tests: add test of rebase with conflict in merge commit It doesn't seem like we had any tests of this. I think it's pretty weird that the two parents we're merging are not the working copy parents during the conflict resolution. Differential Revision: https://phab.mercurial-scm.org/D7824

rebase: always be graft-like, not merge-like, also for merges Rebase works by updating to a commit and then grafting changes on top. However, before this patch, it would actually merge in changes instead of grafting them in in some cases. That is, it would use the common ancestor as base instead of using one of the parents. That seems wrong to me, so I'm changing it so `defineparents()` always returns a value for `base`. This fixes the bad behavior in test-rebase-newancestor.t, which was introduced in 65f215ea3e8e (tests: add test for rebasing merges with ancestors of the rebase destination, 2014-11-30). The difference in test-rebase-dest.t is because the files in the tip revision were A, D, E, F before this patch and A, D, F, G after it. I think both files should ideally be there. Differential Revision: https://phab.mercurial-scm.org/D7907

nodemap: update the index with the newly written data (when appropriate) If we are to use mmap to read the nodemap data, and if the python code is responsible for the IO, we need to refresh the mmap after each write and provide it back to the index. We start this dance without the mmap first. Differential Revision: https://phab.mercurial-scm.org/D7893

nodemap: never read more than the expected data amount Since we are tracking this number we can use it to detect corrupted rawdata file and to only read the correct amount of data when possible. Differential Revision: https://phab.mercurial-scm.org/D7892

nodemap: write new data from the expected current data length If the amount of data in the file exceed the expect amount, we will overwrite the extra data. This is a simple way to be safer. Differential Revision: https://phab.mercurial-scm.org/D7891

nodemap: double check the source docket when doing incremental update In theory, the index will have the information we expect it to have. However by security, it seems safer to double check that the incremental data are generated from the data currently on disk. Differential Revision: https://phab.mercurial-scm.org/D7890

nodemap: track the total and unused amount of data in the rawdata file We need to keep that information around: * total data will allow transaction to start appending new information without confusing other reader. * unused data will allow to detect when we should regenerate new rawdata file. Differential Revision: https://phab.mercurial-scm.org/D7889

nodemap: track the maximum revision tracked in the nodemap We need a simple way to detect when the on disk data contains less revision than the index we read from disk. The docket file is meant for this, we just had to start tracking that data. We should also try to detect strip operation, but we will deal with this in later changesets. Right now we are focusing on defining the API for index supporting persistent nodemap. Differential Revision: https://phab.mercurial-scm.org/D7888

nodemap: add a flag to dump the details of the docket We are about to add more information to the docket. We first introduce a way to debug its content. Differential Revision: https://phab.mercurial-scm.org/D7887

nodemap: introduce append-only incremental update of the persistent data Rewriting the full nodemap for each transaction has a cost we would like to avoid. We introduce a new way to write persistent nodemap data by adding new information at the end for file. Any new and updated block as added at the end of the file. The last block is the new root node. With this method, some of the block already on disk get "dereferenced" and become dead data. In later changesets, We'll start tracking the amount of dead data to eventually re-generate a full nodemap. Differential Revision: https://phab.mercurial-scm.org/D7886

nodemap: keep track of the docket for loaded data To perform incremental update of the on disk data, we need to keep tracks of some aspect of that data. Differential Revision: https://phab.mercurial-scm.org/D7885

nodemap: introduce an explicit class/object for the docket We are about to add more information to this docket, having a clear location to stock them in memory will help. Differential Revision: https://phab.mercurial-scm.org/D7884

nodemap: keep track of the ondisk id of nodemap blocks If we are to incrementally update the files, we need to keep some details about the data we read. Differential Revision: https://phab.mercurial-scm.org/D7883

nodemap: provide the on disk data to indexes who support it Time to start defining the API and prepare the rust index support. We provide a method to do so. We use a distinct method instead of passing them in the constructor because we will need this method anyway later (to refresh the mmap once we update the data on disk). Differential Revision: https://phab.mercurial-scm.org/D7847

nodemap: all check that revision and nodes match in the nodemap More check is always useful. Differential Revision: https://phab.mercurial-scm.org/D7846

nodemap: add basic checking of the on disk nodemap content The simplest check it so verify we have all the revision we needs, and nothing more. Differential Revision: https://phab.mercurial-scm.org/D7845

nodemap: code to parse the persistent binary nodemap data We now have code to read back what we persisted. This will be put to use in later changesets. Differential Revision: https://phab.mercurial-scm.org/D7844

nodemap: move the iteratio inside the Block object Having the iteration inside the serialization function does not help readability. Now that we have a `Block` object, let us move that code there. Differential Revision: https://phab.mercurial-scm.org/D7843

nodemap: use an explicit "Block" object in the reference implementation This will help us to introduce some test around the data currently written on disk. Differential Revision: https://phab.mercurial-scm.org/D7842

nodemap: add a optional `nodemap_add_full` method on indexes This method can be used to obtains persistent data for a full nodemap. The end goal is for some index implementation to managed the nodemap serialization them selves (eg: the rust implementation) Differential Revision: https://phab.mercurial-scm.org/D7841

nodemap: add a (python) index class for persistent nodemap testing Using the persistent nodemap require a compeling performance boost and an existing implementation. The benefit of the persistent nodemap for pure python code is unclear and we don't have a C implementation for it. Yet we would like to actually start testing it in more details and define an API for using that persistent nodemap. We introduce a new `devel` config option to use an index class dedicated to Nodemap Testing. This feature is "pure" only because having using a pure-python index with the `cext` policy proved more difficult than I would like. There is nothing going on in that class for now, but the coming changeset will change that. Differential Revision: https://phab.mercurial-scm.org/D7840

nodemap: delete older raw data file when creating a new ones When we write new full files, it replace an older one with a different name. We add the associated cleanup for the older file to be removed after the transaction. We delete all file matching the expected pattern to give use extra chance to delete orphan files we might have failed to delete earlier. Note: eventually we won't rewrite all data for each transaction. This is coming in later changesets. Differential Revision: https://phab.mercurial-scm.org/D7839

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

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

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

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

nodemap: have some python code writing a nodemap in persistent binary form This python code aims to be as "simple" as possible. It is a reference implementation of the data we are going to write on disk (and possibly, later a way for pure python install to make sure the on disk data are up to date). It is not optimized for performance and rebuild the full data structure from the index every time. This is a stepping stone toward a persistent nodemap on disk. Differential Revision: https://phab.mercurial-scm.org/D7834

cleanup: re-run black on the codebase Looks like a few patches have landed without having been blackened. I strongly suspect I should write a patch for baymax that blackens things on the way in... # skip-blame automatic formatting Differential Revision: https://phab.mercurial-scm.org/D8104