[EVA-2020-02.git] / exec / bkgpslog-plan.org

* bkgpslog task list
** DONE Add job control for short buffer length
   CLOSED: [2020-07-02 Thu 16:04]
2020-07-02T14:56Z; bktei> File write operations were bundled into a
magicWriteBuffer function that is called then detached from the script
shell (job control), but the detached job is not tracked by the main
script. A problem may arise if two instances of magicWriteBuffer
attempt to write to the same tar simultaneously. Two instances of
magicWriteBuffer may exist if the buffer length is low (ex: 1 second);
the default buffer length of 60 seconds should reduce the probability
of a collision but it should be possible for the main script to track
the process ID of a magicWriteBuffer() as soon as it detaches and then
checking (via ~$!~ as described [[https://bashitout.com/2013/05/18/Ampersands-on-the-command-line.html][here]]) that the process is still alive.
2020-07-02T15:23Z; bktei> I found that the Bash ~wait~ built-in can be
used to delay processing until a specified job completes. The ~wait~
command will pause script execution until all backgrounded processes
complete.
2020-07-02T16:03Z; bktei> Added ~wait~.
* bkgpslog narrative
** Initialize environment
*** Init variables
**** Save timeStart (YYYYmmddTHHMMSS±zz)
*** Define Functions
**** Define Debugging functions
**** Define Argument Processing function
**** Define Main function
** Run Main Function
*** Process Arguments
*** Set output encryption and compression option strings
*** Check that critical apps and dirs are available, displag missing ones.
*** Set lifespans of script and buffer
*** Init temp working dir ~DIR_TMP~
Make temporary dir in tmpfs dir: ~/dev/shm/$(nonce)..bkgpslog/~ (~DIR_TMP~)
*** Initialize ~tar~ archive
**** Write ~bkgpslog~ version to ~$DIR_TMP/VERSION~
**** Create empty ~tar~ archive in ~DIR_OUT~ at ~PATHOUT_TAR~

Set output file name to:
: PATHOUT_TAR="$DIR_OUT/YYYYmmdd..hostname_location.gz.age.tar"
Usage: ~iso8601Period $timeStart $timeEnd~ 

**** Append ~VERSION~ file to ~PATHOUT_TAR~

Append ~$DIR_TMP/VERSION~ to ~PATHOUT_TAR~ via ~tar --append~

*** Read/Write Loop (Record gps data until script lifespan ends)
**** Determine output file paths
**** Define GPS conversion commands
**** Fill Bash variable buffer from ~gpspipe~
**** Process bufferBash, save secured chunk set to ~DIR_TMP~
**** Append each secured chunk to ~PATHOUT_TAR~
: tar --append --directory=DIR_TMP --file=PATHOUT_TAR $(basename PATHOUT_{NMEA,GPX,KML} )
**** Remove secured chunk from ~DIR_TMP~
Commit	Line	Data
872c737e SBS	1	* bkgpslog task list
	2	** DONE Add job control for short buffer length
	3	CLOSED: [2020-07-02 Thu 16:04]
	4	2020-07-02T14:56Z; bktei> File write operations were bundled into a
	5	magicWriteBuffer function that is called then detached from the script
	6	shell (job control), but the detached job is not tracked by the main
	7	script. A problem may arise if two instances of magicWriteBuffer
	8	attempt to write to the same tar simultaneously. Two instances of
	9	magicWriteBuffer may exist if the buffer length is low (ex: 1 second);
	10	the default buffer length of 60 seconds should reduce the probability
	11	of a collision but it should be possible for the main script to track
	12	the process ID of a magicWriteBuffer() as soon as it detaches and then
	13	checking (via ~$!~ 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~.
6c30388f SBS	19	* bkgpslog narrative
	20	** Initialize environment
	21	*** Init variables
	22	**** Save timeStart (YYYYmmddTHHMMSS±zz)
	23	*** Define Functions
	24	**** Define Debugging functions
	25	**** Define Argument Processing function
	26	**** Define Main function
	27	** Run Main Function
	28	*** Process Arguments
	29	*** Set output encryption and compression option strings
	30	*** Check that critical apps and dirs are available, displag missing ones.
	31	*** Set lifespans of script and buffer
	32	*** Init temp working dir ~DIR_TMP~
	33	Make temporary dir in tmpfs dir: ~/dev/shm/$(nonce)..bkgpslog/~ (~DIR_TMP~)
	34	*** Initialize ~tar~ archive
	35	**** Write ~bkgpslog~ version to ~$DIR_TMP/VERSION~
	36	**** Create empty ~tar~ archive in ~DIR_OUT~ at ~PATHOUT_TAR~
	37
	38	Set output file name to:
	39	: PATHOUT_TAR="$DIR_OUT/YYYYmmdd..hostname_location.gz.age.tar"
	40	Usage: ~iso8601Period $timeStart $timeEnd~
	41
	42	**** Append ~VERSION~ file to ~PATHOUT_TAR~
	43
	44	Append ~$DIR_TMP/VERSION~ to ~PATHOUT_TAR~ via ~tar --append~
	45
	46	*** Read/Write Loop (Record gps data until script lifespan ends)
	47	**** Determine output file paths
	48	**** Define GPS conversion commands
	49	**** Fill Bash variable buffer from ~gpspipe~
	50	**** Process bufferBash, save secured chunk set to ~DIR_TMP~
	51	**** Append each secured chunk to ~PATHOUT_TAR~
	52	: tar --append --directory=DIR_TMP --file=PATHOUT_TAR $(basename PATHOUT_{NMEA,GPX,KML} )
	53	**** Remove secured chunk from ~DIR_TMP~