view tests/test-mq-git.t @ 39638:d292328e0143

exchangev2: fetch manifest revisions

Now that the server has support for retrieving manifest data, we can
implement the client bits to call it.

We teach the changeset fetching code to capture the manifest revisions
that are encountered on incoming changesets. We then feed this into a
new function which filters out known manifests and then batches up
manifest data requests to the server.

This is different from the previous wire protocol in a few notable
ways.

First, the client fetches manifest data separately and explicitly.
Before, we'd ask the server for data pertaining to some changesets
(via a "getbundle" command) and manifests (and files) would be sent
automatically. Providing an API for looking up just manifest data
separately gives clients much more flexibility for manifest management.
For example, a client may choose to only fetch manifest data on demand
instead of prefetching it (i.e. partial clone).

Second, we send N commands to the server for manifest retrieval instead
of 1. This property has a few nice side-effects. One is that the
deterministic nature of the requests lends itself to server-side
caching. For example, say the remote has 50,000 manifests. If the
server is configured to cache responses, each time a new commit
arrives, you will have a cache miss and need to regenerate all outgoing
data. But if you makes N requests requesting 10,000 manifests each,
a new commit will still yield cache hits on the initial, unchanged
manifest batches/requests.

A derived benefit from these properties is that resumable clone is
conceptually simpler to implement. When making a monolithic request
for all of the repository data, recovering from an interrupted clone
is hard because the server was in the driver's seat and was maintaining
state about all the data that needed transferred. With the client
driving fetching, the client can persist the set of unfetched entities
and retry/resume a fetch if something goes wrong. Or we can fetch all
data N changesets at a time and slowly build up a repository. This
approach is drastically easier to implement when we have server APIs
exposing low-level repository primitives (such as manifests and files).

We don't yet support tree manifests. But it should be possible to
implement that with the existing wire protocol command.

Differential Revision: https://phab.mercurial-scm.org/D4489

# Test the plumbing of mq.git option
# Automatic upgrade itself is tested elsewhere.

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > mq =
  > [diff]
  > nodates = 1
  > EOF

  $ hg init repo-auto
  $ cd repo-auto

git=auto: regular patch creation:

  $ echo a > a
  $ hg add a
  $ hg qnew -d '0 0' -f adda

  $ cat .hg/patches/adda
  # HG changeset patch
  # Date 0 0
  # Parent  0000000000000000000000000000000000000000
  
  diff -r 000000000000 -r ef8dafc9fa4c a
  --- /dev/null
  +++ b/a
  @@ -0,0 +1,1 @@
  +a

git=auto: git patch creation with copy:

  $ hg cp a b
  $ hg qnew -d '0 0' -f copy

  $ cat .hg/patches/copy
  # HG changeset patch
  # Date 0 0
  # Parent  ef8dafc9fa4caff80f6e243eb0171bcd60c455b4
  
  diff --git a/a b/b
  copy from a
  copy to b

git=auto: git patch when using --git:

  $ echo regular > regular
  $ hg add regular
  $ hg qnew -d '0 0' --git -f git

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  99586d5f048c399e20f81cee41fbb3809c0e735d
  
  diff --git a/regular b/regular
  new file mode 100644
  --- /dev/null
  +++ b/regular
  @@ -0,0 +1,1 @@
  +regular

git=auto: regular patch after qrefresh without --git:

  $ hg qrefresh -d '0 0'

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  99586d5f048c399e20f81cee41fbb3809c0e735d
  
  diff -r 99586d5f048c regular
  --- /dev/null
  +++ b/regular
  @@ -0,0 +1,1 @@
  +regular

  $ cd ..

  $ hg init repo-keep
  $ cd repo-keep
  $ echo '[mq]' > .hg/hgrc
  $ echo 'git = KEEP' >> .hg/hgrc

git=keep: git patch with --git:

  $ echo a > a
  $ hg add a
  $ hg qnew -d '0 0' -f --git git

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  0000000000000000000000000000000000000000
  
  diff --git a/a b/a
  new file mode 100644
  --- /dev/null
  +++ b/a
  @@ -0,0 +1,1 @@
  +a

git=keep: git patch after qrefresh without --git:

  $ echo a >> a
  $ hg qrefresh -d '0 0'

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  0000000000000000000000000000000000000000
  
  diff --git a/a b/a
  new file mode 100644
  --- /dev/null
  +++ b/a
  @@ -0,0 +1,2 @@
  +a
  +a
  $ cd ..

  $ hg init repo-yes
  $ cd repo-yes
  $ echo '[mq]' > .hg/hgrc
  $ echo 'git = yes' >> .hg/hgrc

git=yes: git patch:

  $ echo a > a
  $ hg add a
  $ hg qnew -d '0 0' -f git

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  0000000000000000000000000000000000000000
  
  diff --git a/a b/a
  new file mode 100644
  --- /dev/null
  +++ b/a
  @@ -0,0 +1,1 @@
  +a

git=yes: git patch after qrefresh:

  $ echo a >> a
  $ hg qrefresh -d '0 0'

  $ cat .hg/patches/git
  # HG changeset patch
  # Date 0 0
  # Parent  0000000000000000000000000000000000000000
  
  diff --git a/a b/a
  new file mode 100644
  --- /dev/null
  +++ b/a
  @@ -0,0 +1,2 @@
  +a
  +a
  $ cd ..

  $ hg init repo-no
  $ cd repo-no
  $ echo '[diff]' > .hg/hgrc
  $ echo 'git = True' >> .hg/hgrc
  $ echo '[mq]' > .hg/hgrc
  $ echo 'git = False' >> .hg/hgrc

git=no: regular patch with copy:

  $ echo a > a
  $ hg add a
  $ hg qnew -d '0 0' -f adda
  $ hg cp a b
  $ hg qnew -d '0 0' -f regular

  $ cat .hg/patches/regular
  # HG changeset patch
  # Date 0 0
  # Parent  ef8dafc9fa4caff80f6e243eb0171bcd60c455b4
  
  diff -r ef8dafc9fa4c -r a70404f79ba3 b
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +a

git=no: regular patch after qrefresh with copy:

  $ hg cp a c
  $ hg qrefresh -d '0 0'

  $ cat .hg/patches/regular
  # HG changeset patch
  # Date 0 0
  # Parent  ef8dafc9fa4caff80f6e243eb0171bcd60c455b4
  
  diff -r ef8dafc9fa4c b
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +a
  diff -r ef8dafc9fa4c c
  --- /dev/null
  +++ b/c
  @@ -0,0 +1,1 @@
  +a

Test how [diff] configuration influence and cause invalid or lossy patches:

  $ cat <<EOF >> .hg/hgrc
  > [mq]
  > git = AUTO
  > [diff]
  > nobinary = True
  > noprefix = True
  > showfunc = True
  > ignorews = True
  > ignorewsamount = True
  > ignoreblanklines = True
  > unified = 1
  > EOF

  $ echo ' a' > a
  $ hg qnew prepare -d '0 0'
  $ echo '  a' > a
  $ printf '\0' > b
  $ echo >> c
  $ hg qnew diff -d '0 0'

  $ cat .hg/patches/prepare
  # HG changeset patch
  # Date 0 0
  # Parent  cf0bfe72686a47d8d7d7b4529a3adb8b0b449a9f
  
  diff -r cf0bfe72686a -r fb9c4422b0f3 a
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -a
  + a
  $ cat .hg/patches/diff
  # HG changeset patch
  # Date 0 0
  # Parent  fb9c4422b0f37dd576522dd9a3f99b825c177efe
  
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  - a
  +  a
  diff --git a/b b/b
  index 78981922613b2afb6025042ff6bd878ac1994e85..f76dd238ade08917e6712764a16a22005a50573d
  GIT binary patch
  literal 1
  Ic${MZ000310RR91
  
  diff --git a/c b/c
  --- a/c
  +++ b/c
  @@ -1,1 +1,2 @@
   a
  +

  $ cd ..