Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 1 | package packr |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "compress/gzip" |
| 6 | "io/ioutil" |
| 7 | "net/http" |
| 8 | "os" |
| 9 | "path" |
| 10 | "path/filepath" |
| 11 | "runtime" |
| 12 | "strings" |
| 13 | |
| 14 | "github.com/pkg/errors" |
| 15 | ) |
| 16 | |
| 17 | var ( |
| 18 | // ErrResOutsideBox gets returned in case of the requested resources being outside the box |
| 19 | ErrResOutsideBox = errors.New("Can't find a resource outside the box") |
| 20 | ) |
| 21 | |
| 22 | // NewBox returns a Box that can be used to |
| 23 | // retrieve files from either disk or the embedded |
| 24 | // binary. |
| 25 | func NewBox(path string) Box { |
| 26 | var cd string |
| 27 | if !filepath.IsAbs(path) { |
| 28 | _, filename, _, _ := runtime.Caller(1) |
| 29 | cd = filepath.Dir(filename) |
| 30 | } |
| 31 | |
| 32 | // this little hack courtesy of the `-cover` flag!! |
| 33 | cov := filepath.Join("_test", "_obj_test") |
| 34 | cd = strings.Replace(cd, string(filepath.Separator)+cov, "", 1) |
| 35 | if !filepath.IsAbs(cd) && cd != "" { |
| 36 | cd = filepath.Join(GoPath(), "src", cd) |
| 37 | } |
| 38 | |
| 39 | return Box{ |
| 40 | Path: path, |
| 41 | callingDir: cd, |
| 42 | data: map[string][]byte{}, |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | // Box represent a folder on a disk you want to |
| 47 | // have access to in the built Go binary. |
| 48 | type Box struct { |
| 49 | Path string |
| 50 | callingDir string |
| 51 | data map[string][]byte |
| 52 | directories map[string]bool |
| 53 | } |
| 54 | |
| 55 | // AddString converts t to a byteslice and delegates to AddBytes to add to b.data |
| 56 | func (b Box) AddString(path string, t string) { |
| 57 | b.AddBytes(path, []byte(t)) |
| 58 | } |
| 59 | |
| 60 | // AddBytes sets t in b.data by the given path |
| 61 | func (b Box) AddBytes(path string, t []byte) { |
| 62 | b.data[path] = t |
| 63 | } |
| 64 | |
| 65 | // String of the file asked for or an empty string. |
| 66 | func (b Box) String(name string) string { |
| 67 | return string(b.Bytes(name)) |
| 68 | } |
| 69 | |
| 70 | // MustString returns either the string of the requested |
| 71 | // file or an error if it can not be found. |
| 72 | func (b Box) MustString(name string) (string, error) { |
| 73 | bb, err := b.MustBytes(name) |
| 74 | return string(bb), err |
| 75 | } |
| 76 | |
| 77 | // Bytes of the file asked for or an empty byte slice. |
| 78 | func (b Box) Bytes(name string) []byte { |
| 79 | bb, _ := b.MustBytes(name) |
| 80 | return bb |
| 81 | } |
| 82 | |
| 83 | // MustBytes returns either the byte slice of the requested |
| 84 | // file or an error if it can not be found. |
| 85 | func (b Box) MustBytes(name string) ([]byte, error) { |
| 86 | f, err := b.find(name) |
| 87 | if err == nil { |
| 88 | bb := &bytes.Buffer{} |
| 89 | bb.ReadFrom(f) |
| 90 | return bb.Bytes(), err |
| 91 | } |
| 92 | return nil, err |
| 93 | } |
| 94 | |
| 95 | // Has returns true if the resource exists in the box |
| 96 | func (b Box) Has(name string) bool { |
| 97 | _, err := b.find(name) |
| 98 | if err != nil { |
| 99 | return false |
| 100 | } |
| 101 | return true |
| 102 | } |
| 103 | |
| 104 | func (b Box) decompress(bb []byte) []byte { |
| 105 | reader, err := gzip.NewReader(bytes.NewReader(bb)) |
| 106 | if err != nil { |
| 107 | return bb |
| 108 | } |
| 109 | data, err := ioutil.ReadAll(reader) |
| 110 | if err != nil { |
| 111 | return bb |
| 112 | } |
| 113 | return data |
| 114 | } |
| 115 | |
| 116 | func (b Box) find(name string) (File, error) { |
| 117 | if bb, ok := b.data[name]; ok { |
| 118 | return newVirtualFile(name, bb), nil |
| 119 | } |
| 120 | if b.directories == nil { |
| 121 | b.indexDirectories() |
| 122 | } |
| 123 | |
| 124 | cleanName := filepath.ToSlash(filepath.Clean(name)) |
| 125 | // Ensure name is not outside the box |
| 126 | if strings.HasPrefix(cleanName, "../") { |
| 127 | return nil, ErrResOutsideBox |
| 128 | } |
| 129 | // Absolute name is considered as relative to the box root |
| 130 | cleanName = strings.TrimPrefix(cleanName, "/") |
| 131 | |
| 132 | // Try to get the resource from the box |
| 133 | if _, ok := data[b.Path]; ok { |
| 134 | if bb, ok := data[b.Path][cleanName]; ok { |
| 135 | bb = b.decompress(bb) |
| 136 | return newVirtualFile(cleanName, bb), nil |
| 137 | } |
| 138 | if _, ok := b.directories[cleanName]; ok { |
| 139 | return newVirtualDir(cleanName), nil |
| 140 | } |
| 141 | if filepath.Ext(cleanName) != "" { |
| 142 | // The Handler created by http.FileSystem checks for those errors and |
| 143 | // returns http.StatusNotFound instead of http.StatusInternalServerError. |
| 144 | return nil, os.ErrNotExist |
| 145 | } |
| 146 | return nil, os.ErrNotExist |
| 147 | } |
| 148 | |
| 149 | // Not found in the box virtual fs, try to get it from the file system |
| 150 | cleanName = filepath.FromSlash(cleanName) |
| 151 | p := filepath.Join(b.callingDir, b.Path, cleanName) |
| 152 | return fileFor(p, cleanName) |
| 153 | } |
| 154 | |
| 155 | // Open returns a File using the http.File interface |
| 156 | func (b Box) Open(name string) (http.File, error) { |
| 157 | return b.find(name) |
| 158 | } |
| 159 | |
| 160 | // List shows "What's in the box?" |
| 161 | func (b Box) List() []string { |
| 162 | var keys []string |
| 163 | |
| 164 | if b.data == nil || len(b.data) == 0 { |
| 165 | b.Walk(func(path string, info File) error { |
| 166 | finfo, _ := info.FileInfo() |
| 167 | if !finfo.IsDir() { |
| 168 | keys = append(keys, finfo.Name()) |
| 169 | } |
| 170 | return nil |
| 171 | }) |
| 172 | } else { |
| 173 | for k := range b.data { |
| 174 | keys = append(keys, k) |
| 175 | } |
| 176 | } |
| 177 | return keys |
| 178 | } |
| 179 | |
| 180 | func (b *Box) indexDirectories() { |
| 181 | b.directories = map[string]bool{} |
| 182 | if _, ok := data[b.Path]; ok { |
| 183 | for name := range data[b.Path] { |
| 184 | prefix, _ := path.Split(name) |
| 185 | // Even on Windows the suffix appears to be a / |
| 186 | prefix = strings.TrimSuffix(prefix, "/") |
| 187 | b.directories[prefix] = true |
| 188 | } |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | func fileFor(p string, name string) (File, error) { |
| 193 | fi, err := os.Stat(p) |
| 194 | if err != nil { |
| 195 | return nil, err |
| 196 | } |
| 197 | if fi.IsDir() { |
| 198 | return newVirtualDir(p), nil |
| 199 | } |
| 200 | if bb, err := ioutil.ReadFile(p); err == nil { |
| 201 | return newVirtualFile(name, bb), nil |
| 202 | } |
| 203 | return nil, os.ErrNotExist |
| 204 | } |