51095 - mStorageInUse grows faster than required if we update files in cache

Status: VERIFIED FIXED

(Core :: Networking: Cache, defect, P2)

Description

[Suresh Duddi (gone)]

<file already in cache. we hit reload after modifying (decreasing size) say> 
mStorageInUse += newFileSize - (newFileSize - oldFileSize) 

This could grow our notion of cache size faster than the cache actually is 
growing.

Comment 1

[Suresh Duddi (gone)]

When evicting this could be a reason for going into infinite loop ???

Comment 2

[Daniel Bratell]

Strange.
mStorageInUse += newFileSize - (newFileSize - oldFileSize)
is equivalent with
mStorageInUse += oldFileSize

Comment 3

[Suresh Duddi (gone)]

Thats a good one :-) My mistake in swapping old and newfile size in the formula.

<file already in cache. we hit reload after modifying (decreasing size) say>
mStorageInUse += newFileSize - (oldFileSize - newFileSize)

Comment 4

[Suresh Duddi (gone)]

Reassingning to neeti so this will show up on the right radar.

Comment 5

[selmer (gone)]

pdt agrees p2 on the assumption that something bad like the infinite loop can 
happen easily.

Comment 6

[neeti]

Attachment: attached patch for the fix

Comment 7

[neeti]

Checked in a fix

Comment 8

[Brendan Eich [:brendan]]

I'm baffled by the algebra here.

/be

Comment 9

[Suresh Duddi (gone)]

Of course you are.

Comment 10

[Tom Everingham]

verified