feat: add cache, outbound HTTP, request protection, tasks and module scaffolding

cache/redis/redis.go

@@ -0,0 +1,68 @@
+// Package redis adapts go-redis's pooled client to cache.Store.
+package redis
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"time"
+
+	"git.yuntuo.hk/k2safe/go-omni/cache"
+	goredis "github.com/redis/go-redis/v9"
+)
+
+// Store borrows the client; its owner must close the client after users stop.
+type Store struct {
+	client goredis.Cmdable
+	prefix string
+}
+
+func New(client goredis.Cmdable, prefix string) (*Store, error) {
+	if client == nil || len(prefix) > 1024 || strings.ContainsAny(prefix, "\r\n") {
+		return nil, errors.New("cache/redis: invalid client or prefix")
+	}
+	return &Store{client: client, prefix: prefix}, nil
+}
+
+func (s *Store) Get(ctx context.Context, key string) ([]byte, error) {
+	if err := cache.Check(ctx, key, 0); err != nil {
+		return nil, err
+	}
+	value, err := s.client.Get(ctx, s.prefix+key).Bytes()
+	if errors.Is(err, goredis.Nil) {
+		return nil, cache.ErrMiss
+	}
+	return value, err
+}
+
+func (s *Store) Set(ctx context.Context, key string, value []byte, ttl time.Duration) error {
+	if err := cache.Check(ctx, key, ttl); err != nil {
+		return err
+	}
+	// Redis expiration precision is milliseconds; round up, never truncate a
+	// positive duration to an unbounded lifetime.
+	if ttl > 0 && ttl < time.Millisecond {
+		ttl = time.Millisecond
+	}
+	return s.client.Set(ctx, s.prefix+key, value, ttl).Err()
+}
+
+func (s *Store) Delete(ctx context.Context, keys ...string) error {
+	if ctx == nil {
+		return errors.New("cache/redis: nil context")
+	}
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	names := make([]string, len(keys))
+	for i, key := range keys {
+		if err := cache.Check(ctx, key, 0); err != nil {
+			return err
+		}
+		names[i] = s.prefix + key
+	}
+	if len(names) == 0 {
+		return nil
+	}
+	return s.client.Del(ctx, names...).Err()
+}