Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Jan 2020 15:47:50 +0100] rev 44354
nodemap: use an intermediate "docket" file to carry small metadata
This intermediate file will make mmapping, transaction and content validation
easier. (Most of this usefulness will arrive gradually in later changeset). In
particular it will become very useful to append new data are the end of raw file
instead of rewriting on the file on each transaction.
See in code comments for details.
Differential Revision: https://phab.mercurial-scm.org/D7838
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Jan 2020 15:47:40 +0100] rev 44353
nodemap: only use persistent nodemap for non-inlined revlog
Revlog are inlined while they are small (to avoid having too many file to deal
with). The persistent nodemap will only provides a significant boost for large
enough revlog index. So it does not make sens to add an extra file to store
nodemap for small revlog.
We could consider inclining the nodemap data inside the revlog itself, but the
benefit is unclear so let it be an adventure for another time.
Differential Revision: https://phab.mercurial-scm.org/D7837
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Jan 2020 15:47:31 +0100] rev 44352
nodemap: add a function to read the data from disk
This changeset is small and mostly an excuse to introduce an API function
reading the data from disk.
Differential Revision: https://phab.mercurial-scm.org/D7836
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Jan 2020 15:47:21 +0100] rev 44351
nodemap: write nodemap data on disk
Let us start writing data on disk (so that we can read it from there later).
This series of changeset is going to focus first on having data on disk and
updating it.
Right now the data is written right next to the revlog data, in the store. We
might move it to cache (with proper cache validation mechanism) later, but for
now revlog have a storevfs instance and it is simpler to us it. The right
location for this data is not the focus of this series.
Differential Revision: https://phab.mercurial-scm.org/D7835