view tests/test-conflict.t @ 30764:e75463e3179f

protocol: send application/mercurial-0.2 responses to capable clients

With this commit, the HTTP transport now parses the X-HgProto-<N>
header to determine what media type and compression engine to use for
responses. So far, we only compress responses that are already being
compressed with zlib today (stream response types to specific
commands). We can expand things to cover additional response types
later.

The practical side-effect of this commit is that non-zlib compression
engines will be used if both ends support them. This means if both
ends have zstd support, zstd - not zlib - will be used to compress
data!

When cloning the mozilla-unified repository between a local HTTP
server and client, the benefits of non-zlib compression are quite
noticeable:

  engine     server CPU (s)   client CPU (s)    bundle size
zlib (l=6)      174.1            283.2         1,148,547,026
zstd (l=1)       99.2            267.3         1,127,513,841
zstd (l=3)      103.1            266.9         1,018,861,363
zstd (l=7)      128.3            269.7           919,190,278
zstd (l=10)     162.0               -            894,547,179
none             95.3            277.2         4,097,566,064

The default zstd compression level is 3. So if you deploy zstd
capable Mercurial to your clients and servers and CPU time on
your server is dominated by "getbundle" requests (clients cloning
and pulling) - and my experience at Mozilla tells me this is often
the case - this commit could drastically reduce your server-side
CPU usage *and* save on bandwidth costs!

Another benefit of this change is that server operators can install
*any* compression engine. While it isn't enabled by default, the
"none" compression engine can now be used to disable wire protocol
compression completely. Previously, commands like "getbundle" always
zlib compressed output, adding considerable overhead to generating
responses. If you are on a high speed network and your server is under
high load, it might be advantageous to trade bandwidth for CPU.
Although, zstd at level 1 doesn't use that much CPU, so I'm not
convinced that disabling compression wholesale is worthwhile. And, my
data seems to indicate a slow down on the client without compression.
I suspect this is due to a lack of buffering resulting in an increase
in socket read() calls and/or the fact we're transferring an extra 3 GB
of data (parsing HTTP chunked transfer and processing extra TCP packets
can add up). This is definitely worth investigating and optimizing. But
since the "none" compressor isn't enabled by default, I'm inclined to
punt on this issue.

This commit introduces tons of tests. Some of these should arguably
have been implemented on previous commits. But it was difficult to
test without the server functionality in place.

  $ hg init
  $ cat << EOF > a
  > Small Mathematical Series.
  > One
  > Two
  > Three
  > Four
  > Five
  > Hop we are done.
  > EOF
  $ hg add a
  $ hg commit -m ancestor
  $ cat << EOF > a
  > Small Mathematical Series.
  > 1
  > 2
  > 3
  > 4
  > 5
  > Hop we are done.
  > EOF
  $ hg commit -m branch1
  $ hg co 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat << EOF > a
  > Small Mathematical Series.
  > 1
  > 2
  > 3
  > 6
  > 8
  > Hop we are done.
  > EOF
  $ hg commit -m branch2
  created new head

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ hg id
  618808747361+c0c68e4fe667+ tip

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: 618808747361 - test: branch2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    c0c68e4fe667 - test: branch1
  Hop we are done.

  $ hg status
  M a
  ? a.orig

Verify custom conflict markers

  $ hg up -q --clean .
  $ printf "\n[ui]\nmergemarkertemplate={author} {rev}\n" >> .hg/hgrc

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: test 2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    test 1
  Hop we are done.

Verify line splitting of custom conflict marker which causes multiple lines

  $ hg up -q --clean .
  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > mergemarkertemplate={author} {rev}\nfoo\nbar\nbaz
  > EOF

  $ hg -q merge 1
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: test 2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    test 1
  Hop we are done.

Verify line trimming of custom conflict marker using multi-byte characters

  $ hg up -q --clean .
  $ python <<EOF
  > fp = open('logfile', 'w')
  > fp.write('12345678901234567890123456789012345678901234567890' +
  >          '1234567890') # there are 5 more columns for 80 columns
  > 
  > # 2 x 4 = 8 columns, but 3 x 4 = 12 bytes
  > fp.write(u'\u3042\u3044\u3046\u3048'.encode('utf-8'))
  > 
  > fp.close()
  > EOF
  $ hg add logfile
  $ hg --encoding utf-8 commit --logfile logfile

  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > mergemarkertemplate={desc|firstline}
  > EOF

  $ hg -q --encoding utf-8 merge 1
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: 1234567890123456789012345678901234567890123456789012345...
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    branch1
  Hop we are done.

Verify basic conflict markers

  $ hg up -q --clean 2
  $ printf "\n[ui]\nmergemarkers=basic\n" >> .hg/hgrc

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy
  6
  8
  =======
  4
  5
  >>>>>>> merge rev
  Hop we are done.

internal:merge3

  $ hg up -q --clean .

  $ hg merge 1 --tool internal:merge3
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ cat a
  Small Mathematical Series.
  <<<<<<< working copy
  1
  2
  3
  6
  8
  ||||||| base
  One
  Two
  Three
  Four
  Five
  =======
  1
  2
  3
  4
  5
  >>>>>>> merge rev
  Hop we are done.

Add some unconflicting changes on each head, to make sure we really
are merging, unlike :local and :other

  $ hg up -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 other heads for branch "default"
  $ printf "\n\nEnd of file\n" >> a
  $ hg ci -m "Add some stuff at the end"
  $ hg up -r 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ printf "Start of file\n\n\n" > tmp
  $ cat a >> tmp
  $ mv tmp a
  $ hg ci -m "Add some stuff at the beginning"

Now test :merge-other and :merge-local

  $ hg merge
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ hg resolve --tool :merge-other a
  merging a
  (no more unresolved files)
  $ cat a
  Start of file
  
  
  Small Mathematical Series.
  1
  2
  3
  6
  8
  Hop we are done.
  
  
  End of file

  $ hg up -C
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  1 other heads for branch "default"
  $ hg merge --tool :merge-local
  merging a
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat a
  Start of file
  
  
  Small Mathematical Series.
  1
  2
  3
  4
  5
  Hop we are done.
  
  
  End of file