RedisScan

Recursively scans the keyspace of a Redis 2.8+ instance using SCAN, HSCAN, ZSCAN, & SSCAN as well as Lists.

Fairly safe in a production environment as it does NOT use KEYS * to iterate.

Optionally pass a redis pattern to filter from.

Install

npm install redisscan

Example

var redisScan = require('redisscan');
var redis     = require('redis').createClient();


redisScan({
    redis: redis,
    pattern: 'awesome:key:prefix:*',
    keys_only: false,
    each_callback: function (type, key, subkey, length, value, cb) {
        console.log(type, key, subkey, length, value);
        cb();
    },
    done_callback: function (err) {
        console.log("-=-=-=-=-=--=-=-=-");
        redis.quit();
    }
});

redisScan(parameters):

• redis: required node-redis client instance
• pattern: optional wildcard key pattern to match, e.g: some:key:pattern:* docs
• keys_only: optional boolean -- returns nothing but keys, no types,lengths,values etc. (defaults to false)
• count_amt: optional positive/non-zero integer -- redis hint for work done per SCAN operation (defaults to 10) docs
• each_callback: required function (type, key, subkey, length, value, next) This is called for every string, and every subkey/value in a container when not using keys_only, so outer keys may show up multiple times.
  • type may be "string", "hash", "set", "zset", "list"
  • key is the redis key
  • subkey may be null or populated with a hash key
  • length is the length of a set or list
  • value is the value of the key or subkey when appropriate
  • next() should be called as a function with no arguments if successful or an Error object if not.
• done_callback: optional function called when scanning completes with one argument, and Error object if an error ws raised

Note/Warning

If values are changing, there is no guarantee on value integrity. This is not atomic. I recommend using a lock pattern with this function.

License MIT (c) 2014 Nathanael C. Fritz