forgejo/modules/setting/config/value.go
wxiaoguang 9f8d59858a
Refactor system setting (#27000)
This PR reduces the complexity of the system setting system.

It only needs one line to introduce a new option, and the option can be
used anywhere out-of-box.

It is still high-performant (and more performant) because the config
values are cached in the config system.
2023-10-05 09:08:19 +08:00

81 lines
1.7 KiB
Go

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package config
import (
"context"
"strconv"
"sync"
)
type CfgSecKey struct {
Sec, Key string
}
type Value[T any] struct {
mu sync.RWMutex
cfgSecKey CfgSecKey
dynKey string
def, value T
revision int
}
func (value *Value[T]) parse(s string) (v T) {
switch any(v).(type) {
case bool:
b, _ := strconv.ParseBool(s)
return any(b).(T)
default:
panic("unsupported config type, please complete the code")
}
}
func (value *Value[T]) Value(ctx context.Context) (v T) {
dg := GetDynGetter()
if dg == nil {
// this is an edge case: the database is not initialized but the system setting is going to be used
// it should panic to avoid inconsistent config values (from config / system setting) and fix the code
panic("no config dyn value getter")
}
rev := dg.GetRevision(ctx)
// if the revision in database doesn't change, use the last value
value.mu.RLock()
if rev == value.revision {
v = value.value
value.mu.RUnlock()
return v
}
value.mu.RUnlock()
// try to parse the config and cache it
var valStr *string
if dynVal, has := dg.GetValue(ctx, value.dynKey); has {
valStr = &dynVal
} else if cfgVal, has := GetCfgSecKeyGetter().GetValue(value.cfgSecKey.Sec, value.cfgSecKey.Key); has {
valStr = &cfgVal
}
if valStr == nil {
v = value.def
} else {
v = value.parse(*valStr)
}
value.mu.Lock()
value.value = v
value.revision = rev
value.mu.Unlock()
return v
}
func (value *Value[T]) DynKey() string {
return value.dynKey
}
func Bool(def bool, cfgSecKey CfgSecKey, dynKey string) *Value[bool] {
return &Value[bool]{def: def, cfgSecKey: cfgSecKey, dynKey: dynKey}
}