bundle2: add support for a 'stream' parameter to 'getbundle' This parameter can be used to request a stream bundle.

bundle2: add a 'stream' part handler for stream cloning The part contains the necessary arguments and payload to handle a stream bundle v2. It will be put to use in later changesets.

streamclone: rework canperformstreamclone There is code about bundle2 laying around in `canperformstreamclone` but not put to any uses. As we discovered with the previous patch, streambundle 'v1' won't work on bundle2 because they are readline based. So we jump to 'v2' as the first expected supported version.

streamclone: define first iteration of version 2 of stream format (This patch is based on a first draft from Gregory Szorc, with deeper rework) Version 1 of the stream clone format was invented many years ago and suffers from a few deficiencies: 1) Filenames are stored in store-encoded (on filesystem) form rather than in their internal form. This makes future compatibility with new store filename encodings more difficult. 2) File entry "headers" consist of a newline of the file name followed by the string file size. Converting strings to integers is avoidable overhead. We can't store filenames with newlines (manifests have this limitation as well, so it isn't a major concern). But the big concern here is the necessity for readline(). Scanning for newlines means reading ahead and that means extra buffer allocations and slicing (in Python) and this makes performance suffer. 3) Filenames aren't compressed optimally. Filenames should be compressed well since there is a lot of repeated data. However, since they are scattered all over the stream (with revlog data in between), they typically fall outside the window size of the compressor and don't compress. 4) It can only exchange stored based content, being able to exchange caches too would be nice. 5) It is limited to a stream-based protocol and isn't suitable for an on-disk format for general repository reading because the offset of individual file entries requires scanning the entire file to find file records. As part of enabling streaming clones to work in bundle2, #2 proved to have a significant negative impact on performance. Since bundle2 provides the opportunity to start fresh, Gregory Szorc figured he would take the opportunity to invent a new streaming clone data format. The new format devised in this series addresses #1, #2, and #4. It punts on #3 because it was complex without yielding a significant gain and on #5 because devising a new store format that "packs" multiple revlogs into a single "packed revlog" is massive scope bloat. However, this v2 format might be suitable for streaming into a "packed revlog" with minimal processing. If it works, great. If not, we can always invent stream format when it is needed. This patch only introduces the bases of the format. We'll get it usable through bundle2 first, then we'll extend the format in future patches to bring it to its full potential (especially #4).

util: implement varint functions This will be useful in an incoming version-2 of the stream format.

util: move 'readexactly' in the util module This function is used in multiple place, having it in util would be better. (existing caller will be migrated in another series)

lfs: separate a debug message from the subsequent abort message

sshserver: add a couple of tests for argument parsing I noticed that we didn't have any unit tests covering wire protocol argument parsing.

merge with stable

wireproto: split streamres into legacy and modern case A couple of commands currently require transmission of uncompressed frames with the old MIME type. Split this case from streamres into a new streamres_legacy class. Streamline the remaining code accordingly. Add a new flag to streamres to request uncompressed streams. This is useful for sending data that is already compressed like a pre-built bundle. Expect clients to support uncompressed data. For older clients, zlib will still be used. Differential Revision: https://phab.mercurial-scm.org/D1862

localrepo: run cache-warming transaction callback before report callback See in-code comment for details. Differential Revision: https://phab.mercurial-scm.org/D1918

scmutil: 0-pad transaction report callback category Before this patch, the transaction name was '%2i-txnreport', which means the first one would be ' 0-txnreport'. It seems more intuitive for sorting purposes (the callbacks are called in lexicographical order) to make it 0-padded. Differential Revision: https://phab.mercurial-scm.org/D1917

stream: add a test showing we also clone bookmarks Bookmarks are not stored in `.hg/store`. We need to make sure they are cloned with `--stream`.

branch: allow changing branch name to existing name if possible With the functionality added in previous patch we can change branches of a revision but not everytime even if it's possible to do so. For example cosider the following case: o 3 added a (foo) o 2 added b (foo) o 1 added c (bar) o 0 added d (bar) Here if I want to change the branch of rev 2,3 to bar, it was not possible and it will say, "a branch with same name exists". This patch allows us to change branch of 2,3 to bar. The underlying logic for changing branch finds the changesets from the revs passed which have no parents in revs. We only support revsets which have only one such root, so to support this we check whether the parent of the root has the same name as that of the new name and if so, we can use the new name to change branches. Differential Revision: https://phab.mercurial-scm.org/D1913

branch: add a --rev flag to change branch name of given revisions This patch adds a new --rev flag to hg branch which can be used to change branch of revisions. This is motivated from topic extension where you can change topic on revisions but this one has few restrictions which are: 1) You cannot change branch name in between the stack 2) You cannot change branch name and set it to an existing name 3) You cannot change branch of non-linear set of commits 4) You cannot change branch of merge commits. Tests are added for the same. .. feature:: An experimental flag `--rev` to `hg branch` which can be used to change branch of changesets. Differential Revision: https://phab.mercurial-scm.org/D1074

templater: fix crash by empty group expression 'exp' may be None because of '(group None)' node. The error message is copied from revset.py.

log: fix typo in comment about _matchfiles()

sparse: --include 'dir1/dir2' should not include 'dir1/*' In 2015 there was a workaround added (f39bace2d6cad32907c0d7961b3c0dbd64a1b7ad) to sparse in the hg-experimental repo. That workaround: a) no longer seems to be needed, since its testcase passes even with the code removed, and b) caused a new problem: --include 'dir1/dir2' ended up including dir1/* too. (--include 'glob:dir1/dir2' is a user-level workaround.) Remove the offending code, and add a testcase for situation B.

fileset: add kind:pat operator ":" isn't taken as a symbol character but an infix operator so we can write e.g. "path:'foo bar'" as well as "'path:foo bar'". An invalid pattern kind is rejected in the former form as we know a kind is specified explicitly. The binding strength is copied from "x:y" range operator of revset. Perhaps it can be adjusted later if we want to parse "foo:bar()" as "(foo:bar)()", not "foo:(bar())". We can also add "kind:" postfix operator if we want. One possible confusion is that the scope of the leading "set:" vs "kind:pat" operator. The former is consumed by a matcher so applies to the whole fileset expression: $ hg files 'set:foo() or kind:bar or baz' ^^^^^^^^^^^^^^^^^^^^^^^^ Whereas the scope of kind:pat operator is narrow: $ hg files 'set:foo() or kind:bar or baz' ^^^

minifileset: unify handling of symbol and string patterns They must be identical for fileset compatibility.

fileset: move import of match module to top Actually there was no circular import issue.

revlog: group delta computation methods under _deltacomputer object Extracting these methods from revlog will allow changing the implementation of the deltacomputer, by providing this interface: __init__(self, revlog) - constructor that initialize the object from a given revlog buildtext(self, revinfo, fh) - builds the fulltext version of a revision from a _revisioninfo object and the file handle to the .d (or .i for inline mode) file. finddeltainfo(self, revinfo, fh) - find a revision in the revlog against which it is acceptable to build a delta, and build the corresponding _deltainfo. It should now be easier to write an experimental feature that would replace _deltacomputer by another object, for example one that would know how to parallelize the delta computation in order to quicken the storage of multiple revisions.

revlog: refactor out _finddeltainfo from _addrevision Splicing the code into smaller chunks should help understanding it, and eventually override some parts in experimental branches to try optimization.

localrepo: micro-optimize __len__() to bypass repoview Since len(changelog) isn't overridden, we don't have to validate a cache of unfiltered changelog. $ python -m timeit -n 10000 \ -s 'from mercurial import hg, ui; repo = hg.repository(ui.ui());' \ 'len(repo)' orig) 10000 loops, best of 3: 32.1 usec per loop new) 10000 loops, best of 3: 1.79 usec per loop Spotted by Jordi Gutiérrez Hermoso.