path: root/errs/errors.go

package errs

import (
    "fmt"

    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
)

/*
Errors implements an error handler providing standardised errors for a package.
Fields:

 Errors:
  a map from error codes to description

 Package:
  name of the package/component

 Level:
  a function mapping error code to logger.LogLevel (severity)
  if not given, errors default to logger.InfoLevel
*/
type Errors struct {
    Errors  map[int]string
    Package string
    Level   func(code int) logger.LogLevel
}

/*
Error implements the standard go error interface.

  errors.New(code, format, params ...interface{})

Prints as:

 [package] description: details

where details is fmt.Sprintf(self.format, self.params...)
*/
type Error struct {
    Code    int
    Name    string
    Package string
    level   logger.LogLevel
    message string
    format  string
    params  []interface{}
}

func (self *Errors) New(code int, format string, params ...interface{}) *Error {
    name, ok := self.Errors[code]
    if !ok {
        panic("invalid error code")
    }
    level := logger.InfoLevel
    if self.Level != nil {
        level = self.Level(code)
    }
    return &Error{
        Code:    code,
        Name:    name,
        Package: self.Package,
        level:   level,
        format:  format,
        params:  params,
    }
}

func (self Error) Error() (message string) {
    if len(message) == 0 {
        self.message = fmt.Sprintf("[%s] ERROR: %s", self.Package, self.Name)
        if self.format != "" {
            self.message += ": " + fmt.Sprintf(self.format, self.params...)
        }
    }
    return self.message
}

func (self Error) Log(v glog.Verbose) {
    if v {
        v.Infoln(self)
    }
}

/*
err.Fatal() is true if err's severity level is 0 or 1 (logger.ErrorLevel or logger.Silence)
*/
func (self *Error) Fatal() (fatal bool) {
    if self.level < logger.WarnLevel {
        fatal = true
    }
    return
}