#!/bin/bash -u
# iotest v0.1 - lawalsh: open usage allowed

_prgpth="${0:?}"; _prg="${_prgpth##*/}"; _prgdr="${_prgpth%/$_prg}"
[[ -z $_prgdr || $_prg == $_prgdr ]] && $_prgdr="$PWD"
export PATH="$_prgdr:$_prgdr/lib:$PATH"
shopt -s expand_aliases extglob sourcepath ; set -o pipefail

#include stdalias

Dd=$(type -P dd)

[[ $Dd ]] || { echo "Cannot find dd.  Cannot proceed.";  exit 1; }

alias intConst=declare\ -ix int=declare\ -i my=declare
alias string=declare sub=function array=declare\ -a
# 1 num = block size
# num-num = range of block sizes to test; w/increment = "2x", so
# 4M-16M tests 4M, 8M, 16M
# 4M-12M test 4M, 8M, 12M
# count adjusted to xfer 4G, rounding up
#----

#all xfers are using 'devices' (/dev/zero for source, /dev/null for target)
# remote filenames "zero" and "null" should be setup to be remote devices

intConst K=1024
intConst M=$[K*K]
intConst G=$[M*K]
intConst T=$[G*K]

int BS=$[16*M]
int count=256
int IOSIZE=${IOSIZE:-4*G}

#		desuffix 	1st arg = num+suffix -> convert to int
#							2nd arg = optional buff name (else print to stdout)
#							return 0 if no error

sub desuffix {						#convert num+Suff => int store in optional Buff
	string str="${1:?}" ; shift
	string bufnam=""; (($#)) && bufnam=$1
	if [[ $p =~ ^([0-9]+)([KMGT])$ ]]; then 
		int num=${BASH_REMATCH[1]}*${BASH_REMATCH[2]}
		((num)) || return 1
		if [[ $bufnam ]] ; then printf -v $bufnam "%d" "$num"
		else printf "%d" "$num" ; fi
	else 
		return 1
	fi
}




sub hdisp {
	int num=${1:?}; shift
	string bufnam=""; (($#)) && bufnam=$1
	string suf=""
	int ans=num
	array pows=('K' 'M' 'G' 'T')
	for s in ${pows[@]};do
		int si=$s
		if (((num/si)*si==num)); then
			ans=num/si;suf="$s"
		fi
	done
}

sub check_params {
	int num=0
	if (($#)) ; then 
		string p="$1"; shift;
		if [[ $p =~ ([0-9]+)([KMGT]) ]]; then 
			num=${BASH_REMATCH[1]}*${BASH_REMATCH[2]}
		fi
	fi
	((num)) && {
		BS=num
		count=IOSIZE/BS
	}
}

(($#)) && check_params "$@"

array reada=(/h/zero /dev/null)
array writea=(/dev/zero /h/null conv=nocreat,notrunc)

sub dd_need_io  {
	local if="$1" of="$2"; shift 2
	nice --19 $Dd if="$if" of="$of" bs="$BS" count="$count"\
	 		oflag=direct iflag=direct conv=nocreat "$@"
}

sub dd {
	local if="$1" of="$2" ;shift 2
	#echo $dd if="$if" of="$of" bs="$BS" count="$count" "$@" >&2
	array out err
	readarray err < <( \
		readarray out < <(dd_need_io "$if" "$of" "$@";int s=$?; 
											((s)) && echo "stat:$s">&2  ) 2>&1 )
	#
	if ((${#err[@]})) ;then echo "${err[@]}"; exit 1; fi
	return 0
}
	
function dd_format { my ln
	while read ln;do
		echo $ln | while read bytes btxt pnum suffp \
											copt time unitc rate ra_unit; do
			[[ $bytes == records ]] && continue
			[[ ${pnum:0:1} != \( || ${suffp:0-1:1} != \) ]] && continue
			num="${pnum:1}" 
			suff="${suffp%?}" 
			unit="${unitc%?}"
			printf "%s:%s:%s:%s:%s:%s:\n"	"$num" "$suff" "$time" "$unit" "$rate" "$ra_unit"
		done
	done
}

sub onecycle {
	echo -n "R:"; { dd "${reada[@]}"|| exit $?; } | dd_format 
	echo -n "W:";	{ dd "${writea[@]}" || exit $?; } | dd_format 
}

onecycle