R/engineer-features-base.R

In lorenzwalthert/gitsum: Parse and summarize git repositories

#' Add base attributes to a log
#'
#' @param log An unnested log.
#' @details
#' Derives some attributes from the parsed raw log and converts them to the
#' desired format.
#' The following attributes merit special mentioning:
#'
#' * commit_nr: The number of the commit in the repo. This can be used to sort
#'   commits (in contrast to the commit date) in chronological order, that is,
#'   in the oder in which they were committed.
#' @keywords internal
add_attributes_detailed <- function(log) {
  mutate(log,
    date = ymd_hms(paste(.data$year, .data$month, .data$monthday, .data$time)),
    short_hash = substr(.data$hash, 1, 4),
    short_message = substr(.data$message, 1, 20),
    short_description = ifelse(!is.na(.data$message),
                                substr(.data$description, 1, 20), NA
    ),
    is_merge = ifelse(!is.na(.data$left_parent) & !is.na(.data$right_parent),
                       TRUE, FALSE
    )
  ) %>%
    add_is_exact()
}

#' @importFrom hms parse_hm
type_convert_base_attributes <- function(log) {
  log %>%
    mutate(
      monthday = as.integer(.data$monthday),
      month = as.character(.data$month),
      hash = as.character(.data$hash),
      time = parse_hm(.data$time),
      year = as.integer(.data$year),
      total_files_changed = as.integer(.data$total_files_changed),
      total_insertions = as.integer(.data$total_insertions),
      total_deletions = as.integer(.data$total_deletions),
      edits = as.integer(ifelse(edits != "", .data$edits, 0)),
      insertions = ifelse(.data$insertions != "", nchar(.data$insertions), 0),
      deletions = ifelse(.data$deletions != "", nchar(.data$deletions), 0),
      changed_file = trimws(.data$changed_file)
    )
}

#' Is the information exact?
#'
#' Create a column indicating whether insertions and deletions are exact counts.
#' @inheritParams add_attributes_detailed
#' @keywords internal
add_is_exact <- function(log) {
  mutate(log,
    total_approx = .data$insertions + .data$deletions,
    multiplier = .data$edits / .data$total_approx,
    insertions =  as.integer(round(.data$multiplier * .data$insertions)),
    deletions =  as.integer(round(.data$multiplier * .data$deletions)),
    is_exact = if_else((is.na(.data$edits) | .data$multiplier == 1), TRUE, FALSE)
  )  %>%
    select(-.data$multiplier, -.data$total_approx)

}