color: move 'write-err' logic to the core ui class This is similar to what we needed for 'write', we move the logic from the extension to the core class. Beside the dispatch to 'win32print', we just apply label to the argument.

ui: extract low level part of 'write_err' in its own method Same as for 'write' and '_write' we needs it available for some of the color logic.

ui: extract buffer write from protect and timed 'write_err' output That subcall to 'self.write' is never doing actual write but only store things in buffers. So we do not need to protect it for exception not to time its execution. This will make it easier to extract a '_write_err' function as we did for 'write'.

color: move 'write' logic to the core ui class One more step, the support for writing color is not directly in core. No behavior change for the default case ('_colormode' = None). Here are the details of what we have to change to the core method: * apply to 'self.label' to input in the buffered case * dispatch to 'win32print' when applicable * apply to 'self.label' to input when applicable

ui: extract the low level part of 'write' in a dedicated function We are about to add some extra logic related to color. That logic will need to access the low level layer of ui doing the actual write to a stream. (eg: 'win32print'). We extract this logic into a private method for this purpose.

color: add multiple messages input support to 'win32print' All other function doing writes support any number of input message. For simplicity, we make 'win32print' able to do the same.

color: clarify name of an argument of 'win32print' In the current code, the function called to write happens to the 'orig' version of the method calling 'win32print' (obtained with a 'super' call). However, the variable could have a better name. That will be useful when we'll stop having inheritance in play.

color: move the 'colorlabel' call to the core 'ui' class This bring us closer to supporting color in core natively. Core already have a 'label' method that was a no-op. We update its to call the new 'colorlabel' function. Behavior is unchanged when colormode = None.

color: move the 'colorlabel' function in the core module The extract code is relocated in core.

color: extract the label code into its own function We extract the logic into a function. This will allow us to move the logic into the core 'color' module and later call it directly from core.

color: inline the 'showlabel' method This function is quite simple and only have one call site… located a handful of line under the definition. We inline the function for the sake of simplicity. One of the motivation to do that now is that it reduce the amount of new method we will have to add to the core 'ui' class for color support.

color: move '_colormode' to the core 'ui' class Having all 'ui' objects aware of 'color' allows us to update the core code to handle color. The mode will stay 'None' in the default case so that will not introduce any changes.

hgweb: explictly pass basectx in webutil.diffs There's only one case where `basectx` parameter is None (over two usages), so it's probably not worth handling the special case as it makes code-reading harder. Along the way, use ctx.p1() instead of checking for ctx.parents() being empty which should not occur.

serve: mark --stdio and --cmdserver as "(ADVANCED)" flags This will hide them from the default --help output.

help: hide command line options marked as "advanced" Previously, we have keywords like "(DEPRECATED)" and "(EXPERIMENTAL)" to hide command line options in non-verbose help output. However, sometimes an option is neither deprecated nor experimental. It's well-tested and working, but just not designed to average users. This patch adds a keyword "(ADVANCED)" to fit in such use cases. Thanks rom1dep for the suggestion of the word "advanced".

pager: do not try to run an empty pager command If pagercmd is explicitly set to '', the pager process would exit silently and the output would be lost. We'd better disable the pager in such case.

graphlog: restore pager lost at 1cec1d863008

gitweb: add "more" and "less" navigation links in filelog template

context: also return ancestor's line range in blockancestors

context: add a followfirst flag to blockancestors

py3: use pycompat.fsencode() to convert __file__ to bytes __file__ returns unicodes on Python 3. This patch uses pycompat.fsencode() to convert them to bytes.

wireproto: remove unused code Removed an unused line introduced by f3807a135e43.

color: set initial default value for 'colormode' to None This should not introduce any behavior changes when using the color extension. In practive, the colormode will be setup at early at run time to the proper value (from config and environment). We do this change as this gets us closer of a state were we can have all the mechanisms associated to color in core with the feature disabled by default.

color: minor reversal of two conditional clause for clarity Another minor cleanup while reading the code. The two branches of the conditional have similar complexity so we go for the order that give us the simplest condition (we drop the negation).

color: merge two identical 'for' loops The previous changeset made it clear that we are iterating twice on the same items. We gather the two loops into a single one.

color: minor simplification of some terminfo setup code No logic change is introduced. The previous code were using a 'dict.update' with a complex generator. That was a bit confusing to read and not so compact. Instead we now use an explicit loop and conditional for the sake of clarity. This also allow for more simplification coming in the next changeset.

color: make a test for curse availability explicite We won't use terminfo when curse failed to load. Before this change, we were doing an indirect test, relying on the fact some variable ('_terminfo_params') would be empty if curses failed to load. We update the code to be more explicit and directly checks if we managed to load the curse module.

color: move 'win32' declaration to the core module This is another part of moving color implementation into core. before we can move the advance logic, we need to move the basic definition and building bricks. This is one more step on that road.

smartset: preserve istopo for baseset operations This is a follow-up of "smartset: use native set operations as fast paths". It's more correct to just preserve the "istopo" information for "&" and "-" operations, like what filteredset does.

pager: add a config knob to just globally turn off the pager

pager: move most help to a new help topic and deprecate extension

dispatch: rearrange 'unknown command' code to better employ pager dispatch calls help like a ninja if you give it a truly unknown command, and that might want to be paged. If it gets paged, then the 'hg: unknown command' text gets eaten by a grue, unless we call the pager first. This change rearranges the codepaths so we can safely only invoke the pager in the case where we'll have long output from the help command code, rather than just a short message like "did you mean stat instead of start" or "fetch is provided by the fetch extension".

help: move rst formatting of help documents into help.py This slight refactor will help me improve the 'unknown command' experience in our new glorious pager future.

outgoing: avoid running pager until we're actually showing changes Consistent with the new behavior of incoming in the previous patch.

incoming: delay pager activation until right before printing changes This prevents authentication and other brief status messages from being paged.

histedit: modify rollup to discard date from the rollup commit (issue4820) This change adjusts and documents the new behaviour of 'roll'. It now fits nicely with the behaviour of 'commit --amend' and the 'edit' action, by discarding the date as well as the commit message of the second commit. Previously it used the later date, like 'fold', but this often wasn't desirable, for example, in the common use case of using 'roll' to add forgotten changes to a changeset (because 'hg add' was previously forgotten or not all changes were identified while using 'hg record').

histedit: improve documentation and behaviour of dates This clarifies in the histedit documentation that the 'edit' action preserves the date and that the 'fold' action uses the later date. The documentation was previously silent on this issue which left users in doubt.

localrepo: check HG_PENDING strictly Before this patch, checking HG_PENDING for changelog in localrepo.py might cause unintentional reading unrelated '00changelog.i.a' in, because HG_PENDING is checked by str.startswith(). An external hook spawned by inner repository in nested ones satisfies this condition. This patch uses txnutil.mayhavepending() to check HG_PENDING strictly. BTW, this patch may cause failure of bisect in the repository of Mercurial itself, if examination at bisecting assumes that an external hook can see all pending changes while nested transactions across repositories. This invisibility issue will be fixed by subsequent patch, which allows HG_PENDING to refer multiple repositories.

phases: check HG_PENDING strictly Before this patch, checking HG_PENDING in phases.py might cause unintentional reading unrelated 'phaseroots.pending' in, because it just examines existence of HG_PENDING environment variable. This patch uses txnutil.trypending() to check HG_PENDING strictly. BTW, this patch may cause failure of bisect in the repository of Mercurial itself, if examination at bisecting assumes that an external hook can see all pending changes while nested transactions across repositories. This invisibility issue will be fixed by subsequent patch, which allows HG_PENDING to refer multiple repositories.

bookmarks: check HG_PENDING strictly Before this patch, checking HG_PENDING in bookmarks.py might cause unintentional reading unrelated '.hg/bookmarks.pending' in, because it just examines existence of HG_PENDING environment variable. This patch uses txnutil.trypending() to check HG_PENDING strictly. This patch also changes share extension. Enabling share extension (+ bookmark sharing) makes bookmarks._getbkfile() receive repo to be shared (= "srcrepo"). On the other hand, HG_PENDING always refers current working repo (= "currepo"), and bookmarks.pending is written only into currepo. Therefore, we should try to read .hg/bookmarks.pending of currepo in at first. If it doesn't exist, we try to read .hg/bookmarks of srcrepo in. Even after this patch, an external hook spawned in currepo can't see pending changes in currepo via srcrepo, even though such changes become visible after closing transaction, because there is no easy and cheap way to know existence of pending changes in currepo via srcrepo. Please see https://www.mercurial-scm.org/wiki/SharedRepository, too. BTW, this patch may cause failure of bisect in the repository of Mercurial itself, if examination at bisecting assumes that an external hook can see all pending changes while nested transactions across repositories. This invisibility issue will be fixed by subsequent patch, which allows HG_PENDING to refer multiple repositories.

tests: make directory to prevent test process from going out of $TESTTMP Before this patch, test process for test-bookmarks.t goes out of $TESTTMP at "cd .." before creation of "orderrepo" repository. To prevent test process from going out of $TESTTMP, this patch makes directory "repo" sub-directory and executes almost all test scenarios in test-bookmarks.t under it. This is preparation for new test added in subsequent patch.

txnutil: factor out the logic to read file in according to HG_PENDING This patch adds new file txnutil.py, because: - transaction.py is too large to import small utility logic - scmutil.py or so causes cyclic importing in phases.py mayhavepending() is defined separately for convenience in subsequent patch.

repoview: separate cache hash computation from cache reading This change will make it easier for extensions to use another cache hash.

tests: make test suite more immune to environment variables Plenty of tests break when "make tests" is run while environment variables "HGPLAIN" or "HGPLAINEXCEPT" are set (test "test-obsolete- checkheads.t" is just a single example). This patch causes script "run-tests.py" to also remove these two variables from the environment the tests are executed in.

version: enable pager if --verbose is specified `hg version` output is very short without --verbose, but with --verbose it tends to scroll off the user's screen.

tags: enable pager

summary: enable pager

status: enable pager

resolve: enable pager

paths: enable pager

outgoing: enable pager The structure here is similar to incoming, and requires similar treatment.

manifest: enable pager

locate: enable pager

incoming: enable pager The design of incoming means we have to activate the pager in several places, depending on which codepath gets chosen.

help: enable pager

grep: enable pager

files: enable pager

config: activate pager if not starting an editor This demonstrates the power of the non-attend-based pager API.

qdiff: migrate to modern pager API This results in the default pager-attend list being empty. Sadly, we can't let the code be that way, because some legacy extensions depend on hooking the pager's attend list at import time (and we'd like to not break them), and if the list is actually *empty* that triggers magic behavior in the extension that attends everything. Instead, we put a long, improbable command name as the only entry in the attend list.

log: migrate to modern pager API

export: migrate to modern pager API

diff: migrate to modern pager API

cat: migrate to modern pager API

annotate: start pager after we're sure we wont abort This avoids needlessly putting a short error message into the pager.

dispatch: consolidate pager flag handling to a single place This makes a little more sense, thanks to Martin for suggesting it.

ui: rename neverpager to disablepager I agree this is a clearer name for this method.

scmutil: proxy revrange() through repo to break import cycles This was one of the hardest import cycles as scmutil is widely used and revset functions are likely to depend on a variety of modules. New repo.anyrevs() does not expand user aliases by default to copy the behavior of the existing repo.revs(). I don't want to add new function to localrepository, but this function is quite similar to repo.revs() so it won't increase the complexity of the localrepository class so much.

revset: split language services to revsetlang module (API) New revsetlang module hosts parser, tokenizer, and miscellaneous functions working on parsed tree. It does not include functions for evaluation such as getset() and match(). 2288 mercurial/revset.py 684 mercurial/revsetlang.py 2972 total get*() functions are aliased since they are common in revset.py.

revset: import set classes directly from smartset module Follows up 1be65deb3d54.

help: add pointer how to narrow list of resolved/unresolved files (issue5469)

shelve: add -n/--name option to unshelve (issue5475) This makes using shelve/unshelve more consistent because shelving can be done using name option and unshelving as well. Author of the idea of this improvement and solution is joshgold.

smartset: use native set operations as fast paths For set operations like "&" and "-", where we know both basesets have their sets ready, and the first set is sorted, use the native Python set operations as a fast path. Note: "+" is not optimized as that will break the ordering. This leads to noticeable improvements on performance: revset | before | after | delta ---------------------------------------------------------------- draft() & draft() & draft() & draft() | 776 | 477 | -39% draft() + draft() + draft() + draft() | 2849 | 2864 | draft() - draft() + draft() - draft() | 943 | 240 | -75% draft() - draft() - draft() - draft() | 557 | 197 | -64% (time measured in microseconds)

smartset: add some doctests Add doctests explaining the set / list behavior. This will make the following changes more confident.

obsolete: avoid using revset language to compute the obsolete revset This is part of a refactoring that moves some phase query optimization from revset.py to phases.py. See previous patches for the motivation. Now we have APIs in phasecache to get the non-public set efficiently, let's use it directly instead of going through the "not public()" revset language in "obsolete()" computation. This patch was meaured using: for i in 'public()' 'not public()' 'draft()' 'not draft()'; do hg perfrevset "$i"; hg perfrevset "$i" --hidden; done and no noticeable (> 1%) performance difference was observed.

revset: use phasecache.getrevset This is part of a refactoring that moves some phase query optimization from revset.py to phases.py. See the previous patch for motivation. This patch changes revset code to use phasecache.getrevset so it no longer accesses the private field: _phasecache._phasesets directly. For performance impact, this patch was tested using the following query, on my hg-committed repo: for i in 'public()' 'not public()' 'draft()' 'not draft()'; do echo $i; hg perfrevset "$i"; hg perfrevset "$i" --hidden; done For the CPython implementation, most operations are unchanged (within +/- 1%), while "not public()" and "draft()" is noticeably faster on an unfiltered repo. It may be because the new code avoids a set copy if filteredrevs is empty. revset | public() | not public() | draft() | not draft() hidden | yes | no | yes | no | yes | no | yes | no ------------------------------------------------------------------ before | 19006 | 17352 | 239 | 286 | 180 | 228 | 7690 | 5745 after | 19137 | 17231 | 240 | 207 | 182 | 150 | 7687 | 5658 delta | | -38% | | -52% | (timed in microseconds) For the pure Python implementation, some operations are faster while "not draft()" is noticeably slower: revset | public() | not public() | draft() | not draft() hidden | yes | no | yes | no | yes | no | yes | no ------------------------------------------------------------------------ before | 18852 | 17183 | 17758 | 15921 | 17505 | 15973 | 41521 | 39822 after | 18924 | 17380 | 17558 | 14545 | 16727 | 13593 | 48356 | 43992 delta | | -9% | -5% | -15% | +16% | +10% That may be the different performance characters of generatorset vs. filteredset. The "not draft()" query could be optimized in this case where both "public" and "secret" are passed to "getrevsets" so it won't iterate the whole repo twice.

phases: add a getrevset method to phasecache This is part of a refactoring that moves some phase query optimization from revset.py to phases.py. The motivation behind this was chg repo preloading - to make the obsstore depend on less things (like the revset language). The refactoring also looks good by itself - phasecache does not expose its private field "_phasesets" via public methods and revset.py is accessing it in a hacky way. This patch adds a "getrevset" method, which takes multiple phases and returns a revset in an best-effort efficient way - for "public" phase, it returns a lazy generatorset; for "draft" and "secret", it returns efficient "baseset".

smartset: convert set to list lazily If the caller only wants to construct a baseset via a set, and then do "__contains__" tests. It's unnecessary to initialize the list. Testing on my unfiltered hg-committed repo where len(draft()) is 2600, this patch shows about 6% improvement on set intensive queries: Before: $ for i in `seq 5`; hg perfrevset 'draft() & draft() & draft() & draft()' ! wall 0.001196 comb 0.000000 user 0.000000 sys 0.000000 (best of 2011) ! wall 0.001191 comb 0.000000 user 0.000000 sys 0.000000 (best of 2099) ! wall 0.001186 comb 0.010000 user 0.010000 sys 0.000000 (best of 1953) ! wall 0.001182 comb 0.000000 user 0.000000 sys 0.000000 (best of 2135) ! wall 0.001193 comb 0.000000 user 0.000000 sys 0.000000 (best of 2177) After: $ for i in `seq 5`; hg perfrevset 'draft() & draft() & draft() & draft()' ! wall 0.001128 comb 0.000000 user 0.000000 sys 0.000000 (best of 2247) ! wall 0.001119 comb 0.000000 user 0.000000 sys 0.000000 (best of 2317) ! wall 0.001115 comb 0.000000 user 0.000000 sys 0.000000 (best of 2244) ! wall 0.001131 comb 0.000000 user 0.000000 sys 0.000000 (best of 2093) ! wall 0.001124 comb 0.000000 user 0.000000 sys 0.000000 (best of 2134) It could have bigger impact on larger sets in theory.

ui: construct _keepalnum list in a python3-friendly way It'll be more expensive, but it preserves the behavior.

match: making visitdir() deal with non-recursive entries Primarily as an optimization to avoid recursing into directories that will never have a match inside, this classifies each matcher pattern's root as recursive or non-recursive (erring on the side of keeping it recursive, which may lead to wasteful directory or manifest walks that yield no matches). I measured the performance of "rootfilesin" in two repos: - The Firefox repo with tree manifests, with "hg files -r . -I rootfilesin:browser". The browser directory contains about 3K files across 249 subdirectories. - A specific Google-internal directory which contains 75K files across 19K subdirectories, with "hg files -r . -I rootfilesin:REDACTED". I tested with both cold and warm disk caches. Cold cache was produced by running "sync; echo 3 > /proc/sys/vm/drop_caches". Warm cache was produced by re-running the same command a few times. These were the results: Cold cache Warm cache Before After Before After firefox 0m5.1s 0m2.18s 0m0.22s 0m0.14s google3 dir 2m3.9s 0m1.57s 0m8.12s 0m0.16s Certain extensions, notably narrowhg, can depend on this for correctness (not trying to recurse into directories for which it has no information).

match: adding support for matching files inside a directory This adds a new "rootfilesin" matcher type which matches files inside a directory, but not any subdirectories (so it matches non-recursively). This has the "root" prefix per foozy's plan for other matchers (rootglob, rootpath, cwdre, etc.).

runtests: add an IPv6 command line flag Now we have all IPv6 related issues fixed, add a command line flag so people could actually run tests with IPv6.

runtests: always set web.ipv6 Previously, we only set web.ipv6 if IPv6 is used, but not on the IPv4 case. Since we already have set web.address, it makes sense to move "web.ipv6" out from "extra config options".

runtests: set web.address to localhost Previously, "hg serve" will listen on "", which is not clear which interface it will actually listen on - it could listen on all interfaces (ex. 0.0.0.0 on IPv4). The run-tests.py script only checks "localhost" for available ports. So let's make it the same for "hg serve" by explicitly setting "web.address" to "localhost". This resolves some IPv6 EADDRINUSE errors.

tests: use LOCALIP This patch replaces hardcoded 127.0.0.1 with $LOCALIP in all tests. Till now, the IPv6 series should make tests pass on common IPv6 systems where the local device has the address "::1" and the hostname "localhost" resolves to "::1".

dummyssh: use LOCALIP This patch replaces hard-coded 127.0.0.1 with $LOCALIP in dummyssh.

runtests: export LOCALIP Previously, tests hard-code local IP address as "127.0.0.1". That won't work for IPv6. This patch exports the $LOCALIP environment variable, which is set to "::1" if we decide to use IPv6.

tinyproxy: use IPv6 if HGIPV6 is set to 1 This patch makes tinyproxy.py work in IPv6 mode if HGIPV6 is set to 1. This will make test-http-proxy.t pass on IPv6 machines.

dumbhttp: use IPv6 if HGIPV6 is set to 1 This will fix flaky tests using dumbhttp. The patch was tested on gcc112.fsffrance.org using the following command: ./run-tests.py -j 40 --runs-per-test 120 test-bundle2-remote-changegroup.t

runtests: export HGIPV6 to hint test scripts whether to use IPv6 Previously, run-tests.py only exports HGPORT, and scripts in tests do not know if IPv6 should be used. And that breaks scripts like dumbhttp.py which always uses IPv4. This patch makes run-tests.py export HGIPV6, which can help test scripts like dumbhttp.py and tinyproxy.py to decide whether to use IPv6 or not.

runtests: prefer IPv4 to IPv6 To make IPv6 work, there are multiple areas that need to fix. Before they all get fixed, use IPv4 by default. This should fix tests caused on IPv6 systems.

doc: correct example concerning "hg purge" alias in man page "hgrc.5" The "hg purge" alias as currently described in "hgrc.5" issues a possibly confusing error message like rm: missing operand Try 'rm --help' for more information. if no files are to be purged at all. This patch slightly modifies the example by adding a "-f" option to the "rm" command.

tests: prove that ignore works

annotate: migrate to modern pager API

ui: add a debug print right before we start the pager This makes it easier to figure out why a command is getting paginated.

ui: respect historic pager.attend-$COMMAND=no I'm on the fence about this behavior, but the user's intent was pretty specific and it's not expensive to support this case.

tests: clean up a bunch of pager testing that is about to be invalidated All this attend logic and potential bugs just no longer make sense to test.

ui: add ignore-single-command functionality This closes the last feature gap other than the attend list from the extension. For now, I'm leaving the attend list in the extension, because I'm unsure it has merit in a world where commands have been updated to take advantage of the modern API.

ui: introduce neverpager() call I'm about to add direct paging support to some commands, and as a result we need a way to communicate from the higher layers of dispatch that paging is explicitly disabled.

pager: move more behavior into core This moves the global flag and the --pager=yes logic into core. Only functionality change is that users now always get a --pager flag and can enable the pager via the flag without the extension active. Moving the flag into core exposes a defect in the ro localization, which will have to be corrected later.

pager: move pager-initiating code into core No functionality change. A previous version of this API had a category argument on ui.pager(). As I migrated the commands in core, I couldn't come up with good enough consistency in any categorization scheme so I just scrapped the whole idea. It may be worth revisiting in the future.

test-logtoprocess: use cat to wait for outputs Commands started by logtoprocess are running asynchronously. To be able to test the output, we need to block and wait for the output. The patch uses "| cat" to wait for such "asynchronous" outputs, to make the test more reliable. I have also written a short notice at the top, hopefully people would be aware of the pitfall when changing the test.

chgserver: move comments in config example "#" must be the first character of a line to mark the text as comments. So let's change the docstring.

localrepo: move extension loading to a separate method The stateful chg plan [1] requires a special repo object, where ideally all side effects caused by loading the repo object could be reverted by just dropping (gabbage collect) the loaded repo object. Currently, that is impossible because repo.__init__ calls "extensions.loadall", which may have unpredictable side-effects that cannot be reverted by dropping the repo object. This patch moves "extensions.loadall" to a separate method, so chg could subclass localrepository and make extensions loading a no-op. [1]: mercurial-scm.org/pipermail/mercurial-devel/2017-February/092547.html

py3: convert the mode argument of os.fdopen to unicodes Couple of these from the earlier series got lost while rebasing. So this patch converts them again.

runtests: unindent an "if True" block The block was left to make review easier. This patch unindents it.

runtests: set web.ipv6 if we use IPv6 As explained by the previous patch, we need to set "web.ipv6=True" if we decide to use IPv6. Otherwise "hg serve" will still try to listen on IPv4. This patch makes it so by appending web.ipv6 to "extra configs". This patch was tested in a Linux system with IPv6, by the following steps: 1. Change hgweb/server.py temporarily to write a file if IPv6HTTPServer.__init__ is called. 2. run-tests.py -l --keep-tmpdir test-serve.t 3. Check the generated .hgrc, make sure it sets web.ipv6=1. 4. Check the log file to make sure IPv6HTTPServer.__init__ is called.

runtests: checkportisavailable should only check one family As explained by the previous patch, checkportisavailable() should only check the preferred family - either IPv4 or IPv6, not both. This patch makes it so.

runtests: add a function to test if IPv6 is available Previously, checkportisavailable returns True if the port is free either on IPv4 or IPv6, but the hg server only uses IPv4 by default. That leads to issues when IPv4 port is not free but the IPv6 one is. To address that, run-tests should stick with either IPv4 or IPv6. This patch adds a function similar to checkportisavailable to test if IPv6 is available, and assigns the result to a variable. The new function was tested in a Linux system script with the following steps: 1. Run "ip addr del ::1/128 dev lo" to delete lo's IPv6 address, Confirm checkipv6available() returns False. 2. Run "ip addr add ::1/128 dev lo" to add back lo's IPv6 address. Confirm checkipv6available() returns True. 3. Start a web server taking the 8000 port. Confirm checkipv6available(8000) is still True.

histedit: log the time taken to read in the commands list If we're being fed an external command list from stdin (histedit --commands -), then the time spent reading stdin is outside our control. Log it.

extdiff: log time spent in external diff program We can't fix the time external diff programs take to run. Log that duration for us to remove from any stats we gather

crecord: log blocked time waiting for curses input We want to know when we're blocked waiting for the user - log the time spent waiting in the curses keyboard handlers

ui: give editor() a tag of its own We know that calls to ui.editor() always block on the user's configured editor. Use a blocking tag that ensures that we don't see a huge variety of editor options in our logging.

ui: time calls to ui.system We want to know when we're blocked on ui.system, and why. Allow the user to supply a tag - otherwise we record on an unspecific tag derived from cmd.

ui: log time spent blocked on stdio We use a wrapper around Mercurial at Facebook that logs key statistics (like elpased time) to our standard performance tooling. This is less useful than it could be, because we currently can't tell when a command is slow because we need to fix Mercurial versus when a command is slow because the user isn't interacting quickly. Teach Mercurial to log the time it spends blocked, so that our tooling can pick it up and submit it with the elapsed time - we can then do the math in our tooling to see if Mercurial is slow, or if the user simply failed to interact. Combining this with the command duration log means that we can ensure that we concentrate performance efforts on the things that bite Facebook users. The perfwrite microbenchmark shifts from: Linux: ! wall 3.213560 comb 0.410000 user 0.350000 sys 0.060000 (best of 4) Mac: ! wall 0.342325 comb 0.180000 user 0.110000 sys 0.070000 (best of 20) before this change to: ! wall 3.478070 comb 0.500000 user 0.420000 sys 0.080000 (best of 3) Mac: ! wall 0.218112 comb 0.220000 user 0.150000 sys 0.070000 (best of 15) showing a small hit in comb time, but firmly in the noise on wall time.

contrib: add a write microbenchmark to perf.py I'm adding some performance logging to ui.write - this benchmark lets us confirm that the cost of that logging is acceptably low. At this point, the microbenchmark on Linux over SSH shows: ! wall 3.213560 comb 0.410000 user 0.350000 sys 0.060000 (best of 4) while on the Mac locally, it shows: ! wall 0.342325 comb 0.180000 user 0.110000 sys 0.070000 (best of 20)

ui: provide a mechanism to track and log blocked time We want to log the time Mercurial spends trapped in things outside programmatic control. Provide a mechanism to give us both command runtime and as many different sources of blocking as we deem useful.

mercurial: switch to util.timer for all interval timings util.timer is now the best available interval timer, at the expense of not having a known epoch. Let's use it whenever the epoch is irrelevant.

util: introduce timer() As documented for timeit.default_timer, there are better timers available for performance measures on some platforms. These timers don't have a set epoch, and thus are only useful for interval measurements, but have higher resolution, and thus get you a better measurement overall. Use the same selection logic as Python's timeit.default_timer. This is a platform clock on Python 2 and early Python 3, and time.perf_counter on Python 3.3 and later (where time.perf_counter is introduced as the best timer to use).

color: move the '_render_effects' function to the core module

color: move '_effect_str' function into the core module