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Kamd
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 Posted: Tue Apr 09, 2019 7:14 pm Post subject: Question about properly disposing of MemScan and FoundList |
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I made a helper (short and easy to use) function for scanning string values in memory.
Basically, creates MemScan and does firstScan, initializes FoundList and returns the FoundList so I can store it in a variable in my main code.
I have read I need to destroy everything when I'm done using it.
Is the following code going to dispose everything correctly? (I'm worried that the local scoped 'f' variable in scan function won't be disposed?)
| Code: |
function strScan(find)
local ms = createMemScan()
ms.firstScan(...)
ms.waitTillDone()
local f = createFoundList(ms)
f.initialize()
ms.destroy()
return f
end
local someStrings = strScan("hello world")
-- now I use someStrings etc
local strAddr = someStrings[0]
-- and now I'm done, dispose it?
someStrings.destroy()
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EDIT: For clarification, I don't need to manually destroy readString variables? e.g:
| Code: |
function example()
local str = readString("some address")
-- do stuff..
-- do I have to str.destroy() or will this automatically be garbage collected since its only scoped to this function?
end
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Thank you for any feedback.
Last edited by Kamd on Thu Apr 11, 2019 4:34 am; edited 1 time in total |
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ParkourPenguin
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| Posted: Tue Apr 09, 2019 7:55 pm Post subject: |
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readString returns a Lua string. CE does not manage it at all; Lua will garbage collect the string when it's no longer used.
You should destroy the foundlist eventually. Ideally, strScan should do that. Copy the foundlist into a Lua array and return that instead.
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Kamd
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| Posted: Thu Apr 11, 2019 4:44 am Post subject: |
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| ParkourPenguin wrote: | | You should destroy the foundlist eventually. Ideally, strScan should do that. Copy the foundlist into a Lua array and return that instead. |
My bad, my example code I accidentally did strAddr.destroy() instead of the correct someStrings.destroy() - I have updated the original post
So does the FoundList have to be destroyed directly in the strScan function, or is it enough to destroy the variable holding the returned FoundList?
| Code: |
local myScan = strScan("some string")
myScan.destroy()
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If I have to destroy the FoundList (f) directly in the strScan function, would this be the correct way to copy it to an array?
| Code: |
local copy = { f }
f.destroy()
return copy[1]
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Thanks
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ParkourPenguin
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| Posted: Thu Apr 11, 2019 8:48 am Post subject: |
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No, the foundlist doesn't have to be destroyed in the strScan function; it's just better design IMO. Users of the function don't have to remember to destroy it every time they use it (less code duplication; less chance of memory leak), and you can use it like any other Lua array (i.e. it starts at 1; # operator works).
| Code: | --...
local results={}
for i = 0, f.Count-1 do
results[i+1] = getAddress(f[i])
end
f.destroy()
ms.destroy()
return results
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Kamd
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| Posted: Thu Apr 11, 2019 8:17 pm Post subject: |
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| ParkourPenguin wrote: | | Users of the function don't have to remember to destroy it every time they use it (less code duplication; less chance of memory leak) |
Great idea, I will definitely use this method.
getAddress: I read that it returns integer, but I would need the normal string address, would it be fine to store f[i] instead of getAddress[f[i])?
Just some followup questions for curiosity:
- Is there any case where I would actually need the FoundList object rather than the addresses
- Will I never have to destroy the returned results array? (since Lua will garbage collect it automatically?)
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ParkourPenguin
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| Posted: Thu Apr 11, 2019 9:05 pm Post subject: |
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Sure, it's fine to copy the string. I'm usually doing arithmetic with addresses, but if you don't need to, there's little point in turning them into integers.
As far as I can tell, there's no need to keep the foundlist around. It might do something weird with values, but you can read the current value as whatever type you want whenever (and without needing to clean up after it).
Lua will automatically garbage collect that array when it's no longer used. You don't have to do anything to clean it up.
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