view tests/svn/svndump-move.sh @ 46667:93e9f448273c

rhg: Add support for automatic fallback to Python

`rhg` is a command-line application that can do a small subset of what
`hg` can. It is written entirely in Rust, which avoids the cost of starting
a Python interpreter and importing many Python modules.
In a script that runs many `hg` commands, this cost can add up.

However making users decide when to use `rhg` instead of `hg` is
not practical as we want the subset of supported functionality
to grow over time.

Instead we introduce "fallback" behavior where, when `rhg` encounters
something (a sub-command, a repository format, …) that is not implemented
in Rust-only, it does nothing but silently start a subprocess of
Python-based `hg` running the same command.
That way `rhg` becomes a drop-in replacement for `hg` that sometimes
goes faster. Whether Python is used should be an implementation detail
not apparent to users (other than through speed).

A new `fallback` value is added to the previously introduced
`rhg.on-unsupported` configuration key. When in this mode, the new
`rhg.fallback-executable` config is determine what command to use
to run a Python-based `hg`.

The previous `rhg.on-unsupported = abort-silent` configuration was designed
to let a wrapper script call `rhg` and then fall back to `hg` based on the
exit code. This is still available, but having fallback behavior built-in
in rhg might be easier for users instead of leaving that script "as an
exercise for the reader".

Using a subprocess like this is not idea, especially when `rhg` is to be
installed in `$PATH` as `hg`, since the other `hg.py` executable needs
to still be available… somewhere. Eventually this could be replaced
by using PyOxidizer to a have a single executable that embeds a Python
interpreter, but only starts it when needed.

Differential Revision: https://phab.mercurial-scm.org/D10093

#!/bin/sh
#
# Use this script to generate move.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
echo a > trunk/a
mkdir trunk/d1
mkdir trunk/d2
echo b > trunk/d1/b
echo c > trunk/d1/c
echo d > trunk/d2/d
cd ..

svnadmin create svn-repo
svnurl=file://`pwd`/svn-repo
svn import project-orig $svnurl -m "init projA"

svn co $svnurl project
cd project
# Build a module renaming chain which used to confuse the converter.
# Update svn repository
echo a >> trunk/a
echo c >> trunk/d1/c
svn ci -m commitbeforemove
svn mv $svnurl/trunk $svnurl/subproject -m movedtrunk
svn up
mkdir subproject/trunk
svn add subproject/trunk
svn ci -m createtrunk
mkdir subproject/branches
svn add subproject/branches
svn ci -m createbranches
svn mv $svnurl/subproject/d1 $svnurl/subproject/trunk/d1 -m moved1
svn mv $svnurl/subproject/d2 $svnurl/subproject/trunk/d2 -m moved2
svn up
echo b >> subproject/trunk/d1/b

svn rm subproject/trunk/d2
svn ci -m "changeb and rm d2"
svn mv $svnurl/subproject/trunk/d1 $svnurl/subproject/branches/d1 -m moved1again

if svn help copy | grep 'SRC\[@REV\]' > /dev/null 2>&1; then
    # SVN >= 1.5 replaced the -r REV syntax with @REV
    # Copy a file from a past revision
    svn copy $svnurl/subproject/trunk/d2/d@7 $svnurl/subproject/trunk -m copyfilefrompast
    # Copy a directory from a past revision
    svn copy $svnurl/subproject/trunk/d2@7 $svnurl/subproject/trunk -m copydirfrompast
else
    # Copy a file from a past revision
    svn copy -r 7 $svnurl/subproject/trunk/d2/d $svnurl/subproject/trunk -m copyfilefrompast
    # Copy a directory from a past revision
    svn copy -r 7 $svnurl/subproject/trunk/d2 $svnurl/subproject/trunk -m copydirfrompast
fi

# Copy a directory while removing a subdirectory
svn up
mkdir -p subproject/trunk/d3/d31
echo e > subproject/trunk/d3/d31/e
echo f > subproject/trunk/d3/f
svn add subproject/trunk/d3
svn ci -m "add d3"
svn copy subproject/trunk/d3 subproject/trunk/d4
svn rm subproject/trunk/d3/d31
svn ci -m "copy dir and remove subdir"

# Test directory moves
svn up
mkdir -p subproject/trunk/d4old
echo g > subproject/trunk/d4old/g
svn add subproject/trunk/d4old
svn ci -m "add d4old"
svn mv subproject/trunk/d4old subproject/trunk/d4new
svn ci -m "rename d4old into d4new"

cd ..

svnadmin dump svn-repo > ../move.svndump