VOL-2017 voltha-lib moved from voltha-go;
release version 2.2.1
Based on voltha-go commit 5259f8e52b3e3f5c7ad422a4b0e506e1d07f6b36
Change-Id: I8bbecdf456e420714a4016120eafc0d237c80565
diff --git a/vendor/github.com/DataDog/zstd/zstd_stream.go b/vendor/github.com/DataDog/zstd/zstd_stream.go
new file mode 100644
index 0000000..2330353
--- /dev/null
+++ b/vendor/github.com/DataDog/zstd/zstd_stream.go
@@ -0,0 +1,294 @@
+package zstd
+
+/*
+#define ZSTD_STATIC_LINKING_ONLY
+#define ZBUFF_DISABLE_DEPRECATE_WARNINGS
+#include "zstd.h"
+#include "zbuff.h"
+*/
+import "C"
+import (
+ "errors"
+ "fmt"
+ "io"
+ "runtime"
+ "unsafe"
+)
+
+var errShortRead = errors.New("short read")
+
+// Writer is an io.WriteCloser that zstd-compresses its input.
+type Writer struct {
+ CompressionLevel int
+
+ ctx *C.ZSTD_CCtx
+ dict []byte
+ dstBuffer []byte
+ firstError error
+ underlyingWriter io.Writer
+}
+
+func resize(in []byte, newSize int) []byte {
+ if in == nil {
+ return make([]byte, newSize)
+ }
+ if newSize <= cap(in) {
+ return in[:newSize]
+ }
+ toAdd := newSize - len(in)
+ return append(in, make([]byte, toAdd)...)
+}
+
+// NewWriter creates a new Writer with default compression options. Writes to
+// the writer will be written in compressed form to w.
+func NewWriter(w io.Writer) *Writer {
+ return NewWriterLevelDict(w, DefaultCompression, nil)
+}
+
+// NewWriterLevel is like NewWriter but specifies the compression level instead
+// of assuming default compression.
+//
+// The level can be DefaultCompression or any integer value between BestSpeed
+// and BestCompression inclusive.
+func NewWriterLevel(w io.Writer, level int) *Writer {
+ return NewWriterLevelDict(w, level, nil)
+
+}
+
+// NewWriterLevelDict is like NewWriterLevel but specifies a dictionary to
+// compress with. If the dictionary is empty or nil it is ignored. The dictionary
+// should not be modified until the writer is closed.
+func NewWriterLevelDict(w io.Writer, level int, dict []byte) *Writer {
+ var err error
+ ctx := C.ZSTD_createCCtx()
+
+ if dict == nil {
+ err = getError(int(C.ZSTD_compressBegin(ctx,
+ C.int(level))))
+ } else {
+ err = getError(int(C.ZSTD_compressBegin_usingDict(
+ ctx,
+ unsafe.Pointer(&dict[0]),
+ C.size_t(len(dict)),
+ C.int(level))))
+ }
+
+ return &Writer{
+ CompressionLevel: level,
+ ctx: ctx,
+ dict: dict,
+ dstBuffer: make([]byte, CompressBound(1024)),
+ firstError: err,
+ underlyingWriter: w,
+ }
+}
+
+// Write writes a compressed form of p to the underlying io.Writer.
+func (w *Writer) Write(p []byte) (int, error) {
+ if w.firstError != nil {
+ return 0, w.firstError
+ }
+ if len(p) == 0 {
+ return 0, nil
+ }
+ // Check if dstBuffer is enough
+ if len(w.dstBuffer) < CompressBound(len(p)) {
+ w.dstBuffer = make([]byte, CompressBound(len(p)))
+ }
+
+ retCode := C.ZSTD_compressContinue(
+ w.ctx,
+ unsafe.Pointer(&w.dstBuffer[0]),
+ C.size_t(len(w.dstBuffer)),
+ unsafe.Pointer(&p[0]),
+ C.size_t(len(p)))
+
+ if err := getError(int(retCode)); err != nil {
+ return 0, err
+ }
+ written := int(retCode)
+
+ // Write to underlying buffer
+ _, err := w.underlyingWriter.Write(w.dstBuffer[:written])
+
+ // Same behaviour as zlib, we can't know how much data we wrote, only
+ // if there was an error
+ if err != nil {
+ return 0, err
+ }
+ return len(p), err
+}
+
+// Close closes the Writer, flushing any unwritten data to the underlying
+// io.Writer and freeing objects, but does not close the underlying io.Writer.
+func (w *Writer) Close() error {
+ retCode := C.ZSTD_compressEnd(
+ w.ctx,
+ unsafe.Pointer(&w.dstBuffer[0]),
+ C.size_t(len(w.dstBuffer)),
+ unsafe.Pointer(nil),
+ C.size_t(0))
+
+ if err := getError(int(retCode)); err != nil {
+ return err
+ }
+ written := int(retCode)
+ retCode = C.ZSTD_freeCCtx(w.ctx) // Safely close buffer before writing the end
+
+ if err := getError(int(retCode)); err != nil {
+ return err
+ }
+
+ _, err := w.underlyingWriter.Write(w.dstBuffer[:written])
+ if err != nil {
+ return err
+ }
+ return nil
+}
+
+// reader is an io.ReadCloser that decompresses when read from.
+type reader struct {
+ ctx *C.ZBUFF_DCtx
+ compressionBuffer []byte
+ compressionLeft int
+ decompressionBuffer []byte
+ decompOff int
+ decompSize int
+ dict []byte
+ firstError error
+ recommendedSrcSize int
+ underlyingReader io.Reader
+}
+
+// NewReader creates a new io.ReadCloser. Reads from the returned ReadCloser
+// read and decompress data from r. It is the caller's responsibility to call
+// Close on the ReadCloser when done. If this is not done, underlying objects
+// in the zstd library will not be freed.
+func NewReader(r io.Reader) io.ReadCloser {
+ return NewReaderDict(r, nil)
+}
+
+// NewReaderDict is like NewReader but uses a preset dictionary. NewReaderDict
+// ignores the dictionary if it is nil.
+func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser {
+ var err error
+ ctx := C.ZBUFF_createDCtx()
+ if len(dict) == 0 {
+ err = getError(int(C.ZBUFF_decompressInit(ctx)))
+ } else {
+ err = getError(int(C.ZBUFF_decompressInitDictionary(
+ ctx,
+ unsafe.Pointer(&dict[0]),
+ C.size_t(len(dict)))))
+ }
+ cSize := int(C.ZBUFF_recommendedDInSize())
+ dSize := int(C.ZBUFF_recommendedDOutSize())
+ if cSize <= 0 {
+ panic(fmt.Errorf("ZBUFF_recommendedDInSize() returned invalid size: %v", cSize))
+ }
+ if dSize <= 0 {
+ panic(fmt.Errorf("ZBUFF_recommendedDOutSize() returned invalid size: %v", dSize))
+ }
+
+ compressionBuffer := make([]byte, cSize)
+ decompressionBuffer := make([]byte, dSize)
+ return &reader{
+ ctx: ctx,
+ dict: dict,
+ compressionBuffer: compressionBuffer,
+ decompressionBuffer: decompressionBuffer,
+ firstError: err,
+ recommendedSrcSize: cSize,
+ underlyingReader: r,
+ }
+}
+
+// Close frees the allocated C objects
+func (r *reader) Close() error {
+ return getError(int(C.ZBUFF_freeDCtx(r.ctx)))
+}
+
+func (r *reader) Read(p []byte) (int, error) {
+
+ // If we already have enough bytes, return
+ if r.decompSize-r.decompOff >= len(p) {
+ copy(p, r.decompressionBuffer[r.decompOff:])
+ r.decompOff += len(p)
+ return len(p), nil
+ }
+
+ copy(p, r.decompressionBuffer[r.decompOff:r.decompSize])
+ got := r.decompSize - r.decompOff
+ r.decompSize = 0
+ r.decompOff = 0
+
+ for got < len(p) {
+ // Populate src
+ src := r.compressionBuffer
+ reader := r.underlyingReader
+ n, err := TryReadFull(reader, src[r.compressionLeft:])
+ if err != nil && err != errShortRead { // Handle underlying reader errors first
+ return 0, fmt.Errorf("failed to read from underlying reader: %s", err)
+ } else if n == 0 && r.compressionLeft == 0 {
+ return got, io.EOF
+ }
+ src = src[:r.compressionLeft+n]
+
+ // C code
+ cSrcSize := C.size_t(len(src))
+ cDstSize := C.size_t(len(r.decompressionBuffer))
+ retCode := int(C.ZBUFF_decompressContinue(
+ r.ctx,
+ unsafe.Pointer(&r.decompressionBuffer[0]),
+ &cDstSize,
+ unsafe.Pointer(&src[0]),
+ &cSrcSize))
+
+ // Keep src here eventhough, we reuse later, the code might be deleted at some point
+ runtime.KeepAlive(src)
+ if err = getError(retCode); err != nil {
+ return 0, fmt.Errorf("failed to decompress: %s", err)
+ }
+
+ // Put everything in buffer
+ if int(cSrcSize) < len(src) {
+ left := src[int(cSrcSize):]
+ copy(r.compressionBuffer, left)
+ }
+ r.compressionLeft = len(src) - int(cSrcSize)
+ r.decompSize = int(cDstSize)
+ r.decompOff = copy(p[got:], r.decompressionBuffer[:r.decompSize])
+ got += r.decompOff
+
+ // Resize buffers
+ nsize := retCode // Hint for next src buffer size
+ if nsize <= 0 {
+ // Reset to recommended size
+ nsize = r.recommendedSrcSize
+ }
+ if nsize < r.compressionLeft {
+ nsize = r.compressionLeft
+ }
+ r.compressionBuffer = resize(r.compressionBuffer, nsize)
+ }
+ return got, nil
+}
+
+// TryReadFull reads buffer just as ReadFull does
+// Here we expect that buffer may end and we do not return ErrUnexpectedEOF as ReadAtLeast does.
+// We return errShortRead instead to distinguish short reads and failures.
+// We cannot use ReadFull/ReadAtLeast because it masks Reader errors, such as network failures
+// and causes panic instead of error.
+func TryReadFull(r io.Reader, buf []byte) (n int, err error) {
+ for n < len(buf) && err == nil {
+ var nn int
+ nn, err = r.Read(buf[n:])
+ n += nn
+ }
+ if n == len(buf) && err == io.EOF {
+ err = nil // EOF at the end is somewhat expected
+ } else if err == io.EOF {
+ err = errShortRead
+ }
+ return
+}