exec/bkgpslog-plan.org

   1 * bkgpslog task list
   2 ** DONE Add job control for short buffer length
   3    CLOSED: [2020-07-02 Thu 16:04]
   4 2020-07-02T14:56Z; bktei> File write operations were bundled into a
   5 magicWriteBuffer function that is called then detached from the script
   6 shell (job control), but the detached job is not tracked by the main
   7 script. A problem may arise if two instances of magicWriteBuffer
   8 attempt to write to the same tar simultaneously. Two instances of
   9 magicWriteBuffer may exist if the buffer length is low (ex: 1 second);
  10 the default buffer length of 60 seconds should reduce the probability
  11 of a collision but it should be possible for the main script to track
  12 the process ID of a magicWriteBuffer() as soon as it detaches and then
  13 checking (via ~$!~ as described [[https://bashitout.com/2013/05/18/Ampersands-on-the-command-line.html][here]]) that the process is still alive.
  14 2020-07-02T15:23Z; bktei> I found that the Bash ~wait~ built-in can be
  15 used to delay processing until a specified job completes. The ~wait~
  16 command will pause script execution until all backgrounded processes
  17 complete.
  18 2020-07-02T16:03Z; bktei> Added ~wait~.
  19 ** DONE Rewrite tar initialization function
  20    CLOSED: [2020-07-02 Thu 17:23]
  21 2020-07-02T17:23Z; bktei> Simplify tar initialization function so
  22 VERSION file is used to test appendability of tar as well as to mark
  23 when a new session is started.
  24 ** DONE Consolidate tar checking/creation into function
  25    CLOSED: [2020-07-02 Thu 18:33]
  26 2020-07-02T18:33Z; bktei> Simplify how the output tar file's existence
  27 is checked and its status as a valid tar file is validated. This was
  28 done using a new function ~checkMakeTar~.
  29 * bkgpslog narrative
  30 ** Initialize environment
  31 *** Init variables
  32 **** Save timeStart (YYYYmmddTHHMMSS±zz)
  33 *** Define Functions
  34 **** Define Debugging functions
  35 **** Define Argument Processing function
  36 **** Define Main function
  37 ** Run Main Function
  38 *** Process Arguments
  39 *** Set output encryption and compression option strings
  40 *** Check that critical apps and dirs are available, displag missing ones.
  41 *** Set lifespans of script and buffer
  42 *** Init temp working dir ~DIR_TMP~
  43 Make temporary dir in tmpfs dir: ~/dev/shm/$(nonce)..bkgpslog/~ (~DIR_TMP~)
  44 *** Initialize ~tar~ archive
  45 **** Write ~bkgpslog~ version to ~$DIR_TMP/VERSION~
  46 **** Create empty ~tar~ archive in ~DIR_OUT~ at ~PATHOUT_TAR~
  47
  48 Set output file name to:
  49 : PATHOUT_TAR="$DIR_OUT/YYYYmmdd..hostname_location.gz.age.tar"
  50 Usage: ~iso8601Period $timeStart $timeEnd~
  51
  52 **** Append ~VERSION~ file to ~PATHOUT_TAR~
  53
  54 Append ~$DIR_TMP/VERSION~ to ~PATHOUT_TAR~ via ~tar --append~
  55
  56 *** Read/Write Loop (Record gps data until script lifespan ends)
  57 **** Determine output file paths
  58 **** Define GPS conversion commands
  59 **** Fill Bash variable buffer from ~gpspipe~
  60 **** Process bufferBash, save secured chunk set to ~DIR_TMP~
  61 **** Append each secured chunk to ~PATHOUT_TAR~
  62 : tar --append --directory=DIR_TMP --file=PATHOUT_TAR $(basename PATHOUT_{NMEA,GPX,KML} )
  63 **** Remove secured chunk from ~DIR_TMP~