Files
Carles GarciaandGitHub 840fa673c1 metrics-generator: add metrics to estimate cardinality (#5710)
Add tempo_metrics_generator_registry_active_series_demand_estimate that estimates the active series demand.

This is especially useful when the active series reaches the max limit.
It uses HyperLogLog to estimate the cardinality with only 5KB per tenant, without having to store rejected series in memory.
2025-10-10 08:49:20 +02:00

1.6 KiB

Fast hashmap with integer keys for Golang

GoDoc Go Report Card

intmap

import "github.com/kamstrup/intmap"

Package intmap is a fast hashmap implementation for Golang, specialized for maps with integer type keys. The values can be of any type.

It is a full port of https://github.com/brentp/intintmap to use type parameters (aka generics).

It interleaves keys and values in the same underlying array to improve locality. This is also known as open addressing with linear probing.

It is up to 3X faster than the builtin map:

name                             time/op
Map64Fill-8                       201ms ± 5%
IntIntMapFill-8                   207ms ±31%
StdMapFill-8                      371ms ±11%
Map64Get10PercentHitRate-8        148µs ±40%
IntIntMapGet10PercentHitRate-8    171µs ±50%
StdMapGet10PercentHitRate-8       171µs ±33%
Map64Get100PercentHitRate-8      4.50ms ± 5%
IntIntMapGet100PercentHitRate-8  4.82ms ± 6%
StdMapGet100PercentHitRate-8     15.5ms ±32%

Usage

m := intmap.New[int64,int64](32768)
m.Put(int64(1234), int64(-222))
m.Put(int64(123), int64(33))

v, ok := m.Get(int64(222))
v, ok := m.Get(int64(333))

m.Del(int64(222))
m.Del(int64(333))

fmt.Println(m.Len())

m.ForEach(func(k int64, v int64) {
    fmt.Printf("key: %d, value: %d\n", k, v)
})

m.Clear() // all gone, but buffers kept