snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/platform/services/cache/lru_striped_test.go

@@ -0,0 +1,136 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package cache
+
+import (
+	"fmt"
+	"hash/maphash"
+	"testing"
+
+	"github.com/cespare/xxhash/v2"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost/server/public/model"
+)
+
+func makeLRUPredictableTestData(num int) [][2]string {
+	kv := make([][2]string, num)
+	for i := range kv {
+		kv[i] = [2]string{
+			fmt.Sprintf("%d-key-%d", i, i),
+			fmt.Sprintf("%d-val-%d", i, i),
+		}
+	}
+	return kv
+}
+
+func TestNewLRUStriped(t *testing.T) {
+	scache, err := NewLRUStriped(&CacheOptions{StripedBuckets: 3, Size: 20})
+	require.NoError(t, err)
+
+	cache := scache.(LRUStriped)
+
+	require.Len(t, cache.buckets, 3)
+	assert.Equal(t, 8, cache.buckets[0].size)
+	assert.Equal(t, 8, cache.buckets[1].size)
+	assert.Equal(t, 8, cache.buckets[2].size)
+}
+
+func TestLRUStripedKeyDistribution(t *testing.T) {
+	dataset := makeLRUPredictableTestData(100)
+
+	scache, err := NewLRUStriped(&CacheOptions{
+		StripedBuckets: 4,
+		Size:           len(dataset),
+		DefaultExpiry:  0,
+	})
+	require.NoError(t, err)
+	cache := scache.(LRUStriped)
+	for _, kv := range dataset {
+		require.NoError(t, cache.SetWithDefaultExpiry(kv[0], kv[1]))
+		var out string
+		require.NoError(t, cache.Get(kv[0], &out))
+		require.Equal(t, kv[1], out)
+	}
+
+	require.Len(t, cache.buckets, 4)
+	acc := 0
+	for i := range 4 {
+		clen, err := cache.buckets[i].Len()
+		acc += clen
+		assert.NoError(t, err)
+		assert.GreaterOrEqual(t, clen, len(dataset)/2/4, "at least 50%/nbuckets of all keys in each bucket")
+	}
+	// because of the limited size of each bucket and the nature of our data,
+	// we may have around 10% of our keys evicted in this scenario. removing 1% because we cannot predict
+	// accurately what is happening with random data.
+	assert.GreaterOrEqual(t, acc, len(dataset)-(len(dataset)*1.0/100.0))
+}
+
+func TestLRUStriped_Size(t *testing.T) {
+	scache, err := NewLRUStriped(&CacheOptions{StripedBuckets: 2, Size: 128})
+	require.NoError(t, err)
+	cache := scache.(LRUStriped)
+	acc := 0
+	for _, bucket := range cache.buckets {
+		acc += bucket.size
+	}
+	assert.Equal(t, 128+13+1, acc) // +10% +modulo padding
+}
+
+func TestLRUStriped_HashKey(t *testing.T) {
+	scache, err := NewLRUStriped(&CacheOptions{StripedBuckets: 2, Size: 128})
+	require.NoError(t, err)
+	cache := scache.(LRUStriped)
+	first := cache.hashkeyMapHash("key")
+	cache.hashkeyMapHash("other_key_to_ensure_that_result_it’s_not_dependent_on_previous_input")
+	second := cache.hashkeyMapHash("key")
+	require.Equal(t, first, second)
+}
+
+func TestLRUStriped_Get(t *testing.T) {
+	cache, err := NewLRUStriped(&CacheOptions{
+		StripedBuckets: 4,
+		Size:           128,
+		DefaultExpiry:  0,
+	})
+	require.NoError(t, err)
+	var out string
+	require.Equal(t, ErrKeyNotFound, cache.Get("key", &out))
+	require.Zero(t, out)
+
+	require.NoError(t, cache.SetWithDefaultExpiry("key", "value"))
+	require.NoError(t, cache.Get("key", &out))
+	require.Equal(t, "value", out)
+}
+
+var hashSink uint64
+
+func BenchmarkSum64(b *testing.B) {
+	cases := []string{
+		"1",
+		"22",
+		"333",
+		model.NewId(),
+		model.NewId() + model.NewId(),
+	}
+
+	for _, case_ := range cases {
+		b.Run(fmt.Sprintf("maphash_string_len_%d", len(case_)), func(b *testing.B) {
+			seed := maphash.MakeSeed()
+			for b.Loop() {
+				var h maphash.Hash
+				h.SetSeed(seed)
+				h.WriteString(case_) // documentation and code says it never fails
+				hashSink = h.Sum64()
+			}
+		})
+		b.Run(fmt.Sprintf("xxhash_string_len_%d", len(case_)), func(b *testing.B) {
+			for b.Loop() {
+				hashSink = xxhash.Sum64String(case_)
+			}
+		})
+	}
+}