1// Copyright The OpenTelemetry Authors
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//     http://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 codes // import "go.opentelemetry.io/otel/codes"
16
17import (
18	"encoding/json"
19	"fmt"
20	"strconv"
21)
22
23const (
24	// Unset is the default status code.
25	Unset Code = 0
26	// Error indicates the operation contains an error.
27	Error Code = 1
28	// Ok indicates operation has been validated by an Application developers
29	// or Operator to have completed successfully, or contain no error.
30	Ok Code = 2
31
32	maxCode = 3
33)
34
35// Code is an 32-bit representation of a status state.
36type Code uint32
37
38var codeToStr = map[Code]string{
39	Unset: "Unset",
40	Error: "Error",
41	Ok:    "Ok",
42}
43
44var strToCode = map[string]Code{
45	`"Unset"`: Unset,
46	`"Error"`: Error,
47	`"Ok"`:    Ok,
48}
49
50// String returns the Code as a string.
51func (c Code) String() string {
52	return codeToStr[c]
53}
54
55// UnmarshalJSON unmarshals b into the Code.
56//
57// This is based on the functionality in the gRPC codes package:
58// https://github.com/grpc/grpc-go/blob/bb64fee312b46ebee26be43364a7a966033521b1/codes/codes.go#L218-L244
59func (c *Code) UnmarshalJSON(b []byte) error {
60	// From json.Unmarshaler: By convention, to approximate the behavior of
61	// Unmarshal itself, Unmarshalers implement UnmarshalJSON([]byte("null")) as
62	// a no-op.
63	if string(b) == "null" {
64		return nil
65	}
66	if c == nil {
67		return fmt.Errorf("nil receiver passed to UnmarshalJSON")
68	}
69
70	var x interface{}
71	if err := json.Unmarshal(b, &x); err != nil {
72		return err
73	}
74	switch x.(type) {
75	case string:
76		if jc, ok := strToCode[string(b)]; ok {
77			*c = jc
78			return nil
79		}
80		return fmt.Errorf("invalid code: %q", string(b))
81	case float64:
82		if ci, err := strconv.ParseUint(string(b), 10, 32); err == nil {
83			if ci >= maxCode {
84				return fmt.Errorf("invalid code: %q", ci)
85			}
86
87			*c = Code(ci)
88			return nil
89		}
90		return fmt.Errorf("invalid code: %q", string(b))
91	default:
92		return fmt.Errorf("invalid code: %q", string(b))
93	}
94}
95
96// MarshalJSON returns c as the JSON encoding of c.
97func (c *Code) MarshalJSON() ([]byte, error) {
98	if c == nil {
99		return []byte("null"), nil
100	}
101	str, ok := codeToStr[*c]
102	if !ok {
103		return nil, fmt.Errorf("invalid code: %d", *c)
104	}
105	return []byte(fmt.Sprintf("%q", str)), nil
106}
107