Dump: add output format tar and output to stdout (#10376)

* Dump: Use mholt/archive/v3 to support tar including many compressions

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: Allow dump output to stdout

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: Fixed bug present since #6677 where SessionConfig.Provider is never "file"

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: never pack RepoRootPath, LFS.ContentPath and LogRootPath when they are below AppDataPath

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: also dump LFS (fixes #10058)

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: never dump CustomPath if CustomPath is a subdir of or equal to AppDataPath (fixes #10365)

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Use log.Info instead of fmt.Fprintf

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* import ordering

* make fmt

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Matti R <matti@mdranta.net>

vendor/github.com/klauspost/compress/zstd/zstd.go

@@ -0,0 +1,148 @@
+// Package zstd provides decompression of zstandard files.
+//
+// For advanced usage and examples, go to the README: https://github.com/klauspost/compress/tree/master/zstd#zstd
+package zstd
+
+import (
+	"errors"
+	"log"
+	"math"
+	"math/bits"
+)
+
+// enable debug printing
+const debug = false
+
+// Enable extra assertions.
+const debugAsserts = debug || false
+
+// print sequence details
+const debugSequences = false
+
+// print detailed matching information
+const debugMatches = false
+
+// force encoder to use predefined tables.
+const forcePreDef = false
+
+// zstdMinMatch is the minimum zstd match length.
+const zstdMinMatch = 3
+
+// Reset the buffer offset when reaching this.
+const bufferReset = math.MaxInt32 - MaxWindowSize
+
+var (
+	// ErrReservedBlockType is returned when a reserved block type is found.
+	// Typically this indicates wrong or corrupted input.
+	ErrReservedBlockType = errors.New("invalid input: reserved block type encountered")
+
+	// ErrCompressedSizeTooBig is returned when a block is bigger than allowed.
+	// Typically this indicates wrong or corrupted input.
+	ErrCompressedSizeTooBig = errors.New("invalid input: compressed size too big")
+
+	// ErrBlockTooSmall is returned when a block is too small to be decoded.
+	// Typically returned on invalid input.
+	ErrBlockTooSmall = errors.New("block too small")
+
+	// ErrMagicMismatch is returned when a "magic" number isn't what is expected.
+	// Typically this indicates wrong or corrupted input.
+	ErrMagicMismatch = errors.New("invalid input: magic number mismatch")
+
+	// ErrWindowSizeExceeded is returned when a reference exceeds the valid window size.
+	// Typically this indicates wrong or corrupted input.
+	ErrWindowSizeExceeded = errors.New("window size exceeded")
+
+	// ErrWindowSizeTooSmall is returned when no window size is specified.
+	// Typically this indicates wrong or corrupted input.
+	ErrWindowSizeTooSmall = errors.New("invalid input: window size was too small")
+
+	// ErrDecoderSizeExceeded is returned if decompressed size exceeds the configured limit.
+	ErrDecoderSizeExceeded = errors.New("decompressed size exceeds configured limit")
+
+	// ErrUnknownDictionary is returned if the dictionary ID is unknown.
+	// For the time being dictionaries are not supported.
+	ErrUnknownDictionary = errors.New("unknown dictionary")
+
+	// ErrFrameSizeExceeded is returned if the stated frame size is exceeded.
+	// This is only returned if SingleSegment is specified on the frame.
+	ErrFrameSizeExceeded = errors.New("frame size exceeded")
+
+	// ErrCRCMismatch is returned if CRC mismatches.
+	ErrCRCMismatch = errors.New("CRC check failed")
+
+	// ErrDecoderClosed will be returned if the Decoder was used after
+	// Close has been called.
+	ErrDecoderClosed = errors.New("decoder used after Close")
+)
+
+func println(a ...interface{}) {
+	if debug {
+		log.Println(a...)
+	}
+}
+
+func printf(format string, a ...interface{}) {
+	if debug {
+		log.Printf(format, a...)
+	}
+}
+
+// matchLen returns the maximum length.
+// a must be the shortest of the two.
+// The function also returns whether all bytes matched.
+func matchLen(a, b []byte) int {
+	b = b[:len(a)]
+	for i := 0; i < len(a)-7; i += 8 {
+		if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+			return i + (bits.TrailingZeros64(diff) >> 3)
+		}
+	}
+	checked := (len(a) >> 3) << 3
+	a = a[checked:]
+	b = b[checked:]
+	// TODO: We could do a 4 check.
+	for i := range a {
+		if a[i] != b[i] {
+			return int(i) + checked
+		}
+	}
+	return len(a) + checked
+}
+
+// matchLen returns a match length in src between index s and t
+func matchLenIn(src []byte, s, t int32) int32 {
+	s1 := len(src)
+	b := src[t:]
+	a := src[s:s1]
+	b = b[:len(a)]
+	// Extend the match to be as long as possible.
+	for i := range a {
+		if a[i] != b[i] {
+			return int32(i)
+		}
+	}
+	return int32(len(a))
+}
+
+func load3232(b []byte, i int32) uint32 {
+	// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
+	b = b[i:]
+	b = b[:4]
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func load6432(b []byte, i int32) uint64 {
+	// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
+	b = b[i:]
+	b = b[:8]
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+func load64(b []byte, i int) uint64 {
+	// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
+	b = b[i:]
+	b = b[:8]
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}