github.com/rcowham/go-libgitfastimport@v0.1.6/util.go (about) 1 // Copyright (C) 2017, 2021 Luke Shumaker <lukeshu@lukeshu.com> 2 // 3 // This program is free software: you can redistribute it and/or modify 4 // it under the terms of the GNU Affero General Public License as published by 5 // the Free Software Foundation, either version 3 of the License, or 6 // (at your option) any later version. 7 // 8 // This program is distributed in the hope that it will be useful, 9 // but WITHOUT ANY WARRANTY; without even the implied warranty of 10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 // GNU Affero General Public License for more details. 12 // 13 // You should have received a copy of the GNU Affero General Public License 14 // along with this program. If not, see <https://www.gnu.org/licenses/>. 15 16 package libfastimport 17 18 import ( 19 "fmt" 20 "strconv" 21 "strings" 22 23 "github.com/pkg/errors" 24 ) 25 26 func trimLinePrefix(line string, prefix string) string { 27 if !strings.HasPrefix(line, prefix) { 28 n := 80 29 if len(line) < n { 30 n = len(line) 31 } 32 panic(fmt.Sprintf("line didn't have prefix: %s", line[:n])) 33 } 34 if !strings.HasSuffix(line, "\n") { 35 panic("line didn't have LF") 36 } 37 return strings.TrimSuffix(strings.TrimPrefix(line, prefix), "\n") 38 } 39 40 func parse_data(line string) (data string, err error) { 41 nl := strings.IndexByte(line, '\n') 42 if nl < 0 { 43 return "", errors.Errorf("data: expected newline: %q", data) 44 } 45 head := line[:nl+1] 46 rest := line[nl+1:] 47 if !strings.HasPrefix(head, "data ") { 48 return "", errors.Errorf("data: could not parse: %q", data) 49 } 50 if strings.HasPrefix(head, "data <<") { 51 // Delimited format 52 delim := trimLinePrefix(head, "data <<") 53 suffix := "\n" + delim + "\n" 54 if !strings.HasSuffix(rest, suffix) { 55 return "", errors.Errorf("data: did not find suffix: %q", suffix) 56 } 57 data = strings.TrimSuffix(rest, suffix) 58 } else { 59 // Exact byte count format 60 size, err := strconv.Atoi(trimLinePrefix(head, "data ")) 61 if err != nil { 62 return "", err 63 } 64 if size != len(rest) { 65 panic("FIReader should not have let this happen") 66 } 67 data = rest 68 } 69 return 70 }