mirror of
https://github.com/matrix-org/dendrite
synced 2024-12-14 00:43:52 +01:00
95 lines
3.1 KiB
Go
95 lines
3.1 KiB
Go
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package transactions
|
|
|
|
import (
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/matrix-org/util"
|
|
)
|
|
|
|
// DefaultCleanupPeriod represents the default time duration after which cacheCleanService runs.
|
|
const DefaultCleanupPeriod time.Duration = 30 * time.Minute
|
|
|
|
type txnsMap map[CacheKey]*util.JSONResponse
|
|
|
|
// CacheKey is the type for the key in a transactions cache.
|
|
// This is needed because the spec requires transaction IDs to have a per-access token scope.
|
|
type CacheKey struct {
|
|
AccessToken string
|
|
TxnID string
|
|
}
|
|
|
|
// Cache represents a temporary store for response entries.
|
|
// Entries are evicted after a certain period, defined by cleanupPeriod.
|
|
// This works by keeping two maps of entries, and cycling the maps after the cleanupPeriod.
|
|
type Cache struct {
|
|
sync.RWMutex
|
|
txnsMaps [2]txnsMap
|
|
cleanupPeriod time.Duration
|
|
}
|
|
|
|
// New is a wrapper which calls NewWithCleanupPeriod with DefaultCleanupPeriod as argument.
|
|
func New() *Cache {
|
|
return NewWithCleanupPeriod(DefaultCleanupPeriod)
|
|
}
|
|
|
|
// NewWithCleanupPeriod creates a new Cache object, starts cacheCleanService.
|
|
// Takes cleanupPeriod as argument.
|
|
// Returns a reference to newly created Cache.
|
|
func NewWithCleanupPeriod(cleanupPeriod time.Duration) *Cache {
|
|
t := Cache{txnsMaps: [2]txnsMap{make(txnsMap), make(txnsMap)}}
|
|
t.cleanupPeriod = cleanupPeriod
|
|
|
|
// Start clean service as the Cache is created
|
|
go cacheCleanService(&t)
|
|
return &t
|
|
}
|
|
|
|
// FetchTransaction looks up an entry for the (accessToken, txnID) tuple in Cache.
|
|
// Looks in both the txnMaps.
|
|
// Returns (JSON response, true) if txnID is found, else the returned bool is false.
|
|
func (t *Cache) FetchTransaction(accessToken, txnID string) (*util.JSONResponse, bool) {
|
|
t.RLock()
|
|
defer t.RUnlock()
|
|
for _, txns := range t.txnsMaps {
|
|
res, ok := txns[CacheKey{accessToken, txnID}]
|
|
if ok {
|
|
return res, true
|
|
}
|
|
}
|
|
return nil, false
|
|
}
|
|
|
|
// AddTransaction adds an entry for the (accessToken, txnID) tuple in Cache.
|
|
// Adds to the front txnMap.
|
|
func (t *Cache) AddTransaction(accessToken, txnID string, res *util.JSONResponse) {
|
|
t.Lock()
|
|
defer t.Unlock()
|
|
|
|
t.txnsMaps[0][CacheKey{accessToken, txnID}] = res
|
|
}
|
|
|
|
// cacheCleanService is responsible for cleaning up entries after cleanupPeriod.
|
|
// It guarantees that an entry will be present in cache for at least cleanupPeriod & at most 2 * cleanupPeriod.
|
|
// This cycles the txnMaps forward, i.e. back map is assigned the front and front is assigned an empty map.
|
|
func cacheCleanService(t *Cache) {
|
|
ticker := time.NewTicker(t.cleanupPeriod).C
|
|
for range ticker {
|
|
t.Lock()
|
|
t.txnsMaps[1] = t.txnsMaps[0]
|
|
t.txnsMaps[0] = make(txnsMap)
|
|
t.Unlock()
|
|
}
|
|
}
|