65 lines
1.9 KiB
Go
65 lines
1.9 KiB
Go
// Copyright 2014 beego Author. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package cache
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import (
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"context"
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"time"
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"golang.org/x/sync/singleflight"
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"github.com/beego/beego/v2/core/berror"
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)
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// SingleflightCache
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// This is a very simple decorator mode
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type SingleflightCache struct {
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Cache
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group *singleflight.Group
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expiration time.Duration
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loadFunc func(ctx context.Context, key string) (any, error)
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}
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// NewSingleflightCache create SingleflightCache
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func NewSingleflightCache(c Cache, expiration time.Duration,
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loadFunc func(ctx context.Context, key string) (any, error),
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) (Cache, error) {
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if loadFunc == nil {
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return nil, berror.Error(InvalidLoadFunc, "loadFunc cannot be nil")
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}
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return &SingleflightCache{
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Cache: c,
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group: &singleflight.Group{},
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expiration: expiration,
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loadFunc: loadFunc,
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}, nil
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}
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// Get In the Get method, single flight is used to load data and write back the cache.
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func (s *SingleflightCache) Get(ctx context.Context, key string) (any, error) {
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val, err := s.Cache.Get(ctx, key)
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if val == nil || err != nil {
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val, err, _ = s.group.Do(key, func() (interface{}, error) {
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v, er := s.loadFunc(ctx, key)
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if er != nil {
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return nil, berror.Wrap(er, LoadFuncFailed, "cache unable to load data")
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}
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er = s.Cache.Put(ctx, key, v, s.expiration)
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return v, er
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})
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}
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return val, err
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}
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