From ed355dbf46e370c7a9207001a8007ff9bc929b73 Mon Sep 17 00:00:00 2001 From: Stefan Huber Date: Fri, 30 Dec 2022 13:04:06 +0100 Subject: battery-widget: Sanitize total charge computation The code to parse the output of `acpi -i` is fragile as it does not guarantee that the same number of battery status and capacities are read. This causes a wrong computation of the total charge level when batteries of status "Unknown" are reported. For instance, this is what `acpi -i` reports with a Wacom Intuos S attached to a Thinkpad T460s: $ acpi -i Battery 0: Unknown, 0%, rate information unavailable Battery 1: Not charging, 98% Battery 1: design capacity 1857 mAh, last full capacity 1513 mAh = 81% Battery 2: Not charging, 98% Battery 2: design capacity 2051 mAh, last full capacity 1711 mAh = 83% Fix the code by guaranteeing that for each battery status parsed there is also a capacity, which is zero if no capacity can be parsed. This effectively causes the exclusion of such batteries when computing the total charge level. --- battery-widget/battery.lua | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/battery-widget/battery.lua b/battery-widget/battery.lua index 935f680..4b02a7c 100644 --- a/battery-widget/battery.lua +++ b/battery-widget/battery.lua @@ -125,12 +125,21 @@ local function worker(user_args) local battery_info = {} local capacities = {} for s in stdout:gmatch("[^\r\n]+") do + -- Match a line with status and charge level local status, charge_str, _ = string.match(s, '.+: ([%a%s]+), (%d?%d?%d)%%,?(.*)') if status ~= nil then + -- Enforce that for each entry in battery_info there is an + -- entry in capacities of zero. If a battery has status + -- "Unknown" then there is no capacity reported and we treat it + -- as zero capactiy for later calculations. table.insert(battery_info, {status = status, charge = tonumber(charge_str)}) - else - local cap_str = string.match(s, '.+:.+last full capacity (%d+)') - table.insert(capacities, tonumber(cap_str)) + table.insert(capacities, 0) + end + + -- Match a line where capacity is reported + local cap_str = string.match(s, '.+:.+last full capacity (%d+)') + if cap_str ~= nil then + capacities[#capacities] = tonumber(cap_str) or 0 end end @@ -144,6 +153,9 @@ local function worker(user_args) -- this is arbitrary, and maybe another metric should be used end + -- Adds up total (capacity-weighted) charge and total capacity. + -- It effectively ignores batteries with status "Unknown" as we + -- treat them with capacity zero. charge = charge + batt.charge * capacities[i] capacity = capacity + capacities[i] end -- cgit v1.2.3