The goal of this plugin is to mirror GHTorrent.

This stage reduces all commits to a stats object keyed on their commit date (hourly). The stats object looks like this:

  case class Stats(date: String, commitStats: CommitStats)

  case class CommitStats(totalCommits: Long, filesEdited: List[Extension])

  case class Extension(name: String,
                       additions: Long,
                       deletions: Long,
                       added: Long,
                       removed: Long,
                       modified: Long)

In summary, every commit is keyed by date (e.g. 2019-01-01 09) and then its stats are deduced and merged. Finally these stats are saved (and updated) in MongoDB. Example stats object:

{
    "date" : "2013-02-06 11",
    "commitStats" : {
        "totalCommits" : 1,
        "filesEdited" : [ 
            {
                "name" : "js",
                "additions" : 28,
                "deletions" : 23,
                "added" : 0,
                "removed" : 0,
                "modified" : 1
            }, 
            {
                "name" : "css",
                "additions" : 1,
                "deletions" : 2,
                "added" : 0,
                "removed" : 0,
                "modified" : 1
            }
        ]
    }
}

The idea of this stage is to enrich Commit data with their corresponding PushEvent (if available). I.e. Add the push_id and push_date to a Commit.

The commit is enriched in the following case class:

  case class Pushed(push_id: Long,
                    push_date: Date,
                    pushed_from_github: Boolean = false)

  case class EnrichedCommit(push: Option[Pushed], commit: Commit)

All data is pushed into the cf_commit topic.

The flow diagram of this low-level join can be found below:

The potential outcomes are:

• PushEvent can be found and Commit is enriched with push_id and push_date.
• PushEvent can not be found but it is derived that Commit is directly pushed from GH. The Commit is then enriched with no push_id and the push_date == commit_date.
• No PushEvent can be found and Commit is just forwarded without Pushed data.