(Food/Dirt/Temperature) decay get updated each time one enters sector or access map inventory by overwriting the uiTimeCurrentSectorWasLastLoaded.
Despite it has 'loaded' in the name, this variable is used to determine when the player was IN the sector (entered tactical) and gets updated everytime the map gets undloaded.
Used for updating rotting corpses, smoke effects, possibly even handling quests, everything that needs to know when the map (not just the items of a map) was last loaded. Might be totaly wrong but thats what the comment implies.

Showing sector inventory currently loaded and saved the items multiple times.
In addition to the repeadadly accessing the harddrive there are also multiple loops traversing several times the item list(s), sometimes just to get the size and often to adjust a single value or to copy to another array. Those redundant code can and should be replaced.

During timing tests I figured there are actually only two problematic functions: SectorInventoryCooldownFunctions() and BuildStashForSelectedSector().
To sum up the number of loops, file reads and writes:

(multi means the whole file is read/written,
single means a single word is read/written,
loop means there is a loop traversing all read items.)
best/worst case call count:

When entering sector (allways same sector as the loaded one):
-1x load items in a call of EnterSector() (single,multi)
-1x calc decay in HandleSectorCooldownFunctions() (loop)
-1x save items in SectorInventoryCooldownFunctions() (single,multi)

When accessing sector inventory (same sector/different sector then the loaded one):
-0x/1x load items in SectorInventoryCooldownFunctions() (single,multi)
-1x/2x calc decay in HandleSectorCooldownFunctions() (loop)
-1x/2x save items in SectorInventoryCooldownFunctions() (single,multi)
-0x/1x load items in GetSizeOfStashInSector() calculated by:
-accessing total number from file (single),
-calling GetNumberOfActiveWorldItemsFromTempFile() (single, multi and loop)
-loop all stacks and add the itemcount (loop)
-0x/1x load items in BuildStashForSelectedSector() to get total number of items (single)
-0x/1x load items in GetNumberOfActiveWorldItemsFromTempFile() to get number of existing items (single, multi, loop)
-0x/1x load items into local array (multi)
-1x/1x loop all itemstacks and add existing ones to global vector (loop)
-1x/1x loop all itemstacks and add unseen (filtered) ones to global array (loop)

As you see entering sector has one loop, but accessing sector inventory has multiple loops.
Therfore it is not possible to eliminate all redundant loops.
But we can make a huge boost in loading speed when reducing 11 reads, 4 writes and 6 loops down to -> 2 loops, 2 read (1x single,1x multi) and 2 write (1x single, 1x multi). That is more than 300% improvement.

If you wonder why I also count a single word read in a file as an issue: you have to add the access time to the file as well. In that time the CPU is able to do thousands and thousands of instructions (like checking all items in a sector and decay them as neccessary)

Option 1:
Introduce another variable inside SECTORINFO used for the last time (game minutes) we have updated all items for that sector.
This approach brakes savegame compatibility.

Option 2:
Create a static array inside the decay handling function which holds the time at which all items in various sectors has been updated.
There is a problem here: one cant determine if a completly different savegame is loaded. To do make it work we need some global variable which tells us if our current save game is the one which matches our static times.
This also requires frequent recalculation of the static array after autosave, save and load.

Option 3:
Dont update uiTimeCurrentSectorWasLastLoaded when showing items in sector inventory.
Instead one must add the delta decay to the items before showing them and remove the delta decay (or trash the itemlists) when closing the sector inventory.
Let the final modification be handled when player is actually entering the sector.

Option 4:
Dont update item decay when showing the sector inventory.
The player will see outdated values in DB and tooltips and needs to enter a sector to get the correct values.

Option 5:
update decay as usual on enterSector and on showing the sector inventory by overwriting the uiTimeCurrentSectorWasLastLoaded.
This may brake some (potential) quest code, visual effects like smoke, rotting corpse ec.
They are actually broken allready, so we dont care!?

Option 1:
relocate the decay handling function from SectorInventoryCooldownFunctions() to avoid multiple loadings of the same data:
For entering a sector this needs to be inside the EnterSector() function after we loaded the items or inside LoadWorld(), PrepareLoadedSector(),...

For accessing sector inventory a good place is right below the buildStashForSelectedSector() call in CreateDestroyMapInventoryPoolButtons() where the original call to SectorInventoryCooldownFunctions() was.

Because of Option 3 above we can use a hook where the stash actually gets build. Saving to tempfile can be omitted.
Merge all loading functions which have to get information from item temp file into a single function, at least those for building the sector stash.

Option 2:
Turn off Overheating, Food and Dirtsystem? - not a real option
Extend the parameter list of various functions to return some known facts about read data (number of active items, total number,...). This however does not eliminate the loops which also are responsible for long loading times.

For a patch with savegame compatibility I used options 5/1. You can download the patch later here (using rev6401 as a base).

For a more robust patch options 1/1 will be used. Until that is finnished the first patch should allready contain a lot of improvement. Changing to another variable is not that hard. Possibly this can be added later to the trunk once we have another savegame incompatible update.


Note that this just handles the loading part - the saving (closing sector inventory) is a different kettle of fish.


The test save is the one from LootFragg in this thread but on another day (d10, 15:00)
after moving the HandleSectorCooldownFunctions() to enterSector and to CreateDestroyPoolButtons() in order to avoid 1 multi word load and 1 single word load the timings are:
timings (ms) before patch: after patch:
13977---to load save (into map view)----14040
10359---to show sector inventory D13----8034
6708----to close sector inventory-------6178
10140---to enter sector-----------------11372

Because of variance its probably around 1 second faster to show the stash.

During implementation of Option5 I figured that we can skip the save on showing stash (see Option3)
timings using 5/1 and using option 3/1:
14165---to load save (into map view)----14040
3267----to show sector inventory D13----1529
7379----to close sector inventory-------6178
10140---to enter sector-----------------11372

Unfortunatly this introduced a bug: viewing the inventory works fine, all items decay as suspected until one puts an item into the stash. The item decays compleatly after closing and reopening stash.