formatter.go (2353B)
1 package logrus 2 3 import "time" 4 5 // Default key names for the default fields 6 const ( 7 defaultTimestampFormat = time.RFC3339 8 FieldKeyMsg = "msg" 9 FieldKeyLevel = "level" 10 FieldKeyTime = "time" 11 FieldKeyLogrusError = "logrus_error" 12 FieldKeyFunc = "func" 13 FieldKeyFile = "file" 14 ) 15 16 // The Formatter interface is used to implement a custom Formatter. It takes an 17 // `Entry`. It exposes all the fields, including the default ones: 18 // 19 // * `entry.Data["msg"]`. The message passed from Info, Warn, Error .. 20 // * `entry.Data["time"]`. The timestamp. 21 // * `entry.Data["level"]. The level the entry was logged at. 22 // 23 // Any additional fields added with `WithField` or `WithFields` are also in 24 // `entry.Data`. Format is expected to return an array of bytes which are then 25 // logged to `logger.Out`. 26 type Formatter interface { 27 Format(*Entry) ([]byte, error) 28 } 29 30 // This is to not silently overwrite `time`, `msg`, `func` and `level` fields when 31 // dumping it. If this code wasn't there doing: 32 // 33 // logrus.WithField("level", 1).Info("hello") 34 // 35 // Would just silently drop the user provided level. Instead with this code 36 // it'll logged as: 37 // 38 // {"level": "info", "fields.level": 1, "msg": "hello", "time": "..."} 39 // 40 // It's not exported because it's still using Data in an opinionated way. It's to 41 // avoid code duplication between the two default formatters. 42 func prefixFieldClashes(data Fields, fieldMap FieldMap, reportCaller bool) { 43 timeKey := fieldMap.resolve(FieldKeyTime) 44 if t, ok := data[timeKey]; ok { 45 data["fields."+timeKey] = t 46 delete(data, timeKey) 47 } 48 49 msgKey := fieldMap.resolve(FieldKeyMsg) 50 if m, ok := data[msgKey]; ok { 51 data["fields."+msgKey] = m 52 delete(data, msgKey) 53 } 54 55 levelKey := fieldMap.resolve(FieldKeyLevel) 56 if l, ok := data[levelKey]; ok { 57 data["fields."+levelKey] = l 58 delete(data, levelKey) 59 } 60 61 logrusErrKey := fieldMap.resolve(FieldKeyLogrusError) 62 if l, ok := data[logrusErrKey]; ok { 63 data["fields."+logrusErrKey] = l 64 delete(data, logrusErrKey) 65 } 66 67 // If reportCaller is not set, 'func' will not conflict. 68 if reportCaller { 69 funcKey := fieldMap.resolve(FieldKeyFunc) 70 if l, ok := data[funcKey]; ok { 71 data["fields."+funcKey] = l 72 } 73 fileKey := fieldMap.resolve(FieldKeyFile) 74 if l, ok := data[fileKey]; ok { 75 data["fields."+fileKey] = l 76 } 77 } 78 }