rhg: stop manifest traversal when no more files are needed Stopping the traversal early can skip a significant part of the manifest traversal, to avoid some of its cost. The worst-case benchmarks are favorable, as well. Running [hg cat] on the last file in the manifest of a large repo, I'm seeing a ~4ms improvement (150ms -> 146ms), so this time is now almost indistinguishable from the baseline ("brute force") implementation. Running [hg cat] on ~220 files together with the last file of the repo is further improved by ~5ms or so. I suspect the raw performance improvements are caused by splitting the manifest search and the file data access into separate phases, instead of interleaving them. Differential Revision: https://phab.mercurial-scm.org/D11616

rhg: faster hg cat when many files are requested With this patch I'm seeing a ~39ms improvement (220ms -> 181ms) when running [hg cat] on ~220 files in a ~260k-file repo. The timing for [hg cat] on an individual file becomes slightly worse (losing 5ms: 145ms -> 150ms). A follow-up commit is intended to improve that. Differential Revision: https://phab.mercurial-scm.org/D11615