imcache

imcache is a zero-dependency generic in-memory cache Go library.

It supports absolute expiration, sliding expiration, max entries limit, eviction callbacks and sharding. It's safe for concurrent use by multiple goroutines.

import "github.com/erni27/imcache"

Usage

package main

import (
	"fmt"

	"github.com/erni27/imcache"
)

func main() {
	// Zero value Cache is a valid non-sharded cache
	// with no expiration, no sliding expiration,
	// no entry limit and no eviction callback.
	var c imcache.Cache[uint32, string]
	c.Set(1, "one", imcache.WithNoExpiration())
	value, ok := c.Get(1)
	if !ok {
		panic("value for the key '1' not found")
	}
	fmt.Println(value)
}

Expiration

imcache supports the following expiration options:

• WithNoExpiration - the entry will never expire.
• WithExpiration - the entry will expire after a certain time.
• WithExpirationDate - the entry will expire at a certain date.
• WithSlidingExpiration - the entry will expire after a certain time if it hasn't been accessed. The expiration time is reset every time the entry is accessed. It is slided to now + sliding expiration time when now is the time when the entry was accessed.

// The entry will never expire.
c.Set(1, "one", imcache.WithNoExpiration())
// The entry will expire after 1 second.
c.Set(2, "two", imcache.WithExpiration(time.Second))
// The entry will expire at the given date.
c.Set(3, "three", imcache.WithExpirationDate(time.Now().Add(time.Second)))
// The entry will expire after 1 second if it hasn't been accessed.
// Otherwise, the expiration time will slide to the access time + 1 second.
c.Set(4, "four", imcache.WithSlidingExpiration(time.Second))

One can also use the WithExpirationOption and WithSlidingExpirationOption options to set the default expiration time for the given cache instance. By default, the default expiration time is set to no expiration.

// Create a new cache instance with the default expiration time equal to 1 second.
c1 := imcache.New[int32, string](imcache.WithDefaultExpirationOption[int32, string](time.Second))
// The entry will expire after 1 second (the default expiration time).
c1.Set(1, "one", imcache.WithDefaultExpiration())

// Create a new cache instance with the default sliding expiration time equal to 1 second.
c2 := imcache.New[int32, string](imcache.WithDefaultSlidingExpirationOption[int32, string](time.Second))
// The entry will expire after 1 second (the default expiration time) if it hasn't been accessed.
// Otherwise, the expiration time will slide to the access time + 1 second.
c2.Set(1, "one", imcache.WithDefaultExpiration())

Key eviction

imcache actively evicts expired entries. It removes expired entries when they are accessed by most of Cache methods (both read and write). Peek, PeekMultiple and PeekAll methods are the exception. They don't remove the expired entries and do not slide the expiration time (if the sliding expiration is set).

It is possible to use the Cleaner to periodically remove expired entries from the cache. The Cleaner is a background goroutine that periodically removes expired entries from the cache. The Cleaner is disabled by default. One can use the WithCleanerOption option to enable the Cleaner and set the cleaning interval.

// Create a new Cache with a Cleaner which will remove expired entries every 5 minutes.
c := imcache.New[string, string](imcache.WithCleanerOption[string, string](5 * time.Minute))
// Close the Cache. This will stop the Cleaner if it is running.
defer c.Close()

To be notified when the entry is evicted from the cache, one can use the EvictionCallback. It's a function that accepts the key and the value of the evicted entry along with the reason why the entry was evicted. One can use the WithEvictionCallbackOption option to set the EvictionCallback for the given cache instance.

package main

import (
	"log"
	"time"

	"github.com/erni27/imcache"
)

func LogEvictedEntry(key string, value interface{}, reason imcache.EvictionReason) {
	log.Printf("Evicted entry: %s=%v (%s)", key, value, reason)
}

func main() {
	c := imcache.New[string, interface{}](
		imcache.WithDefaultExpirationOption[string, interface{}](time.Second),
		imcache.WithEvictionCallbackOption[string, interface{}](LogEvictedEntry),
	)
	c.Set("foo", "bar", imcache.WithDefaultExpiration())

	time.Sleep(time.Second)

	_, ok := c.Get("foo")
	if ok {
		panic("expected entry to be expired")
	}
}

EvictionCallback is invoked in a separate goroutine to not block any Cache method.

Max entries limit

imcache supports setting the max entries limit. When the max entries limit is reached, the entry is evicted according to the chosen eviction policy. imcache supports the following eviction policies:

• EvictionPolicyLRU - the least recently used entry is evicted.
• EvictionPolicyLFU - the least frequently used entry is evicted.
• EvictionPolicyRandom - a random entry is evicted.

One can use the WithMaxEntriesLimitOption option to set the max entries limit and the eviction policy for the given cache instance.

c := imcache.New[uint32, string](imcache.WithMaxEntriesLimitOption[uint32, string](1000, imcache.EvictionPolicyLRU))

Sharding

imcache supports sharding. Each shard is a separate Cache instance. A shard for a given key is selected by computing the hash of the key and taking the modulus of the number of shards. imcache exposes the Hasher64 interface that wraps Sum64 accepting a key and returning a 64-bit hash of the input key. It can be used to implement custom sharding algorithms.

A Sharded instance can be created by calling the NewSharded method.

c := imcache.NewSharded[string, string](4, imcache.DefaultStringHasher64{})

All previous examples apply to Sharded type as well. Note that Option(s) are applied to each shard (Cache instance separately) not to the Sharded instance itself.

Performance

imcache was compared to the vanilla Go map with simple locking mechanism. The benchmarks were run on an Apple M1 Pro 8-core CPU with 32 GB of RAM running macOS Ventura 13.4.1 using Go 1.21.6.

Reads

go version
go version go1.21.6 darwin/arm64
go test -benchmem -bench "Get_|Get$|Peek_|Peek$"
goos: darwin
goarch: arm64
pkg: github.com/erni27/imcache
BenchmarkCache_Get-8                                                                 2655246	       428.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/2_Shards-8                                                      2810713	       436.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/4_Shards-8                                                      2732820	       444.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/8_Shards-8                                                      2957444	       445.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/16_Shards-8                                                     2773999	       447.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/32_Shards-8                                                     2752075	       443.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/64_Shards-8                                                     2752899	       439.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get/128_Shards-8                                                    2771691	       456.3 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyLRU-8                               2410712	       526.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/2_Shards-8                    2346715	       543.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/4_Shards-8                    2317453	       566.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/8_Shards-8                    2293774	       556.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/16_Shards-8                   2292554	       557.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/32_Shards-8                   2262634	       542.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/64_Shards-8                   2318079	       544.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU/128_Shards-8                  2278434	       565.6 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyLFU-8                               2482602	       528.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/2_Shards-8                    2403782	       534.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/4_Shards-8                    2286364	       548.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/8_Shards-8                    2239857	       576.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/16_Shards-8                   2198414	       556.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/32_Shards-8                   2109063	       554.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/64_Shards-8                   2251125	       550.6 ns/op	      23 B/op	       2 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU/128_Shards-8                  2172662	       551.0 ns/op	      23 B/op	       2 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyRandom-8                            2959924	       433.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/2_Shards-8                 2909020	       429.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/4_Shards-8                 2890734	       438.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/8_Shards-8                 2947471	       432.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/16_Shards-8                2937757	       456.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/32_Shards-8                2963146	       427.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/64_Shards-8                2794441	       430.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom/128_Shards-8               2965760	       466.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Peek-8                                                                3034557	       419.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/2_Shards-8                                                     2907327	       452.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/4_Shards-8                                                     2918097	       441.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/8_Shards-8                                                     2923375	       442.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/16_Shards-8                                                    2927227	       443.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/32_Shards-8                                                    2843028	       439.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/64_Shards-8                                                    2898458	       461.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek/128_Shards-8                                                   2805452	       460.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkMap_Get-8                                                                   4693522	       327.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Get_Parallel-8                                                        2272208	       546.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/2_Shards-8                                             3216616	       416.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/4_Shards-8                                             3898989	       327.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/8_Shards-8                                             5443684	       241.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/16_Shards-8                                            6995467	       186.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/32_Shards-8                                            8505585	       154.6 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/64_Shards-8                                            10256752	       170.9 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_Parallel/128_Shards-8                                           12003910	       113.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel-8                      1995304	       627.3 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/2_Shards-8           2628376	       474.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/4_Shards-8           3056476	       407.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/8_Shards-8           4281996	       304.3 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/16_Shards-8          5438091	       237.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/32_Shards-8          6442630	       209.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/64_Shards-8          8096386	       177.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLRU_Parallel/128_Shards-8         9417211	       137.3 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel-8                      1463374	       796.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/2_Shards-8           2112945	       591.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/4_Shards-8           3008568	       412.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/8_Shards-8           4302746	       296.3 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/16_Shards-8          5671981	       231.8 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/32_Shards-8          6828380	       186.5 ns/op	      23 B/op	       2 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/64_Shards-8          7074661	       161.5 ns/op	      23 B/op	       2 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyLFU_Parallel/128_Shards-8         9294237	       139.2 ns/op	      23 B/op	       2 allocs/op
BenchmarkCache_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel-8                   1838180	       675.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/2_Shards-8        2781007	       455.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/4_Shards-8        4072056	       341.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/8_Shards-8        5529966	       227.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/16_Shards-8       7354364	       211.7 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/32_Shards-8       8624466	       138.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/64_Shards-8       11442829	       161.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Get_MaxEntriesLimit_EvictionPolicyRandom_Parallel/128_Shards-8      12071902	       104.4 ns/op	      23 B/op	       1 allocs/op
BenchmarkCache_Peek_Parallel-8                                                       7957777	       155.1 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/2_Shards-8                                            7781154	       163.5 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/4_Shards-8                                           12301404	       112.0 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/8_Shards-8                                           12828216	       106.2 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/16_Shards-8                                          13837890	       94.11 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/32_Shards-8                                          14921073	       89.67 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/64_Shards-8                                          15708536	       87.81 ns/op	      23 B/op	       1 allocs/op
BenchmarkSharded_Peek_Parallel/128_Shards-8                                         16547871	       84.76 ns/op	      23 B/op	       1 allocs/op
BenchmarkMap_Get_Parallel-8                                                          3098846	       453.0 ns/op	      23 B/op	       1 allocs/op
PASS
ok  	github.com/erni27/imcache	366.377s

Writes

go version
go version go1.21.6 darwin/arm64
go test -benchmem -bench "_Set"
goos: darwin
goarch: arm64
pkg: github.com/erni27/imcache
BenchmarkCache_Set-8                                                                 2942062	       461.7 ns/op	     161 B/op	       2 allocs/op
BenchmarkSharded_Set/2_Shards-8                                                      2939275	       487.5 ns/op	     162 B/op	       2 allocs/op
BenchmarkSharded_Set/4_Shards-8                                                      2827146	       497.1 ns/op	     166 B/op	       2 allocs/op
BenchmarkSharded_Set/8_Shards-8                                                      2837316	       509.1 ns/op	     165 B/op	       2 allocs/op
BenchmarkSharded_Set/16_Shards-8                                                     2818513	       495.7 ns/op	     166 B/op	       2 allocs/op
BenchmarkSharded_Set/32_Shards-8                                                     2793490	       506.3 ns/op	     167 B/op	       2 allocs/op
BenchmarkSharded_Set/64_Shards-8                                                     2815544	       499.7 ns/op	     166 B/op	       2 allocs/op
BenchmarkSharded_Set/128_Shards-8                                                    2738779	       511.2 ns/op	     170 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyLRU-8                               3217950	       423.2 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/2_Shards-8                    2893335	       458.4 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/4_Shards-8                    2940762	       460.9 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/8_Shards-8                    2976267	       462.5 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/16_Shards-8                   2849967	       478.1 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/32_Shards-8                   2859116	       472.2 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/64_Shards-8                   2842370	       466.6 ns/op	      68 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU/128_Shards-8                  2863222	       481.6 ns/op	      68 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyLFU-8                               3198320	       417.6 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/2_Shards-8                    2944507	       450.2 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/4_Shards-8                    2915707	       456.9 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/8_Shards-8                    2820458	       464.4 ns/op	      68 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/16_Shards-8                   2833208	       479.6 ns/op	      68 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/32_Shards-8                   2864629	       460.9 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/64_Shards-8                   2846596	       491.7 ns/op	      68 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU/128_Shards-8                  2841228	       493.6 ns/op	      68 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyRandom-8                            2988330	       459.8 ns/op	      59 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/2_Shards-8                 2713388	       495.6 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/4_Shards-8                 2756364	       493.7 ns/op	      58 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/8_Shards-8                 2691565	       484.5 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/16_Shards-8                2710840	       479.6 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/32_Shards-8                2728695	       496.0 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/64_Shards-8                2690887	       507.6 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom/128_Shards-8               2663871	       495.1 ns/op	      57 B/op	       2 allocs/op
BenchmarkMap_Set-8                                                                   5847526	       339.0 ns/op	     106 B/op	       2 allocs/op
BenchmarkCache_Set_Parallel-8                                                        2347249	       527.7 ns/op	     123 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/2_Shards-8                                             3112208	       444.3 ns/op	     156 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/4_Shards-8                                             3323001	       401.2 ns/op	     149 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/8_Shards-8                                             4130948	       291.3 ns/op	     131 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/16_Shards-8                                            5516203	       274.4 ns/op	     169 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/32_Shards-8                                            6069385	       219.0 ns/op	     158 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/64_Shards-8                                            7290878	       187.9 ns/op	     141 B/op	       2 allocs/op
BenchmarkSharded_Set_Parallel/128_Shards-8                                           8021259	       163.6 ns/op	     133 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel-8                      2402929	       555.8 ns/op	      66 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/2_Shards-8           2835458	       418.2 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/4_Shards-8           3219746	       393.8 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/8_Shards-8           4225972	       301.9 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/16_Shards-8          5186444	       246.7 ns/op	      67 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/32_Shards-8          6100933	       222.6 ns/op	      70 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/64_Shards-8          7518198	       180.7 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLRU_Parallel/128_Shards-8         8257630	       180.1 ns/op	      65 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel-8                      2344273	       543.1 ns/op	      66 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/2_Shards-8           2973801	       442.6 ns/op	      69 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/4_Shards-8           3416180	       383.2 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/8_Shards-8           4511509	       293.7 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/16_Shards-8          5374215	       230.7 ns/op	      68 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/32_Shards-8          6602998	       205.1 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/64_Shards-8          7730086	       171.8 ns/op	      65 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyLFU_Parallel/128_Shards-8         8232051	       154.6 ns/op	      65 B/op	       2 allocs/op
BenchmarkCache_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel-8                   2186001	       592.0 ns/op	      55 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/2_Shards-8        2716564	       438.3 ns/op	      57 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/4_Shards-8        3548733	       366.0 ns/op	      55 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/8_Shards-8        4665452	       296.7 ns/op	      55 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/16_Shards-8       6088111	       240.0 ns/op	      59 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/32_Shards-8       7442355	       197.1 ns/op	      55 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/64_Shards-8       8089219	       163.0 ns/op	      55 B/op	       2 allocs/op
BenchmarkSharded_Set_MaxEntriesLimit_EvictionPolicyRandom_Parallel/128_Shards-8      9815180	       144.8 ns/op	      56 B/op	       2 allocs/op
BenchmarkMap_Set_Parallel-8                                                          3541270	       407.3 ns/op	      92 B/op	       2 allocs/op
PASS
ok  	github.com/erni27/imcache	135.166s