They did add it; I think it wasn’t there in v0.1[0]. Nowadays, the revlog contains a sequence of either snapshots or deltas[1], a bit like video codecs I-frame

They did add it; I think it wasn’t there in v0.1[0]. Nowadays, the revlog contains a sequence of either snapshots or deltas[1], a bit like video codecs I-frame and P-frame, except the heuristic is how much data must be read to check out the file; so most are likely deltas. [0]: https://lore.kernel.org/lkml/42692470.9050605@tmr.com/T/ https://lore.kernel.org/lkml/42692470.9050605@tmr.com/T/ [1]: http://hgbook.red-bean.com/read/behind-the-scenes.html http://hgbook.red-bean.com/read/behind-the-scenes.html