, bound)
+ }
+
+ srcPtr := C.uintptr_t(uintptr(0)) // Do not point anywhere, if src is empty
+ if len(src) > 0 {
+ srcPtr = C.uintptr_t(uintptr(unsafe.Pointer(&src[0])))
+ }
+
+ cWritten := C.ZSTD_compress_wrapper(
+ C.uintptr_t(uintptr(unsafe.Pointer(&dst[0]))),
+ C.size_t(len(dst)),
+ srcPtr,
+ C.size_t(len(src)),
+ C.int(level))
+
+ written := int(cWritten)
+ // Check if the return is an Error code
+ if err := getError(written); err != nil {
+ return nil, err
+ }
+ return dst[:written], nil
+}
+
+// Decompress src into dst. If you have a buffer to use, you can pass it to
+// prevent allocation. If it is too small, or if nil is passed, a new buffer
+// will be allocated and returned.
+func Decompress(dst, src []byte) ([]byte, error) {
+ if len(src) == 0 {
+ return []byte{}, ErrEmptySlice
+ }
+ decompress := func(dst, src []byte) ([]byte, error) {
+
+ cWritten := C.ZSTD_decompress_wrapper(
+ C.uintptr_t(uintptr(unsafe.Pointer(&dst[0]))),
+ C.size_t(len(dst)),
+ C.uintptr_t(uintptr(unsafe.Pointer(&src[0]))),
+ C.size_t(len(src)))
+
+ written := int(cWritten)
+ // Check error
+ if err := getError(written); err != nil {
+ return nil, err
+ }
+ return dst[:written], nil
+ }
+
+ if dst == nil {
+ // Attempt to use zStd to determine decompressed size (may result in error or 0)
+ size := int(C.size_t(C.ZSTD_getDecompressedSize(unsafe.Pointer(&src[0]), C.size_t(len(src)))))
+
+ if err := getError(size); err != nil {
+ return nil, err
+ }
+
+ if size > 0 {
+ dst = make([]byte, size)
+ } else {
+ dst = make([]byte, len(src)*3) // starting guess
+ }
+ }
+ for i := 0; i < 3; i++ { // 3 tries to allocate a bigger buffer
+ result, err := decompress(dst, src)
+ if !IsDstSizeTooSmallError(err) {
+ return result, err
+ }
+ dst = make([]byte, len(dst)*2) // Grow buffer by 2
+ }
+
+ // We failed getting a dst buffer of correct size, use stream API
+ r := NewReader(bytes.NewReader(src))
+ defer r.Close()
+ return ioutil.ReadAll(r)
+}