RepoMirrors
/
prometheus
mirror of https://github.com/prometheus/prometheus
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

labels: shrink stack arrays in Builder.Range 

Go spends some time initializing all the elements of these arrays to
zero, so reduce the size from 1024 to 128. This is still much bigger
than we ever expect for a set of labels.

(If someone does have more than 128 labels it will still work, but via
heap allocation.)

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This commit is contained in:
Bryan Boreham 2023-03-22 17:11:24 +00:00
parent 5d90dc0627
commit ee1157c14a
2 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
model/labels/labels.go
View File

@ -547,8 +547,8 @@ func (b *Builder) Get(n string) string {
// Range calls f on each label in the Builder.
func (b *Builder) Range(f func(l Label)) {
// Stack-based arrays to avoid heap allocation in most cases.
var addStack [1024]Label
var delStack [1024]string
var addStack [128]Label
var delStack [128]string
// Take a copy of add and del, so they are unaffected by calls to Set() or Del().
origAdd, origDel := append(addStack[:0], b.add...), append(delStack[:0], b.del...)
b.base.Range(func(l Label) {

4
model/labels/labels_string.go
View File

@ -601,8 +601,8 @@ func (b *Builder) Get(n string) string {
// Range calls f on each label in the Builder.
func (b *Builder) Range(f func(l Label)) {
// Stack-based arrays to avoid heap allocation in most cases.
var addStack [1024]Label
var delStack [1024]string
var addStack [128]Label
var delStack [128]string
// Take a copy of add and del, so they are unaffected by calls to Set() or Del().
origAdd, origDel := append(addStack[:0], b.add...), append(delStack[:0], b.del...)
b.base.Range(func(l Label) {