changegroup: remove _clnodetorev cgpacker._clnodetorev is a glorified cache/index of changelog nodes to revision numbers. I'm not sure why it exists. Maybe performance? But its presence is making refactoring of this code more complicated than it needs to be. This commit removes the cache and replaces it with direct lookups against the changelog. If this cache was for performance reasons, we should be able to restore it easily enough... after the changegroup refactor is complete. Differential Revision: https://phab.mercurial-scm.org/D4189

changegroup: rename _fullnodes to _fullclnodes So it is obvious which nodes we are talking about. And sneak in a docs change to reflect that this variable is a set. Differential Revision: https://phab.mercurial-scm.org/D4188

changegroup: move part of _revisiondeltanarrow into group() Now all the logic for determining which delta generation code is called lives in a single function. Differential Revision: https://phab.mercurial-scm.org/D4187

changegroup: populate _clnodetorev as part of changelog linknode lookup The thing that matters is that self._clnodetorev is populated with changesets that are being sent. Back when this code was in an extension, it wasn't possible to monkeypatch the changelog lookup function. Now that the code is in core, we can move this code to where it logically belongs. Differential Revision: https://phab.mercurial-scm.org/D4186

tests: rename variables in revlog index parse test for clarity Now it's unambiguous which one is the expected value. c_res_{1,2} was also misleading a bit because in --pure mode we're testing the old slow Python version against the modern optimized Python version. Differential Revision: https://phab.mercurial-scm.org/D4180

tests: move assertion closer to want/got declarations in test-parseindex2.py I find this easier to understand. Differential Revision: https://phab.mercurial-scm.org/D4179

tests: move chunks of test-parseindex2.py to use unittest properly This doesn't touch the version-detection tests yet, because those are more involved. Differential Revision: https://phab.mercurial-scm.org/D4178

tests: fix up indent width in test-parseindex2.py Differential Revision: https://phab.mercurial-scm.org/D4177

tests: start moving test-parseindex2.py to a unittest Using 2-space indents in this revision to make the code motion easier to review. I'll fix it in the next commit. Differential Revision: https://phab.mercurial-scm.org/D4176

tests: port test-absorb-filefixupstate to Python 3 Mostly b prefixes, but also some isinstance() checks and a couple of maplist() instances. The test now passes on Python 3. Differential Revision: https://phab.mercurial-scm.org/D4175

absorb: port partway to Python 3 Use pycompat.maplist() in the one place that matters and use the default iterator of a dict instead of iterkeys(). Two new tests pass on Python 3. Differential Revision: https://phab.mercurial-scm.org/D4174

localrepo: better error when a repo exists but we lack permissions Claiming "repository foo not found" when the repository does exist causes confusion regularly ("where is the typo?"). Differential Revision: https://phab.mercurial-scm.org/D4122

changegroup: extract _revisiondeltanormal() to standalone function It wasn't accessing anything important on the cgpacker that warranted it being a method instead of a function. Differential Revision: https://phab.mercurial-scm.org/D4142

changegroup: inline _revchunk() into group() _revchunk() was pretty minimal. I think having all the code for generating data composing the changegroup in one function makes things easier to understand. As part of the refactor, we now call the _revisiondelta* functions explicitly. This paves the road to refactor their argument signatures. Differential Revision: https://phab.mercurial-scm.org/D4141

changegroup: pass mfdicts properly With the narrow code part of core, the hacky pass-argument-via- attribute-on-self can be accomplished with a regular function argument. Differential Revision: https://phab.mercurial-scm.org/D4140

changegroup: pass sorted revisions into group() (API) Currently, group() receives a list of nodes and calls _sortgroup() to sort them and turn them into revs. Since the sorting behavior varies depending on the type of data being transferred, I think it makes sense to perform the sorting before group() is invoked. This commit extracts _sortgroup() to a pair of standalone functions. It then moves the calling of these functions to the 3 call sites of group(). group() now receives an iterable of revs instead of nodes. Differential Revision: https://phab.mercurial-scm.org/D4139

changegroup: pull _fileheader out of cgpacker It doesn't need any state from the packer. Differential Revision: https://phab.mercurial-scm.org/D4138

changegroup: factor changelogdone into an argument The variable was basically tracking whether the current operation is being performed against the changelog or something else. So let's just pass such a flag to everything that needs to access it. I'm still not a huge fan of building changelog awareness into low-level functions like revision delta generation. But passing an argument is strictly better than state on the packer instance. Differential Revision: https://phab.mercurial-scm.org/D4137

changegroup: record changelogdone after fully consuming its data Setting this as a side-effect of calling _close() is wonky. There's only one group for changelog data. So we can wait until after all data has been emitted before recording it. Differential Revision: https://phab.mercurial-scm.org/D4136

changegroup: key off changelogdone We use self._changelogdone for similar checks. Let's make things consistent. Differential Revision: https://phab.mercurial-scm.org/D4135

perf: call _generatechangelog() instead of group() Now that we have a separate function for generating just the changelog bits, the perf command should call it so it gets more accurate behavior. This changes the results of this command on my hg repo significantly: ! wall 1.390502 comb 1.390000 user 1.370000 sys 0.020000 (best of 8) ! wall 1.768750 comb 1.760000 user 1.760000 sys 0.000000 (best of 6) Profiling seems to reveal that ~20% of execution time is spent in progress bar accounting and printing! If we run with progress.disable=true: ! wall 1.639134 comb 1.650000 user 1.630000 sys 0.020000 (best of 7) A nice speedup. But profiling still shows a good chunk of time being spent in progress bar accounting code. The reason is that the progress bar is conditionally enabled via an argument to cgpacker.group(). The previous code in perf.py calling into group() did not enable the progress bar but _generatechangelog() always does. I think it is important for the perf* commands to capture real-world use cases. And this code always runs with an active progress bar. So the regression is acceptable. That being said, terminal printing performance can vary substantially. I don't think perf* commands should test terminal printing unless explicitly desired. So I've disabled progress bar printing in this command. Differential Revision: https://phab.mercurial-scm.org/D4134

changegroup: factor changelog chunk generation into own function We have separate functions for generating manifests and filelogs. Let's split changelog into its own function so things are consistent. As part of this, we refactor the code slightly. Before, the changelog linknode callback was updating state on variables inherited via a closure. Since the closure is now separate from generate(), we need to a way pass state between generate() and _generatechangelog(). The return value of _generatechangelog() is a 2-tuple where the first item is a dict containing accumulated state. We then alias some of its members into the scope of generate() to reduce code churn. I will be converting other functions to a similar pattern in future commits. Differential Revision: https://phab.mercurial-scm.org/D4133

changegroup: pass function to resolve delta parents into constructor Previously, _deltaparent() encapsulated the logic for all 3 delta parent modes of operation. The choice of delta parent is static for the lifetime of the packer and can be passed into the packer as a callable. So do that. Differential Revision: https://phab.mercurial-scm.org/D4132

changegroup: restore original behavior of _nextclrevtolocalrev 0548f696795b accidentally changed the behavior of cgpacker._close(). The old behavior moved _nextclrevtolocalrev to _clrevtolocalrev only when _nextclrevtolocalrev was present and then removed _nextclrevtolocalrev. The bad behavior performed this move then cleared _clrevtolocalrev because it was the same object as _nextclrevtolocalrev. This commit restores the previous behavior. Surprisingly, no tests changed as a result of this bad logic. I'm not sure why. Differential Revision: https://phab.mercurial-scm.org/D4155

py3: whitelist another test caught by the ratchet Differential Revision: https://phab.mercurial-scm.org/D4173

debugcommands: force import of fileset in debugfileset It looks like Python 3's lazy importer is better than Python 2's for this command, and as a result we had no symbols in the filesetlang symbol table, which resulted in some really mysterious test-fileset.t failures around withstatus optimizations. Inserting this explicit import and forcing its evaluation fixes the test failure. Differential Revision: https://phab.mercurial-scm.org/D4172

linelog: optimize replacelines The optimization to avoid calling `annotate` inside `replacelines` is significant for practical use patterns. Before this patch: hg perflinelogedits ! wall 6.778478 comb 6.710000 user 6.700000 sys 0.010000 (best of 3) After this patch: hg perflinelogedits ! wall 0.136573 comb 0.140000 user 0.130000 sys 0.010000 (best of 63) Differential Revision: https://phab.mercurial-scm.org/D4150

linelog: extract `len(self._program)` to a local function This is a micro optimization prepared for following changes where `len(self._program)` is used in a loop. Differential Revision: https://phab.mercurial-scm.org/D4149

perf: add a command to benchmark linelog edits The use pattern of creating a linelog is usually by calling "replacelines" multiple times. Add a command to benchmark it. Differential Revision: https://phab.mercurial-scm.org/D4148

linelog: update internal help text This clarifies the details asked by @martinvonz on D3990. Differential Revision: https://phab.mercurial-scm.org/D4147

fix: determine fixer tool failure by exit code instead of stderr This seems like the more natural thing, and it probably should have been this way to beign with. It is more flexible because it allows tools to emit diagnostic information while also modifying a file. An example would be an automatic code formatter that also prints any remaining lint issues. Differential Revision: https://phab.mercurial-scm.org/D4158

status: advertise --abort instead of 'update -C .' to abort graft Recent release got us a --abort flag for 'hg graft' command which is nice UI and we should advertise that to stop the graft instead of 'update -C .' which is kind of ugly. Differential Revision: https://phab.mercurial-scm.org/D4169