+++ /dev/null
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package txtar implements a trivial text-based file archive format.
-//
-// The goals for the format are:
-//
-// - be trivial enough to create and edit by hand.
-// - be able to store trees of text files describing go command test cases.
-// - diff nicely in git history and code reviews.
-//
-// Non-goals include being a completely general archive format,
-// storing binary data, storing file modes, storing special files like
-// symbolic links, and so on.
-//
-// Txtar format
-//
-// A txtar archive is zero or more comment lines and then a sequence of file entries.
-// Each file entry begins with a file marker line of the form "-- FILENAME --"
-// and is followed by zero or more file content lines making up the file data.
-// The comment or file content ends at the next file marker line.
-// The file marker line must begin with the three-byte sequence "-- "
-// and end with the three-byte sequence " --", but the enclosed
-// file name can be surrounding by additional white space,
-// all of which is stripped.
-//
-// If the txtar file is missing a trailing newline on the final line,
-// parsers should consider a final newline to be present anyway.
-//
-// There are no possible syntax errors in a txtar archive.
-package txtar
-
-import (
- "bytes"
- "fmt"
- "io/ioutil"
- "strings"
-)
-
-// An Archive is a collection of files.
-type Archive struct {
- Comment []byte
- Files []File
-}
-
-// A File is a single file in an archive.
-type File struct {
- Name string // name of file ("foo/bar.txt")
- Data []byte // text content of file
-}
-
-// Format returns the serialized form of an Archive.
-// It is assumed that the Archive data structure is well-formed:
-// a.Comment and all a.File[i].Data contain no file marker lines,
-// and all a.File[i].Name is non-empty.
-func Format(a *Archive) []byte {
- var buf bytes.Buffer
- buf.Write(fixNL(a.Comment))
- for _, f := range a.Files {
- fmt.Fprintf(&buf, "-- %s --\n", f.Name)
- buf.Write(fixNL(f.Data))
- }
- return buf.Bytes()
-}
-
-// ParseFile parses the named file as an archive.
-func ParseFile(file string) (*Archive, error) {
- data, err := ioutil.ReadFile(file)
- if err != nil {
- return nil, err
- }
- return Parse(data), nil
-}
-
-// Parse parses the serialized form of an Archive.
-// The returned Archive holds slices of data.
-func Parse(data []byte) *Archive {
- a := new(Archive)
- var name string
- a.Comment, name, data = findFileMarker(data)
- for name != "" {
- f := File{name, nil}
- f.Data, name, data = findFileMarker(data)
- a.Files = append(a.Files, f)
- }
- return a
-}
-
-var (
- newlineMarker = []byte("\n-- ")
- marker = []byte("-- ")
- markerEnd = []byte(" --")
-)
-
-// findFileMarker finds the next file marker in data,
-// extracts the file name, and returns the data before the marker,
-// the file name, and the data after the marker.
-// If there is no next marker, findFileMarker returns before = fixNL(data), name = "", after = nil.
-func findFileMarker(data []byte) (before []byte, name string, after []byte) {
- var i int
- for {
- if name, after = isMarker(data[i:]); name != "" {
- return data[:i], name, after
- }
- j := bytes.Index(data[i:], newlineMarker)
- if j < 0 {
- return fixNL(data), "", nil
- }
- i += j + 1 // positioned at start of new possible marker
- }
-}
-
-// isMarker checks whether data begins with a file marker line.
-// If so, it returns the name from the line and the data after the line.
-// Otherwise it returns name == "" with an unspecified after.
-func isMarker(data []byte) (name string, after []byte) {
- if !bytes.HasPrefix(data, marker) {
- return "", nil
- }
- if i := bytes.IndexByte(data, '\n'); i >= 0 {
- data, after = data[:i], data[i+1:]
- }
- if !bytes.HasSuffix(data, markerEnd) {
- return "", nil
- }
- return strings.TrimSpace(string(data[len(marker) : len(data)-len(markerEnd)])), after
-}
-
-// If data is empty or ends in \n, fixNL returns data.
-// Otherwise fixNL returns a new slice consisting of data with a final \n added.
-func fixNL(data []byte) []byte {
- if len(data) == 0 || data[len(data)-1] == '\n' {
- return data
- }
- d := make([]byte, len(data)+1)
- copy(d, data)
- d[len(data)] = '\n'
- return d
-}
projects / dotfiles / .git / blobdiff