view tests/test-clone-uncompressed.t @ 29859:a1092e2d70a3

help: internals topic for wire protocol

The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.

This patch adds the beginnings of "internals" documentation on the
wire protocol.

The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.

As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.

This patch starts with the scaffolding for a new internals page.

#require serve

Initialize repository
the status call is to check for issue5130

  $ hg init server
  $ cd server
  $ touch foo
  $ hg -q commit -A -m initial
  >>> for i in range(1024):
  ...     with open(str(i), 'wb') as fh:
  ...         fh.write(str(i))
  $ hg -q commit -A -m 'add a lot of files'
  $ hg st
  $ hg serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

Basic clone

  $ hg clone --uncompressed -U http://localhost:$HGPORT clone1
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*/sec) (glob)
  searching for changes
  no changes found

Clone with background file closing enabled

  $ hg --debug --config worker.backgroundclose=true --config worker.backgroundcloseminfilecount=1 clone --uncompressed -U http://localhost:$HGPORT clone-background | grep -v adding
  using http://localhost:$HGPORT/
  sending capabilities command
  sending branchmap command
  streaming all changes
  sending stream_out command
  1027 files to transfer, 96.3 KB of data
  starting 4 threads for background file closing
  transferred 96.3 KB in * seconds (*/sec) (glob)
  query 1; heads
  sending batch command
  searching for changes
  all remote heads known locally
  no changes found
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-part: total payload size 58
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-bundle: 1 parts total
  checking for updated bookmarks


Stream clone while repo is changing:

  $ mkdir changing
  $ cd changing

extension for delaying the server process so we reliably can modify the repo
while cloning

  $ cat > delayer.py <<EOF
  > import time
  > from mercurial import extensions, scmutil
  > def __call__(orig, self, path, *args, **kwargs):
  >     if path == 'data/f1.i':
  >         time.sleep(2)
  >     return orig(self, path, *args, **kwargs)
  > extensions.wrapfunction(scmutil.vfs, '__call__', __call__)
  > EOF

prepare repo with small and big file to cover both code paths in emitrevlogdata

  $ hg init repo
  $ touch repo/f1
  $ $TESTDIR/seq.py 50000 > repo/f2
  $ hg -R repo ci -Aqm "0"
  $ hg -R repo serve -p $HGPORT1 -d --pid-file=hg.pid --config extensions.delayer=delayer.py
  $ cat hg.pid >> $DAEMON_PIDS

clone while modifying the repo between stating file with write lock and
actually serving file content

  $ hg clone -q --uncompressed -U http://localhost:$HGPORT1 clone &
  $ sleep 1
  $ echo >> repo/f1
  $ echo >> repo/f2
  $ hg -R repo ci -m "1"
  $ wait
  $ hg -R clone id
  000000000000