Notice: This repository is no longer maintained as of 3/26/2024

WHOOP Erlang utils

A collection of useful Erlang modules

Include wutils in your application list to use it.

Build

$ rebar3 compile

Contents

Database pool

Episcina + pgsql for Postgres database pooling.

Include the following in your configuration (size and timeout may be changed):

{episcina,
  [{pools,
    [{primary,
      [{size, 10}
      ,{timeout, 20000}
      ,{connect_provider, {wutils_db, ep_open, []}}
      ,{close_provider, {wutils_db, ep_close, []}}
    ]}
  ]}
]}

Connection info comes from the environment variables: PGUSER, PGPASSWORD, PGDATABASE, PGHOST, PGPORT

Use the pool like this:

PG = wutils_db:open(),
Result = PG:simple_query("SELECT hello FROM world"),
wutils_db:close(PG),
Result.

or the shorter form for one-off queryies:

Result = wutils_db:run("SELECT hello FROM world WHERE id = $1", [Id]).

SQL query repository

Read a directory full of SQL queries and store them in memory for later use

Include the following in your configuration:

{wutils,
  [{sql_source_applications, [app1, app2]}
]}

where app1 and app2 are application names. For each item in the list, the application is expected to have a priv directory which will be scanned for .sql files. Each file is loaded as a query.

Listing more than one application will behave as if the directories have been merged. It's an error to have files with the same name and different content.

Datetime utilities

wutils_time:datetime() is an extended datetime format: {{Year, Month, Day}, {Hour, Minute, Second, Millisecond}}

epoch_to_datetime/1 and datetime_to_epoch convert between the datetime tuple and milliseconds since Unix epoch.

parse_iso/1 and format_iso/1 convert between the datetime tuple and the ISO8601 date+time string format. The parser is not terrifically robust, but will handle JavaScript's Date.prototype.toISOString().