| package engine |
| |
| import ( |
| "bytes" |
| "encoding/json" |
| "fmt" |
| "io" |
| "strconv" |
| "strings" |
| ) |
| |
| type Env []string |
| |
| func (env *Env) Get(key string) (value string) { |
| // FIXME: use Map() |
| for _, kv := range *env { |
| if strings.Index(kv, "=") == -1 { |
| continue |
| } |
| parts := strings.SplitN(kv, "=", 2) |
| if parts[0] != key { |
| continue |
| } |
| if len(parts) < 2 { |
| value = "" |
| } else { |
| value = parts[1] |
| } |
| } |
| return |
| } |
| |
| func (env *Env) Exists(key string) bool { |
| _, exists := env.Map()[key] |
| return exists |
| } |
| |
| func (env *Env) GetBool(key string) (value bool) { |
| s := strings.ToLower(strings.Trim(env.Get(key), " \t")) |
| if s == "" || s == "0" || s == "no" || s == "false" || s == "none" { |
| return false |
| } |
| return true |
| } |
| |
| func (env *Env) SetBool(key string, value bool) { |
| if value { |
| env.Set(key, "1") |
| } else { |
| env.Set(key, "0") |
| } |
| } |
| |
| func (env *Env) GetInt(key string) int { |
| return int(env.GetInt64(key)) |
| } |
| |
| func (env *Env) GetInt64(key string) int64 { |
| s := strings.Trim(env.Get(key), " \t") |
| val, err := strconv.ParseInt(s, 10, 64) |
| if err != nil { |
| return -1 |
| } |
| return val |
| } |
| |
| func (env *Env) SetInt(key string, value int) { |
| env.Set(key, fmt.Sprintf("%d", value)) |
| } |
| |
| func (env *Env) SetInt64(key string, value int64) { |
| env.Set(key, fmt.Sprintf("%d", value)) |
| } |
| |
| // Returns nil if key not found |
| func (env *Env) GetList(key string) []string { |
| sval := env.Get(key) |
| if sval == "" { |
| return nil |
| } |
| l := make([]string, 0, 1) |
| if err := json.Unmarshal([]byte(sval), &l); err != nil { |
| l = append(l, sval) |
| } |
| return l |
| } |
| |
| func (env *Env) GetJson(key string, iface interface{}) error { |
| sval := env.Get(key) |
| if sval == "" { |
| return nil |
| } |
| return json.Unmarshal([]byte(sval), iface) |
| } |
| |
| func (env *Env) SetJson(key string, value interface{}) error { |
| sval, err := json.Marshal(value) |
| if err != nil { |
| return err |
| } |
| env.Set(key, string(sval)) |
| return nil |
| } |
| |
| func (env *Env) SetList(key string, value []string) error { |
| return env.SetJson(key, value) |
| } |
| |
| func (env *Env) Set(key, value string) { |
| *env = append(*env, key+"="+value) |
| } |
| |
| func NewDecoder(src io.Reader) *Decoder { |
| return &Decoder{ |
| json.NewDecoder(src), |
| } |
| } |
| |
| type Decoder struct { |
| *json.Decoder |
| } |
| |
| func (decoder *Decoder) Decode() (*Env, error) { |
| m := make(map[string]interface{}) |
| if err := decoder.Decoder.Decode(&m); err != nil { |
| return nil, err |
| } |
| env := &Env{} |
| for key, value := range m { |
| env.SetAuto(key, value) |
| } |
| return env, nil |
| } |
| |
| // DecodeEnv decodes `src` as a json dictionary, and adds |
| // each decoded key-value pair to the environment. |
| // |
| // If `src` cannot be decoded as a json dictionary, an error |
| // is returned. |
| func (env *Env) Decode(src io.Reader) error { |
| m := make(map[string]interface{}) |
| if err := json.NewDecoder(src).Decode(&m); err != nil { |
| return err |
| } |
| for k, v := range m { |
| env.SetAuto(k, v) |
| } |
| return nil |
| } |
| |
| func (env *Env) SetAuto(k string, v interface{}) { |
| // FIXME: we fix-convert float values to int, because |
| // encoding/json decodes integers to float64, but cannot encode them back. |
| // (See http://golang.org/src/pkg/encoding/json/decode.go#L46) |
| if fval, ok := v.(float64); ok { |
| env.SetInt64(k, int64(fval)) |
| } else if sval, ok := v.(string); ok { |
| env.Set(k, sval) |
| } else if val, err := json.Marshal(v); err == nil { |
| env.Set(k, string(val)) |
| } else { |
| env.Set(k, fmt.Sprintf("%v", v)) |
| } |
| } |
| |
| func (env *Env) Encode(dst io.Writer) error { |
| m := make(map[string]interface{}) |
| for k, v := range env.Map() { |
| var val interface{} |
| if err := json.Unmarshal([]byte(v), &val); err == nil { |
| // FIXME: we fix-convert float values to int, because |
| // encoding/json decodes integers to float64, but cannot encode them back. |
| // (See http://golang.org/src/pkg/encoding/json/decode.go#L46) |
| if fval, isFloat := val.(float64); isFloat { |
| val = int(fval) |
| } |
| m[k] = val |
| } else { |
| m[k] = v |
| } |
| } |
| if err := json.NewEncoder(dst).Encode(&m); err != nil { |
| return err |
| } |
| return nil |
| } |
| |
| func (env *Env) WriteTo(dst io.Writer) (n int64, err error) { |
| // FIXME: return the number of bytes written to respect io.WriterTo |
| return 0, env.Encode(dst) |
| } |
| |
| func (env *Env) Export(dst interface{}) (err error) { |
| defer func() { |
| if err != nil { |
| err = fmt.Errorf("ExportEnv %s", err) |
| } |
| }() |
| var buf bytes.Buffer |
| // step 1: encode/marshal the env to an intermediary json representation |
| if err := env.Encode(&buf); err != nil { |
| return err |
| } |
| // step 2: decode/unmarshal the intermediary json into the destination object |
| if err := json.NewDecoder(&buf).Decode(dst); err != nil { |
| return err |
| } |
| return nil |
| } |
| |
| func (env *Env) Import(src interface{}) (err error) { |
| defer func() { |
| if err != nil { |
| err = fmt.Errorf("ImportEnv: %s", err) |
| } |
| }() |
| var buf bytes.Buffer |
| if err := json.NewEncoder(&buf).Encode(src); err != nil { |
| return err |
| } |
| if err := env.Decode(&buf); err != nil { |
| return err |
| } |
| return nil |
| } |
| |
| func (env *Env) Map() map[string]string { |
| m := make(map[string]string) |
| for _, kv := range *env { |
| parts := strings.SplitN(kv, "=", 2) |
| m[parts[0]] = parts[1] |
| } |
| return m |
| } |