Function cmdFirstKeyPosWithInfo

command.go:285–319

cmdFirstKeyPosWithInfo returns the first key position in a command's args (0 if none). Uses CommandInfo.FirstKeyPos when available (via cache peek, no network call), falling back to a hardcoded table. eval/evalsha variants are resolved from the runtime numkeys arg.

(cmd Cmder, info *CommandInfo)

// Uses CommandInfo.FirstKeyPos when available (via cache peek, no network call), falling
// back to a hardcoded table. eval/evalsha variants are resolved from the runtime numkeys arg.
func cmdFirstKeyPosWithInfo(cmd Cmder, info *CommandInfo) int {
	if pos := cmd.firstKeyPos(); pos != 0 {
		return int(pos)
	}

	name := cmd.Name()

	// first check if the command is keyless
	if _, ok := keylessCommands[name]; ok {
		return 0
	}

	switch name {
	case "eval", "evalsha", "eval_ro", "evalsha_ro":
		if cmd.stringArg(2) != "0" {
			return 3
		}

		return 0
	case "memory":
		// https://github.com/redis/redis/issues/7493
		if cmd.stringArg(1) == "usage" {
			return 2
		}
		// CommandInfo (if available) gives the correct answer
		// otherwise the hardcoded fallback applies.
	}

	// Use CommandInfo cache when warm (in-memory only, no extra round-trips).
	if info != nil {
		return int(info.FirstKeyPos)
	}

	return 1
}

func cmdString(cmd Cmder, val interface{}) string {
	b := make([]byte, 0, 64)