logger-core.go 3.3 KB

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  1. package log
  2. import (
  3. "fmt"
  4. "path/filepath"
  5. "slices"
  6. )
  7. // loggerCore is the essential part of Logger.
  8. type loggerCore struct {
  9. nonZero bool
  10. names []string
  11. values []interface{}
  12. // Propagate on NOTSET?
  13. defaultLevel Level
  14. // Use propagation on NOTSET.
  15. filterLevel Level
  16. msgMaps []func(Msg) Msg
  17. Handlers []Handler
  18. }
  19. func (l loggerCore) asLogger() Logger {
  20. return Logger{l}
  21. }
  22. // Returns a logger that adds the given values to logged messages.
  23. func (l loggerCore) WithValues(v ...interface{}) Logger {
  24. l.assertNonZero()
  25. l.values = append(slices.Clone(l.values), v...)
  26. return l.asLogger()
  27. }
  28. // Returns a logger that for a given message propagates the result of `f` instead.
  29. func (l loggerCore) WithMap(f func(m Msg) Msg) Logger {
  30. l.msgMaps = append(l.msgMaps, f)
  31. return l.asLogger()
  32. }
  33. func (l loggerCore) WithDefaultLevel(level Level) Logger {
  34. l.defaultLevel = level
  35. return l.asLogger()
  36. }
  37. func (l loggerCore) WithFilterLevel(minLevel Level) Logger {
  38. l.filterLevel = minLevel
  39. return l.asLogger()
  40. }
  41. // Deprecated. Use WithFilterLevel. This method name is misleading and doesn't follow the convention
  42. // elsewhere.
  43. func (l loggerCore) FilterLevel(minLevel Level) Logger {
  44. return l.WithFilterLevel(minLevel)
  45. }
  46. func (l loggerCore) IsZero() bool {
  47. return !l.nonZero
  48. }
  49. // Deprecated. This should require a msg, since filtering includes the location a msg is created at.
  50. // That would require building a message before we can do checks, which means lazily constructing
  51. // the message but not the caller location.
  52. func (l loggerCore) IsEnabledFor(level Level) bool {
  53. // TODO: Take a message?
  54. return true
  55. }
  56. func (l loggerCore) LazyLog(level Level, f func() Msg) {
  57. l.lazyLog(level, 1, f)
  58. }
  59. func (l loggerCore) LazyLogDefaultLevel(f func() Msg) {
  60. l.lazyLog(NotSet, 1, f)
  61. }
  62. func (l loggerCore) lazyLog(level Level, skip int, f func() Msg) {
  63. if level.isNotSet() {
  64. level = l.defaultLevel
  65. }
  66. r := f().Skip(skip + 1)
  67. msgLoc := getMsgLogLoc(r)
  68. names := append(
  69. l.names[:len(l.names):len(l.names)],
  70. msgLoc.Package,
  71. fmt.Sprintf("%v:%v", filepath.Base(msgLoc.File), msgLoc.Line),
  72. )
  73. if rulesLevel, ok := levelFromRules(names); ok {
  74. if level.LessThan(rulesLevel) {
  75. return
  76. }
  77. } else if level.LessThan(l.filterLevel) {
  78. return
  79. }
  80. for i := len(l.msgMaps) - 1; i >= 0; i-- {
  81. r = l.msgMaps[i](r)
  82. }
  83. r = r.WithValues(l.values...)
  84. l.handle(level, r, names)
  85. }
  86. // Goes from an affirmative decision to log, to sending it to the handlers in the right form.
  87. func (l loggerCore) handle(level Level, m Msg, names []string) {
  88. r := Record{
  89. // Do we really need to be passing the full Msg caller context at this point?
  90. Msg: m.Skip(1),
  91. Level: level,
  92. Names: names,
  93. }
  94. l.assertNonZero()
  95. for _, h := range l.Handlers {
  96. h.Handle(r)
  97. }
  98. }
  99. func (l loggerCore) WithNames(names ...string) Logger {
  100. // Avoid sharing after appending. This might not be enough because some formatters might add
  101. // more elements concurrently, or names could be empty.
  102. l.names = append(l.names[:len(l.names):len(l.names)], names...)
  103. return l.asLogger()
  104. }
  105. // Clobber the Loggers Handlers. Note this breaks convention by not returning a new Logger, but
  106. // seems to fit here.
  107. func (l *loggerCore) SetHandlers(h ...Handler) {
  108. l.Handlers = h
  109. l.nonZero = true
  110. }
  111. func (l *loggerCore) assertNonZero() {
  112. if !l.nonZero {
  113. panic(fmt.Sprintf("Logger uninitialized. names=%q", l.names))
  114. }
  115. }