Merge pull request #2344 from monkey92t/hook

docs: add a description of the hook

cluster.go

@@ -136,10 +136,13 @@ func (opt *ClusterOptions) init() {
 
 // ParseClusterURL parses a URL into ClusterOptions that can be used to connect to Redis.
 // The URL must be in the form:
+//
 //	redis://<user>:<password>@<host>:<port>
 //	or
 //	rediss://<user>:<password>@<host>:<port>
+//
 // To add additional addresses, specify the query parameter, "addr" one or more times. e.g:
+//
 //	redis://<user>:<password>@<host>:<port>?addr=<host2>:<port2>&addr=<host3>:<port3>
 //	or
 //	rediss://<user>:<password>@<host>:<port>?addr=<host2>:<port2>&addr=<host3>:<port3>
@@ -156,7 +159,9 @@ func (opt *ClusterOptions) init() {
 //     URL attributes (scheme, host, userinfo, resp.), query paremeters using these
 //     names will be treated as unknown parameters
 //   - unknown parameter names will result in an error
+//
 // Example:
+//
 //	redis://user:password@localhost:6789?dial_timeout=3&read_timeout=6s&addr=localhost:6790&addr=localhost:6791
 //	is equivalent to:
 //	&ClusterOptions{

command.go

@@ -1110,15 +1110,16 @@ func (cmd *KeyValueSliceCmd) String() string {
 }
 
 // Many commands will respond to two formats:
-//  1) 1) "one"
-//     2) (double) 1
-//  2) 1) "two"
-//     2) (double) 2
+//  1. 1) "one"
+//  2. (double) 1
+//  2. 1) "two"
+//  2. (double) 2
+//
 // OR:
-//  1) "two"
-//  2) (double) 2
-//  3) "one"
-//  4) (double) 1
+//  1. "two"
+//  2. (double) 2
+//  3. "one"
+//  4. (double) 1
 func (cmd *KeyValueSliceCmd) readReply(rd *proto.Reader) error { // nolint:dupl
 	n, err := rd.ReadArrayLen()
 	if err != nil {

internal/once.go

@@ -32,7 +32,9 @@ type Once struct {
 
 // Do calls the function f if and only if Do has not been invoked
 // without error for this instance of Once.  In other words, given
+//
 //	var once Once
+//
 // if once.Do(f) is called multiple times, only the first call will
 // invoke f, even if f has a different value in each invocation unless
 // f returns an error.  A new instance of Once is required for each
@@ -41,6 +43,7 @@ type Once struct {
 // Do is intended for initialization that must be run exactly once.  Since f
 // is niladic, it may be necessary to use a function literal to capture the
 // arguments to a function to be invoked by Do:
+//
 //	err := config.once.Do(func() error { return config.init(filename) })
 func (o *Once) Do(f func() error) error {
 	if atomic.LoadUint32(&o.done) == 1 {

internal/proto/scan.go

@@ -11,6 +11,7 @@ import (
 )
 
 // Scan parses bytes `b` to `v` with appropriate type.
+//
 //nolint:gocyclo
 func Scan(b []byte, v interface{}) error {
 	switch v := v.(type) {

options.go

@@ -223,9 +223,13 @@ func NewDialer(opt *Options) func(context.Context, string, string) (net.Conn, er
 // Scheme is required.
 // There are two connection types: by tcp socket and by unix socket.
 // Tcp connection:
+//
 //	redis://<user>:<password>@<host>:<port>/<db_number>
+//
 // Unix connection:
+//
 //	unix://<user>:<password>@</path/to/redis.sock>?db=<db_number>
+//
 // Most Option fields can be set using query parameters, with the following restrictions:
 //   - field names are mapped using snake-case conversion: to set MaxRetries, use max_retries
 //   - only scalar type fields are supported (bool, int, time.Duration)
@@ -238,7 +242,9 @@ func NewDialer(opt *Options) func(context.Context, string, string) (net.Conn, er
 //     URL attributes (scheme, host, userinfo, resp.), query paremeters using these
 //     names will be treated as unknown parameters
 //   - unknown parameter names will result in an error
+//
 // Examples:
+//
 //	redis://user:password@localhost:6789/3?dial_timeout=3&db=1&read_timeout=6s&max_retries=2
 //	is equivalent to:
 //	&Options{

redis.go

@@ -29,9 +29,9 @@ func SetLogger(logger internal.Logging) {
 //------------------------------------------------------------------------------
 
 type Hook interface {
-	DialHook(hook DialHook) DialHook
-	ProcessHook(hook ProcessHook) ProcessHook
-	ProcessPipelineHook(hook ProcessPipelineHook) ProcessPipelineHook
+	DialHook(next DialHook) DialHook
+	ProcessHook(next ProcessHook) ProcessHook
+	ProcessPipelineHook(next ProcessPipelineHook) ProcessPipelineHook
 }
 
 type (
@@ -48,6 +48,43 @@ type hooks struct {
 	processTxPipelineHook ProcessPipelineHook
 }
 
+// AddHook is to add a hook to the queue.
+// Hook is a function executed during network connection, command execution, and pipeline,
+// it is a first-in-last-out stack queue (FILO).
+// The first to be added to the queue is the execution function of the redis command (the last to be executed).
+// You need to execute the next hook in each hook, unless you want to terminate the execution of the command.
+// For example, you added hook-1, hook-2:
+//
+//	client.AddHook(hook-1, hook-2)
+//
+// hook-1:
+//
+//	func (Hook1) ProcessHook(next redis.ProcessHook) redis.ProcessHook {
+//	 	return func(ctx context.Context, cmd Cmder) error {
+//		 	print("hook-1 start")
+//		 	next(ctx, cmd)
+//		 	print("hook-1 end")
+//		 	return nil
+//	 	}
+//	}
+//
+// hook-2:
+//
+//	func (Hook2) ProcessHook(next redis.ProcessHook) redis.ProcessHook {
+//		return func(ctx context.Context, cmd redis.Cmder) error {
+//			print("hook-2 start")
+//			next(ctx, cmd)
+//			print("hook-2 end")
+//			return nil
+//		}
+//	}
+//
+// The execution sequence is:
+//
+//	hook-2 start -> hook-1 start -> exec redis cmd -> hook-1 end -> hook-2 end
+//
+// Please note: "next(ctx, cmd)" is very important, it will call the next hook,
+// if "next(ctx, cmd)" is not executed in hook-1, the redis command will not be executed.
 func (hs *hooks) AddHook(hook Hook) {
 	hs.slice = append(hs.slice, hook)
 	hs.dialHook = hook.DialHook(hs.dialHook)
@@ -575,7 +612,7 @@ func (c *Client) Conn() *Conn {
 	return newConn(c.opt, pool.NewStickyConnPool(c.connPool))
 }
 
-// Do creates a Cmd from the args and processes the cmd.
+// Do create a Cmd from the args and processes the cmd.
 func (c *Client) Do(ctx context.Context, args ...interface{}) *Cmd {
 	cmd := NewCmd(ctx, args...)
 	_ = c.Process(ctx, cmd)