lfs: prefetch lfs blobs during revert The revert command oddly prints out what it will do before requesting the files to be prefetched. But the 'need to transfer' line indicates the blobs are being grouped.

cmdutil: convert _revertprefetch() to a generic stored file hook (API) This will be used by LFS to fetch required files in a group for multiple commands, prior to being accessed. That avoids the one-at-a-time fetch when the filelog wrapper goes to access it, and it is missing locally (which costs two round trips to the server.) The core command list that needs this is probably at least: - annotate - archive (which is also used by extdiff) - cat - diff - export - grep - verify (sadly) - anything that has the '{data}' template There are no core users of the revert prefetch hook, and never have been since it was introduced in 45e02cfad4bd for remotefilelog. Thanks to Yuya for figuring out a way to reliably trigger the deprecated warning. Unfortunately, it wanted to blame the caller of revert. Passing along an adjusted stack level seemed the least bad choice (although it still blames a core function). One thing to note is that the store lock isn't being held when this is called. I'm not at all familiar with remotefilelog or its locking requirements, so this may not be a big deal. Currently, LFS doesn't hold a lock when downloading files. Even though largefiles doesn't either, I'm starting to think it should, and maybe the .hg/store/lock isn't good enough to cover the globally shared cache. .. api:: The cmdutil._revertprefetch() hook point for prefetching stored files has been replaced by the command agnostic cmdutil._prefetchfiles(). The new function takes a list of files, instead of a list of lists of files.

lfs: prefetch lfs blobs when applying merge updates In addition to merge, this method ultimately gets called by many commands: - backout - bisect - clone - fetch - graft - import (without --bypass) - pull -u - rebase - strip - share - transplant - unbundle - update Additionally, it's also called by histedit, shelve, unshelve, and split, but it seems that the related blobs should always be available locally for these. For `hg update`, it happens after the normal argument checking and pre-update hook processing, and remote corruption is detected prior to manipulating the working directory. Other commands could use this treatment (archive, cat, revert, etc), but this covers so many of the frequently used bulk commands, it seems like a good starting point. Losing the verbose message that prints the file name before a corrupt blob aborts the command is a little sad, because there's no easy way to go from oid to file name. I'd like to change that message to list the file name so it looks cleaner and less cryptic, but the pointer object is nowhere near where it needs to be to do this. So punt on that for now.

lfs: factor out a method for extracting the pointer of a single file This will be useful for filesets, among other things, instead of traversing the whole context.

py3: add b'' to literals in check-config.py # skip-blame because we are just adding b'' Differential Revision: https://phab.mercurial-scm.org/D2046

check-config: specify the mode 'rb' to open the file Differential Revision: https://phab.mercurial-scm.org/D2045

py3: use open() instead of file() file() is not present in Python 3 Differential Revision: https://phab.mercurial-scm.org/D2044

py3: use pycompat.strkwargs() to convert kwargs' key to str Differential Revision: https://phab.mercurial-scm.org/D2043

py3: add __bytes__() for mq.patchheader and make sure __str__ returns str Before this patch, __str__() function for mq.patchheader class return bytes which is not str on Python 3. So let's move that logic to __bytes__() and for __str__() convert the return value of __bytes__() to str. Differential Revision: https://phab.mercurial-scm.org/D2042

py3: use "%d" to convert integer to bytes Differential Revision: https://phab.mercurial-scm.org/D2041