[VOL-1386] This commit add "dep" as the package management tool
for voltha-go.
Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/pierrec/lz4/writer.go b/vendor/github.com/pierrec/lz4/writer.go
new file mode 100644
index 0000000..0120438
--- /dev/null
+++ b/vendor/github.com/pierrec/lz4/writer.go
@@ -0,0 +1,267 @@
+package lz4
+
+import (
+ "encoding/binary"
+ "fmt"
+ "io"
+
+ "github.com/pierrec/lz4/internal/xxh32"
+)
+
+// Writer implements the LZ4 frame encoder.
+type Writer struct {
+ Header
+
+ buf [19]byte // magic number(4) + header(flags(2)+[Size(8)+DictID(4)]+checksum(1)) does not exceed 19 bytes
+ dst io.Writer // Destination.
+ checksum xxh32.XXHZero // Frame checksum.
+ zdata []byte // Compressed data.
+ data []byte // Data to be compressed.
+ idx int // Index into data.
+ hashtable [winSize]int // Hash table used in CompressBlock().
+}
+
+// NewWriter returns a new LZ4 frame encoder.
+// No access to the underlying io.Writer is performed.
+// The supplied Header is checked at the first Write.
+// It is ok to change it before the first Write but then not until a Reset() is performed.
+func NewWriter(dst io.Writer) *Writer {
+ return &Writer{dst: dst}
+}
+
+// writeHeader builds and writes the header (magic+header) to the underlying io.Writer.
+func (z *Writer) writeHeader() error {
+ // Default to 4Mb if BlockMaxSize is not set.
+ if z.Header.BlockMaxSize == 0 {
+ z.Header.BlockMaxSize = bsMapID[7]
+ }
+ // The only option that needs to be validated.
+ bSize := z.Header.BlockMaxSize
+ bSizeID, ok := bsMapValue[bSize]
+ if !ok {
+ return fmt.Errorf("lz4: invalid block max size: %d", bSize)
+ }
+ // Allocate the compressed/uncompressed buffers.
+ // The compressed buffer cannot exceed the uncompressed one.
+ if n := 2 * bSize; cap(z.zdata) < n {
+ z.zdata = make([]byte, n, n)
+ }
+ z.zdata = z.zdata[:bSize]
+ z.data = z.zdata[:cap(z.zdata)][bSize:]
+ z.idx = 0
+
+ // Size is optional.
+ buf := z.buf[:]
+
+ // Set the fixed size data: magic number, block max size and flags.
+ binary.LittleEndian.PutUint32(buf[0:], frameMagic)
+ flg := byte(Version << 6)
+ flg |= 1 << 5 // No block dependency.
+ if z.Header.BlockChecksum {
+ flg |= 1 << 4
+ }
+ if z.Header.Size > 0 {
+ flg |= 1 << 3
+ }
+ if !z.Header.NoChecksum {
+ flg |= 1 << 2
+ }
+ buf[4] = flg
+ buf[5] = bSizeID << 4
+
+ // Current buffer size: magic(4) + flags(1) + block max size (1).
+ n := 6
+ // Optional items.
+ if z.Header.Size > 0 {
+ binary.LittleEndian.PutUint64(buf[n:], z.Header.Size)
+ n += 8
+ }
+
+ // The header checksum includes the flags, block max size and optional Size.
+ buf[n] = byte(xxh32.ChecksumZero(buf[4:n]) >> 8 & 0xFF)
+ z.checksum.Reset()
+
+ // Header ready, write it out.
+ if _, err := z.dst.Write(buf[0 : n+1]); err != nil {
+ return err
+ }
+ z.Header.done = true
+ if debugFlag {
+ debug("wrote header %v", z.Header)
+ }
+
+ return nil
+}
+
+// Write compresses data from the supplied buffer into the underlying io.Writer.
+// Write does not return until the data has been written.
+func (z *Writer) Write(buf []byte) (int, error) {
+ if !z.Header.done {
+ if err := z.writeHeader(); err != nil {
+ return 0, err
+ }
+ }
+ if debugFlag {
+ debug("input buffer len=%d index=%d", len(buf), z.idx)
+ }
+
+ zn := len(z.data)
+ var n int
+ for len(buf) > 0 {
+ if z.idx == 0 && len(buf) >= zn {
+ // Avoid a copy as there is enough data for a block.
+ if err := z.compressBlock(buf[:zn]); err != nil {
+ return n, err
+ }
+ n += zn
+ buf = buf[zn:]
+ continue
+ }
+ // Accumulate the data to be compressed.
+ m := copy(z.data[z.idx:], buf)
+ n += m
+ z.idx += m
+ buf = buf[m:]
+ if debugFlag {
+ debug("%d bytes copied to buf, current index %d", n, z.idx)
+ }
+
+ if z.idx < len(z.data) {
+ // Buffer not filled.
+ if debugFlag {
+ debug("need more data for compression")
+ }
+ return n, nil
+ }
+
+ // Buffer full.
+ if err := z.compressBlock(z.data); err != nil {
+ return n, err
+ }
+ z.idx = 0
+ }
+
+ return n, nil
+}
+
+// compressBlock compresses a block.
+func (z *Writer) compressBlock(data []byte) error {
+ if !z.NoChecksum {
+ z.checksum.Write(data)
+ }
+
+ // The compressed block size cannot exceed the input's.
+ var zn int
+ var err error
+
+ if level := z.Header.CompressionLevel; level != 0 {
+ zn, err = CompressBlockHC(data, z.zdata, level)
+ } else {
+ zn, err = CompressBlock(data, z.zdata, z.hashtable[:])
+ }
+
+ var zdata []byte
+ var bLen uint32
+ if debugFlag {
+ debug("block compression %d => %d", len(data), zn)
+ }
+ if err == nil && zn > 0 && zn < len(data) {
+ // Compressible and compressed size smaller than uncompressed: ok!
+ bLen = uint32(zn)
+ zdata = z.zdata[:zn]
+ } else {
+ // Uncompressed block.
+ bLen = uint32(len(data)) | compressedBlockFlag
+ zdata = data
+ }
+ if debugFlag {
+ debug("block compression to be written len=%d data len=%d", bLen, len(zdata))
+ }
+
+ // Write the block.
+ if err := z.writeUint32(bLen); err != nil {
+ return err
+ }
+ if _, err := z.dst.Write(zdata); err != nil {
+ return err
+ }
+
+ if z.BlockChecksum {
+ checksum := xxh32.ChecksumZero(zdata)
+ if debugFlag {
+ debug("block checksum %x", checksum)
+ }
+ if err := z.writeUint32(checksum); err != nil {
+ return err
+ }
+ }
+ if debugFlag {
+ debug("current frame checksum %x", z.checksum.Sum32())
+ }
+
+ return nil
+}
+
+// Flush flushes any pending compressed data to the underlying writer.
+// Flush does not return until the data has been written.
+// If the underlying writer returns an error, Flush returns that error.
+func (z *Writer) Flush() error {
+ if debugFlag {
+ debug("flush with index %d", z.idx)
+ }
+ if z.idx == 0 {
+ return nil
+ }
+
+ return z.compressBlock(z.data[:z.idx])
+}
+
+// Close closes the Writer, flushing any unwritten data to the underlying io.Writer, but does not close the underlying io.Writer.
+func (z *Writer) Close() error {
+ if !z.Header.done {
+ if err := z.writeHeader(); err != nil {
+ return err
+ }
+ }
+
+ if err := z.Flush(); err != nil {
+ return err
+ }
+
+ if debugFlag {
+ debug("writing last empty block")
+ }
+ if err := z.writeUint32(0); err != nil {
+ return err
+ }
+ if !z.NoChecksum {
+ checksum := z.checksum.Sum32()
+ if debugFlag {
+ debug("stream checksum %x", checksum)
+ }
+ if err := z.writeUint32(checksum); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// Reset clears the state of the Writer z such that it is equivalent to its
+// initial state from NewWriter, but instead writing to w.
+// No access to the underlying io.Writer is performed.
+func (z *Writer) Reset(w io.Writer) {
+ z.Header = Header{}
+ z.dst = w
+ z.checksum.Reset()
+ z.zdata = z.zdata[:0]
+ z.data = z.data[:0]
+ z.idx = 0
+}
+
+// writeUint32 writes a uint32 to the underlying writer.
+func (z *Writer) writeUint32(x uint32) error {
+ buf := z.buf[:4]
+ binary.LittleEndian.PutUint32(buf, x)
+ _, err := z.dst.Write(buf)
+ return err
+}