| package bencode |
| |
| import ( |
| "reflect" |
| "strings" |
| "unicode" |
| ) |
| |
| // tagOptions is the string following a comma in a struct field's "bencode" |
| // tag, or the empty string. It does not include the leading comma. |
| type tagOptions string |
| |
| // parseTag splits a struct field's tag into its name and |
| // comma-separated options. |
| func parseTag(tag string) (string, tagOptions) { |
| if idx := strings.Index(tag, ","); idx != -1 { |
| return tag[:idx], tagOptions(tag[idx+1:]) |
| } |
| return tag, tagOptions("") |
| } |
| |
| // Contains returns whether checks that a comma-separated list of options |
| // contains a particular substr flag. substr must be surrounded by a |
| // string boundary or commas. |
| func (options tagOptions) Contains(optionName string) bool { |
| s := string(options) |
| for s != "" { |
| var next string |
| i := strings.Index(s, ",") |
| if i >= 0 { |
| s, next = s[:i], s[i+1:] |
| } |
| if s == optionName { |
| return true |
| } |
| s = next |
| } |
| return false |
| } |
| |
| func isValidTag(key string) bool { |
| if key == "" { |
| return false |
| } |
| for _, c := range key { |
| if c != ' ' && c != '$' && c != '-' && c != '_' && c != '.' && !unicode.IsLetter(c) && !unicode.IsDigit(c) { |
| return false |
| } |
| } |
| return true |
| } |
| |
| func matchName(key string) func(string) bool { |
| return func(s string) bool { |
| return strings.ToLower(key) == strings.ToLower(s) |
| } |
| } |
| |
| func isEmptyValue(v reflect.Value) bool { |
| switch v.Kind() { |
| case reflect.Array, reflect.Map, reflect.Slice, reflect.String: |
| return v.Len() == 0 |
| case reflect.Bool: |
| return !v.Bool() |
| case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| return v.Int() == 0 |
| case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| return v.Uint() == 0 |
| case reflect.Float32, reflect.Float64: |
| return v.Float() == 0 |
| case reflect.Interface, reflect.Ptr: |
| return v.IsNil() |
| } |
| |
| return false |
| } |