origin(url) {
  url
  snapshots
}

snapshots(origin-url, limit)  // not a must have

snapshot(sha1) {
  sha1
  origin
  timestamp        // timestamp from the visit table, a bit tricky as there could be many visits pointing to the same snapshot
  branches(limit) {
     name
     head revision
  }
}

revision(sha1) {
  sha1
  origins(limit)    // a bit tricky, one revision can be in many origins
  snapshots(limit)  // a bit tricky
  author
  ...
  parent revisions(limit)
  directory
}

directory(sha1) {
  sha1
  name
  ...
  contents(limit)
}

content(sha1) {
  sha1
  name
  ...
}