I have a simple tactic for all very close encounters. My wife, who has no military training and little range time, she can do it. What I do is hold out my off hand in a stop gesture, and it does literally mean stop, but this prevents the attacker from getting any closer while my right hand draws.
I can draw in the blink of an eye, and when I do it reflexively out of surprise, it seems crazy fast. Still, if the guy were close enough, I expect to get cut, but getting a booboo on your hand or wrist, that is a whole lot different from getting disemboweled or losing an eye. After the draw, I don't extend the pistol, I hold it next to my torso so it can't be easily taken away, and with my off hand still extended, I fire, point shooting "from the hip" although the pistol is actually closer to my ribcage. If there are no obstacles, I may back up carefully while doing this. All of this will look better in court too when you think about it --the entire tactic is purely defensive and even looks that way to anyone observing, especially if you are backing up. This looks like you are trying to get away and really don't want to shoot (which you should be).
Most folks can't fight with a knife. H. Gracie told this to a buddy of mine that lived in Brazil and trained with the man himself for a year. We just don't know how in general, a lost skill, firearms replaced 'em for the most part. So for me, a simple defensive plan is all I need. Biggest thing about knives in a fight is they can do much more serious damage up close real fast, and in the hands of a real knife fighter, I guess you are screwed if you let them get too close. You want to protect arteries and organs first and foremost, and you want to get the upper hand too. You may end up getting cut, but sacrificing your off hand to buy you a second for the draw seems okay to me. Chances are you won't feel it for a bit anyway. Even if they cut off your whole hand, you won't bleed out fast enough to die (although you may pass out or get woozy if you are one of those...). Take off your gun belt and turn it into a tourniquet, presto.
In addition to this, my wife, she carries a 649 revolver. Thinking about getting the Crimson Trace grips for her as both a deterrent and aiming aid; although point shooting is 95% of this tactic, the laser has and can deter the attacker, and in the heat of a very close encounter, it can aid in aiming.
Hope this helps. It is really the best I could think of... I assume anyone attacking me is armed and can close the distance fast, so I use the same simple tactic. If my target is farther away, I complete the draw by bringing the shooting hand up and forming a two hand stance. All nice and fluid. This also works for when you take fire and must return fire fast --you can get two rounds off WHILE completing the draw --one when it clears the holster and another as you extend. Again, it all happens in a split second.
Having one simple tactic that works great for most public encounters is ideal for most of us. Although this might not work everytime, it will work most of the time, and it is very simple to learn and employ. It is also natural, if attacked and trying to draw, many folks instinctively put out a hand anyway almost as if saying, "Wait, I'm not ready!"
Try it out. Get a rubber knife or make a cardboard one and try it. Make sure to unload your pistol first! Then try it out with the wife or a friend or whatever. You'll see it works pretty well, and in fact, so well I can't really think of another way to respond.
Whatever you do, don't try disarm procedures unless you know what you are doing and have done this in training. Especially if armed. I'd only do a disarm technique if I were very close and unarmed and had no other choice.