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mirror of https://github.com/redis/go-redis.git synced 2025-07-18 00:20:57 +03:00
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go-redis/internal/pushnotif/types.go
Nedyalko Dyakov 1606de8b73 feat: implement strongly typed HandlerContext interface
Convert HandlerContext from struct to interface with strongly typed getters
for different client types. This provides better type safety and a cleaner
API for push notification handlers while maintaining flexibility.

Key Changes:

1. HandlerContext Interface Design:
   - Converted HandlerContext from struct to interface
   - Added strongly typed getters for different client types
   - GetClusterClient() returns ClusterClientInterface
   - GetSentinelClient() returns SentinelClientInterface
   - GetFailoverClient() returns FailoverClientInterface
   - GetRegularClient() returns RegularClientInterface
   - GetPubSub() returns PubSubInterface

2. Client Type Interfaces:
   - Defined ClusterClientInterface for cluster client access
   - Defined SentinelClientInterface for sentinel client access
   - Defined FailoverClientInterface for failover client access
   - Defined RegularClientInterface for regular client access
   - Defined PubSubInterface for pub/sub access
   - Each interface provides String() method for basic operations

3. Concrete Implementation:
   - Created handlerContext struct implementing HandlerContext interface
   - Added NewHandlerContext constructor function
   - Implemented type-safe getters with interface casting
   - Returns nil for incorrect client types (type safety)

4. Updated All Usage:
   - Updated Handler interface to use HandlerContext interface
   - Updated ProcessorInterface to use HandlerContext interface
   - Updated all processor implementations (Processor, VoidProcessor)
   - Updated all handler context creation sites
   - Updated test handlers and test context creation

5. Helper Methods:
   - Updated pushNotificationHandlerContext() in baseClient
   - Updated pushNotificationHandlerContext() in PubSub
   - Consistent context creation across all client types
   - Proper parameter passing for different connection types

6. Type Safety Benefits:
   - Handlers can safely cast to specific client types
   - Compile-time checking for client type access
   - Clear API for accessing different client capabilities
   - No runtime panics from incorrect type assertions

7. API Usage Example:
   ```go
   func (h *MyHandler) HandlePushNotification(
       ctx context.Context,
       handlerCtx HandlerContext,
       notification []interface{},
   ) bool {
       // Strongly typed access
       if clusterClient := handlerCtx.GetClusterClient(); clusterClient != nil {
           // Handle cluster-specific logic
       }
       if sentinelClient := handlerCtx.GetSentinelClient(); sentinelClient != nil {
           // Handle sentinel-specific logic
       }
       return true
   }
   ```

8. Backward Compatibility:
   - Interface maintains same functionality as original struct
   - All existing handler patterns continue to work
   - No breaking changes to handler implementations
   - Smooth migration path for existing code

Benefits:
- Strong type safety for client access in handlers
- Clear API with explicit client type getters
- Compile-time checking prevents runtime errors
- Flexible interface allows future extensions
- Better separation of concerns between client types
- Enhanced developer experience with IntelliSense support

This enhancement provides handlers with strongly typed access to different
Redis client types while maintaining the flexibility and context information
needed for sophisticated push notification handling, particularly important
for hitless upgrades and cluster management operations.
2025-07-04 19:53:19 +03:00

179 lines
6.0 KiB
Go

package pushnotif
import (
"context"
"github.com/redis/go-redis/v9/internal/pool"
"github.com/redis/go-redis/v9/internal/proto"
)
// HandlerContext provides context information about where a push notification was received.
// This interface allows handlers to make informed decisions based on the source of the notification
// with strongly typed access to different client types.
type HandlerContext interface {
// GetClient returns the Redis client instance that received the notification.
// Returns nil if no client context is available.
GetClient() interface{}
// GetClusterClient returns the client as a ClusterClient if it is one.
// Returns nil if the client is not a ClusterClient or no client context is available.
GetClusterClient() ClusterClientInterface
// GetSentinelClient returns the client as a SentinelClient if it is one.
// Returns nil if the client is not a SentinelClient or no client context is available.
GetSentinelClient() SentinelClientInterface
// GetFailoverClient returns the client as a FailoverClient if it is one.
// Returns nil if the client is not a FailoverClient or no client context is available.
GetFailoverClient() FailoverClientInterface
// GetRegularClient returns the client as a regular Client if it is one.
// Returns nil if the client is not a regular Client or no client context is available.
GetRegularClient() RegularClientInterface
// GetConnPool returns the connection pool from which the connection was obtained.
// Returns nil if no connection pool context is available.
GetConnPool() interface{}
// GetPubSub returns the PubSub instance that received the notification.
// Returns nil if this is not a PubSub connection.
GetPubSub() PubSubInterface
// GetConn returns the specific connection on which the notification was received.
// Returns nil if no connection context is available.
GetConn() *pool.Conn
// IsBlocking returns true if the notification was received on a blocking connection.
IsBlocking() bool
}
// Client interfaces for strongly typed access
type ClusterClientInterface interface {
// Add methods that handlers might need from ClusterClient
String() string
}
type SentinelClientInterface interface {
// Add methods that handlers might need from SentinelClient
String() string
}
type FailoverClientInterface interface {
// Add methods that handlers might need from FailoverClient
String() string
}
type RegularClientInterface interface {
// Add methods that handlers might need from regular Client
String() string
}
type PubSubInterface interface {
// Add methods that handlers might need from PubSub
String() string
}
// handlerContext is the concrete implementation of HandlerContext interface
type handlerContext struct {
client interface{}
connPool interface{}
pubSub interface{}
conn *pool.Conn
isBlocking bool
}
// NewHandlerContext creates a new HandlerContext implementation
func NewHandlerContext(client, connPool, pubSub interface{}, conn *pool.Conn, isBlocking bool) HandlerContext {
return &handlerContext{
client: client,
connPool: connPool,
pubSub: pubSub,
conn: conn,
isBlocking: isBlocking,
}
}
// GetClient returns the Redis client instance that received the notification
func (h *handlerContext) GetClient() interface{} {
return h.client
}
// GetClusterClient returns the client as a ClusterClient if it is one
func (h *handlerContext) GetClusterClient() ClusterClientInterface {
if client, ok := h.client.(ClusterClientInterface); ok {
return client
}
return nil
}
// GetSentinelClient returns the client as a SentinelClient if it is one
func (h *handlerContext) GetSentinelClient() SentinelClientInterface {
if client, ok := h.client.(SentinelClientInterface); ok {
return client
}
return nil
}
// GetFailoverClient returns the client as a FailoverClient if it is one
func (h *handlerContext) GetFailoverClient() FailoverClientInterface {
if client, ok := h.client.(FailoverClientInterface); ok {
return client
}
return nil
}
// GetRegularClient returns the client as a regular Client if it is one
func (h *handlerContext) GetRegularClient() RegularClientInterface {
if client, ok := h.client.(RegularClientInterface); ok {
return client
}
return nil
}
// GetConnPool returns the connection pool from which the connection was obtained
func (h *handlerContext) GetConnPool() interface{} {
return h.connPool
}
// GetPubSub returns the PubSub instance that received the notification
func (h *handlerContext) GetPubSub() PubSubInterface {
if pubSub, ok := h.pubSub.(PubSubInterface); ok {
return pubSub
}
return nil
}
// GetConn returns the specific connection on which the notification was received
func (h *handlerContext) GetConn() *pool.Conn {
return h.conn
}
// IsBlocking returns true if the notification was received on a blocking connection
func (h *handlerContext) IsBlocking() bool {
return h.isBlocking
}
// Handler defines the interface for push notification handlers.
type Handler interface {
// HandlePushNotification processes a push notification with context information.
// The handlerCtx provides information about the client, connection pool, and connection
// on which the notification was received, allowing handlers to make informed decisions.
// Returns true if the notification was handled, false otherwise.
HandlePushNotification(ctx context.Context, handlerCtx HandlerContext, notification []interface{}) bool
}
// ProcessorInterface defines the interface for push notification processors.
type ProcessorInterface interface {
GetHandler(pushNotificationName string) Handler
ProcessPendingNotifications(ctx context.Context, handlerCtx HandlerContext, rd *proto.Reader) error
RegisterHandler(pushNotificationName string, handler Handler, protected bool) error
}
// RegistryInterface defines the interface for push notification registries.
type RegistryInterface interface {
RegisterHandler(pushNotificationName string, handler Handler, protected bool) error
UnregisterHandler(pushNotificationName string) error
GetHandler(pushNotificationName string) Handler
GetRegisteredPushNotificationNames() []string
}