1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
# Lua Bloom Filter Module
## Overview
A Bloom filter is a space-efficient probabilistic data structure that is used to
test whether an element is a member of a set.
## Module
### Example Usage
```lua
require "bloom_filter"
local bf = bloom_filter.new(1000, 0.01)
local found = bf:query("test")
-- found == false
bf:add("test")
found = bf:query("test")
-- found == true
```
### Functions
#### new
```lua
require "bloom_filter"
local bf = bloom_filter.new(1000, 0.01)
```
Import the Lua _bloom_filter_ via the Lua 'require' function. The module is
globally registered and returned by the require function.
*Arguments*
- items (unsigned) The maximum number of items to be inserted into the filter
(must be > 1)
- probability (double) The probability of false positives (must be between 0
and 1)
*Return*
- bloom_filter userdata object.
#### version
```lua
require "bloom_filter"
local v = bloom_filter.version()
-- v == "1.0.0"
```
Returns a string with the running version of bloom_filter.
*Arguments*
- none
*Return*
- Semantic version string
### Methods
#### add
```lua
local added = bf:add(key)
```
Adds an item to the bloom filter.
*Arguments*
- key (string/number) The key to add in the bloom filter.
*Return*
- True if the key was added, false if it already existed.
#### query
```lua
local found = bf:query(key)
```
Checks for the existence of the key in the bloom filter.
*Arguments*
- key (string/number) The key to lookup in the bloom filter.
*Return*
- True if the key exists, false if it doesn't.
#### count
```lua
local added = bf:count()
```
Returns the number of items in the bloom.
*Arguments*
- none
*Return*
- Returns the number of distinct items added to the set.
#### clear
```lua
bf:clear()
```
Resets the bloom filter to an empty set.
*Arguments*
- none
*Return*
- none
|
