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If you use persistent data structures, you can store the total state, and you'll get deduplication of the common parts, which brings down the memory usage to a

If you use persistent data structures, you can store the total state, and you'll get deduplication of the common parts, which brings down the memory usage to a more reasonable amount. This is what git does essentially, which gets you O(1) checkout to arbitrary steps in the future/past. This also means you don't need to design/pick a diffing algorithm, which you would be locked into (since changing the diffing algorithm would mean you couldn't consume old diffs).

account42 4y ago
Git does store deltas when packing objects because storing all distinct objects as-is would be too inefficient for large repos. This isn't the same text diffs as shown to the user but there is still a diffing algorithm that all future git versions need to support (well, at least the patch counterpart).