base/bif/cardinality-counter.bif.zeek¶
-
GLOBAL
¶
Functions to create and manipulate probabilistic cardinality counters.
Namespace: | GLOBAL |
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Summary¶
Functions¶
hll_cardinality_add : function |
Adds an element to a HyperLogLog cardinality counter. |
hll_cardinality_copy : function |
Copy a HLL cardinality counter. |
hll_cardinality_estimate : function |
Estimate the current cardinality of an HLL cardinality counter. |
hll_cardinality_init : function |
Initializes a probabilistic cardinality counter that uses the HyperLogLog algorithm. |
hll_cardinality_merge_into : function |
Merges a HLL cardinality counter into another. |
Detailed Interface¶
Functions¶
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hll_cardinality_add
¶ Type: function
(handle:opaque
of cardinality, elem:any
) :bool
Adds an element to a HyperLogLog cardinality counter.
Handle: the HLL handle. Elem: the element to add. Returns: true on success. See also:
hll_cardinality_estimate
,hll_cardinality_merge_into
,hll_cardinality_init
,hll_cardinality_copy
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hll_cardinality_copy
¶ Type: function
(handle:opaque
of cardinality) :opaque
of cardinalityCopy a HLL cardinality counter.
Handle: cardinality counter to copy. Returns: copy of handle. See also:
hll_cardinality_estimate
,hll_cardinality_merge_into
,hll_cardinality_add
,hll_cardinality_init
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hll_cardinality_estimate
¶ Type: function
(handle:opaque
of cardinality) :double
Estimate the current cardinality of an HLL cardinality counter.
Handle: the HLL handle. Returns: the cardinality estimate. Returns -1.0 if the counter is empty. See also:
hll_cardinality_merge_into
,hll_cardinality_add
,hll_cardinality_init
,hll_cardinality_copy
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hll_cardinality_init
¶ Type: function
(err:double
, confidence:double
) :opaque
of cardinalityInitializes a probabilistic cardinality counter that uses the HyperLogLog algorithm.
Err: the desired error rate (e.g. 0.01). Confidence: the desired confidence for the error rate (e.g., 0.95). Returns: a HLL cardinality handle. See also:
hll_cardinality_estimate
,hll_cardinality_merge_into
,hll_cardinality_add
,hll_cardinality_copy
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hll_cardinality_merge_into
¶ Type: function
(handle1:opaque
of cardinality, handle2:opaque
of cardinality) :bool
Merges a HLL cardinality counter into another.
Note
The same restrictions as for Bloom filter merging apply, see
bloomfilter_merge
.Handle1: the first HLL handle, which will contain the merged result. Handle2: the second HLL handle, which will be merged into the first. Returns: true on success. See also:
hll_cardinality_estimate
,hll_cardinality_add
,hll_cardinality_init
,hll_cardinality_copy