README
¶
gcache 
gcache is a gRPC caching library that provides a simple way to cache gRPC requests and responses. It is designed to be used with gRPC services that have a high request rate and where caching can improve the performance of the service.
It uses a plain old ETag and If-None-Match headers to cache the responses. The cache is stored in memory and is not persistent (unless you use a persistent cache store).
It also provides a server-side caching implementation.
Installation
go get -u github.com/cappuccinotm/gcache
Usage
Client-side caching
icptr := gcache.NewInterceptor(gcache.WithLogger(slog.Default()))
conn, err := grpc.NewClient("localhost:8080",
grpc.WithTransportCredentials(insecure.NewCredentials()),
grpc.WithUnaryInterceptor(icptr.UnaryClientInterceptor()),
)
if err != nil {
return fmt.Errorf("dial localhost:8080: %w", err)
}
client := order.NewOrderServiceClient(conn)
Client-side interceptor seeks for server's ETag header in the response, if the server has provided one, it stores the response in the cache. When the client sends a request, the interceptor adds the If-None-Match header to the request. If the server responds with code Aborted and the ETag header, equal to the one that has been sent by client, the interceptor returns the cached response.
Server-side caching
icptr := gcache.NewInterceptor(gcache.WithLogger(slog.Default()))
server := grpc.NewServer(
grpc.WithTransportCredentials(insecure.NewCredentials()),
grpc.WithUnaryInterceptor(icptr.UnaryServerInterceptor()),
)
Server-side interceptor always sends the cached response unless client has specifically set the Cache-Control: no-cache header.
Documentation
¶
Overview ¶
Package gcache provides caching interceptors for gRPC clients.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrKey = "error"
ErrKey specifies the error key for logging.
Functions ¶
Types ¶
type Interceptor ¶
type Interceptor struct {
// contains filtered or unexported fields
}
Interceptor is a cache interceptor. It looks over the ETag header and caches the response ONLY if the ETag is present.
func NewInterceptor ¶
func NewInterceptor(opts ...Option) *Interceptor
NewInterceptor makes a new Interceptor.
func (*Interceptor) UnaryClientInterceptor ¶
func (c *Interceptor) UnaryClientInterceptor() grpc.UnaryClientInterceptor
UnaryClientInterceptor returns a new unary client interceptor that caches the response.
func (*Interceptor) UnaryServerInterceptor ¶
func (c *Interceptor) UnaryServerInterceptor() grpc.UnaryServerInterceptor
UnaryServerInterceptor returns a new unary server interceptor that caches the response. It doesn't use ETag header, but Cache-Control header.
type LRUBackend ¶
type LRUBackend interface {
Add(key string, value Entry) (evicted bool)
Get(key string) (value Entry, ok bool)
Remove(key string) (present bool)
}
LRUBackend specifies interface to be implemented by hashicorp LRU cache backends.
type Option ¶
type Option func(*Interceptor)
Option is a configuration option.
func WithFilter ¶
WithFilter sets the filter that is used to match the methods that must be cached.
type RawBytesCodec ¶
type RawBytesCodec struct{}
RawBytesCodec sets the received bytes as-is to the target, whether it is a byte slice or a proto.Message. For proto.Message, it uses proto.Marshal and proto.Unmarshal.
type RedisOption ¶
type RedisOption func(*redisStore)
RedisOption is a configuration option.
func WithRedisLogger ¶
func WithRedisLogger(l *slog.Logger) RedisOption
WithRedisLogger sets the logger.
func WithRedisSkipLocalCache ¶
func WithRedisSkipLocalCache(skipLocalCache bool) RedisOption
WithRedisSkipLocalCache sets the skipLocalCache.
type Store ¶
type Store interface {
Get(ctx context.Context, key string) (e Entry, ok bool)
Set(ctx context.Context, key string, e Entry)
Remove(ctx context.Context, key string)
}
Store is a cache store.
func NewLRU ¶
func NewLRU(backend LRUBackend) Store
NewLRU wraps hashicorp/golang-lru/v2 cache implementations to be used as interceptor's store.
func NewRedis ¶
func NewRedis(backend *rediscache.Cache, opts ...RedisOption) Store
NewRedis returns a new redisStore cache store.
Source Files
Directories