[Campaign] Optimize Showtime

[pulzarraider]

Changes:

• allow to disable fetching data for one time banners with env ONE_TIME_BANNER_ENABLED set to false (no more keys(...*) calls in redis),
• parsing the user agent is done only once,
• store results of device detection in redis (will save CPU in parsing user agent, fetching huge regexpes from Redis Cache for second request, but will consume more redis memory),
• fetch all running campaign with one mget() redis call instead of multiple get(),
• fetch maps with onemget() redis call instead of multiple get().
• add env REDIS_PERSISTENT for presistent redis connection.
• store result of browser/user segment check in array (will omit duplicated calls for campaigns with same sagments).
• refresh redis instance in Segment after deserialization to avoid duplicated redis connection in showtime.php

According to our performance tests against showtime.php (ab -n 10000 -c 20) the Campaign will be more efficient:

• v. 3.3.1: 12.25 req/s
• with this MR: 17.64 req/s (+5.39 req/s)

The optimization was developed by Petit Press a.s., which also created the DAM (Digital Asset Management) project in partnership with Google. This project is free and open source. Petit Press a.s. operates the www.sme.sk website.

[rootpd]

Thanks for the contribution. Since this is only the mirrored repository and we did rebase/squash the changes internally, they were side-merged via https://github.com/remp2020/remp/commit/f7272b826524e8360590b84f5736a24f56520168.