view tests/test-qrecord.t @ 39764:e4e881572382

localrepo: iteratively derive local repository type

This commit implements the dynamic local repository type derivation
that was explained in the recent commit
bfeab472e3c0 "localrepo: create new function for instantiating a local
repo object."

Instead of a static localrepository class/type which must be customized
after construction, we now dynamically construct a type by building up
base classes/types to represent specific repository interfaces.

Conceptually, the end state is similar to what was happening when
various extensions would monkeypatch the __class__ of newly-constructed
repo instances. However, the approach is inverted. Instead of making
the instance then customizing it, we do the customization up front
by influencing the behavior of the type then we instantiate that
custom type.

This approach gives us much more flexibility. For example, we can
use completely separate classes for implementing different aspects
of the repository. For example, we could have one class representing
revlog-based file storage and another representing non-revlog based
file storage. When then choose which implementation to use based on
the presence of repo requirements.

A concern with this approach is that it creates a lot more types
and complexity and that complexity adds overhead. Yes, it is true that
this approach will result in more types being created. Yes, this is
more complicated than traditional "instantiate a static type." However,
I believe the alternatives to supporting alternate storage backends
are just as complicated. (Before I arrived at this solution, I had
patches storing factory functions on local repo instances for e.g.
constructing a file storage instance. We ended up having a handful
of these. And this was logically identical to assigning custom
methods. Since we were logically changing the type of the instance,
I figured it would be better to just use specialized types instead
of introducing levels of abstraction at run-time.)

On the performance front, I don't believe that having N base classes
has any significant performance overhead compared to just a single base
class. Intuition says that Python will need to iterate the base classes
to find an attribute. However, CPython caches method lookups: as long as
the __class__ or MRO isn't changing, method attribute lookup should be
constant time after first access. And non-method attributes are stored
in __dict__, of which there is only 1 per object, so the number of
base classes for __dict__ is irrelevant.

Anyway, this commit splits up the monolithic completelocalrepository
interface into sub-interfaces: 1 for file storage and 1 representing
everything else.

We've taught ``makelocalrepository()`` to call a series of factory
functions which will produce types implementing specific interfaces.
It then calls type() to create a new type from the built-up list of
base types.

This commit should be considered a start and not the end state. I
suspect we'll hit a number of problems as we start to implement
alternate storage backends:

* Passing custom arguments to __init__ and setting custom attributes
  on __dict__.
* Customizing the set of interfaces that are needed. e.g. the
  "readonly" intent could translate to not requesting an interface
  providing methods related to writing.
* More ergonomic way for extensions to insert themselves so their
  callbacks aren't unconditionally called.
* Wanting to modify vfs instances, other arguments passed to __init__.

That being said, this code is usable in its current state and I'm
convinced future commits will demonstrate the value in this approach.

Differential Revision: https://phab.mercurial-scm.org/D4642

Create configuration

  $ echo "[ui]" >> $HGRCPATH
  $ echo "interactive=true" >> $HGRCPATH

help record (no record)

  $ hg help record
  record extension - commands to interactively select changes for
  commit/qrefresh (DEPRECATED)
  
  The feature provided by this extension has been moved into core Mercurial as
  'hg commit --interactive'.
  
  (use 'hg help extensions' for information on enabling extensions)

help qrecord (no record)

  $ hg help qrecord
  'qrecord' is provided by the following extension:
  
      record        commands to interactively select changes for commit/qrefresh
                    (DEPRECATED)
  
  (use 'hg help extensions' for information on enabling extensions)

  $ echo "[extensions]"     >> $HGRCPATH
  $ echo "record="          >> $HGRCPATH

help record (record)

  $ hg help record
  hg record [OPTION]... [FILE]...
  
  interactively select changes to commit
  
      If a list of files is omitted, all changes reported by 'hg status' will be
      candidates for recording.
  
      See 'hg help dates' for a list of formats valid for -d/--date.
  
      If using the text interface (see 'hg help config'), you will be prompted
      for whether to record changes to each modified file, and for files with
      multiple changes, for each change to use. For each query, the following
      responses are possible:
  
        y - record this change
        n - skip this change
        e - edit this change manually
  
        s - skip remaining changes to this file
        f - record remaining changes to this file
  
        d - done, skip remaining changes and files
        a - record all changes to all remaining files
        q - quit, recording no changes
  
        ? - display help
  
      This command is not available when committing a merge.
  
  (use 'hg help -e record' to show help for the record extension)
  
  options ([+] can be repeated):
  
   -A --addremove           mark new/missing files as added/removed before
                            committing
      --close-branch        mark a branch head as closed
      --amend               amend the parent of the working directory
   -s --secret              use the secret phase for committing
   -e --edit                invoke editor on commit messages
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
   -d --date DATE           record the specified date as commit date
   -u --user USER           record the specified user as committer
   -S --subrepos            recurse into subrepositories
   -w --ignore-all-space    ignore white space when comparing lines
   -b --ignore-space-change ignore changes in the amount of white space
   -B --ignore-blank-lines  ignore changes whose lines are all blank
   -Z --ignore-space-at-eol ignore changes in whitespace at EOL
  
  (some details hidden, use --verbose to show complete help)

help (no mq, so no qrecord)

  $ hg help qrecord
  hg qrecord [OPTION]... PATCH [FILE]...
  
  interactively record a new patch
  
      See 'hg help qnew' & 'hg help record' for more information and usage.
  
  (some details hidden, use --verbose to show complete help)

  $ hg init a

qrecord (mq not present)

  $ hg -R a qrecord
  hg qrecord: invalid arguments
  hg qrecord [OPTION]... PATCH [FILE]...
  
  interactively record a new patch
  
  (use 'hg qrecord -h' to show more help)
  [255]

qrecord patch (mq not present)

  $ hg -R a qrecord patch
  abort: 'mq' extension not loaded
  [255]

help (bad mq)

  $ echo "mq=nonexistent" >> $HGRCPATH
  $ hg help qrecord
  *** failed to import extension mq from nonexistent: [Errno *] * (glob)
  hg qrecord [OPTION]... PATCH [FILE]...
  
  interactively record a new patch
  
      See 'hg help qnew' & 'hg help record' for more information and usage.
  
  (some details hidden, use --verbose to show complete help)

help (mq present)

  $ sed 's/mq=nonexistent/mq=/' $HGRCPATH > hgrc.tmp
  $ mv hgrc.tmp $HGRCPATH

  $ hg help qrecord
  hg qrecord [OPTION]... PATCH [FILE]...
  
  interactively record a new patch
  
      See 'hg help qnew' & 'hg help record' for more information and usage.
  
  options ([+] can be repeated):
  
   -e --edit                invoke editor on commit messages
   -g --git                 use git extended diff format
   -U --currentuser         add "From: <current user>" to patch
   -u --user USER           add "From: <USER>" to patch
   -D --currentdate         add "Date: <current date>" to patch
   -d --date DATE           add "Date: <DATE>" to patch
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
   -w --ignore-all-space    ignore white space when comparing lines
   -b --ignore-space-change ignore changes in the amount of white space
   -B --ignore-blank-lines  ignore changes whose lines are all blank
   -Z --ignore-space-at-eol ignore changes in whitespace at EOL
      --mq                  operate on patch repository
  
  (some details hidden, use --verbose to show complete help)

  $ cd a

Base commit

  $ cat > 1.txt <<EOF
  > 1
  > 2
  > 3
  > 4
  > 5
  > EOF
  $ cat > 2.txt <<EOF
  > a
  > b
  > c
  > d
  > e
  > f
  > EOF

  $ mkdir dir
  $ cat > dir/a.txt <<EOF
  > hello world
  > 
  > someone
  > up
  > there
  > loves
  > me
  > EOF

  $ hg add 1.txt 2.txt dir/a.txt
  $ hg commit -m 'initial checkin'

Changing files

  $ sed -e 's/2/2 2/;s/4/4 4/' 1.txt > 1.txt.new
  $ sed -e 's/b/b b/' 2.txt > 2.txt.new
  $ sed -e 's/hello world/hello world!/' dir/a.txt > dir/a.txt.new

  $ mv -f 1.txt.new 1.txt
  $ mv -f 2.txt.new 2.txt
  $ mv -f dir/a.txt.new dir/a.txt

Whole diff

  $ hg diff --nodates
  diff -r 1057167b20ef 1.txt
  --- a/1.txt
  +++ b/1.txt
  @@ -1,5 +1,5 @@
   1
  -2
  +2 2
   3
  -4
  +4 4
   5
  diff -r 1057167b20ef 2.txt
  --- a/2.txt
  +++ b/2.txt
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  diff -r 1057167b20ef dir/a.txt
  --- a/dir/a.txt
  +++ b/dir/a.txt
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up

qrecord with bad patch name, should abort before prompting

  $ hg qrecord .hg
  abort: patch name cannot begin with ".hg"
  [255]
  $ hg qrecord ' foo'
  abort: patch name cannot begin or end with whitespace
  [255]
  $ hg qrecord 'foo '
  abort: patch name cannot begin or end with whitespace
  [255]

qrecord a.patch

  $ hg qrecord -d '0 0' -m aaa a.patch <<EOF
  > y
  > y
  > n
  > y
  > y
  > n
  > EOF
  diff --git a/1.txt b/1.txt
  2 hunks, 2 lines changed
  examine changes to '1.txt'? [Ynesfdaq?] y
  
  @@ -1,3 +1,3 @@
   1
  -2
  +2 2
   3
  record change 1/4 to '1.txt'? [Ynesfdaq?] y
  
  @@ -3,3 +3,3 @@
   3
  -4
  +4 4
   5
  record change 2/4 to '1.txt'? [Ynesfdaq?] n
  
  diff --git a/2.txt b/2.txt
  1 hunks, 1 lines changed
  examine changes to '2.txt'? [Ynesfdaq?] y
  
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  record change 3/4 to '2.txt'? [Ynesfdaq?] y
  
  diff --git a/dir/a.txt b/dir/a.txt
  1 hunks, 1 lines changed
  examine changes to 'dir/a.txt'? [Ynesfdaq?] n
  

After qrecord a.patch 'tip'"

  $ hg tip -p
  changeset:   1:5d1ca63427ee
  tag:         a.patch
  tag:         qbase
  tag:         qtip
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     aaa
  
  diff -r 1057167b20ef -r 5d1ca63427ee 1.txt
  --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   1
  -2
  +2 2
   3
   4
   5
  diff -r 1057167b20ef -r 5d1ca63427ee 2.txt
  --- a/2.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/2.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   a
  -b
  +b b
   c
   d
   e
  

After qrecord a.patch 'diff'"

  $ hg diff --nodates
  diff -r 5d1ca63427ee 1.txt
  --- a/1.txt
  +++ b/1.txt
  @@ -1,5 +1,5 @@
   1
   2 2
   3
  -4
  +4 4
   5
  diff -r 5d1ca63427ee dir/a.txt
  --- a/dir/a.txt
  +++ b/dir/a.txt
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up

qrecord b.patch

  $ hg qrecord -d '0 0' -m bbb b.patch <<EOF
  > y
  > y
  > y
  > y
  > EOF
  diff --git a/1.txt b/1.txt
  1 hunks, 1 lines changed
  examine changes to '1.txt'? [Ynesfdaq?] y
  
  @@ -1,5 +1,5 @@
   1
   2 2
   3
  -4
  +4 4
   5
  record change 1/2 to '1.txt'? [Ynesfdaq?] y
  
  diff --git a/dir/a.txt b/dir/a.txt
  1 hunks, 1 lines changed
  examine changes to 'dir/a.txt'? [Ynesfdaq?] y
  
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up
  record change 2/2 to 'dir/a.txt'? [Ynesfdaq?] y
  

After qrecord b.patch 'tip'

  $ hg tip -p
  changeset:   2:b056198bf878
  tag:         b.patch
  tag:         qtip
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     bbb
  
  diff -r 5d1ca63427ee -r b056198bf878 1.txt
  --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,5 +1,5 @@
   1
   2 2
   3
  -4
  +4 4
   5
  diff -r 5d1ca63427ee -r b056198bf878 dir/a.txt
  --- a/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,4 +1,4 @@
  -hello world
  +hello world!
   
   someone
   up
  

After qrecord b.patch 'diff'

  $ hg diff --nodates

  $ cd ..