Merge pull request #339 from grafana/20221020_reproduce-profile-panics

Reproduce panicing python profile

Author: simonswine

pkg/phlaredb/head_test.go

@@ -333,18 +333,23 @@ func TestHeadIngestRealProfiles(t *testing.T) {
 	profilePaths := []string{
 		"testdata/heap",
 		"testdata/profile",
+		"testdata/profile_uncompressed",
+		"testdata/profile_python",
 	}
 
 	head := newTestHead(t)
 	ctx := context.Background()
 
 	for pos := range profilePaths {
-		profile := parseProfile(t, profilePaths[pos])
-		require.NoError(t, head.Ingest(ctx, profile, uuid.New()))
+		path := profilePaths[pos]
+		t.Run(path, func(t *testing.T) {
+			profile := parseProfile(t, profilePaths[pos])
+			require.NoError(t, head.Ingest(ctx, profile, uuid.New()))
+		})
 	}
 
 	require.NoError(t, head.Flush(ctx))
-	t.Logf("strings=%d samples=%d", len(head.strings.slice), len(head.profiles.slice[0].Samples))
+	t.Logf("strings=%d samples=%d", len(head.strings.slice), head.totalSamples.Load())
 }
 
 func BenchmarkHeadIngestProfiles(t *testing.B) {

pkg/phlaredb/locations.go

@@ -53,7 +53,10 @@ func (*locationsHelper) addToRewriter(r *rewriter, elemRewriter idConversionTabl
 }
 
 func (*locationsHelper) rewrite(r *rewriter, l *profilev1.Location) error {
-	r.mappings.rewriteUint64(&l.MappingId)
+	// when mapping id is not 0, rewrite it
+	if l.MappingId != 0 {
+		r.mappings.rewriteUint64(&l.MappingId)
+	}
 
 	for pos := range l.Line {
 		r.functions.rewriteUint64(&l.Line[pos].FunctionId)