miracle091/dnscrypt-proxy
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dnscrypt-proxy
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Code Issues Releases Wiki Activity

Refactor cache reading to reduce number of return values

This commit is contained in:
William Elwood 2019-10-30 23:40:06 +00:00 committed by Frank Denis
parent fe34d07b68
commit 4a792026eb
2 changed files with 20 additions and 27 deletions
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43
dnscrypt-proxy/sources.go
View File

@ -47,27 +47,23 @@ func (source *Source) checkSignature(bin, sig []byte) (err error) {
// timeNow can be replaced by tests to provide a static value
var timeNow = time.Now
func fetchFromCache(cacheFile string, refreshDelay time.Duration) (bin []byte, expired bool, delayTillNextUpdate time.Duration, err error) {
expired = false
func fetchFromCache(cacheFile string, refreshDelay time.Duration) (bin []byte, delayTillNextUpdate time.Duration, err error) {
delayTillNextUpdate = time.Duration(0)
if refreshDelay < MinSourcesUpdateDelay {
refreshDelay = MinSourcesUpdateDelay
}
fi, err := os.Stat(cacheFile)
if err != nil {
dlog.Debugf("Cache file [%s] not present", cacheFile)
var fi os.FileInfo
if fi, err = os.Stat(cacheFile); err != nil {
return
}
if bin, err = ioutil.ReadFile(cacheFile); err != nil {
return
}
elapsed := timeNow().Sub(fi.ModTime())
if elapsed < refreshDelay {
if elapsed := timeNow().Sub(fi.ModTime()); elapsed < refreshDelay {
dlog.Debugf("Cache file [%s] is still fresh", cacheFile)
delayTillNextUpdate = MinSourcesUpdateDelay - elapsed
} else {
dlog.Debugf("Cache file [%s] needs to be refreshed", cacheFile)
expired = true
}
return
}
@ -82,16 +78,15 @@ func fetchFromURL(xTransport *XTransport, u *url.URL) (bin []byte, err error) {
}
func fetchWithCache(xTransport *XTransport, urlStr string, cacheFile string, refreshDelay time.Duration) (bin []byte, delayTillNextUpdate time.Duration, err error) {
expired := false
bin, expired, delayTillNextUpdate, err = fetchFromCache(cacheFile, refreshDelay)
if err == nil && !expired {
dlog.Debugf("Delay till next update: %v", delayTillNextUpdate)
return
}
if len(urlStr) == 0 {
if !expired {
err = fmt.Errorf("Cache file [%s] not present and no URL given to retrieve it", cacheFile)
if bin, delayTillNextUpdate, err = fetchFromCache(cacheFile, refreshDelay); err != nil {
if len(urlStr) == 0 {
dlog.Errorf("Cache file [%s] not present and no URL given to retrieve it", cacheFile)
return
}
dlog.Debugf("Cache file [%s] not present", cacheFile)
}
if err == nil && delayTillNextUpdate > 0 {
dlog.Debugf("Delay till next update: %v", delayTillNextUpdate)
return
}
@ -123,14 +118,14 @@ type URLToPrefetch struct {
when time.Time
}
func NewSource(xTransport *XTransport, urls []string, minisignKeyStr string, cacheFile string, formatStr string, refreshDelay time.Duration) (Source, []URLToPrefetch, error) {
source := Source{urls: urls}
func NewSource(xTransport *XTransport, urls []string, minisignKeyStr string, cacheFile string, formatStr string, refreshDelay time.Duration) (source Source, urlsToPrefetch []URLToPrefetch, err error) {
source = Source{urls: urls}
urlsToPrefetch = []URLToPrefetch{}
if formatStr == "v2" {
source.format = SourceFormatV2
} else {
return source, []URLToPrefetch{}, fmt.Errorf("Unsupported source format: [%s]", formatStr)
}
urlsToPrefetch := []URLToPrefetch{}
if minisignKey, err := minisign.NewPublicKey(minisignKeyStr); err == nil {
source.minisignKey = &minisignKey
} else {
@ -141,7 +136,7 @@ func NewSource(xTransport *XTransport, urls []string, minisignKeyStr string, cac
var bin, sig []byte
var delayTillNextUpdate, sigDelayTillNextUpdate time.Duration
var err, sigErr error
var sigErr error
var preloadURL string
if len(urls) <= 0 {
bin, delayTillNextUpdate, err = fetchWithCache(xTransport, "", cacheFile, refreshDelay)
@ -169,15 +164,15 @@ func NewSource(xTransport *XTransport, urls []string, minisignKeyStr string, cac
err = sigErr
}
if err != nil {
return source, urlsToPrefetch, err
return
}
if err = source.checkSignature(bin, sig); err != nil {
return source, urlsToPrefetch, err
return
}
dlog.Noticef("Source [%s] loaded", cacheFile)
source.in = bin
return source, urlsToPrefetch, nil
return
}
func (source *Source) Parse(prefix string) ([]RegisteredServer, error) {

4
dnscrypt-proxy/sources_test.go
View File

@ -255,7 +255,7 @@ func prepSourceTestCache(t *testing.T, d *SourceTestData, e *SourceTestExpect, s
case TestStatePartial, TestStatePartialSig:
e.err = "signature"
case TestStateMissing, TestStateMissingSig:
e.err = "not present"
e.err = "stat"
case TestStateOpenErr, TestStateOpenSigErr:
e.err = os.ErrPermission.Error()
}
@ -302,8 +302,6 @@ func prepSourceTestDownload(t *testing.T, d *SourceTestData, e *SourceTestExpect
if e.success {
e.err = ""
}
} else if !e.success {
e.err = "no URL"
}
}