79 lines
1.5 KiB
Go
79 lines
1.5 KiB
Go
package redispkg
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import (
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"context"
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"crypto/rand"
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"encoding/hex"
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"log"
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"time"
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"github.com/redis/go-redis/v9"
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)
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type R struct{ c *redis.Client }
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func New(url string) *R {
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if url == "" {
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return &R{}
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}
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opt, err := redis.ParseURL(url)
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if err != nil {
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log.Printf("bad REDIS_URL (%v): redis disabled", err)
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return &R{}
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}
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return &R{c: redis.NewClient(opt)}
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}
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func (r *R) Get(ctx context.Context, key string) (string, bool) {
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if r.c == nil {
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return "", false
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}
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v, err := r.c.Get(ctx, key).Result()
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if err != nil {
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return "", false // 故障=miss
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}
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return v, true
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}
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func (r *R) Set(ctx context.Context, key, val string, ttl time.Duration) {
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if r.c == nil {
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return
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}
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if err := r.c.Set(ctx, key, val, ttl).Err(); err != nil {
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log.Printf("redis set %s: %v", key, err)
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}
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}
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func (r *R) IncrWindow(ctx context.Context, key string, ttl time.Duration) int {
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if r.c == nil {
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return 1
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}
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n, err := r.c.Incr(ctx, key).Result()
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if err != nil {
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return 1
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}
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if n == 1 {
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r.c.Expire(ctx, key, ttl)
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}
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return int(n)
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}
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func (r *R) Lock(ctx context.Context, key string, ttl time.Duration) (func(), bool) {
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noop := func() {}
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if r.c == nil {
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return noop, true
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}
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b := make([]byte, 8)
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rand.Read(b)
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tok := hex.EncodeToString(b)
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ok, err := r.c.SetNX(ctx, key, tok, ttl).Result()
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if err != nil || !ok {
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return noop, false
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}
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return func() {
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r.c.Eval(ctx,
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"if redis.call('get',KEYS[1])==ARGV[1] then return redis.call('del',KEYS[1]) else return 0 end",
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[]string{key}, tok)
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}, true
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}
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