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Merge pull request #37887 from bruceauyeung/k8s-branch-use-bytes-buffer-instead-of-append-for-error-string-concat

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Automatic merge from submit-queue

use bytes.Buffer instead of append for error string concat

**What this PR does / why we need it**:
1. in my benchmark test, `bytes.Buffer` takes much less time ( about 1:1000 ) than string append( `+=` ). 
>BenchmarkAppendConcat-4           100000            151438 ns/op          578181 B/op          2 allocs/op
BenchmarkBufferSprintf-4         3000000               487 ns/op              65 B/op          3 allocs/op
BenchmarkBufferConcat-4          5000000               271 ns/op              47 B/op          1 allocs/op

the benchmark codes is here  https://play.golang.org/p/LS52zGuwZN

2. in our `RunInitMasterChecks`, `RunJoinNodeChecks` there are lots of preflight checks. they may result in a huge error message. so `bytes.Buffer` can bring considerable performance enhancement in the worst of conditions.

beyond that, this PR 
1. fix an exported struct comment,
1. and use `found = append( found, errs...)` instead of for loop for simplicity.


Signed-off-by: bruceauyeung <ouyang.qinhua@zte.com.cn>
This commit is contained in:
Kubernetes Submit Queue 2016-12-23 03:56:32 -08:00 committed by GitHub
commit 9d38145cfb
1 changed files with 6 additions and 8 deletions
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14
cmd/kubeadm/app/preflight/checks.go
View File

@ -18,7 +18,7 @@ package preflight
import ( import (
"bufio" "bufio"
"errors" "bytes"
"fmt" "fmt"
"io" "io"
"net" "net"
@ -182,7 +182,7 @@ func (fac FileAvailableCheck) Check() (warnings, errors []error) {
return nil, errors return nil, errors
} }
// InPathChecks checks if the given executable is present in the path. // InPathCheck checks if the given executable is present in the path.
type InPathCheck struct { type InPathCheck struct {
executable string executable string
mandatory bool mandatory bool
@ -356,16 +356,14 @@ func RunChecks(checks []PreFlightCheck, ww io.Writer) error {
for _, w := range warnings { for _, w := range warnings {
io.WriteString(ww, fmt.Sprintf("[preflight] WARNING: %s\n", w)) io.WriteString(ww, fmt.Sprintf("[preflight] WARNING: %s\n", w))
} }
for _, e := range errs { found = append(found, errs...)
found = append(found, e)
}
} }
if len(found) > 0 { if len(found) > 0 {
errs := "" var errs bytes.Buffer
for _, i := range found { for _, i := range found {
errs += "\t" + i.Error() + "\n" errs.WriteString("\t" + i.Error() + "\n")
} }
return &PreFlightError{Msg: errors.New(errs).Error()} return &PreFlightError{Msg: errs.String()}
} }
return nil return nil
} }