drone/cache/redis_cache.go

115 lines
2.6 KiB
Go

// Copyright 2023 Harness, Inc.
//
// 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 cache
import (
"context"
"errors"
"fmt"
"sync/atomic"
"time"
"github.com/go-redis/redis/v8"
)
type LogErrFn func(context.Context, error)
type Redis[K any, V any] struct {
client redis.UniversalClient
duration time.Duration
getter Getter[K, V]
keyEncoder func(K) string
codec Codec[V]
countHit atomic.Int64
countMiss atomic.Int64
logErrFn LogErrFn
}
type Encoder[V any] interface {
Encode(value V) string
}
type Decoder[V any] interface {
Decode(encoded string) (V, error)
}
type Codec[V any] interface {
Encoder[V]
Decoder[V]
}
func NewRedis[K any, V any](
client redis.UniversalClient,
getter Getter[K, V],
keyEncoder func(K) string,
codec Codec[V],
duration time.Duration,
logErrFn LogErrFn,
) *Redis[K, V] {
return &Redis[K, V]{
client: client,
duration: duration,
getter: getter,
keyEncoder: keyEncoder,
codec: codec,
logErrFn: logErrFn,
}
}
// Stats returns number of cache hits and misses and can be used to monitor the cache efficiency.
func (c *Redis[K, V]) Stats() (int64, int64) {
return c.countHit.Load(), c.countMiss.Load()
}
// Get implements the cache.Cache interface.
func (c *Redis[K, V]) Get(ctx context.Context, key K) (V, error) {
var nothing V
strKey := c.keyEncoder(key)
raw, err := c.client.Get(ctx, strKey).Result()
if err == nil {
value, decErr := c.codec.Decode(raw)
if decErr == nil {
c.countHit.Add(1)
return value, nil
}
} else if !errors.Is(err, redis.Nil) && c.logErrFn != nil {
c.logErrFn(ctx, err)
}
c.countMiss.Add(1)
item, err := c.getter.Find(ctx, key)
if err != nil {
return nothing, fmt.Errorf("cache: failed to find one: %w", err)
}
err = c.client.Set(ctx, strKey, c.codec.Encode(item), c.duration).Err()
if err != nil && c.logErrFn != nil {
c.logErrFn(ctx, err)
}
return item, nil
}
func (c *Redis[K, V]) Evict(ctx context.Context, key K) {
strKey := c.keyEncoder(key)
err := c.client.Del(ctx, strKey).Err()
if err != nil && c.logErrFn != nil {
c.logErrFn(ctx, err)
}
}