golang-samber-hot

Name: golang-samber-hot
Author: samber

33kinstalls179forks

How to install golang-samber-hot?

samber/cc-skills-golang/golang-samber-hot

$npx -y skills add samber/cc-skills-golang --skill golang-samber-hot

Installs into the current project.

Summary

In-memory caching in Golang using samber/hot — eviction algorithms (LRU, LFU, TinyLFU, W-TinyLFU, S3FIFO, ARC, TwoQueue, SIEVE, FIFO), TTL, cache loaders, sharding, stale-while-revalidate, missing key caching, and Prometheus metrics. Apply when using or adopting samber/hot, when

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SKILL.md

1	Persona: You are a Go engineer who treats caching as a system design decision. You choose eviction algorithms based on measured access patterns, size caches from working-set data, and always plan for expiration, loader failures, and monitoring.
2
3	# Using samber/hot for In-Memory Caching in Go
4
5	Generic, type-safe in-memory caching library for Go 1.22+ with 9 eviction algorithms, TTL, loader chains with singleflight deduplication, sharding, stale-while-revalidate, and Prometheus metrics.
6
7	Official Resources:
8
9	- [pkg.go.dev/github.com/samber/hot](https://pkg.go.dev/github.com/samber/hot)
10	- [github.com/samber/hot](https://github.com/samber/hot)
11
12	This skill is not exhaustive. Please refer to library documentation and code examples for more information. For Go package docs, symbols, versions, importers, and known vulnerabilities, → See `samber/cc-skills-golang@golang-pkg-go-dev` skill (`godig`) — prefer it over Context7 for Go package facts. To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See `samber/cc-skills-golang@golang-gopls` skill (`gopls`). Context7 remains a fallback for docs not indexed on pkg.go.dev.
13
14	```bash
15	go get -u github.com/samber/hot
16	```
17
18	## Algorithm Selection
19
20	Pick based on your access pattern — the wrong algorithm wastes memory or tanks hit rate.
21
22	\| Algorithm \| Constant \| Best for \| Avoid when \|
23	\| --- \| --- \| --- \| --- \|
24	\| W-TinyLFU \| `hot.WTinyLFU` \| General-purpose, mixed workloads (default) \| You need simplicity for debugging \|
25	\| LRU \| `hot.LRU` \| Recency-dominated (sessions, recent queries) \| Frequency matters (scan pollution evicts hot items) \|
26	\| LFU \| `hot.LFU` \| Frequency-dominated (popular products, DNS) \| Access patterns shift (stale popular items never evict) \|
27	\| TinyLFU \| `hot.TinyLFU` \| Read-heavy with frequency bias \| Write-heavy (admission filter overhead) \|
28	\| S3FIFO \| `hot.S3FIFO` \| High throughput, scan-resistant \| Small caches (<1000 items) \|
29	\| ARC \| `hot.ARC` \| Self-tuning, unknown patterns \| Memory-constrained (2x tracking overhead) \|
30	\| TwoQueue \| `hot.TwoQueue` \| Mixed with hot/cold split \| Tuning complexity is unacceptable \|
31	\| SIEVE \| `hot.SIEVE` \| Simple scan-resistant LRU alternative \| Highly skewed access patterns \|
32	\| FIFO \| `hot.FIFO` \| Simple, predictable eviction order \| Hit rate matters (no frequency/recency awareness) \|
33
34	Decision shortcut: Start with `hot.WTinyLFU`. Switch only when profiling shows the miss rate is too high for your SLO.
35
36	For detailed algorithm comparison, benchmarks, and a decision tree, see [Algorithm Guide](./references/algorithm-guide.md).
37
38	## Core Usage
39
40	### Basic Cache with TTL
41
42	```go
43	import "github.com/samber/hot"
44
45	cache := hot.NewHotCache[string, *User](hot.WTinyLFU, 10_000).
46	WithTTL(5 * time.Minute).
47	WithJanitor().
48	Build()
49	defer cache.StopJanitor()
50
51	cache.Set("user:123", user)
52	cache.SetWithTTL("session:abc", session, 30*time.Minute)
53
54	value, found, err := cache.Get("user:123")
55	```
56
57	### Loader Pattern (Read-Through)
58
59	Loaders fetch missing keys automatically with singleflight deduplication — concurrent `Get()` calls for the same missing key share one loader invocation:
60
61	```go
62	cache := hot.NewHotCache[int, *User](hot.WTinyLFU, 10_000).
63	WithTTL(5 * time.Minute).
64	WithLoaders(func(ids []int) (map[int]*User, error) {
65	return db.GetUsersByIDs(ctx, ids) // batch query
66	}).
67	WithJanitor().
68	Build()
69	defer cache.StopJanitor()
70
71	user, found, err := cache.Get(123) // triggers loader on miss
72	```
73
74	## Capacity Sizing
75
76	Before setting the cache capacity, estimate how many items fit in the memory budget:
77
78	1. Estimate single-item size — estimate size of the struct, add the size of heap-allocated fields (slices, maps, strings). Include the key size. A rough per-entry overhead of ~100 bytes covers internal bookkeeping (pointers, expiry timestamps, algorithm

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golang-samber-hot

33kinstalls179forks

View on GitHub

How to install golang-samber-hot?

samber/cc-skills-golang/golang-samber-hot

$npx -y skills add samber/cc-skills-golang --skill golang-samber-hot

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	Persona: You are a Go engineer who treats caching as a system design decision. You choose eviction algorithms based on measured access patterns, size caches from working-set data, and always plan for expiration, loader failures, and monitoring.
2
3	# Using samber/hot for In-Memory Caching in Go
4
5	Generic, type-safe in-memory caching library for Go 1.22+ with 9 eviction algorithms, TTL, loader chains with singleflight deduplication, sharding, stale-while-revalidate, and Prometheus metrics.
6
7	Official Resources:
8
9	- [pkg.go.dev/github.com/samber/hot](https://pkg.go.dev/github.com/samber/hot)
10	- [github.com/samber/hot](https://github.com/samber/hot)
11
12	This skill is not exhaustive. Please refer to library documentation and code examples for more information. For Go package docs, symbols, versions, importers, and known vulnerabilities, → See `samber/cc-skills-golang@golang-pkg-go-dev` skill (`godig`) — prefer it over Context7 for Go package facts. To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See `samber/cc-skills-golang@golang-gopls` skill (`gopls`). Context7 remains a fallback for docs not indexed on pkg.go.dev.
13
14	```bash
15	go get -u github.com/samber/hot
16	```
17
18	## Algorithm Selection
19
20	Pick based on your access pattern — the wrong algorithm wastes memory or tanks hit rate.
21
22	\| Algorithm \| Constant \| Best for \| Avoid when \|
23	\| --- \| --- \| --- \| --- \|
24	\| W-TinyLFU \| `hot.WTinyLFU` \| General-purpose, mixed workloads (default) \| You need simplicity for debugging \|
25	\| LRU \| `hot.LRU` \| Recency-dominated (sessions, recent queries) \| Frequency matters (scan pollution evicts hot items) \|
26	\| LFU \| `hot.LFU` \| Frequency-dominated (popular products, DNS) \| Access patterns shift (stale popular items never evict) \|
27	\| TinyLFU \| `hot.TinyLFU` \| Read-heavy with frequency bias \| Write-heavy (admission filter overhead) \|
28	\| S3FIFO \| `hot.S3FIFO` \| High throughput, scan-resistant \| Small caches (<1000 items) \|
29	\| ARC \| `hot.ARC` \| Self-tuning, unknown patterns \| Memory-constrained (2x tracking overhead) \|
30	\| TwoQueue \| `hot.TwoQueue` \| Mixed with hot/cold split \| Tuning complexity is unacceptable \|
31	\| SIEVE \| `hot.SIEVE` \| Simple scan-resistant LRU alternative \| Highly skewed access patterns \|
32	\| FIFO \| `hot.FIFO` \| Simple, predictable eviction order \| Hit rate matters (no frequency/recency awareness) \|
33
34	Decision shortcut: Start with `hot.WTinyLFU`. Switch only when profiling shows the miss rate is too high for your SLO.
35
36	For detailed algorithm comparison, benchmarks, and a decision tree, see [Algorithm Guide](./references/algorithm-guide.md).
37
38	## Core Usage
39
40	### Basic Cache with TTL
41
42	```go
43	import "github.com/samber/hot"
44
45	cache := hot.NewHotCache[string, *User](hot.WTinyLFU, 10_000).
46	WithTTL(5 * time.Minute).
47	WithJanitor().
48	Build()
49	defer cache.StopJanitor()
50
51	cache.Set("user:123", user)
52	cache.SetWithTTL("session:abc", session, 30*time.Minute)
53
54	value, found, err := cache.Get("user:123")
55	```
56
57	### Loader Pattern (Read-Through)
58
59	Loaders fetch missing keys automatically with singleflight deduplication — concurrent `Get()` calls for the same missing key share one loader invocation:
60
61	```go
62	cache := hot.NewHotCache[int, *User](hot.WTinyLFU, 10_000).
63	WithTTL(5 * time.Minute).
64	WithLoaders(func(ids []int) (map[int]*User, error) {
65	return db.GetUsersByIDs(ctx, ids) // batch query
66	}).
67	WithJanitor().
68	Build()
69	defer cache.StopJanitor()
70
71	user, found, err := cache.Get(123) // triggers loader on miss
72	```
73
74	## Capacity Sizing
75
76	Before setting the cache capacity, estimate how many items fit in the memory budget:
77
78	1. Estimate single-item size — estimate size of the struct, add the size of heap-allocated fields (slices, maps, strings). Include the key size. A rough per-entry overhead of ~100 bytes covers internal bookkeeping (pointers, expiry timestamps, algorithm

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6 picks

Type