From bec5abc4dc63831dfbfba50bc3230a6fea6b78e0 Mon Sep 17 00:00:00 2001 From: Bryan Boreham Date: Tue, 20 Dec 2022 16:54:07 +0000 Subject: [PATCH] scrape: remove unsafe code The `yolostring` routine was intended to avoid an allocation when converting from a `[]byte` to a `string` for map lookup. However, since 2014 Go has recognized this pattern and does not make a copy of the data when looking up a map. So the unsafe code is not necessary. In line with this, constants like `scrapeHealthMetricName` also become `[]byte`. Signed-off-by: Bryan Boreham --- scrape/scrape.go | 57 ++++++++++++++++++++----------------------- scrape/scrape_test.go | 10 ++++---- 2 files changed, 31 insertions(+), 36 deletions(-) diff --git a/scrape/scrape.go b/scrape/scrape.go index 10e9119a2..c57e7b406 100644 --- a/scrape/scrape.go +++ b/scrape/scrape.go @@ -27,7 +27,6 @@ import ( "strconv" "sync" "time" - "unsafe" "github.com/go-kit/log" "github.com/go-kit/log/level" @@ -1006,8 +1005,8 @@ func (c *scrapeCache) iterDone(flushCache bool) { } } -func (c *scrapeCache) get(met string) (*cacheEntry, bool) { - e, ok := c.series[met] +func (c *scrapeCache) get(met []byte) (*cacheEntry, bool) { + e, ok := c.series[string(met)] if !ok { return nil, false } @@ -1015,11 +1014,11 @@ func (c *scrapeCache) get(met string) (*cacheEntry, bool) { return e, true } -func (c *scrapeCache) addRef(met string, ref storage.SeriesRef, lset labels.Labels, hash uint64) { +func (c *scrapeCache) addRef(met []byte, ref storage.SeriesRef, lset labels.Labels, hash uint64) { if ref == 0 { return } - c.series[met] = &cacheEntry{ref: ref, lastIter: c.iter, lset: lset, hash: hash} + c.series[string(met)] = &cacheEntry{ref: ref, lastIter: c.iter, lset: lset, hash: hash} } func (c *scrapeCache) addDropped(met string) { @@ -1027,8 +1026,8 @@ func (c *scrapeCache) addDropped(met string) { c.droppedSeries[met] = &iter } -func (c *scrapeCache) getDropped(met string) bool { - iterp, ok := c.droppedSeries[met] +func (c *scrapeCache) getDropped(met []byte) bool { + iterp, ok := c.droppedSeries[string(met)] if ok { *iterp = c.iter } @@ -1052,7 +1051,7 @@ func (c *scrapeCache) forEachStale(f func(labels.Labels) bool) { func (c *scrapeCache) setType(metric []byte, t textparse.MetricType) { c.metaMtx.Lock() - e, ok := c.metadata[yoloString(metric)] + e, ok := c.metadata[string(metric)] if !ok { e = &metaEntry{Metadata: metadata.Metadata{Type: textparse.MetricTypeUnknown}} c.metadata[string(metric)] = e @@ -1069,12 +1068,12 @@ func (c *scrapeCache) setType(metric []byte, t textparse.MetricType) { func (c *scrapeCache) setHelp(metric, help []byte) { c.metaMtx.Lock() - e, ok := c.metadata[yoloString(metric)] + e, ok := c.metadata[string(metric)] if !ok { e = &metaEntry{Metadata: metadata.Metadata{Type: textparse.MetricTypeUnknown}} c.metadata[string(metric)] = e } - if e.Help != yoloString(help) { + if e.Help != string(help) { e.Help = string(help) e.lastIterChange = c.iter } @@ -1086,12 +1085,12 @@ func (c *scrapeCache) setHelp(metric, help []byte) { func (c *scrapeCache) setUnit(metric, unit []byte) { c.metaMtx.Lock() - e, ok := c.metadata[yoloString(metric)] + e, ok := c.metadata[string(metric)] if !ok { e = &metaEntry{Metadata: metadata.Metadata{Type: textparse.MetricTypeUnknown}} c.metadata[string(metric)] = e } - if e.Unit != yoloString(unit) { + if e.Unit != string(unit) { e.Unit = string(unit) e.lastIterChange = c.iter } @@ -1509,7 +1508,7 @@ func (sl *scrapeLoop) append(app storage.Appender, b []byte, contentType string, sl.cache.metaMtx.Lock() defer sl.cache.metaMtx.Unlock() - metaEntry, metaOk := sl.cache.metadata[yoloString([]byte(lset.Get(labels.MetricName)))] + metaEntry, metaOk := sl.cache.metadata[lset.Get(labels.MetricName)] if metaOk && (isNewSeries || metaEntry.lastIterChange == sl.cache.iter) { metadataChanged = true meta.Type = metaEntry.Type @@ -1584,10 +1583,10 @@ loop: meta = metadata.Metadata{} metadataChanged = false - if sl.cache.getDropped(yoloString(met)) { + if sl.cache.getDropped(met) { continue } - ce, ok := sl.cache.get(yoloString(met)) + ce, ok := sl.cache.get(met) var ( ref storage.SeriesRef lset labels.Labels @@ -1654,7 +1653,7 @@ loop: // Bypass staleness logic if there is an explicit timestamp. sl.cache.trackStaleness(hash, lset) } - sl.cache.addRef(mets, ref, lset, hash) + sl.cache.addRef(met, ref, lset, hash) if sampleAdded && sampleLimitErr == nil { seriesAdded++ } @@ -1719,10 +1718,6 @@ loop: return } -func yoloString(b []byte) string { - return *((*string)(unsafe.Pointer(&b))) -} - // Adds samples to the appender, checking the error, and then returns the # of samples added, // whether the caller should continue to process more samples, and any sample limit errors. func (sl *scrapeLoop) checkAddError(ce *cacheEntry, met []byte, tp *int64, err error, sampleLimitErr *error, appErrs *appendErrors) (bool, error) { @@ -1775,15 +1770,15 @@ func (sl *scrapeLoop) checkAddExemplarError(err error, e exemplar.Exemplar, appE // The constants are suffixed with the invalid \xff unicode rune to avoid collisions // with scraped metrics in the cache. -const ( - scrapeHealthMetricName = "up" + "\xff" - scrapeDurationMetricName = "scrape_duration_seconds" + "\xff" - scrapeSamplesMetricName = "scrape_samples_scraped" + "\xff" - samplesPostRelabelMetricName = "scrape_samples_post_metric_relabeling" + "\xff" - scrapeSeriesAddedMetricName = "scrape_series_added" + "\xff" - scrapeTimeoutMetricName = "scrape_timeout_seconds" + "\xff" - scrapeSampleLimitMetricName = "scrape_sample_limit" + "\xff" - scrapeBodySizeBytesMetricName = "scrape_body_size_bytes" + "\xff" +var ( + scrapeHealthMetricName = []byte("up" + "\xff") + scrapeDurationMetricName = []byte("scrape_duration_seconds" + "\xff") + scrapeSamplesMetricName = []byte("scrape_samples_scraped" + "\xff") + samplesPostRelabelMetricName = []byte("scrape_samples_post_metric_relabeling" + "\xff") + scrapeSeriesAddedMetricName = []byte("scrape_series_added" + "\xff") + scrapeTimeoutMetricName = []byte("scrape_timeout_seconds" + "\xff") + scrapeSampleLimitMetricName = []byte("scrape_sample_limit" + "\xff") + scrapeBodySizeBytesMetricName = []byte("scrape_body_size_bytes" + "\xff") ) func (sl *scrapeLoop) report(app storage.Appender, start time.Time, duration time.Duration, scraped, added, seriesAdded, bytes int, scrapeErr error) (err error) { @@ -1859,7 +1854,7 @@ func (sl *scrapeLoop) reportStale(app storage.Appender, start time.Time) (err er return } -func (sl *scrapeLoop) addReportSample(app storage.Appender, s string, t int64, v float64) error { +func (sl *scrapeLoop) addReportSample(app storage.Appender, s []byte, t int64, v float64) error { ce, ok := sl.cache.get(s) var ref storage.SeriesRef var lset labels.Labels @@ -1870,7 +1865,7 @@ func (sl *scrapeLoop) addReportSample(app storage.Appender, s string, t int64, v // The constants are suffixed with the invalid \xff unicode rune to avoid collisions // with scraped metrics in the cache. // We have to drop it when building the actual metric. - lset = labels.FromStrings(labels.MetricName, s[:len(s)-1]) + lset = labels.FromStrings(labels.MetricName, string(s[:len(s)-1])) lset = sl.reportSampleMutator(lset) } diff --git a/scrape/scrape_test.go b/scrape/scrape_test.go index 4fa871a3e..384a30627 100644 --- a/scrape/scrape_test.go +++ b/scrape/scrape_test.go @@ -1586,21 +1586,21 @@ func TestScrapeLoopAppendCacheEntryButErrNotFound(t *testing.T) { fakeRef := storage.SeriesRef(1) expValue := float64(1) - metric := `metric{n="1"} 1` - p, warning := textparse.New([]byte(metric), "") + metric := []byte(`metric{n="1"} 1`) + p, warning := textparse.New(metric, "") require.NoError(t, warning) var lset labels.Labels p.Next() - mets := p.Metric(&lset) + p.Metric(&lset) hash := lset.Hash() // Create a fake entry in the cache - sl.cache.addRef(mets, fakeRef, lset, hash) + sl.cache.addRef(metric, fakeRef, lset, hash) now := time.Now() slApp := sl.appender(context.Background()) - _, _, _, err := sl.append(slApp, []byte(metric), "", now) + _, _, _, err := sl.append(slApp, metric, "", now) require.NoError(t, err) require.NoError(t, slApp.Commit())