pyrate_limiter.buckets.redis_bucket module#
Bucket implementation using Redis
- class pyrate_limiter.buckets.redis_bucket.LuaScript#
Bases:
objectScripts that deal with bucket operations
- PUT_ITEM = "\n local bucket = KEYS[1]\n local now = ARGV[1]\n local space_required = tonumber(ARGV[2])\n local item_name = ARGV[3]\n local rates_count = tonumber(ARGV[4])\n\n for i=1,rates_count do\n local offset = (i - 1) * 2\n local interval = tonumber(ARGV[5 + offset])\n local limit = tonumber(ARGV[5 + offset + 1])\n local count = redis.call('ZCOUNT', bucket, now - interval, now)\n local space_available = limit - tonumber(count)\n if space_available < space_required then\n return i - 1\n end\n end\n\n for i=1,space_required do\n redis.call('ZADD', bucket, now, item_name..i)\n end\n return -1\n "#
- class pyrate_limiter.buckets.redis_bucket.RedisBucket(rates, redis, bucket_key, script_hash)#
Bases:
pyrate_limiter.abstracts.bucket.AbstractBucketA bucket using redis for storing data - We are not using redis’ built-in TIME since it is non-deterministic - In distributed context, use local server time or a remote time server - Each bucket instance use a dedicated connection to avoid race-condition - can be either sync or async
- bucket_key#
- count()#
Count number of items in the bucket
- flush()#
Flush the whole bucket - Must remove failing-rate after flushing
- classmethod init(rates, redis, bucket_key)#
- leak(current_timestamp=None)#
leaking bucket - removing items that are outdated
- peek(index)#
Peek at the rate-item at a specific index in latest-to-earliest order NOTE: The reason we cannot peek from the start of the queue(earliest-to-latest) is we can’t really tell how many outdated items are still in the queue
- rates#
- redis#
- script_hash#