storj/pkg/utils/utils.go

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// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information.
package utils
import (
"bytes"
"encoding/gob"
"net/url"
"strings"
"time"
)
// GetBytes transforms an empty interface type into a byte slice
func GetBytes(key interface{}) ([]byte, error) {
var buf bytes.Buffer
enc := gob.NewEncoder(&buf)
err := enc.Encode(key)
if err != nil {
return nil, err
}
return buf.Bytes(), nil
}
// ParseURL extracts database parameters from a string as a URL
// bolt://storj.db
// bolt://C:\storj.db
// redis://hostname
func ParseURL(s string) (*url.URL, error) {
if strings.HasPrefix(s, "bolt://") {
return &url.URL{
Scheme: "bolt",
Path: strings.TrimPrefix(s, "bolt://"),
}, nil
}
return url.Parse(s)
}
// CombineErrors combines multiple errors to a single error
2018-09-11 14:57:12 +01:00
func CombineErrors(errs ...error) error {
var errlist combinedError
for _, err := range errs {
if err != nil {
errlist = append(errlist, err)
}
}
if len(errlist) == 0 {
return nil
} else if len(errlist) == 1 {
return errlist[0]
}
return errlist
}
type combinedError []error
func (errs combinedError) Cause() error {
if len(errs) > 0 {
return errs[0]
}
return nil
}
func (errs combinedError) Error() string {
if len(errs) > 0 {
limit := 5
if len(errs) < limit {
limit = len(errs)
}
allErrors := errs[0].Error()
for _, err := range errs[1:limit] {
allErrors += "\n" + err.Error()
}
return allErrors
}
return ""
}
// CollectErrors returns first error from channel and all errors that happen within duration
func CollectErrors(errch chan error, duration time.Duration) error {
errch = discardNil(errch)
errs := []error{<-errch}
timeout := time.After(duration)
for {
select {
case err := <-errch:
errs = append(errs, err)
case <-timeout:
return CombineErrors(errs...)
}
}
}
// discard nil errors that are returned from services
func discardNil(ch chan error) chan error {
r := make(chan error)
go func() {
for err := range ch {
if err == nil {
continue
}
r <- err
}
close(r)
}()
return r
}