| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package logs |
| 4 | |
| 5 | import ( |
| 6 | "bufio" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "strconv" |
| 10 | |
| 11 | "github.com/valyala/fastjson" |
| 12 | ) |
| 13 | |
| 14 | type JSONConfig struct { |
| 15 | Mapping map[string]string `yaml:"mapping" json:"mapping"` |
| 16 | } |
| 17 | |
| 18 | type JSONParser struct { |
| 19 | reader *bufio.Reader |
| 20 | parser fastjson.Parser |
| 21 | buf []byte |
| 22 | mapping map[string]string |
| 23 | } |
| 24 | |
| 25 | func NewJSONParser(config JSONConfig, in io.Reader) (*JSONParser, error) { |
| 26 | parser := &JSONParser{ |
| 27 | reader: bufio.NewReader(in), |
| 28 | mapping: config.Mapping, |
| 29 | buf: make([]byte, 0, 100), |
| 30 | } |
| 31 | return parser, nil |
| 32 | } |
| 33 | |
| 34 | func (p *JSONParser) ReadLine(line LogLine) error { |
| 35 | row, err := p.reader.ReadSlice('\n') |
| 36 | if err != nil && len(row) == 0 { |
| 37 | return err |
| 38 | } |
| 39 | if len(row) > 0 && row[len(row)-1] == '\n' { |
| 40 | row = row[:len(row)-1] |
| 41 | } |
| 42 | return p.Parse(row, line) |
| 43 | } |
| 44 | |
| 45 | func (p *JSONParser) Parse(row []byte, line LogLine) error { |
| 46 | val, err := p.parser.ParseBytes(row) |
| 47 | if err != nil { |
| 48 | return err |
| 49 | } |
| 50 | |
| 51 | if err := p.parseObject("", val, line); err != nil { |
| 52 | return &ParseError{msg: fmt.Sprintf("json parse: %v", err), err: err} |
| 53 | } |
| 54 | |
| 55 | return nil |
| 56 | } |
| 57 | |
| 58 | func (p *JSONParser) parseObject(prefix string, val *fastjson.Value, line LogLine) error { |
| 59 | obj, err := val.Object() |
| 60 | if err != nil { |
| 61 | return err |
| 62 | } |
| 63 | |
| 64 | obj.Visit(func(key []byte, v *fastjson.Value) { |
| 65 | if err != nil { |
| 66 | return |
| 67 | } |
| 68 | |
| 69 | k := jsonObjKey(prefix, string(key)) |
| 70 | |
| 71 | switch v.Type() { |
| 72 | case fastjson.TypeString, fastjson.TypeNumber: |
| 73 | err = p.parseStringNumber(k, v, line) |
| 74 | case fastjson.TypeArray: |
| 75 | err = p.parseArray(k, v, line) |
| 76 | case fastjson.TypeObject: |
| 77 | err = p.parseObject(k, v, line) |
| 78 | default: |
| 79 | return |
| 80 | } |
| 81 | }) |
| 82 | |
| 83 | return err |
| 84 | } |
| 85 | |
| 86 | func jsonObjKey(prefix, key string) string { |
| 87 | if prefix == "" { |
| 88 | return key |
| 89 | } |
| 90 | return prefix + "." + key |
| 91 | } |
| 92 | |
| 93 | func (p *JSONParser) parseArray(key string, val *fastjson.Value, line LogLine) error { |
| 94 | arr, err := val.Array() |
| 95 | if err != nil { |
| 96 | return err |
| 97 | } |
| 98 | |
| 99 | for i, v := range arr { |
| 100 | k := jsonObjKey(key, strconv.Itoa(i)) |
| 101 | |
| 102 | switch v.Type() { |
| 103 | case fastjson.TypeString, fastjson.TypeNumber: |
| 104 | err = p.parseStringNumber(k, v, line) |
| 105 | case fastjson.TypeArray: |
| 106 | err = p.parseArray(k, v, line) |
| 107 | case fastjson.TypeObject: |
| 108 | err = p.parseObject(k, v, line) |
| 109 | default: |
| 110 | continue |
| 111 | } |
| 112 | |
| 113 | if err != nil { |
| 114 | return err |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | return err |
| 119 | } |
| 120 | |
| 121 | func (p *JSONParser) parseStringNumber(key string, val *fastjson.Value, line LogLine) error { |
| 122 | if mapped, ok := p.mapping[key]; ok { |
| 123 | key = mapped |
| 124 | } |
| 125 | |
| 126 | p.buf = p.buf[:0] |
| 127 | if p.buf = val.MarshalTo(p.buf); len(p.buf) == 0 { |
| 128 | return nil |
| 129 | } |
| 130 | |
| 131 | if val.Type() == fastjson.TypeString { |
| 132 | // trim " |
| 133 | return line.Assign(key, string(p.buf[1:len(p.buf)-1])) |
| 134 | } |
| 135 | return line.Assign(key, string(p.buf)) |
| 136 | } |
| 137 | |
| 138 | func (p *JSONParser) Info() string { |
| 139 | return fmt.Sprintf("json: %q", p.mapping) |
| 140 | } |