BF.INSERT

BF.INSERT

BF.INSERT key [CAPACITY capacity] [ERROR error]
  [EXPANSION expansion] [NOCREATE] [NONSCALING] ITEMS item [item
  ...]

Available in:

Redis Stack / Bloom 1.0.0

Time complexity:

O(k * n), where k is the number of hash functions and n is the number of items

BF.INSERT is a sugarcoated combination of BF.RESERVE and BF.ADD. It creates a new filter if the key does not exist using the relevant arguments (see BF.RESERVE). Next, all ITEMS are inserted.

Parameters

• key: The name of the filter
• item: One or more items to add. The ITEMS keyword must precede the list of items to add.

Optional parameters:

• NOCREATE: (Optional) Indicates that the filter should not be created if it does not already exist. If the filter does not yet exist, an error is returned rather than creating it automatically. This may be used where a strict separation between filter creation and filter addition is desired. It is an error to specify NOCREATE together with either CAPACITY or ERROR.
• capacity: (Optional) Specifies the desired capacity for the filter to be created. This parameter is ignored if the filter already exists. If the filter is automatically created and this parameter is absent, then the module-level capacity is used. See BF.RESERVE for more information about the impact of this value.
• error: (Optional) Specifies the error ratio of the newly created filter if it does not yet exist. If the filter is automatically created and error is not specified then the module-level error rate is used. See BF.RESERVE for more information about the format of this value.
• NONSCALING: Prevents the filter from creating additional sub-filters if initial capacity is reached. Non-scaling filters require slightly less memory than their scaling counterparts. The filter returns an error when capacity is reached.
• expansion: When capacity is reached, an additional sub-filter is created. The size of the new sub-filter is the size of the last sub-filter multiplied by expansion. If the number of elements to be stored in the filter is unknown, we recommend that you use an expansion of 2 or more to reduce the number of sub-filters. Otherwise, we recommend that you use an expansion of 1 to reduce memory consumption. The default expansion value is 2.

Return

An array of booleans (integers). Each element is either true or false depending on whether the corresponding input element was newly added to the filter or may have previously existed.

Examples

Add three items to a filter with default parameters if the filter does not already exist:

BF.INSERT filter ITEMS foo bar baz

Add one item to a filter with a capacity of 10000 if the filter does not already exist:

BF.INSERT filter CAPACITY 10000 ITEMS hello

Add 2 items to a filter with an error if the filter does not already exist:

BF.INSERT filter NOCREATE ITEMS foo bar