Add support for LCS Command

[SoulPancake]

Fixes #2403

[monkey92t]

my thoughts:

type LCSMatch struct {
	Matches []LCSMatchedPosition
	Len     int
}

type LCSMatchedPosition struct {
        // or A/B ?
	Key1     LCSPosition
	Key2     LCSPosition

        // only for withMatchLen is true
	MatchLen int
}

type LCSPosition struct {
	Start int
	End   int
}

// lcs key1 key2
func LCS(key1, key2 string) *StringCmd {}

// lcs key1 key2 len
func LCSLen(key1, key2 string) *IntCmd {}

// lcs key1 key2 idx minmatchlen minMatchLen withmatchlen
// or *LCSMatchCmd
func LCSIdx(key1, key2 string, minMatchLen int, withMatchLen bool) *LCSCmd {}

//--------------

// OR
type LCSQuery struct {
	Key1         string
	Key2         string
	Len          bool
	Idx          bool
	MinMatchLen  int
	WithMatchLen bool
}

func LCS(key1, key2 string, len, idx bool, minMatchLen int, withMatchLen bool) *LCSCmd {}
func LCS(q *LCSQuery) *LCSCmd{}

😀😀😀😀 comments are welcome~

[monkey92t]

exp:

type LCSMatch struct {
	MatchString string
	Matches     []LCSMatchedPosition
	Len         int64
}

type LCSMatchedPosition struct {
	// or A/B ?
	Key1 LCSPosition
	Key2 LCSPosition

	// only for withMatchLen is true
	MatchLen int
}

type LCSPosition struct {
	Start int
	End   int
}

type LCSCmd struct {
	baseCmd

	// 1: match string
	// 2: match len
	// 3: match idx LCSMatch
	readType uint8
	val      *LCSMatch
}

func (cmd *LCSCmd) readReply(rd *proto.Reader) (err error) {
	lcs := &LCSMatch{}
	switch cmd.readType {
	case 1:
		// match string
		lcs.MatchString, err = rd.ReadString()
	case 2:
		// match len
		if lcs.Len, err = rd.ReadInt(); err != nil {
			return err
		}
	case 3:
		// read LCSMatch
		if err = rd.ReadFixedMapLen(2); err != nil {
			return err
		}

		key, err := rd.ReadString()
		if err != nil {
			return err
		}

		// we should not depend on the order of the map.
		switch key {
		case "matches":
			n, err := rd.ReadArrayLen()
			if err != nil && err != Nil {
				return err
			}
			for i := 0; i < n; i++ {
				// read LCSMatchedPosition
				// miss..
			}
		case "len":
			if lcs.Len, err = rd.ReadInt(); err != nil {
				return err
			}
		}
	}

	cmd.val = lcs
	return nil
}

type LCSQuery struct {
	Key1         string
	Key2         string
	Len          bool
	Idx          bool
	MinMatchLen  int
	WithMatchLen bool
}

func LCS(ctx context.Context, q *LCSQuery) *LCSCmd {
	// ...miss
	return &LCSCmd{}
}

// call
lcs, err := rdb.LCS(ctx, &LCSQuery{
	//...
}).Result()

lcs.MatchString()
lcs.Len()
lcs.Matches[0].Key1.Start

[monkey92t]

any thoughts on my example?

[SoulPancake]

any thoughts on my example?

Thanks for your example!
It seems like a good approach
@monkey92t I am trying to build using your example only as you can see in the latest pushes

[SoulPancake]

Hi @monkey92t
Need some help here
I am not sure if I should implement the MarshalBinary() function for the interface slice or should I read some other way
I am having difficulty in this, Can you please guide me

[monkey92t]

I don't quite understand what you mean. What does this have to do with MarshalBinary?

[SoulPancake]

@monkey92t As I'm getting the error for the same on the test
And it is mentioned https://github.com/SoulPancake/go-redis/blob/e69c70c7b6e63da86eb5853ddd493bea7dda2a1d/commands.go#L1403 here to implement it
Is this the right approach?

[monkey92t]

No, that's not it. I will make some modifications to the PR later.

[SoulPancake]

Thanks @monkey92t :) I was overcomplicating it

[SoulPancake]

@monkey92t As this looks good , we can merge it right?
Is there anything else left to do here?

[SoulPancake]

LGTM

[SoulPancake]

@monkey92t The build failure seems unrelated

[monkey92t]

@monkey92t The build failure seems unrelated

We use redis-server/sentinel/cluster to perform tests, and sometimes encounter failures due to network errors.

[SoulPancake]

@monkey92t Had a general question, how were you able to run the build actions again without pushing a new commit?

[monkey92t]

@monkey92t Had a general question, how were you able to run the build actions again without pushing a new commit?

You need to manually build or rebuild the projects that you have permissions for in Github Actions.