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RefCounts are dead. Long live lazy copy-on-write.
- To: <mark>
- Subject: RefCounts are dead. Long live lazy copy-on-write.
- From: Eric Dean Tribble <tribble>
- Date: Sat, 18 Nov 89 14:57:51 PST
- Cc: <xanatech>
- In-reply-to: <MarkS.Miller'smessageofSat>,57 PST <8911182149.AA01279@xanadu>
Your suggestion strikes me as an interesting variant of a
copy-on-write implementation. It covers making ImmuTables from either
MuTables or ImmuTables. I don't think it handles making a MuTable
from an ImmuTable (or MuTable).
Ah. I understand. Supporting this case requires trailing backward
deltas for all changes to a MuTable. I imgined a scheme that only
makes deltas when one collection gets made from another. In my
scheme, B could be made from A, but if B gets changed, the backwards
delta stored in A is no longer sufficient.
This wasn't too coherent, but I hope you get the gist.