1// Copyright 2020, 2021 Google LLC 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// https://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package runfiles 16 17import ( 18 "bufio" 19 "fmt" 20 "os" 21 "path" 22 "path/filepath" 23 "strings" 24) 25 26// ManifestFile specifies the location of the runfile manifest file. You can 27// pass this as an option to New. If unset or empty, use the value of the 28// environmental variable RUNFILES_MANIFEST_FILE. 29type ManifestFile string 30 31func (f ManifestFile) new(sourceRepo SourceRepo) (*Runfiles, error) { 32 m, err := f.parse() 33 if err != nil { 34 return nil, err 35 } 36 r := &Runfiles{ 37 impl: m, 38 env: manifestFileVar + "=" + string(f), 39 sourceRepo: string(sourceRepo), 40 } 41 err = r.loadRepoMapping() 42 return r, err 43} 44 45type manifest map[string]string 46 47func (f ManifestFile) parse() (manifest, error) { 48 r, err := os.Open(string(f)) 49 if err != nil { 50 return nil, fmt.Errorf("runfiles: can’t open manifest file: %w", err) 51 } 52 defer r.Close() 53 54 s := bufio.NewScanner(r) 55 m := make(manifest) 56 for s.Scan() { 57 fields := strings.SplitN(s.Text(), " ", 2) 58 if len(fields) != 2 || fields[0] == "" { 59 return nil, fmt.Errorf("runfiles: bad manifest line %q in file %s", s.Text(), f) 60 } 61 m[fields[0]] = filepath.FromSlash(fields[1]) 62 } 63 64 if err := s.Err(); err != nil { 65 return nil, fmt.Errorf("runfiles: error parsing manifest file %s: %w", f, err) 66 } 67 68 return m, nil 69} 70 71func (m manifest) path(s string) (string, error) { 72 r, ok := m[s] 73 if ok && r == "" { 74 return "", ErrEmpty 75 } 76 if ok { 77 return r, nil 78 } 79 80 // If path references a runfile that lies under a directory that itself is a 81 // runfile, then only the directory is listed in the manifest. Look up all 82 // prefixes of path in the manifest. 83 for prefix := s; prefix != ""; prefix, _ = path.Split(prefix) { 84 prefix = strings.TrimSuffix(prefix, "/") 85 if prefixMatch, ok := m[prefix]; ok { 86 return prefixMatch + filepath.FromSlash(strings.TrimPrefix(s, prefix)), nil 87 } 88 } 89 90 return "", os.ErrNotExist 91} 92