forgejo/modules/setting/cache.go
zeripath 2f725cbc9e
Add LRU mem cache implementation (#16226)
The current default memory cache implementation is unbounded in size and number of
objects cached. This is hardly ideal.

This PR proposes creating a TwoQueue LRU cache as the underlying cache for Gitea.
The cache is limited by the number of objects stored in the cache (rather than size)
for simplicity. The default number of objects is 50000 - which is perhaps too small
as most of our objects cached are going to be much less than 1kB.

It may be worth considering using a different LRU implementation that actively limits
sizes or avoids GC - however, this is just a beginning implementation.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-07-10 23:54:15 +02:00

112 lines
2.8 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package setting
import (
"strings"
"time"
"code.gitea.io/gitea/modules/log"
)
// Cache represents cache settings
type Cache struct {
Enabled bool
Adapter string
Interval int
Conn string
TTL time.Duration `ini:"ITEM_TTL"`
}
var (
// CacheService the global cache
CacheService = struct {
Cache `ini:"cache"`
LastCommit struct {
Enabled bool
TTL time.Duration `ini:"ITEM_TTL"`
CommitsCount int64
} `ini:"cache.last_commit"`
}{
Cache: Cache{
Enabled: true,
Adapter: "memory",
Interval: 60,
TTL: 16 * time.Hour,
},
LastCommit: struct {
Enabled bool
TTL time.Duration `ini:"ITEM_TTL"`
CommitsCount int64
}{
Enabled: true,
TTL: 8760 * time.Hour,
CommitsCount: 1000,
},
}
)
// MemcacheMaxTTL represents the maximum memcache TTL
const MemcacheMaxTTL = 30 * 24 * time.Hour
func newCacheService() {
sec := Cfg.Section("cache")
if err := sec.MapTo(&CacheService); err != nil {
log.Fatal("Failed to map Cache settings: %v", err)
}
CacheService.Adapter = sec.Key("ADAPTER").In("memory", []string{"memory", "redis", "memcache", "twoqueue"})
switch CacheService.Adapter {
case "memory":
case "redis", "memcache":
CacheService.Conn = strings.Trim(sec.Key("HOST").String(), "\" ")
case "twoqueue":
CacheService.Conn = strings.TrimSpace(sec.Key("HOST").String())
if CacheService.Conn == "" {
CacheService.Conn = "50000"
}
case "": // disable cache
CacheService.Enabled = false
default:
log.Fatal("Unknown cache adapter: %s", CacheService.Adapter)
}
if CacheService.Enabled {
log.Info("Cache Service Enabled")
} else {
log.Warn("Cache Service Disabled so that captcha disabled too")
// captcha depends on cache service
Service.EnableCaptcha = false
}
sec = Cfg.Section("cache.last_commit")
if !CacheService.Enabled {
CacheService.LastCommit.Enabled = false
}
CacheService.LastCommit.CommitsCount = sec.Key("COMMITS_COUNT").MustInt64(1000)
if CacheService.LastCommit.Enabled {
log.Info("Last Commit Cache Service Enabled")
}
}
// TTLSeconds returns the TTLSeconds or unix timestamp for memcache
func (c Cache) TTLSeconds() int64 {
if c.Adapter == "memcache" && c.TTL > MemcacheMaxTTL {
return time.Now().Add(c.TTL).Unix()
}
return int64(c.TTL.Seconds())
}
// LastCommitCacheTTLSeconds returns the TTLSeconds or unix timestamp for memcache
func LastCommitCacheTTLSeconds() int64 {
if CacheService.Adapter == "memcache" && CacheService.LastCommit.TTL > MemcacheMaxTTL {
return time.Now().Add(CacheService.LastCommit.TTL).Unix()
}
return int64(CacheService.LastCommit.TTL.Seconds())
}