volume analysis

[samparsky]

Fix #200

[Ivshti]

also test it with adex-explorer and do a PR there to support this

[Ivshti]

this should work on counts too; it should be a parameter like event-aggregates

the event type (IMPRESSION) should be a parameter too

[Ivshti]

@samparsky I will approve/merge that when the relevant PR is made in adex-explorer

[Ivshti]

bugs/issues:

• setting period to 0 for authenticated users doesn't make any sense cause you allow after to be set only if period is truthy
• allowDiskUse shouldn't be needed if indexes are done right; using it is not a good practice
• never convert to a number with +, it's not intuitive
• getting user-specific data doesn't really work; it only matches aggregates that contain that user, but it still sums all the stats from them, rather than only extracting the user-specific stats
• eventCounts now saves ${uid}:${adUnitId}, so not even the $match for that would work, since it's a strict match for eventCounts.${uid}
• caching does not account for the UID, so one user would be getting the cached data for the user who previously queried

don't touch for now, I'm rewriting

[Ivshti]

another one

• must be celebrate({ query: ... rather than body