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/dsnet/compress/internal/prefix/wrap.go

@@ -0,0 +1,146 @@
+// Copyright 2015, Joe Tsai. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE.md file.
+
+package prefix
+
+import (
+	"bytes"
+	"io"
+	"strings"
+)
+
+// For some of the common Readers, we wrap and extend them to satisfy the
+// compress.BufferedReader interface to improve performance.
+
+type buffer struct {
+	*bytes.Buffer
+}
+
+type bytesReader struct {
+	*bytes.Reader
+	pos int64
+	buf []byte
+	arr [512]byte
+}
+
+type stringReader struct {
+	*strings.Reader
+	pos int64
+	buf []byte
+	arr [512]byte
+}
+
+func (r *buffer) Buffered() int {
+	return r.Len()
+}
+
+func (r *buffer) Peek(n int) ([]byte, error) {
+	b := r.Bytes()
+	if len(b) < n {
+		return b, io.EOF
+	}
+	return b[:n], nil
+}
+
+func (r *buffer) Discard(n int) (int, error) {
+	b := r.Next(n)
+	if len(b) < n {
+		return len(b), io.EOF
+	}
+	return n, nil
+}
+
+func (r *bytesReader) Buffered() int {
+	r.update()
+	if r.Len() > len(r.buf) {
+		return len(r.buf)
+	}
+	return r.Len()
+}
+
+func (r *bytesReader) Peek(n int) ([]byte, error) {
+	if n > len(r.arr) {
+		return nil, io.ErrShortBuffer
+	}
+
+	// Return sub-slice of local buffer if possible.
+	r.update()
+	if len(r.buf) >= n {
+		return r.buf[:n], nil
+	}
+
+	// Fill entire local buffer, and return appropriate sub-slice.
+	cnt, err := r.ReadAt(r.arr[:], r.pos)
+	r.buf = r.arr[:cnt]
+	if cnt < n {
+		return r.arr[:cnt], err
+	}
+	return r.arr[:n], nil
+}
+
+func (r *bytesReader) Discard(n int) (int, error) {
+	var err error
+	if n > r.Len() {
+		n, err = r.Len(), io.EOF
+	}
+	r.Seek(int64(n), io.SeekCurrent)
+	return n, err
+}
+
+// update reslices the internal buffer to be consistent with the read offset.
+func (r *bytesReader) update() {
+	pos, _ := r.Seek(0, io.SeekCurrent)
+	if off := pos - r.pos; off >= 0 && off < int64(len(r.buf)) {
+		r.buf, r.pos = r.buf[off:], pos
+	} else {
+		r.buf, r.pos = nil, pos
+	}
+}
+
+func (r *stringReader) Buffered() int {
+	r.update()
+	if r.Len() > len(r.buf) {
+		return len(r.buf)
+	}
+	return r.Len()
+}
+
+func (r *stringReader) Peek(n int) ([]byte, error) {
+	if n > len(r.arr) {
+		return nil, io.ErrShortBuffer
+	}
+
+	// Return sub-slice of local buffer if possible.
+	r.update()
+	if len(r.buf) >= n {
+		return r.buf[:n], nil
+	}
+
+	// Fill entire local buffer, and return appropriate sub-slice.
+	cnt, err := r.ReadAt(r.arr[:], r.pos)
+	r.buf = r.arr[:cnt]
+	if cnt < n {
+		return r.arr[:cnt], err
+	}
+	return r.arr[:n], nil
+}
+
+func (r *stringReader) Discard(n int) (int, error) {
+	var err error
+	if n > r.Len() {
+		n, err = r.Len(), io.EOF
+	}
+	r.Seek(int64(n), io.SeekCurrent)
+	return n, err
+}
+
+// update reslices the internal buffer to be consistent with the read offset.
+func (r *stringReader) update() {
+	pos, _ := r.Seek(0, io.SeekCurrent)
+	if off := pos - r.pos; off >= 0 && off < int64(len(r.buf)) {
+		r.buf, r.pos = r.buf[off:], pos
+	} else {
+		r.buf, r.pos = nil, pos
+	}
+}