+++ /dev/null
-package log
-
-import "fmt"
-
-type level byte
-
-const (
- levelDebug level = 1 << iota
- levelInfo
- levelError
-)
-
-type filter struct {
- next Logger
- allowed level // XOR'd levels for default case
- allowedKeyvals map[keyval]level // When key-value match, use this level
-}
-
-type keyval struct {
- key interface{}
- value interface{}
-}
-
-// NewFilter wraps next and implements filtering. See the commentary on the
-// Option functions for a detailed description of how to configure levels. If
-// no options are provided, all leveled log events created with Debug, Info or
-// Error helper methods are squelched.
-func NewFilter(next Logger, options ...Option) Logger {
- l := &filter{
- next: next,
- allowedKeyvals: make(map[keyval]level),
- }
- for _, option := range options {
- option(l)
- }
- return l
-}
-
-func (l *filter) Info(msg string, keyvals ...interface{}) {
- levelAllowed := l.allowed&levelInfo != 0
- if !levelAllowed {
- return
- }
- l.next.Info(msg, keyvals...)
-}
-
-func (l *filter) Debug(msg string, keyvals ...interface{}) {
- levelAllowed := l.allowed&levelDebug != 0
- if !levelAllowed {
- return
- }
- l.next.Debug(msg, keyvals...)
-}
-
-func (l *filter) Error(msg string, keyvals ...interface{}) {
- levelAllowed := l.allowed&levelError != 0
- if !levelAllowed {
- return
- }
- l.next.Error(msg, keyvals...)
-}
-
-// With implements Logger by constructing a new filter with a keyvals appended
-// to the logger.
-//
-// If custom level was set for a keyval pair using one of the
-// Allow*With methods, it is used as the logger's level.
-//
-// Examples:
-// logger = log.NewFilter(logger, log.AllowError(), log.AllowInfoWith("module", "crypto"))
-// logger.With("module", "crypto").Info("Hello") # produces "I... Hello module=crypto"
-//
-// logger = log.NewFilter(logger, log.AllowError(), log.AllowInfoWith("module", "crypto"), log.AllowNoneWith("user", "Sam"))
-// logger.With("module", "crypto", "user", "Sam").Info("Hello") # returns nil
-//
-// logger = log.NewFilter(logger, log.AllowError(), log.AllowInfoWith("module", "crypto"), log.AllowNoneWith("user", "Sam"))
-// logger.With("user", "Sam").With("module", "crypto").Info("Hello") # produces "I... Hello module=crypto user=Sam"
-func (l *filter) With(keyvals ...interface{}) Logger {
- for i := len(keyvals) - 2; i >= 0; i -= 2 {
- for kv, allowed := range l.allowedKeyvals {
- if keyvals[i] == kv.key && keyvals[i+1] == kv.value {
- return &filter{next: l.next.With(keyvals...), allowed: allowed, allowedKeyvals: l.allowedKeyvals}
- }
- }
- }
- return &filter{next: l.next.With(keyvals...), allowed: l.allowed, allowedKeyvals: l.allowedKeyvals}
-}
-
-//--------------------------------------------------------------------------------
-
-// Option sets a parameter for the filter.
-type Option func(*filter)
-
-// AllowLevel returns an option for the given level or error if no option exist
-// for such level.
-func AllowLevel(lvl string) (Option, error) {
- switch lvl {
- case "debug":
- return AllowDebug(), nil
- case "info":
- return AllowInfo(), nil
- case "error":
- return AllowError(), nil
- case "none":
- return AllowNone(), nil
- default:
- return nil, fmt.Errorf("Expected either \"info\", \"debug\", \"error\" or \"none\" level, given %s", lvl)
- }
-}
-
-// AllowAll is an alias for AllowDebug.
-func AllowAll() Option {
- return AllowDebug()
-}
-
-// AllowDebug allows error, info and debug level log events to pass.
-func AllowDebug() Option {
- return allowed(levelError | levelInfo | levelDebug)
-}
-
-// AllowInfo allows error and info level log events to pass.
-func AllowInfo() Option {
- return allowed(levelError | levelInfo)
-}
-
-// AllowError allows only error level log events to pass.
-func AllowError() Option {
- return allowed(levelError)
-}
-
-// AllowNone allows no leveled log events to pass.
-func AllowNone() Option {
- return allowed(0)
-}
-
-func allowed(allowed level) Option {
- return func(l *filter) { l.allowed = allowed }
-}
-
-// AllowDebugWith allows error, info and debug level log events to pass for a specific key value pair.
-func AllowDebugWith(key interface{}, value interface{}) Option {
- return func(l *filter) { l.allowedKeyvals[keyval{key, value}] = levelError | levelInfo | levelDebug }
-}
-
-// AllowInfoWith allows error and info level log events to pass for a specific key value pair.
-func AllowInfoWith(key interface{}, value interface{}) Option {
- return func(l *filter) { l.allowedKeyvals[keyval{key, value}] = levelError | levelInfo }
-}
-
-// AllowErrorWith allows only error level log events to pass for a specific key value pair.
-func AllowErrorWith(key interface{}, value interface{}) Option {
- return func(l *filter) { l.allowedKeyvals[keyval{key, value}] = levelError }
-}
-
-// AllowNoneWith allows no leveled log events to pass for a specific key value pair.
-func AllowNoneWith(key interface{}, value interface{}) Option {
- return func(l *filter) { l.allowedKeyvals[keyval{key, value}] = 0 }
-}
OSDN Git Service
