view tests/test-narrow-widen.t @ 36426:23d12524a202

http: drop custom http client logic

Eight and a half years ago, as my starter bug on code.google.com, I
investigated a mysterious "broken pipe" error from seemingly random
clients[0]. That investigation revealed a tragic story: the Python
standard library's httplib was (and remains) barely functional. During
large POSTs, if a server responds early with an error (even a
permission denied error!) the client only notices that the server
closed the connection and everything breaks. Such server behavior is
implicitly legal under RFC 2616 (the latest HTTP RFC as of when I was
last working on this), and my understanding is that later RFCs have
made it explicitly legal to respond early with any status code outside
the 2xx range.

I embarked, probably foolishly, on a journey to write a new http
library with better overall behavior. The http library appears to work
well in most cases, but it can get confused in the presence of
proxies, and it depends on select(2) which limits its utility if a lot
of file descriptors are open. I haven't touched the http library in
almost two years, and in the interim the Python community has
discovered a better way[1] of writing network code. In theory some day
urllib3 will have its own home-grown http library built on h11[2], or
we could do that. Either way, it's time to declare our current
confusingly-named "http2" client logic and move on. I do hope to
revisit this some day: it's still garbage that we can't even respond
with a 401 or 403 without reading the entire POST body from the
client, but the goalposts on writing a new http client library have
moved substantially. We're almost certainly better off just switching
to requests and eventually picking up their http fixes than trying to
live with something that realistically only we'll ever use. Another
approach would be to write an adapter so that Mercurial can use pycurl
if it's installed. Neither of those approaches seem like they should
be investigated prior to a release of Mercurial that works on Python
3: that's where the mindshare is going to be for any improvements to
the state of the http client art.

0: http://web.archive.org/web/20130501031801/http://code.google.com/p/support/issues/detail?id=2716
1: http://sans-io.readthedocs.io/
2: https://github.com/njsmith/h11

Differential Revision: https://phab.mercurial-scm.org/D2444

#testcases flat tree
  $ . "$TESTDIR/narrow-library.sh"

#if tree
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > treemanifest = 1
  > EOF
#endif

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [narrow]
  > serveellipses=True
  > EOF

  $ mkdir inside
  $ echo 'inside' > inside/f
  $ hg add inside/f
  $ hg commit -m 'add inside'

  $ mkdir widest
  $ echo 'widest' > widest/f
  $ hg add widest/f
  $ hg commit -m 'add widest'

  $ mkdir outside
  $ echo 'outside' > outside/f
  $ hg add outside/f
  $ hg commit -m 'add outside'

  $ cd ..

narrow clone the inside file

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets *:* (glob)
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow
  $ hg tracked
  I path:inside
  $ ls
  inside
  $ cat inside/f
  inside
  $ cd ..

add more upstream files which we will include in a wider narrow spec

  $ cd master

  $ mkdir wider
  $ echo 'wider' > wider/f
  $ hg add wider/f
  $ echo 'widest v2' > widest/f
  $ hg commit -m 'add wider, update widest'

  $ echo 'widest v3' > widest/f
  $ hg commit -m 'update widest v3'

  $ echo 'inside v2' > inside/f
  $ hg commit -m 'update inside'

  $ mkdir outside2
  $ echo 'outside2' > outside2/f
  $ hg add outside2/f
  $ hg commit -m 'add outside2'

  $ echo 'widest v4' > widest/f
  $ hg commit -m 'update widest v4'

  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  *: update widest v4 (glob)
  *: add outside2 (glob)
  *: update inside (glob)
  *: update widest v3 (glob)
  *: add wider, update widest (glob)
  *: add outside (glob)
  *: add widest (glob)
  *: add inside (glob)

  $ cd ..

Widen the narrow spec to see the wider file. This should not get the newly
added upstream revisions.

  $ cd narrow
  $ hg tracked --addinclude wider/f
  comparing with ssh://user@dummy/master
  searching for changes
  no changes found
  saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-widen.hg (glob)
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  new changesets *:* (glob)
  $ hg tracked
  I path:inside
  I path:wider/f

Pull down the newly added upstream revision.

  $ hg pull
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 2 changes to 2 files
  new changesets *:* (glob)
  (run 'hg update' to get a working copy)
  $ hg update -r 'desc("add wider")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat wider/f
  wider

  $ hg update -r 'desc("update inside")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat wider/f
  wider
  $ cat inside/f
  inside v2

  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  ...*: update widest v4 (glob)
  *: update inside (glob)
  ...*: update widest v3 (glob)
  *: add wider, update widest (glob)
  ...*: add outside (glob)
  *: add inside (glob)

Check that widening with a newline fails

  $ hg tracked --addinclude 'widest
  > '
  abort: newlines are not allowed in narrowspec paths
  [255]

widen the narrow spec to include the widest file

  $ hg tracked --addinclude widest
  comparing with ssh://user@dummy/master
  searching for changes
  no changes found
  saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-widen.hg (glob)
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 3 files
  new changesets *:* (glob)
  $ hg tracked
  I path:inside
  I path:wider/f
  I path:widest
  $ hg update 'desc("add widest")'
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cat widest/f
  widest
  $ hg update 'desc("add wider, update widest")'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat wider/f
  wider
  $ cat widest/f
  widest v2
  $ hg update 'desc("update widest v3")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat widest/f
  widest v3
  $ hg update 'desc("update widest v4")'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat widest/f
  widest v4

  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  *: update widest v4 (glob)
  ...*: add outside2 (glob)
  *: update inside (glob)
  *: update widest v3 (glob)
  *: add wider, update widest (glob)
  ...*: add outside (glob)
  *: add widest (glob)
  *: add inside (glob)

separate suite of tests: files from 0-10 modified in changes 0-10. This allows
more obvious precise tests tickling particular corner cases.

  $ cd ..
  $ hg init upstream
  $ cd upstream
  $ cat >> .hg/hgrc <<EOF
  > [narrow]
  > serveellipses=True
  > EOF
  $ for x in `$TESTDIR/seq.py 0 10`
  > do
  >   mkdir d$x
  >   echo $x > d$x/f
  >   hg add d$x/f
  >   hg commit -m "add d$x/f"
  > done
  $ hg log -T "{node|short}: {desc}\n"
  *: add d10/f (glob)
  *: add d9/f (glob)
  *: add d8/f (glob)
  *: add d7/f (glob)
  *: add d6/f (glob)
  *: add d5/f (glob)
  *: add d4/f (glob)
  *: add d3/f (glob)
  *: add d2/f (glob)
  *: add d1/f (glob)
  *: add d0/f (glob)

make narrow clone with every third node.

  $ cd ..
  $ hg clone --narrow ssh://user@dummy/upstream narrow2 --include d0 --include d3 --include d6 --include d9
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 4 changes to 4 files
  new changesets *:* (glob)
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow2
  $ hg tracked
  I path:d0
  I path:d3
  I path:d6
  I path:d9
  $ hg verify
  checking changesets
  checking manifests
  checking directory manifests (tree !)
  crosschecking files in changesets and manifests
  checking files
  4 files, 8 changesets, 4 total revisions
  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  ...*: add d10/f (glob)
  *: add d9/f (glob)
  ...*: add d8/f (glob)
  *: add d6/f (glob)
  ...*: add d5/f (glob)
  *: add d3/f (glob)
  ...*: add d2/f (glob)
  *: add d0/f (glob)
  $ hg tracked --addinclude d1
  comparing with ssh://user@dummy/upstream
  searching for changes
  no changes found
  saved backup bundle to $TESTTMP/narrow2/.hg/strip-backup/*-widen.hg (glob)
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 5 changes to 5 files
  new changesets *:* (glob)
  $ hg tracked
  I path:d0
  I path:d1
  I path:d3
  I path:d6
  I path:d9
  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  ...*: add d10/f (glob)
  *: add d9/f (glob)
  ...*: add d8/f (glob)
  *: add d6/f (glob)
  ...*: add d5/f (glob)
  *: add d3/f (glob)
  ...*: add d2/f (glob)
  *: add d1/f (glob)
  *: add d0/f (glob)

Verify shouldn't claim the repo is corrupt after a widen.

  $ hg verify
  checking changesets
  checking manifests
  checking directory manifests (tree !)
  crosschecking files in changesets and manifests
  checking files
  5 files, 9 changesets, 5 total revisions

Widening preserves parent of local commit

  $ cd ..
  $ hg clone -q --narrow ssh://user@dummy/upstream narrow3 --include d2 -r 2
  $ cd narrow3
  $ hg log -T "{if(ellipsis, '...')}{node|short}: {desc}\n"
  *: add d2/f (glob)
  ...*: add d1/f (glob)
  $ hg pull -q -r 3
  $ hg co -q tip
  $ hg pull -q -r 4
  $ echo local > d2/f
  $ hg ci -m local
  created new head
  $ hg tracked -q --addinclude d0 --addinclude d9

Widening preserves bookmarks

  $ cd ..
  $ hg clone -q --narrow ssh://user@dummy/upstream narrow-bookmarks --include d4
  $ cd narrow-bookmarks
  $ echo local > d4/f
  $ hg ci -m local
  $ hg bookmarks bookmark
  $ hg bookmarks
   * bookmark                  3:* (glob)
  $ hg -q tracked --addinclude d2
  $ hg bookmarks
   * bookmark                  5:* (glob)
  $ hg log -r bookmark -T '{desc}\n'
  local

Widening that fails can be recovered from

  $ cd ..
  $ hg clone -q --narrow ssh://user@dummy/upstream interrupted --include d0
  $ cd interrupted
  $ echo local > d0/f
  $ hg ci -m local
  $ hg log -T "{if(ellipsis, '...')}{rev}: {desc}\n"
  2: local
  ...1: add d10/f
  0: add d0/f
  $ hg bookmarks bookmark
  $ hg --config hooks.pretxnchangegroup.bad=false tracked --addinclude d1
  comparing with ssh://user@dummy/upstream
  searching for changes
  no changes found
  saved backup bundle to $TESTTMP/interrupted/.hg/strip-backup/*-widen.hg (glob)
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.bad hook exited with status 1
  [255]
  $ hg log -T "{if(ellipsis, '...')}{rev}: {desc}\n"
  $ hg bookmarks
  no bookmarks set
  $ hg unbundle .hg/strip-backup/*-widen.hg
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 1 files
  new changesets *:* (glob)
  (run 'hg update' to get a working copy)
  $ hg log -T "{if(ellipsis, '...')}{rev}: {desc}\n"
  2: local
  ...1: add d10/f
  0: add d0/f
  $ hg bookmarks
   * bookmark                  2:* (glob)