update vendor

vendor/github.com/pierrec/lz4/LICENSE

@@ -0,0 +1,28 @@
+Copyright (c) 2015, Pierre Curto
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of xxHash nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+

vendor/github.com/pierrec/lz4/README.md

@@ -0,0 +1,92 @@
+# lz4 : LZ4 compression in pure Go
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/pierrec/lz4/v4.svg)](https://pkg.go.dev/github.com/pierrec/lz4/v4)
+[![CI](https://github.com/pierrec/lz4/workflows/ci/badge.svg)](https://github.com/pierrec/lz4/actions)
+[![Go Report Card](https://goreportcard.com/badge/github.com/pierrec/lz4)](https://goreportcard.com/report/github.com/pierrec/lz4)
+[![GitHub tag (latest SemVer)](https://img.shields.io/github/tag/pierrec/lz4.svg?style=social)](https://github.com/pierrec/lz4/tags)
+
+## Overview
+
+This package provides a streaming interface to [LZ4 data streams](http://fastcompression.blogspot.fr/2013/04/lz4-streaming-format-final.html) as well as low level compress and uncompress functions for LZ4 data blocks.
+The implementation is based on the reference C [one](https://github.com/lz4/lz4).
+
+## Install
+
+Assuming you have the go toolchain installed:
+
+```
+go get github.com/pierrec/lz4/v4
+```
+
+There is a command line interface tool to compress and decompress LZ4 files.
+
+```
+go install github.com/pierrec/lz4/v4/cmd/lz4c
+```
+
+Usage
+
+```
+Usage of lz4c:
+  -version
+        print the program version
+
+Subcommands:
+Compress the given files or from stdin to stdout.
+compress [arguments] [<file name> ...]
+  -bc
+        enable block checksum
+  -l int
+        compression level (0=fastest)
+  -sc
+        disable stream checksum
+  -size string
+        block max size [64K,256K,1M,4M] (default "4M")
+
+Uncompress the given files or from stdin to stdout.
+uncompress [arguments] [<file name> ...]
+
+```
+
+
+## Example
+
+```
+// Compress and uncompress an input string.
+s := "hello world"
+r := strings.NewReader(s)
+
+// The pipe will uncompress the data from the writer.
+pr, pw := io.Pipe()
+zw := lz4.NewWriter(pw)
+zr := lz4.NewReader(pr)
+
+go func() {
+	// Compress the input string.
+	_, _ = io.Copy(zw, r)
+	_ = zw.Close() // Make sure the writer is closed
+	_ = pw.Close() // Terminate the pipe
+}()
+
+_, _ = io.Copy(os.Stdout, zr)
+
+// Output:
+// hello world
+```
+
+## Contributing
+
+Contributions are very welcome for bug fixing, performance improvements...!
+
+- Open an issue with a proper description
+- Send a pull request with appropriate test case(s)
+
+## Contributors
+
+Thanks to all [contributors](https://github.com/pierrec/lz4/graphs/contributors)  so far!
+
+Special thanks to [@Zariel](https://github.com/Zariel) for his asm implementation of the decoder.
+
+Special thanks to [@greatroar](https://github.com/greatroar) for his work on the asm implementations of the decoder for amd64 and arm64.
+
+Special thanks to [@klauspost](https://github.com/klauspost) for his work on optimizing the code.

vendor/github.com/pierrec/lz4/go.mod

@@ -0,0 +1,3 @@
+module github.com/pierrec/lz4/v4
+
+go 1.14

vendor/github.com/pierrec/lz4/lz4.go

@@ -0,0 +1,157 @@
+// Package lz4 implements reading and writing lz4 compressed data.
+//
+// The package supports both the LZ4 stream format,
+// as specified in http://fastcompression.blogspot.fr/2013/04/lz4-streaming-format-final.html,
+// and the LZ4 block format, defined at
+// http://fastcompression.blogspot.fr/2011/05/lz4-explained.html.
+//
+// See https://github.com/lz4/lz4 for the reference C implementation.
+package lz4
+
+import (
+	"github.com/pierrec/lz4/v4/internal/lz4block"
+	"github.com/pierrec/lz4/v4/internal/lz4errors"
+)
+
+func _() {
+	// Safety checks for duplicated elements.
+	var x [1]struct{}
+	_ = x[lz4block.CompressionLevel(Fast)-lz4block.Fast]
+	_ = x[Block64Kb-BlockSize(lz4block.Block64Kb)]
+	_ = x[Block256Kb-BlockSize(lz4block.Block256Kb)]
+	_ = x[Block1Mb-BlockSize(lz4block.Block1Mb)]
+	_ = x[Block4Mb-BlockSize(lz4block.Block4Mb)]
+}
+
+// CompressBlockBound returns the maximum size of a given buffer of size n, when not compressible.
+func CompressBlockBound(n int) int {
+	return lz4block.CompressBlockBound(n)
+}
+
+// UncompressBlock uncompresses the source buffer into the destination one,
+// and returns the uncompressed size.
+//
+// The destination buffer must be sized appropriately.
+//
+// An error is returned if the source data is invalid or the destination buffer is too small.
+func UncompressBlock(src, dst []byte) (int, error) {
+	return lz4block.UncompressBlock(src, dst, nil)
+}
+
+// UncompressBlockWithDict uncompresses the source buffer into the destination one using a
+// dictionary, and returns the uncompressed size.
+//
+// The destination buffer must be sized appropriately.
+//
+// An error is returned if the source data is invalid or the destination buffer is too small.
+func UncompressBlockWithDict(src, dst, dict []byte) (int, error) {
+	return lz4block.UncompressBlock(src, dst, dict)
+}
+
+// A Compressor compresses data into the LZ4 block format.
+// It uses a fast compression algorithm.
+//
+// A Compressor is not safe for concurrent use by multiple goroutines.
+//
+// Use a Writer to compress into the LZ4 stream format.
+type Compressor struct{ c lz4block.Compressor }
+
+// CompressBlock compresses the source buffer src into the destination dst.
+//
+// If compression is successful, the first return value is the size of the
+// compressed data, which is always >0.
+//
+// If dst has length at least CompressBlockBound(len(src)), compression always
+// succeeds. Otherwise, the first return value is zero. The error return is
+// non-nil if the compressed data does not fit in dst, but it might fit in a
+// larger buffer that is still smaller than CompressBlockBound(len(src)). The
+// return value (0, nil) means the data is likely incompressible and a buffer
+// of length CompressBlockBound(len(src)) should be passed in.
+func (c *Compressor) CompressBlock(src, dst []byte) (int, error) {
+	return c.c.CompressBlock(src, dst)
+}
+
+// CompressBlock compresses the source buffer into the destination one.
+// This is the fast version of LZ4 compression and also the default one.
+//
+// The argument hashTable is scratch space for a hash table used by the
+// compressor. If provided, it should have length at least 1<<16. If it is
+// shorter (or nil), CompressBlock allocates its own hash table.
+//
+// The size of the compressed data is returned.
+//
+// If the destination buffer size is lower than CompressBlockBound and
+// the compressed size is 0 and no error, then the data is incompressible.
+//
+// An error is returned if the destination buffer is too small.
+
+// CompressBlock is equivalent to Compressor.CompressBlock.
+// The final argument is ignored and should be set to nil.
+//
+// This function is deprecated. Use a Compressor instead.
+func CompressBlock(src, dst []byte, _ []int) (int, error) {
+	return lz4block.CompressBlock(src, dst)
+}
+
+// A CompressorHC compresses data into the LZ4 block format.
+// Its compression ratio is potentially better than that of a Compressor,
+// but it is also slower and requires more memory.
+//
+// A Compressor is not safe for concurrent use by multiple goroutines.
+//
+// Use a Writer to compress into the LZ4 stream format.
+type CompressorHC struct {
+	// Level is the maximum search depth for compression.
+	// Values <= 0 mean no maximum.
+	Level CompressionLevel
+	c     lz4block.CompressorHC
+}
+
+// CompressBlock compresses the source buffer src into the destination dst.
+//
+// If compression is successful, the first return value is the size of the
+// compressed data, which is always >0.
+//
+// If dst has length at least CompressBlockBound(len(src)), compression always
+// succeeds. Otherwise, the first return value is zero. The error return is
+// non-nil if the compressed data does not fit in dst, but it might fit in a
+// larger buffer that is still smaller than CompressBlockBound(len(src)). The
+// return value (0, nil) means the data is likely incompressible and a buffer
+// of length CompressBlockBound(len(src)) should be passed in.
+func (c *CompressorHC) CompressBlock(src, dst []byte) (int, error) {
+	return c.c.CompressBlock(src, dst, lz4block.CompressionLevel(c.Level))
+}
+
+// CompressBlockHC is equivalent to CompressorHC.CompressBlock.
+// The final two arguments are ignored and should be set to nil.
+//
+// This function is deprecated. Use a CompressorHC instead.
+func CompressBlockHC(src, dst []byte, depth CompressionLevel, _, _ []int) (int, error) {
+	return lz4block.CompressBlockHC(src, dst, lz4block.CompressionLevel(depth))
+}
+
+const (
+	// ErrInvalidSourceShortBuffer is returned by UncompressBlock or CompressBLock when a compressed
+	// block is corrupted or the destination buffer is not large enough for the uncompressed data.
+	ErrInvalidSourceShortBuffer = lz4errors.ErrInvalidSourceShortBuffer
+	// ErrInvalidFrame is returned when reading an invalid LZ4 archive.
+	ErrInvalidFrame = lz4errors.ErrInvalidFrame
+	// ErrInternalUnhandledState is an internal error.
+	ErrInternalUnhandledState = lz4errors.ErrInternalUnhandledState
+	// ErrInvalidHeaderChecksum is returned when reading a frame.
+	ErrInvalidHeaderChecksum = lz4errors.ErrInvalidHeaderChecksum
+	// ErrInvalidBlockChecksum is returned when reading a frame.
+	ErrInvalidBlockChecksum = lz4errors.ErrInvalidBlockChecksum
+	// ErrInvalidFrameChecksum is returned when reading a frame.
+	ErrInvalidFrameChecksum = lz4errors.ErrInvalidFrameChecksum
+	// ErrOptionInvalidCompressionLevel is returned when the supplied compression level is invalid.
+	ErrOptionInvalidCompressionLevel = lz4errors.ErrOptionInvalidCompressionLevel
+	// ErrOptionClosedOrError is returned when an option is applied to a closed or in error object.
+	ErrOptionClosedOrError = lz4errors.ErrOptionClosedOrError
+	// ErrOptionInvalidBlockSize is returned when
+	ErrOptionInvalidBlockSize = lz4errors.ErrOptionInvalidBlockSize
+	// ErrOptionNotApplicable is returned when trying to apply an option to an object not supporting it.
+	ErrOptionNotApplicable = lz4errors.ErrOptionNotApplicable
+	// ErrWriterNotClosed is returned when attempting to reset an unclosed writer.
+	ErrWriterNotClosed = lz4errors.ErrWriterNotClosed
+)

vendor/github.com/pierrec/lz4/options.go

@@ -0,0 +1,214 @@
+package lz4
+
+import (
+	"fmt"
+	"reflect"
+	"runtime"
+
+	"github.com/pierrec/lz4/v4/internal/lz4block"
+	"github.com/pierrec/lz4/v4/internal/lz4errors"
+)
+
+//go:generate go run golang.org/x/tools/cmd/stringer -type=BlockSize,CompressionLevel -output options_gen.go
+
+type (
+	applier interface {
+		Apply(...Option) error
+		private()
+	}
+	// Option defines the parameters to setup an LZ4 Writer or Reader.
+	Option func(applier) error
+)
+
+// String returns a string representation of the option with its parameter(s).
+func (o Option) String() string {
+	return o(nil).Error()
+}
+
+// Default options.
+var (
+	DefaultBlockSizeOption = BlockSizeOption(Block4Mb)
+	DefaultChecksumOption  = ChecksumOption(true)
+	DefaultConcurrency     = ConcurrencyOption(1)
+	defaultOnBlockDone     = OnBlockDoneOption(nil)
+)
+
+const (
+	Block64Kb BlockSize = 1 << (16 + iota*2)
+	Block256Kb
+	Block1Mb
+	Block4Mb
+)
+
+// BlockSizeIndex defines the size of the blocks to be compressed.
+type BlockSize uint32
+
+// BlockSizeOption defines the maximum size of compressed blocks (default=Block4Mb).
+func BlockSizeOption(size BlockSize) Option {
+	return func(a applier) error {
+		switch w := a.(type) {
+		case nil:
+			s := fmt.Sprintf("BlockSizeOption(%s)", size)
+			return lz4errors.Error(s)
+		case *Writer:
+			size := uint32(size)
+			if !lz4block.IsValid(size) {
+				return fmt.Errorf("%w: %d", lz4errors.ErrOptionInvalidBlockSize, size)
+			}
+			w.frame.Descriptor.Flags.BlockSizeIndexSet(lz4block.Index(size))
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// BlockChecksumOption enables or disables block checksum (default=false).
+func BlockChecksumOption(flag bool) Option {
+	return func(a applier) error {
+		switch w := a.(type) {
+		case nil:
+			s := fmt.Sprintf("BlockChecksumOption(%v)", flag)
+			return lz4errors.Error(s)
+		case *Writer:
+			w.frame.Descriptor.Flags.BlockChecksumSet(flag)
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// ChecksumOption enables/disables all blocks or content checksum (default=true).
+func ChecksumOption(flag bool) Option {
+	return func(a applier) error {
+		switch w := a.(type) {
+		case nil:
+			s := fmt.Sprintf("ChecksumOption(%v)", flag)
+			return lz4errors.Error(s)
+		case *Writer:
+			w.frame.Descriptor.Flags.ContentChecksumSet(flag)
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// SizeOption sets the size of the original uncompressed data (default=0). It is useful to know the size of the
+// whole uncompressed data stream.
+func SizeOption(size uint64) Option {
+	return func(a applier) error {
+		switch w := a.(type) {
+		case nil:
+			s := fmt.Sprintf("SizeOption(%d)", size)
+			return lz4errors.Error(s)
+		case *Writer:
+			w.frame.Descriptor.Flags.SizeSet(size > 0)
+			w.frame.Descriptor.ContentSize = size
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// ConcurrencyOption sets the number of go routines used for compression.
+// If n <= 0, then the output of runtime.GOMAXPROCS(0) is used.
+func ConcurrencyOption(n int) Option {
+	if n <= 0 {
+		n = runtime.GOMAXPROCS(0)
+	}
+	return func(a applier) error {
+		switch rw := a.(type) {
+		case nil:
+			s := fmt.Sprintf("ConcurrencyOption(%d)", n)
+			return lz4errors.Error(s)
+		case *Writer:
+			rw.num = n
+			return nil
+		case *Reader:
+			rw.num = n
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// CompressionLevel defines the level of compression to use. The higher the better, but slower, compression.
+type CompressionLevel uint32
+
+const (
+	Fast   CompressionLevel = 0
+	Level1 CompressionLevel = 1 << (8 + iota)
+	Level2
+	Level3
+	Level4
+	Level5
+	Level6
+	Level7
+	Level8
+	Level9
+)
+
+// CompressionLevelOption defines the compression level (default=Fast).
+func CompressionLevelOption(level CompressionLevel) Option {
+	return func(a applier) error {
+		switch w := a.(type) {
+		case nil:
+			s := fmt.Sprintf("CompressionLevelOption(%s)", level)
+			return lz4errors.Error(s)
+		case *Writer:
+			switch level {
+			case Fast, Level1, Level2, Level3, Level4, Level5, Level6, Level7, Level8, Level9:
+			default:
+				return fmt.Errorf("%w: %d", lz4errors.ErrOptionInvalidCompressionLevel, level)
+			}
+			w.level = lz4block.CompressionLevel(level)
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+func onBlockDone(int) {}
+
+// OnBlockDoneOption is triggered when a block has been processed. For a Writer, it is when is has been compressed,
+// for a Reader, it is when it has been uncompressed.
+func OnBlockDoneOption(handler func(size int)) Option {
+	if handler == nil {
+		handler = onBlockDone
+	}
+	return func(a applier) error {
+		switch rw := a.(type) {
+		case nil:
+			s := fmt.Sprintf("OnBlockDoneOption(%s)", reflect.TypeOf(handler).String())
+			return lz4errors.Error(s)
+		case *Writer:
+			rw.handler = handler
+			return nil
+		case *Reader:
+			rw.handler = handler
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}
+
+// LegacyOption provides support for writing LZ4 frames in the legacy format.
+//
+// See https://github.com/lz4/lz4/blob/dev/doc/lz4_Frame_format.md#legacy-frame.
+//
+// NB. compressed Linux kernel images use a tweaked LZ4 legacy format where
+// the compressed stream is followed by the original (uncompressed) size of
+// the kernel (https://events.static.linuxfound.org/sites/events/files/lcjpcojp13_klee.pdf).
+// This is also supported as a special case.
+func LegacyOption(legacy bool) Option {
+	return func(a applier) error {
+		switch rw := a.(type) {
+		case nil:
+			s := fmt.Sprintf("LegacyOption(%v)", legacy)
+			return lz4errors.Error(s)
+		case *Writer:
+			rw.legacy = legacy
+			return nil
+		}
+		return lz4errors.ErrOptionNotApplicable
+	}
+}

vendor/github.com/pierrec/lz4/options_gen.go

@@ -0,0 +1,92 @@
+// Code generated by "stringer -type=BlockSize,CompressionLevel -output options_gen.go"; DO NOT EDIT.
+
+package lz4
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Block64Kb-65536]
+	_ = x[Block256Kb-262144]
+	_ = x[Block1Mb-1048576]
+	_ = x[Block4Mb-4194304]
+}
+
+const (
+	_BlockSize_name_0 = "Block64Kb"
+	_BlockSize_name_1 = "Block256Kb"
+	_BlockSize_name_2 = "Block1Mb"
+	_BlockSize_name_3 = "Block4Mb"
+)
+
+func (i BlockSize) String() string {
+	switch {
+	case i == 65536:
+		return _BlockSize_name_0
+	case i == 262144:
+		return _BlockSize_name_1
+	case i == 1048576:
+		return _BlockSize_name_2
+	case i == 4194304:
+		return _BlockSize_name_3
+	default:
+		return "BlockSize(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+}
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Fast-0]
+	_ = x[Level1-512]
+	_ = x[Level2-1024]
+	_ = x[Level3-2048]
+	_ = x[Level4-4096]
+	_ = x[Level5-8192]
+	_ = x[Level6-16384]
+	_ = x[Level7-32768]
+	_ = x[Level8-65536]
+	_ = x[Level9-131072]
+}
+
+const (
+	_CompressionLevel_name_0 = "Fast"
+	_CompressionLevel_name_1 = "Level1"
+	_CompressionLevel_name_2 = "Level2"
+	_CompressionLevel_name_3 = "Level3"
+	_CompressionLevel_name_4 = "Level4"
+	_CompressionLevel_name_5 = "Level5"
+	_CompressionLevel_name_6 = "Level6"
+	_CompressionLevel_name_7 = "Level7"
+	_CompressionLevel_name_8 = "Level8"
+	_CompressionLevel_name_9 = "Level9"
+)
+
+func (i CompressionLevel) String() string {
+	switch {
+	case i == 0:
+		return _CompressionLevel_name_0
+	case i == 512:
+		return _CompressionLevel_name_1
+	case i == 1024:
+		return _CompressionLevel_name_2
+	case i == 2048:
+		return _CompressionLevel_name_3
+	case i == 4096:
+		return _CompressionLevel_name_4
+	case i == 8192:
+		return _CompressionLevel_name_5
+	case i == 16384:
+		return _CompressionLevel_name_6
+	case i == 32768:
+		return _CompressionLevel_name_7
+	case i == 65536:
+		return _CompressionLevel_name_8
+	case i == 131072:
+		return _CompressionLevel_name_9
+	default:
+		return "CompressionLevel(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+}

vendor/github.com/pierrec/lz4/reader.go

@@ -0,0 +1,263 @@
+package lz4
+
+import (
+	"io"
+
+	"github.com/pierrec/lz4/v4/internal/lz4block"
+	"github.com/pierrec/lz4/v4/internal/lz4errors"
+	"github.com/pierrec/lz4/v4/internal/lz4stream"
+)
+
+var readerStates = []aState{
+	noState:     newState,
+	errorState:  newState,
+	newState:    readState,
+	readState:   closedState,
+	closedState: newState,
+}
+
+// NewReader returns a new LZ4 frame decoder.
+func NewReader(r io.Reader) *Reader {
+	return newReader(r, false)
+}
+
+func newReader(r io.Reader, legacy bool) *Reader {
+	zr := &Reader{frame: lz4stream.NewFrame()}
+	zr.state.init(readerStates)
+	_ = zr.Apply(DefaultConcurrency, defaultOnBlockDone)
+	zr.Reset(r)
+	return zr
+}
+
+// Reader allows reading an LZ4 stream.
+type Reader struct {
+	state   _State
+	src     io.Reader        // source reader
+	num     int              // concurrency level
+	frame   *lz4stream.Frame // frame being read
+	data    []byte           // block buffer allocated in non concurrent mode
+	reads   chan []byte      // pending data
+	idx     int              // size of pending data
+	handler func(int)
+	cum     uint32
+	dict    []byte
+}
+
+func (*Reader) private() {}
+
+func (r *Reader) Apply(options ...Option) (err error) {
+	defer r.state.check(&err)
+	switch r.state.state {
+	case newState:
+	case errorState:
+		return r.state.err
+	default:
+		return lz4errors.ErrOptionClosedOrError
+	}
+	for _, o := range options {
+		if err = o(r); err != nil {
+			return
+		}
+	}
+	return
+}
+
+// Size returns the size of the underlying uncompressed data, if set in the stream.
+func (r *Reader) Size() int {
+	switch r.state.state {
+	case readState, closedState:
+		if r.frame.Descriptor.Flags.Size() {
+			return int(r.frame.Descriptor.ContentSize)
+		}
+	}
+	return 0
+}
+
+func (r *Reader) isNotConcurrent() bool {
+	return r.num == 1
+}
+
+func (r *Reader) init() error {
+	err := r.frame.ParseHeaders(r.src)
+	if err != nil {
+		return err
+	}
+	if !r.frame.Descriptor.Flags.BlockIndependence() {
+		// We can't decompress dependent blocks concurrently.
+		// Instead of throwing an error to the user, silently drop concurrency
+		r.num = 1
+	}
+	data, err := r.frame.InitR(r.src, r.num)
+	if err != nil {
+		return err
+	}
+	r.reads = data
+	r.idx = 0
+	size := r.frame.Descriptor.Flags.BlockSizeIndex()
+	r.data = size.Get()
+	r.cum = 0
+	return nil
+}
+
+func (r *Reader) Read(buf []byte) (n int, err error) {
+	defer r.state.check(&err)
+	switch r.state.state {
+	case readState:
+	case closedState, errorState:
+		return 0, r.state.err
+	case newState:
+		// First initialization.
+		if err = r.init(); r.state.next(err) {
+			return
+		}
+	default:
+		return 0, r.state.fail()
+	}
+	for len(buf) > 0 {
+		var bn int
+		if r.idx == 0 {
+			if r.isNotConcurrent() {
+				bn, err = r.read(buf)
+			} else {
+				lz4block.Put(r.data)
+				r.data = <-r.reads
+				if len(r.data) == 0 {
+					// No uncompressed data: something went wrong or we are done.
+					err = r.frame.Blocks.ErrorR()
+				}
+			}
+			switch err {
+			case nil:
+			case io.EOF:
+				if er := r.frame.CloseR(r.src); er != nil {
+					err = er
+				}
+				lz4block.Put(r.data)
+				r.data = nil
+				return
+			default:
+				return
+			}
+		}
+		if bn == 0 {
+			// Fill buf with buffered data.
+			bn = copy(buf, r.data[r.idx:])
+			r.idx += bn
+			if r.idx == len(r.data) {
+				// All data read, get ready for the next Read.
+				r.idx = 0
+			}
+		}
+		buf = buf[bn:]
+		n += bn
+		r.handler(bn)
+	}
+	return
+}
+
+// read uncompresses the next block as follow:
+// - if buf has enough room, the block is uncompressed into it directly
+//   and the lenght of used space is returned
+// - else, the uncompress data is stored in r.data and 0 is returned
+func (r *Reader) read(buf []byte) (int, error) {
+	block := r.frame.Blocks.Block
+	_, err := block.Read(r.frame, r.src, r.cum)
+	if err != nil {
+		return 0, err
+	}
+	var direct bool
+	dst := r.data[:cap(r.data)]
+	if len(buf) >= len(dst) {
+		// Uncompress directly into buf.
+		direct = true
+		dst = buf
+	}
+	dst, err = block.Uncompress(r.frame, dst, r.dict, true)
+	if err != nil {
+		return 0, err
+	}
+	if !r.frame.Descriptor.Flags.BlockIndependence() {
+		if len(r.dict)+len(dst) > 128*1024 {
+			preserveSize := 64*1024 - len(dst)
+			if preserveSize < 0 {
+				preserveSize = 0
+			}
+			r.dict = r.dict[len(r.dict)-preserveSize:]
+		}
+		r.dict = append(r.dict, dst...)
+	}
+	r.cum += uint32(len(dst))
+	if direct {
+		return len(dst), nil
+	}
+	r.data = dst
+	return 0, nil
+}
+
+// Reset clears the state of the Reader r such that it is equivalent to its
+// initial state from NewReader, but instead writing to writer.
+// No access to reader is performed.
+//
+// w.Close must be called before Reset.
+func (r *Reader) Reset(reader io.Reader) {
+	if r.data != nil {
+		lz4block.Put(r.data)
+		r.data = nil
+	}
+	r.frame.Reset(r.num)
+	r.state.reset()
+	r.src = reader
+	r.reads = nil
+}
+
+// WriteTo efficiently uncompresses the data from the Reader underlying source to w.
+func (r *Reader) WriteTo(w io.Writer) (n int64, err error) {
+	switch r.state.state {
+	case closedState, errorState:
+		return 0, r.state.err
+	case newState:
+		if err = r.init(); r.state.next(err) {
+			return
+		}
+	default:
+		return 0, r.state.fail()
+	}
+	defer r.state.nextd(&err)
+
+	var data []byte
+	if r.isNotConcurrent() {
+		size := r.frame.Descriptor.Flags.BlockSizeIndex()
+		data = size.Get()
+		defer lz4block.Put(data)
+	}
+	for {
+		var bn int
+		var dst []byte
+		if r.isNotConcurrent() {
+			bn, err = r.read(data)
+			dst = data[:bn]
+		} else {
+			lz4block.Put(dst)
+			dst = <-r.reads
+			bn = len(dst)
+			if bn == 0 {
+				// No uncompressed data: something went wrong or we are done.
+				err = r.frame.Blocks.ErrorR()
+			}
+		}
+		switch err {
+		case nil:
+		case io.EOF:
+			err = r.frame.CloseR(r.src)
+			return
+		default:
+			return
+		}
+		r.handler(bn)
+		bn, err = w.Write(dst)
+		n += int64(bn)
+		if err != nil {
+			return
+		}
+	}
+}

vendor/github.com/pierrec/lz4/state.go

@@ -0,0 +1,75 @@
+package lz4
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/pierrec/lz4/v4/internal/lz4errors"
+)
+
+//go:generate go run golang.org/x/tools/cmd/stringer -type=aState -output state_gen.go
+
+const (
+	noState     aState = iota // uninitialized reader
+	errorState                // unrecoverable error encountered
+	newState                  // instantiated object
+	readState                 // reading data
+	writeState                // writing data
+	closedState               // all done
+)
+
+type (
+	aState uint8
+	_State struct {
+		states []aState
+		state  aState
+		err    error
+	}
+)
+
+func (s *_State) init(states []aState) {
+	s.states = states
+	s.state = states[0]
+}
+
+func (s *_State) reset() {
+	s.state = s.states[0]
+	s.err = nil
+}
+
+// next sets the state to the next one unless it is passed a non nil error.
+// It returns whether or not it is in error.
+func (s *_State) next(err error) bool {
+	if err != nil {
+		s.err = fmt.Errorf("%s: %w", s.state, err)
+		s.state = errorState
+		return true
+	}
+	s.state = s.states[s.state]
+	return false
+}
+
+// nextd is like next but for defers.
+func (s *_State) nextd(errp *error) bool {
+	return errp != nil && s.next(*errp)
+}
+
+// check sets s in error if not already in error and if the error is not nil or io.EOF,
+func (s *_State) check(errp *error) {
+	if s.state == errorState || errp == nil {
+		return
+	}
+	if err := *errp; err != nil {
+		s.err = fmt.Errorf("%w[%s]", err, s.state)
+		if !errors.Is(err, io.EOF) {
+			s.state = errorState
+		}
+	}
+}
+
+func (s *_State) fail() error {
+	s.state = errorState
+	s.err = fmt.Errorf("%w[%s]", lz4errors.ErrInternalUnhandledState, s.state)
+	return s.err
+}

vendor/github.com/pierrec/lz4/state_gen.go

@@ -0,0 +1,28 @@
+// Code generated by "stringer -type=aState -output state_gen.go"; DO NOT EDIT.
+
+package lz4
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[noState-0]
+	_ = x[errorState-1]
+	_ = x[newState-2]
+	_ = x[readState-3]
+	_ = x[writeState-4]
+	_ = x[closedState-5]
+}
+
+const _aState_name = "noStateerrorStatenewStatereadStatewriteStateclosedState"
+
+var _aState_index = [...]uint8{0, 7, 17, 25, 34, 44, 55}
+
+func (i aState) String() string {
+	if i >= aState(len(_aState_index)-1) {
+		return "aState(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _aState_name[_aState_index[i]:_aState_index[i+1]]
+}

vendor/github.com/pierrec/lz4/writer.go

@@ -0,0 +1,233 @@
+package lz4
+
+import (
+	"io"
+
+	"github.com/pierrec/lz4/v4/internal/lz4block"
+	"github.com/pierrec/lz4/v4/internal/lz4errors"
+	"github.com/pierrec/lz4/v4/internal/lz4stream"
+)
+
+var writerStates = []aState{
+	noState:     newState,
+	newState:    writeState,
+	writeState:  closedState,
+	closedState: newState,
+	errorState:  newState,
+}
+
+// NewWriter returns a new LZ4 frame encoder.
+func NewWriter(w io.Writer) *Writer {
+	zw := &Writer{frame: lz4stream.NewFrame()}
+	zw.state.init(writerStates)
+	_ = zw.Apply(DefaultBlockSizeOption, DefaultChecksumOption, DefaultConcurrency, defaultOnBlockDone)
+	zw.Reset(w)
+	return zw
+}
+
+// Writer allows writing an LZ4 stream.
+type Writer struct {
+	state   _State
+	src     io.Writer                 // destination writer
+	level   lz4block.CompressionLevel // how hard to try
+	num     int                       // concurrency level
+	frame   *lz4stream.Frame          // frame being built
+	data    []byte                    // pending data
+	idx     int                       // size of pending data
+	handler func(int)
+	legacy  bool
+}
+
+func (*Writer) private() {}
+
+func (w *Writer) Apply(options ...Option) (err error) {
+	defer w.state.check(&err)
+	switch w.state.state {
+	case newState:
+	case errorState:
+		return w.state.err
+	default:
+		return lz4errors.ErrOptionClosedOrError
+	}
+	for _, o := range options {
+		if err = o(w); err != nil {
+			return
+		}
+	}
+	w.Reset(w.src)
+	return
+}
+
+func (w *Writer) isNotConcurrent() bool {
+	return w.num == 1
+}
+
+// init sets up the Writer when in newState. It does not change the Writer state.
+func (w *Writer) init() error {
+	w.frame.InitW(w.src, w.num, w.legacy)
+	if true || !w.isNotConcurrent() {
+		size := w.frame.Descriptor.Flags.BlockSizeIndex()
+		w.data = size.Get()
+	}
+	w.idx = 0
+	return w.frame.Descriptor.Write(w.frame, w.src)
+}
+
+func (w *Writer) Write(buf []byte) (n int, err error) {
+	defer w.state.check(&err)
+	switch w.state.state {
+	case writeState:
+	case closedState, errorState:
+		return 0, w.state.err
+	case newState:
+		if err = w.init(); w.state.next(err) {
+			return
+		}
+	default:
+		return 0, w.state.fail()
+	}
+
+	zn := len(w.data)
+	for len(buf) > 0 {
+		if w.isNotConcurrent() && w.idx == 0 && len(buf) >= zn {
+			// Avoid a copy as there is enough data for a block.
+			if err = w.write(buf[:zn], false); err != nil {
+				return
+			}
+			n += zn
+			buf = buf[zn:]
+			continue
+		}
+		// Accumulate the data to be compressed.
+		m := copy(w.data[w.idx:], buf)
+		n += m
+		w.idx += m
+		buf = buf[m:]
+
+		if w.idx < len(w.data) {
+			// Buffer not filled.
+			return
+		}
+
+		// Buffer full.
+		if err = w.write(w.data, true); err != nil {
+			return
+		}
+		if !w.isNotConcurrent() {
+			size := w.frame.Descriptor.Flags.BlockSizeIndex()
+			w.data = size.Get()
+		}
+		w.idx = 0
+	}
+	return
+}
+
+func (w *Writer) write(data []byte, safe bool) error {
+	if w.isNotConcurrent() {
+		block := w.frame.Blocks.Block
+		err := block.Compress(w.frame, data, w.level).Write(w.frame, w.src)
+		w.handler(len(block.Data))
+		return err
+	}
+	c := make(chan *lz4stream.FrameDataBlock)
+	w.frame.Blocks.Blocks <- c
+	go func(c chan *lz4stream.FrameDataBlock, data []byte, safe bool) {
+		b := lz4stream.NewFrameDataBlock(w.frame)
+		c <- b.Compress(w.frame, data, w.level)
+		<-c
+		w.handler(len(b.Data))
+		b.Close(w.frame)
+		if safe {
+			// safe to put it back as the last usage of it was FrameDataBlock.Write() called before c is closed
+			lz4block.Put(data)
+		}
+	}(c, data, safe)
+
+	return nil
+}
+
+// Close closes the Writer, flushing any unwritten data to the underlying io.Writer,
+// but does not close the underlying io.Writer.
+func (w *Writer) Close() (err error) {
+	switch w.state.state {
+	case writeState:
+	case errorState:
+		return w.state.err
+	default:
+		return nil
+	}
+	defer w.state.nextd(&err)
+	if w.idx > 0 {
+		// Flush pending data, disable w.data freeing as it is done later on.
+		if err = w.write(w.data[:w.idx], false); err != nil {
+			return err
+		}
+		w.idx = 0
+	}
+	err = w.frame.CloseW(w.src, w.num)
+	// It is now safe to free the buffer.
+	if w.data != nil {
+		lz4block.Put(w.data)
+		w.data = nil
+	}
+	return
+}
+
+// Reset clears the state of the Writer w such that it is equivalent to its
+// initial state from NewWriter, but instead writing to writer.
+// Reset keeps the previous options unless overwritten by the supplied ones.
+// No access to writer is performed.
+//
+// w.Close must be called before Reset or pending data may be dropped.
+func (w *Writer) Reset(writer io.Writer) {
+	w.frame.Reset(w.num)
+	w.state.reset()
+	w.src = writer
+}
+
+// ReadFrom efficiently reads from r and compressed into the Writer destination.
+func (w *Writer) ReadFrom(r io.Reader) (n int64, err error) {
+	switch w.state.state {
+	case closedState, errorState:
+		return 0, w.state.err
+	case newState:
+		if err = w.init(); w.state.next(err) {
+			return
+		}
+	default:
+		return 0, w.state.fail()
+	}
+	defer w.state.check(&err)
+
+	size := w.frame.Descriptor.Flags.BlockSizeIndex()
+	var done bool
+	var rn int
+	data := size.Get()
+	if w.isNotConcurrent() {
+		// Keep the same buffer for the whole process.
+		defer lz4block.Put(data)
+	}
+	for !done {
+		rn, err = io.ReadFull(r, data)
+		switch err {
+		case nil:
+		case io.EOF, io.ErrUnexpectedEOF: // read may be partial
+			done = true
+		default:
+			return
+		}
+		n += int64(rn)
+		err = w.write(data[:rn], true)
+		if err != nil {
+			return
+		}
+		w.handler(rn)
+		if !done && !w.isNotConcurrent() {
+			// The buffer will be returned automatically by go routines (safe=true)
+			// so get a new one fo the next round.
+			data = size.Get()
+		}
+	}
+	err = w.Close()
+	return
+}