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-rw-r--r--textproto/fastimport.go108
1 files changed, 108 insertions, 0 deletions
diff --git a/textproto/fastimport.go b/textproto/fastimport.go
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index 0000000..b43c378
--- /dev/null
+++ b/textproto/fastimport.go
@@ -0,0 +1,108 @@
+// Copyright (C) 2017-2018 Luke Shumaker <lukeshu@lukeshu.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package textproto
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "strconv"
+ "strings"
+)
+
+// FIReader is a low-level parser of a fast-import stream.
+type FIReader struct {
+ r *bufio.Reader
+
+ line *string
+ err error
+}
+
+// NewFIReader creates a new FIReader parser.
+func NewFIReader(r io.Reader) *FIReader {
+ return &FIReader{
+ r: bufio.NewReader(r),
+ }
+}
+
+// ReadLine reads a "line" from the stream; with special handling for
+// the "data" command, which isn't really a single line, but rather
+// contains arbitrary binary data.
+func (fir *FIReader) ReadLine() (line string, err error) {
+ for len(line) <= 1 {
+ line, err = fir.r.ReadString('\n')
+ if err != nil {
+ return
+ }
+ }
+
+ if strings.HasPrefix(line, "data ") {
+ if line[5:7] == "<<" {
+ // Delimited format
+ delim := line[7 : len(line)-1]
+ suffix := "\n" + delim + "\n"
+
+ for !strings.HasSuffix(line, suffix) {
+ var _line string
+ _line, err = fir.r.ReadString('\n')
+ line += _line
+ if err != nil {
+ return
+ }
+ }
+ } else {
+ // Exact byte count format
+ var size int
+ size, err = strconv.Atoi(line[5 : len(line)-1])
+ if err != nil {
+ return
+ }
+ data := make([]byte, size)
+ _, err = io.ReadFull(fir.r, data)
+ line += string(data)
+ }
+ }
+ return
+}
+
+// FIWriter is a low-level marshaller of a fast-import stream.
+type FIWriter struct {
+ w io.Writer
+}
+
+// NewFIWriter creates a new FIWriter marshaller.
+func NewFIWriter(w io.Writer) *FIWriter {
+ return &FIWriter{
+ w: w,
+ }
+}
+
+// WriteLine writes an ordinary line to the stream; arguments are
+// handled similarly to fmt.Println.
+func (fiw *FIWriter) WriteLine(a ...interface{}) error {
+ _, err := fmt.Fprintln(fiw.w, a...)
+ return err
+}
+
+// WriteData writes a 'data' command to the stream.
+func (fiw *FIWriter) WriteData(data string) error {
+ err := fiw.WriteLine("data", len(data))
+ if err != nil {
+ return err
+ }
+ _, err = io.WriteString(fiw.w, data)
+ return err
+}