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Diffstat (limited to 'textproto/fastimport.go')
-rw-r--r-- | textproto/fastimport.go | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/textproto/fastimport.go b/textproto/fastimport.go new file mode 100644 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 +} |