remotefilelog: import pruned-down remotefilelog extension from hg-experimental This is remotefilelog as of my recent patches for compatibility with current tip of hg, minus support for old versions of Mercurial and some FB-specific features like their treemanifest extension and fetching linkrev data from a patched phabricator. The file extutil.py moved from hgext3rd to remotefilelog. This is not yet ready to be landed, consider it a preview for now. Planned changes include: * replace lz4 with zstd * rename some capabilities, requirements and wireproto commands to mark them as experimental * consolidate bits of shallowutil with related functions (eg readfile) I'm certainly open to other (small) changes, but my rough mission is to land this largely as-is so we can use it as a model of the functionality we need going forward for lazy-fetching of file contents from a server. # no-check-commit because of a few foo_bar functions Differential Revision: https://phab.mercurial-scm.org/D4782

store: introduce _matchtrackedpath() and use it to filter store files This patch introduces a function to filter store files on the basis of the path which they are tracking. The function assumes that the entries can be of two types, 'meta/*' and 'data/*' which means it will just work on revlog based storage and not with another storage ways. For the 'data/*' entries, we remove the 'data/' part and '.i/.d' part from the beginning and the end then pass that to matcher. For the 'meta/*' entries, we remove the 'meta/' and '/00manifest.(i/d)' part from beginning and end then call matcher.visitdir() with it to make sure all the parent directories are also downloaded. Since the storage filtering for narrow stream clones is implemented with this patch, we remove the un-implemented error message, add some more tests and add the treemanifest case to tests too. The tests demonstrate that it works correctly. After this patch, we have now narrow stream clones working. Narrow stream clones are a very important feature for large repositories who have good internet connection because they use streamclones for cloning and if they do normal narrow clone, that takes more time then a full streamclone. Also narrow-stream clone will drastically speed up clone timings. Differential Revision: https://phab.mercurial-scm.org/D5139

narrow: only send includepats and excludepats if they are not empty If we send an empty includepats or excludepats argument to getbundle, it's translated to `['']` on the server which causes problems because even though it's empty, bool of that value if True and we end up creating differencematcher with narrowspec.match() which results in unexpected behavior. Differential Revision: https://phab.mercurial-scm.org/D5138

exchange: pass includepats and excludepats as arguments to getbundle() This will help in implementing narrow stream clones. Also narrow extension used to add these arguments, now we add them by default if they are not empty. Since reading includepats and excludepats on the server only works when narrow is enabled, we check if narrow if enabled or not before passing them. Differential Revision: https://phab.mercurial-scm.org/D5119

catapult: add a bit more documentation on how to use catapult tracing Differential Revision: https://phab.mercurial-scm.org/D5217

catapult: introduce HGTESTCATAPULTSERVERPIPE to control run-tests' tracing If unset, it will inherit its value from HGCATAPULTSERVERPIPE (which hg itself also respects). By setting only HGTESTCATAPULTSERVERPIPE, we can get per-command breakdowns of the test runtimes for the whole test suite without overloading the trace file with the contents of the tracing from hg (such as demandimport, etc.) Differential Revision: https://phab.mercurial-scm.org/D5216