#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Basic tests on writing to trace_marker_raw
# requires: trace_marker_raw
# flags: instance

check_awk_strtonum || exit_unresolved

is_little_endian() {
	if lscpu | grep -q 'Little Endian'; then
		echo 1;
	else
		echo 0;
	fi
}

little=`is_little_endian`

make_str() {
	id=$1
	cnt=$2

	if [ $little -eq 1 ]; then
		val=`printf "\\%03o\\%03o\\%03o\\%03o" \
			$(($id & 0xff)) \
			$((($id >> 8) & 0xff)) \
			$((($id >> 16) & 0xff)) \
			$((($id >> 24) & 0xff))`
	else
		val=`printf "\\%03o\\%03o\\%03o\\%03o" \
			$((($id >> 24) & 0xff)) \
			$((($id >> 16) & 0xff)) \
			$((($id >> 8) & 0xff)) \
			$(($id & 0xff))`
	fi

	data=`printf -- 'X%.0s' $(seq $cnt)`

	# Return escape-sequence text (e.g. "\003\000..."); the caller
	# converts to binary. Shell command substitution strips NUL bytes,
	# so the binary form cannot survive being captured into a variable.
	printf '%s' "${val}${data}"
}

write_buffer() {
	id=$1
	size=$2

	str=`make_str $id $size`
	len=`printf "$str" | wc -c`
	# Pipe through dd to ensure a single atomic write() syscall
	# on architectures with 64K pages, where shell's printf builtin
	# uses stdio buffering which may split the output into multiple
	# writes.
	printf "$str" | dd of=trace_marker_raw bs=$len iflag=fullblock
}


test_multiple_writes() {

	# Write a bunch of data where the id is the count of
	# data to write
	for i in `seq 1 10` `seq 101 110` `seq 1001 1010`; do
		write_buffer $i $i
	done

	# add a little buffer
	echo stop > trace_marker

	# Check to make sure the number of entries is the id (rounded up by 4)
	awk '/.*: # [0-9a-f]* / {
			print;
			cnt = -1;
			for (i = 0; i < NF; i++) {
				# The counter is after the "#" marker
				if ( $i == "#" ) {
					i++;
					cnt = strtonum("0x" $i);
					num = NF - (i + 1);
					# The number of items is always rounded up by 4
					cnt2 = int((cnt + 3) / 4) * 4;
					if (cnt2 != num) {
						exit 1;
					}
					break;
				}
			}
		}
	// { if (NR > 30) { exit 0; } } ' trace_pipe;
}


get_buffer_data_size() {
	sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page
}

test_buffer() {

	# The id must be four bytes, test that 3 bytes fails a write
	if echo -n abc > ./trace_marker_raw ; then
		echo "Too small of write expected to fail but did not"
		echo ${ORIG} > buffer_size_kb
		exit_fail
	fi

	size=`get_buffer_data_size`
	echo size = $size

	# Now add a little more than what it can handle

	if write_buffer 0xdeadbeef $size ; then
		echo "Too big of write expected to fail but did not"
		echo ${ORIG} > buffer_size_kb
		exit_fail
	fi
}

ORIG=`cat buffer_size_kb`

# test_multiple_writes test needs at least 12KB buffer
NEW_SIZE=12

if [ ${ORIG} -lt ${NEW_SIZE} ]; then
	echo ${NEW_SIZE} > buffer_size_kb
fi

test_buffer
if ! test_multiple_writes; then
	echo ${ORIG} > buffer_size_kb
	exit_fail
fi

echo ${ORIG} > buffer_size_kb