Node.js Redis get all values in a hashmap

Question

I'm converting some code that used hashmaps to redis. I ran into an issue when trying to duplicate the Hashmap function .values().

With hashmaps:

 var hTest = new HashMap();
 hTest.set('1','hello');
 hTest.set('2','world'});
 console.log(hTest.values());

Outputs: ['hello','world']

But Redis doesn't seem to have an equivalent. Closest I have found was:

client.hset("rTest", "1", 'hello'); 
client.hset("rTest", "2", 'world'});
client.hgetall("rTest",function(err, values){
 console.log(values)
});

Outputs {'1','hello','2','world'}

I know I can create a for loop and cycle through the reply but I'm hoping there's a command similar to the hashmap.values() one.

Answer 1

You can use HVALS commands to get all values in the hash.

However, if the hash is very large, it's always a bad idea to call HVALS or HGETALL. It might block Redis for a long time, since Redis is single-threaded.

Instead, you can use HSCAN to incrementally iterate the hash. And that should be the recommended way for getting all values of a large hash.

• Woodsy: Thank you. The maps I'm dealing with should never get very large, a couple of values at most so HVALS will work. (I'm sure I just jinxed myself and this map will grow to a couple million records now now)