gitloc.R

#!/usr/bin/R

# this script is poorly-written, so use at your own risk.
 
# ---------------------------------------------------------------
#
# THIS HAS A VERY GOOD CHANCE OF COMPLETELY DESTROYING YOUR REPO;
# ONLY RUN THIS ON A COPY OF THE REPO!!!
#
# ----------------------------------------------------------------

require("ggplot2")
require("dplyr")

get_git_loc <- function( id = "Rcpp11/Rcpp11", filter ){
    repo <- sub( "^.*/", "", id )  
  
    owd <- setwd( tempdir() )
    on.exit( setwd(owd) )
    if( file.exists(repo) ) unlink(repo, recursive = TRUE)  
    system( sprintf( "git clone -q https://github.com/%s.git", id) )    
    setwd( repo )
    
    # -- grab the ids for each commit in the repo
    commit_ids <- lapply( 
        strsplit(system('git rev-list --all --pretty=oneline', intern = TRUE), '\n'), 
        function (line) {
            strsplit(line, ' ')[[1]][1]
        }
    )
     
    # -- your head will usually be the most recent commit, so checkout most recent commit first.
     
    current_HEAD <- commit_ids[[1]]
    system(paste0('git checkout -q ', current_HEAD))
     
    # if you have lots of commits or are testing adjust this slice to 1..100 or something similar
    commit_ids <- commit_ids[1:length(commit_ids)]
     
    ls_cmd <- if( missing(filter) ){
        'git ls-files | xargs wc -l'
    } else {
        sprintf('git ls-files | grep "%s" | xargs wc -l', filter)
    }
    
    commit_info <- lapply(commit_ids, function (id) {
     
        invisible( system(paste0('git checkout -q ', id)) )
     
        # -- get information on the version controlled lines of code
        all_lines <- system(ls_cmd, intern = TRUE)
        lines <- strsplit(all_lines, '\n')
     
        # get the number giving the lines of code
        lines_of_code <- if( length(lines) ){
            as.numeric(gsub('[^0-9]', '', lines[[length(lines)]]))
        } else {
            0  
        }
      
        # get the date of the current commit
        date  <- as.POSIXct(as.numeric( system(paste('git show -s --format=%ct', id), intern = TRUE) ), origin = "1970-01-01" )
        msg   <- paste( system("git show -s --format=%B", intern = TRUE), collapse = " " )
        data.frame(lines = lines_of_code, time = date, id = id, msg = msg, stringsAsFactors = FALSE)
    })
    
    rbind_all(commit_info) %>% filter(lines > 0, !is.na(time)) 
}

Rcpp11 <- get_git_loc( "Rcpp11/Rcpp11", filter = "h$" )
Rcpp   <- get_git_loc( "RcppCore/Rcpp", filter = "h$" )

data   <- rbind( cbind(Rcpp11, impl = "Rcpp11" ), cbind(Rcpp, impl = "Rcpp" ) )
# just avoiding last spike due to git 
data   <- filter( data, id != "21e9666c6b7b2154be3c28e55251965eb2a42662" )

print(
  ggplot(data, aes(time, lines, by = impl, colour = impl) ) + geom_line()
)