vislee / lua-resty-hyperloglog

Hyperloglog for openresty.

lua-resty-hyperloglog

lua-resty-hyperloglog is hyperloglog for openresty.

Table of Contents

• Status
• Synopsis
• Methods
  • new
  • insert
  • count
  • merge
  • close
• Author
• Copyright and License

Status

This library is still under early development and is still experimental.

Synopsis

http {

    ...

    lua_shared_dict hll_count 10m;

    init_by_lua_block {
        local hll = require "resty.hyperloglog"
        h = hll.new("hll_count", 12)
    }

    server {
        listen 8080;

        location / {
            access_by_lua_block {
                h:insert(ngx.var.uri)
            }

            ...
        }

        location = /stats {
            content_by_lua_block {
                ngx.print("count:", h:count())
                ngx.exit(ngx.HTTP_OK)
            }
        }
    }
}

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Methods

new

syntax: h, err = hll.new(name, log2m)

Create a hyperloglog object with 2^log2m bucket. Returns nil on error.

insert

syntax: h:insert(str)

Insert a string to hyperloglog object.

count

syntax: c = h:count()

Returns the cardinality of the hyperloglog object.

merge

syntax: ok, err = h:merge(h2)

Merge another hyperloglog object(h2) into h. Returns false on error.

close

syntax: h:close()

Close the hyperloglog object.

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Author

wenqiang li(vislee)

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Copyright and License

This module is licensed under the BSD License.

Copyright (C) by vislee.

All rights reserved.

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