/kləNGk/
noun
A heavy, dull sound such as that made by thick pieces of metal striking together.
Talking to Postgres via sockets. At this point in time, I'm just experimenting with Clojure; learning core.async.
Running The Tests
You need to have a Postgres (13) Database up and running.
docker compose up -dNow you can run the tests with
clj -X:testExample
(ns scratch.client
(:require
[clojure.core.async :as async]
[com.clunk.core :as clunk]))
(def cfg {:username "jimmy"
:password "banana"
:database "world"
:debug true})We can now create a client, and connect to the postgres instance:
(def client (clunk/client cfg))
(clunk/connect client)We will see a bunch of received messages:
{:type :AuthenticationMD5, :salt #object["[B" 0x5ea94109 "[B@5ea94109"]}
{:type :AuthenticationOk}
{:type :ParameterStatus, :param "application_name", :status ""}
{:type :ParameterStatus, :param "client_encoding", :status "UTF8"}
{:type :ParameterStatus, :param "DateStyle", :status "ISO, MDY"}
{:type :ParameterStatus, :param "integer_datetimes", :status "on"}
{:type :ParameterStatus, :param "IntervalStyle", :status "postgres"}
{:type :ParameterStatus, :param "is_superuser", :status "on"}
{:type :ParameterStatus, :param "server_encoding", :status "UTF8"}
{:type :ParameterStatus, :param "server_version", :status "13.4 (Debian 13.4-1.pgdg100+1)"}
{:type :ParameterStatus, :param "session_authorization", :status "jimmy"}
{:type :ParameterStatus, :param "standard_conforming_strings", :status "on"}
{:type :ParameterStatus, :param "TimeZone", :status "Etc/UTC"}
{:type :BackendKeyData, :id 239, :key 2031531424}
{:type :ReadyForQuery, :status 73}Finally we can define and run a query. The <query! macro is shorthand for an async take on the channel returned from clunk/query. It must be run inside a go block.
(def qs "SELECT name, region, population FROM country ORDER BY name LIMIT 10;")
(async/go-loop
[]
(when-let [recv (clunk/<query! client qs)]
(println recv)
(recur)))The above async loop prints out the following:
{:name Afghanistan, :region Southern and Central Asia, :population 22720000}
{:name Albania, :region Southern Europe, :population 3401200}
{:name Algeria, :region Northern Africa, :population 31471000}
{:name American Samoa, :region Polynesia, :population 68000}
{:name Andorra, :region Southern Europe, :population 78000}
{:name Angola, :region Central Africa, :population 12878000}
{:name Anguilla, :region Caribbean, :population 8000}
{:name Antarctica, :region Antarctica, :population 0}
{:name Antigua and Barbuda, :region Caribbean, :population 68000}
{:name Argentina, :region South America, :population 37032000}And lastly, close the client:
(clunk/close client)Rough Todo / Help needed
- Build out CLJS test suite
- Figure out a good way to provide async query results
- Fix core.async channel closing issues
- Flush out frontend/backend message parsers
- Deploy to Clojars
- Deploy to npm