Reader API refactor

[rster2002]

Current reader progress:

• LogDir
  • DirIter (blocking)
  • DirIter (async)
  • LiveDirIter (blocking)
  • LiveDirIter (async)
  • LatestIter (blocking)
  • LatestIter (async)
  • JournalIter (blocking, always live)
  • JournalIter (async, always live)
• LogFile
  • Iter (blocking)
  • Iter (async)
  • LiveIter (blocking)
  • LiveIter (async)

[rster2002]

Current idea:

let log_dir = LogDir::new("some/path");
let mut live_dir_iter = log_dir.live_iter();

for log_file in live_dir_iter {
    let mut live_file_iter = log_file.live_iter();

    for log_event in live_file_iter {
        dbg!(log_event);
    }
}

[rster2002]

let log_dir = LogDir::new("some/path");

for latest in live_latest.live_latest() {
    for entry in latest.live_iter() {
        dbg!(entry);
    }
}