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/ulikunitz/xz/lzma/decoderdict.go

@@ -0,0 +1,135 @@
+// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+import (
+	"errors"
+	"fmt"
+)
+
+// decoderDict provides the dictionary for the decoder. The whole
+// dictionary is used as reader buffer.
+type decoderDict struct {
+	buf  buffer
+	head int64
+}
+
+// newDecoderDict creates a new decoder dictionary. The whole dictionary
+// will be used as reader buffer.
+func newDecoderDict(dictCap int) (d *decoderDict, err error) {
+	// lower limit supports easy test cases
+	if !(1 <= dictCap && int64(dictCap) <= MaxDictCap) {
+		return nil, errors.New("lzma: dictCap out of range")
+	}
+	d = &decoderDict{buf: *newBuffer(dictCap)}
+	return d, nil
+}
+
+// Reset clears the dictionary. The read buffer is not changed, so the
+// buffered data can still be read.
+func (d *decoderDict) Reset() {
+	d.head = 0
+}
+
+// WriteByte writes a single byte into the dictionary. It is used to
+// write literals into the dictionary.
+func (d *decoderDict) WriteByte(c byte) error {
+	if err := d.buf.WriteByte(c); err != nil {
+		return err
+	}
+	d.head++
+	return nil
+}
+
+// pos returns the position of the dictionary head.
+func (d *decoderDict) pos() int64 { return d.head }
+
+// dictLen returns the actual length of the dictionary.
+func (d *decoderDict) dictLen() int {
+	capacity := d.buf.Cap()
+	if d.head >= int64(capacity) {
+		return capacity
+	}
+	return int(d.head)
+}
+
+// byteAt returns a byte stored in the dictionary. If the distance is
+// non-positive or exceeds the current length of the dictionary the zero
+// byte is returned.
+func (d *decoderDict) byteAt(dist int) byte {
+	if !(0 < dist && dist <= d.dictLen()) {
+		return 0
+	}
+	i := d.buf.front - dist
+	if i < 0 {
+		i += len(d.buf.data)
+	}
+	return d.buf.data[i]
+}
+
+// writeMatch writes the match at the top of the dictionary. The given
+// distance must point in the current dictionary and the length must not
+// exceed the maximum length 273 supported in LZMA.
+//
+// The error value ErrNoSpace indicates that no space is available in
+// the dictionary for writing. You need to read from the dictionary
+// first.
+func (d *decoderDict) writeMatch(dist int64, length int) error {
+	if !(0 < dist && dist <= int64(d.dictLen())) {
+		return errors.New("writeMatch: distance out of range")
+	}
+	if !(0 < length && length <= maxMatchLen) {
+		return errors.New("writeMatch: length out of range")
+	}
+	if length > d.buf.Available() {
+		return ErrNoSpace
+	}
+	d.head += int64(length)
+
+	i := d.buf.front - int(dist)
+	if i < 0 {
+		i += len(d.buf.data)
+	}
+	for length > 0 {
+		var p []byte
+		if i >= d.buf.front {
+			p = d.buf.data[i:]
+			i = 0
+		} else {
+			p = d.buf.data[i:d.buf.front]
+			i = d.buf.front
+		}
+		if len(p) > length {
+			p = p[:length]
+		}
+		if _, err := d.buf.Write(p); err != nil {
+			panic(fmt.Errorf("d.buf.Write returned error %s", err))
+		}
+		length -= len(p)
+	}
+	return nil
+}
+
+// Write writes the given bytes into the dictionary and advances the
+// head.
+func (d *decoderDict) Write(p []byte) (n int, err error) {
+	n, err = d.buf.Write(p)
+	d.head += int64(n)
+	return n, err
+}
+
+// Available returns the number of available bytes for writing into the
+// decoder dictionary.
+func (d *decoderDict) Available() int { return d.buf.Available() }
+
+// Read reads data from the buffer contained in the decoder dictionary.
+func (d *decoderDict) Read(p []byte) (n int, err error) { return d.buf.Read(p) }
+
+// Buffered returns the number of bytes currently buffered in the
+// decoder dictionary.
+func (d *decoderDict) buffered() int { return d.buf.Buffered() }
+
+// Peek gets data from the buffer without advancing the rear index.
+func (d *decoderDict) peek(p []byte) (n int, err error) { return d.buf.Peek(p) }