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#pragma section-numbers 2
= Convert extension =
'''This extension is distributed with Mercurial.'''

''Author: several people''

Implementation information can be found here: ConvertExtensionImplementation


== Overview ==
The Convert extension converts repositories from other SCMs (or even Mercurial itself) into Mercurial repositories, with options for filtering and renaming. It can also be used to filter Mercurial repositories to get subsets of an existing one.

The current release supports the following repository types as sources:

 * CVS
 * Subversion
 * Git
 * Darcs
 * Monotone
 * Bazaar
 * GNU Arch
 * Mercurial
 * Perforce

== Configuration ==
Add the following lines to your ''`.hgrc`'' or to enable the extension :

== Usage ==
`hg convert [OPTION]... SOURCE [DEST [REVMAP]]`

`SOURCE` points to the data to be imported. It can be:

 * the name of the (local) directory containing the code checked out from remote repository (for example, name of the directory checked out from CVS)
 * (in some cases) address of the remote repository (for example, Subversion repository URL). See below for information for which systems such syntax is possible.

`DEST` is a local directory name where the conversion data will go to (Mercurial repository will be created or updated). If `DEST` is not provided, it will be created by adding `-hg` suffix to the source directory name. For example if source is in `/my/cvs/dir`, default destination is `/my/cvs/dir-hg`. When URLs are supplied, repository name is inferred from the last path component, `http://foo.bar/repo/trunk` gives `trunk-hg`.

`REVMAP` is a a simple text file that maps each source commit ID to the destination ID for each revision. Unless specified, it defaults to the `.hg/shamap` in the destination directory. This file is automatically created and updated on each commit copied, its purpose is to track which commits were already imported and which were not - and thanks to it allow to resume interrupted import and to make incremental updates. It is important to note that this `REVMAP` file is not copied when you a clone a repository. So you need to manually move it over if you are going to make incremental updates on a clone of the original import repository.

/!\ When converting to Mercurial, the destination working directory is used as a temporary storage for file revisions but is not updated. `hg status` lists all these temporary files as unknown. Purge them and update to get a correct view of the converted repository.

== Options ==
=== --rev ===
Convert can optionally stop importing at a given revision, if the `--rev` option is provided. The argument should be given in terms the source understands (e.g. a revision number for Subversion sources, or a hash for git sources). Revisions newer than specified by this parameter are not imported.

This can also be useful to do incremental conversions. Incremental conversions may be useful not only when tracking newer changes in the source repo but also in very huge repos which would need huge resources for a whole conversion and can be better handled with an incremental one.

=== --authors / --authormap ===
Convert can also remap author names during conversion, if the `--authormap` option is provided. The argument should be a simple text file that maps each source commit author to a destination commit author. It is handy for source SCMs that use UNIX logins to identify authors (e.g., CVS). Example:

john=John Smith <John.Smith@someplace.net>
tom=Tom Johnson <Tom.Johnson@bigcity.com>

Note: It is recommended to use the `--authormap` option instead of `--authors` as it is now deprecated.

=== --filemap ===
Convert can also filter or rename files during conversion, when you supply it a mapping via the `--filemap` option.

The filemap is a file that specifies which files are to be included, renamed, or omitted. By default all files are included (empty filemap means include everything).

Each line can contain one of the following directives:

 * `include path/to/file`
 * `exclude path/to/file`
 * `rename from/file to/file`

All paths should be specified as relative paths rooted in the converted directory. Unix path syntax should be used, regardless of OS.

The `include` directive causes a file, or all files under a directory, to be included in the destination repository, and the exclusion of any other element that's not under an inclusion rule.

The `exclude` directive causes files or directories to be omitted.

The `rename` directive renames a file or directory. To rename from a subdirectory into the root of the repository, use `.` as the path to rename to.

It is also possible to use comments, comment lines start with `#`.

Entries are parsed like Unix shell commands and should be quoted accordingly. This means that you must quote filenames containing spaces -- it does not mean that you can use glob patterns like `*.so`.

For example, to import all files except `doc` subdirectory, but include `doc/foo bar.txt` and include `doc/FAQ` renaming it to `faq`, use:

# Documentation is to be converted to separate repository.
exclude "doc"
include "doc/foo bar.txt"
rename "doc/FAQ" "faq"
=== --splicemap ===
This one is intended to specify new parents on specific revisions. Its main use is to put a (converted) history at the end of another one by specifying the last revision of the existing history as being the parent of the new one. In that case, the splicemap file will have one line being:

first-revision-of-to-be-converted-history tip-of-existing-history
Other usages of this file includes splicing one series of commits in between two other commits, removing commits from the history (by connecting their antecedent and descendant directly together), or forging a merge (by adding a second parent to a commit).

The format of revisions in the splicemap is identical to the one used in the file `.hg/shamap`, that is created when converting a repository. For Mercurial revisions you must use the full 40-digit hexadecimal hash to specify a revision and for Subversion revision the format is:

You can obtain the the UUID of a Subversion repository by running `svn info`.

The file format of the splice map is simple: each splice is one line. The first revision identifier on the line is the child cset whose parents you are editing, and must be specified relative to the source repository. After a single space, the second revision identifier is the first parent being set. To set a second parent, separate the two revision identifiers with a comma. The second and optional third are from either the source or destination repository. Note that blank lines in the splicemap file will cause a parse error.

=== --branchmap ===
''Since v1.3''

The branchmap is a file that allows you to rename a branch when it is being brought in from whatever external repository. When used in conjunction with a splicemap, it allows for a powerful combination to help fix even the most badly mismanaged repositories and turn them into nicely structured Mercurial repositories. The branchmap contains lines of the form

original_branch_name new_branch_name
`original_branch_name` is the name of the branch in the source repository, and `new_branch_name` is the name of the branch is the destination repository. This can be used to move code in one repository from "default" to a named branch.

Remember that "default" identifies the default branch of Mercurial repositories, which is not displayed by default by log, heads or parents commands. To erase named branch markers, convert it to "default" with a branchmap like

original_branch_name default
The revisions will still be there but no longer attached to the original named branch.

=== --branchsort, --datesort, --sourcesort ===
Normally convert will import revisions in an order that produces the fewest jumps between branches in the commit log. If you want to make the revision order in the destination more closely match that of the parent, use the `--datesort` flag. Note that this option might well increase the size of the destination repo by 10-20 times. You have been warned.

 --branchsort:: convert from parent to child revision when possible, which means branches are usually converted one after the other. It generates more compact repositories.
 --datesort:: sort revisions by date. Converted repositories have good-looking changelogs but are often an order of magnitude larger than the same ones generated by `--branchsort`.
 --sourcesort:: try to preserve source revisions order, only supported by Mercurial sources.

== Repository Conversion ==
=== Converting from Bazaar ===
==== Ubuntu Linux ====
Use Mercurial v1.5 or later, from [[https://launchpad.net/~mercurial-ppa/+archive/releases|ppa]] if necessary.

# install mercurial 1.6 on ubuntu 10
sudo add-apt-repository ppa:mercurial-ppa/releases
sudo apt-get update
sudo apt-get install mercurial

# the actual conversion
hg convert path/to/foo-bzr-branch foo-hg
cd foo-hg
hg update
The convert extension uses the Bazaar branch nick as the name for the branch in the hg repository. Bazaar by default uses the repository directory name as the nick. This means the branch in Mercurial is probably not going to be named "default." To make the Mercurial branch name be "default" use the `--branchmap FILE` option to convert.

In the FILE create a mapping:
bzr_nick default
where `bzr_nick` is the name returned by running `bzr nick` on the Bazaar repository.

==== Windows ====
 * Python binaries for Windows (see http://www.python.org/download/)
 * Mercurial as Python module (see [[Download]])
 * Bazaar as Python module (see http://wiki.bazaar.canonical.com/WindowsDownloads)
 * Python for Windows extension (see http://sourceforge.net/projects/pywin32/files/pywin32/)

The `.msi` installers don't include the necessary Python libraries. Also, if you have installed TortoiseHg, you will probably need to install Python. You will also need to install Bazaar modules (see http://wiki.bazaar.canonical.com/WindowsInstall for instructions on how to install Bazaar).

To ensure you are running the Python module version of Mercurial, you must call the Mercurial script directly. Otherwise you might need to use the executable file (`hg.exe`) from TortoiseHg.

C:\python26\scripts\hg convert -s bzr path/to/foo-bzr-branch foo-hg
cd foo-hg
hg update
When finished, the installed Python tools can be cleanly removed using the normal Add/Remove Programs method.

==== Other ====
You may also try a [[https://bitbucket.org/gkraser/bzrlib_load|simpler method]] which uses the Bazaar version already installed on your system.

=== Converting from CVS ===

 * commandline CVS client
 * [[http://www.cobite.com/cvsps/|cvsps]] (not needed as of Mercurial v1.3 or later)

Note: on Windows, cvsps currently requires [[http://www.cygwin.com/|Cygwin]]. Work is underway to make cvsps work without cygwin - see http://repo.or.cz/w/cvsps/4msysgit.git/.

The convert extension requires using CVS "working directory" since it uses cvsps (it is not possible to convert using direct CVS repository URL).

Example conversion:

# Normal CVS checkout (existing checkout may also be used)
cvs -d :pserver:user@repository.host:/repo/path checkout somemodule
# Actual conversion
hg convert somemodule
# New Mercurial repo is created in somemodule-hg directory
If you prefer another destination, just specify it, for example:

hg convert somemodule /some/where/somemodule.hg
It is possible to customize the way cvsps is called (program name, args etc). Enter the following in ''`hgrc`'':

# This is default
cvsps = cvsps -A -u --cvs-direct -q
The `-A` option is necessary, one can play with the rest. Possible ideas:

 * remove `-q` to see cvsps warnings and to track its progress (''do it if conversion fails or hangs!'')
 * remove `--cvs-direct` if you seem to have problems with communication with CVS server (without `--cvs-direct` cvsps will use your cvs client instead of builtin CVS client code)
 * add `-Z 1` (or similar) option to enable compression
 * pipe cvsps output through some script (say, log messages encoding conversion)

It is strongly recommended to use a fresh, newly made CVS checkout for the conversion. Problems were reported when people tried converting old checkouts made with old CVS versions. An example is an error like

cvs server: cvs [checkout aborted]: Absolute module reference invalid: `/path/to/some_module/subdirectory/file_name'

Incremental conversion works, too. Just repeat the

hg convert somemodule /some/where/somemodule.hg
command to grab new updates from CVS. It is not necessary to `cvs update` in the `somemodule` directory. It may be necessary if new directories were created - to be tested.

==== CVS keyword expansion ====
By default, the convert extension does not expand CVS keywords. If you want to import files with CVS keywords expanded, go to the Mercurial source code and change options passed to a CVS command, in particular `-kk` to `-kkv` (file `hgext/convert/cvs.py`, around line 255, search for string `"-N -P -kk -r %s --"`).

==== Other tools ====
See RepositoryConversion#CVS for other conversion tools that can be used.

=== Converting from Darcs ===
The converter does not currently handle patch conflicts very well. For more detail, see the notes in [[http://selenic.com/repo/hg/file/tip/tests/test-convert-darcs|tests/test-convert-darcs]]. If you encounter this problem, try using the deprecated {{{contrib/darcs2hg.py}}} script instead.

=== Converting from Perforce ===

 * Perforce client

Steps to migrate an existing Perforce depot to a new Mercurial repository and push it to a remote instance

 * Create a workspace in Perforce that contains the files/folders that you want to convert to Mercurial
 * Sync to the new workspace (the files have to be present for the conversion)
 * Run hg convert to migrate the files and history
 * Update the local Mercurial repository to get the files into your workspace
 * Clone the new local repository to your remote Mercurial instance

Sample bash script:

export P4CLIENT=your_client_spec_name
export P4PORT=your_p4_server:1234
export P4USER=username
export P4PASSWD=password

mkdir p4depot
cd p4depot
p4 sync -f ...
mkdir ../hgdepot
cd ../hgdepot
hg convert -s p4 //sample_app/... new_hg_repo
cd new_hg_repo
hg update
hg clone . ssh://account@your_remote_server.com/new_hg_repo

=== Converting from RCS ===
(kudos to the author of http://utcc.utoronto.ca/~cks/space/blog/sysadmin/RCStoMercurial)

First convert to a dummy CVS repo, then convert from a CVS checkout as shown below or as in ConvertExtension#Converting_from_CVS .

Converting RCS to CVS:

$ mkdir /tmp/cvs-repo;
$ cvs -d /tmp/cvs-repo init
$ ls -F /tmp/cvs-repo
$ rsync -a ~/my-scripts/RCS/ /tmp/cvs-repo/my-scripts
$ ls -F /tmp/cvs-repo
CVSROOT/ my-scripts/
$ cvs -d /tmp/cvs-repo co -d /tmp/my-scripts my-scripts
cvs checkout: updating my-scripts
U /tmp/my-scripts/foo.sh
U /tmp/my-scripts/bar.sh
A simplified conversion to hg (version 1.5.1):

$ mkdir ~/my-repo.hg
$ hg convert --datesort /tmp/cvs-checkout/my-scripts ~/my-repo.hg
$ cd ~/my-repo.hg
$ ls -aF
./ ../ .hg/
$ hg update
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ ls -aF
./ ../ .hg/ foo.sh bar.sh

 * run `hg convert` with the `--datesort` option - all RCS changesets will be in strict date order
 * to incrementally add other RCS collections, convert each to a new CVS module in `/tmp/cvs-repo`, check out and run `convert` against `my-repo.hg`

=== Converting from Subversion ===
See WorkingWithSubversion for examples of Mercurial over Subversion workflows.

 * Subversion's Python bindings (see http://subversion.tigris.org/)

{i} Bindings are included with the TortoiseHg distribution package and the Win32 InnoSetup (non-MSI) binaries for Mercurial, so if you install either of them you don't need to install additional packages.

You may need to use a Mercurial installed on top of a stand-alone Python, and you may also need to do something like

set HG=python c:\Python25\Scripts\hg
to override the default Win32 binaries if you have those installed also. For Mac OS X, the easiest way is to install the [[http://www.collab.net/downloads/community/|CollabNet Subversion build]], and then copy the content of `/opt/subversion/lib/svn-python` to the `site-package` directory of the Python installation.

The source may be a URL or a path to a subversion repository or working directory.

==== Options ====
The converter supports a few Subversion-specific options:

 svn.trunk:: Relative path to the trunk (default: "trunk")
 svn.branches:: Relative path to tree of branches (default: "branches")
 svn.tags:: Relative path to tree of tags (default: "tags")
 svn.startrev:: Start subversion revision. Work for single branches conversions only.

Set these under `[convert]` in a ''`.hgrc`'', or on the command line as follows:

hg --config convert.svn.trunk=wackoname convert [...]
/!\ A child Mercurial process is spawned to fetch subversion revision information. The heuristic used to find the Mercurial executable is simple but good enough for basic setups. If you are running the convert extension from a Mercurial installation which is not the primary one (not in $PATH), you should set the $HG environment variable to the location of your Mercurial executable or script, so the child process will be spawned with the expected Mercurial version.

==== More about Subversion URL and Paths Handling ====
Let's see what we can do to convert `http://code.sixapart.com/svn/memcached`. '''trunk''' can be converted directly with:

hg convert http://code.sixapart.com/svn/memcached/trunk
Here, convert retrieves all revisions down to the first one created in '''trunk''' or coming from a copy living somewhere else. What's important to note is *not all revisions* existing in '''trunk''' may be converted: if '''trunk''' is overwritten at revision A by a branch coming from another part of the repository, the conversion will stop at revision A. `http://code.sixapart.com/svn/memcached/trunk` is the root URL, only revisions touching files in its subtree will be converted.

Things are different if we run:

hg convert http://code.sixapart.com/svn/memcached
The root URL is `http://code.sixapart.com/svn/memcached`. The convert extension tries to detect canonical trunk/branches/tags layout automatically. Here, '''trunk''' will be detected and added to the modules to convert. It will also detect the `branches` subdirectory and add its children directories to conversion targets. Starting at these heads, module history is unrolled like when converting '''trunk''', only this time branching information is detected. For instance, if the `branches/memcached-1.1.x` module is branched from '''trunk''' at revision 255, both will be related in the converted repository. Note the ''do not follow history below root URL'' still applies but is usually irrelevant with well behaving trunk/branches/tags layouts. Branches are named after their module name, like `memcached-1.1.x` and this may be preserved by the destination backend (Mercurial backend defaulting to `convert.hg.branchnames=1`, named branches are created after these module names). Finally, the `tags` directory is detected automatically, branching points computed and used to tag converted revisions.

If your repository layout differs from the canonical trunk/branches/tags, these can be redefined with `convert.svn.trunk`, `convert.svn.branches` and `convert.svn.tags` configuration options. Values are relative paths from the root URL, like `archive/2006/memcached-old` for `http://code.sixapart.com/svn/memcached/archive/2006/memcached-old`.

Local repositories must be converted using local URLs. Under Unix, a local '''memcached''' repository would be converted with:

$ hg convert file://`pwd`/memcached-repo/memcached
Under Windows (assuming '''memcached-repo''' in '''c:\dev'''), it would be:

$ hg convert file:///c:/dev/memcached-repo/memcached
The extension works from checkouts:

$ hg convert memcached
==== Working around Network and Bindings Issues ====
Sometimes, conversion of remote repositories is complicated by poor network connectivity, remote server misconfiguration, SVN bindings issues or bugs in the converter when handling remote sources. The converter fetches whole files and not just deltas, so it is not very efficient. Often, you would like to have the SVN repository locally to play and replay the conversion with different parameters or track bugs more quickly. One solution is to mirror it locally using the [[http://svn.apache.org/repos/asf/subversion/trunk/notes/svnsync.txt|svnsync]] script ([[http://svnbook.red-bean.com/en/1.6/svn.ref.svnsync.html|docs]]) provided with SVN distributions.

For example:

$ svnadmin create foomirror
$ echo '#!/bin/sh' > foomirror/hooks/pre-revprop-change # make insecure dummy hook. On windows this can be an empty file with the .bat suffix
$ chmod +x foomirror/hooks/pre-revprop-change
$ svnsync init --source-username <username> file://`pwd`/foomirror https://foo.svn.sourceforge.net/svnroot/foo
Copied properties for revision 0.
$ svnsync sync file://`pwd`/foomirror
Committed revision 1.
Copied properties for revision 1.
Committed revision 2.
Copied properties for revision 2.
$ svn co file:///`pwd`/foomirror foomirror-svn # - if you want to make a checkout from your repo mirror
$ hg convert foomirror # convert directly from repo mirror to foomirror-hg

==== Other tools ====
See RepositoryConversion#Subversion for other methods that can be used.

=== Converting from Mercurial ===
It's also useful to filter Mercurial repositories to get subsets of an existing one. For example to transform a subdirectory `subfoo` of a repository `foo` into a repository with its own life (while keeping its full history), do the following:

$ echo include subfoo > /tmp/myfilemap
$ echo rename subfoo . >> /tmp/myfilemap
$ hg convert --filemap /tmp/myfilemap /path/to/repo/foo /tmp/mysubfoo-repo
'''hg.ignoreerrors''' also let missing revlog errors to be ignored when reading the source, which may be useful to fix a repository with a damaged store. Set this option to True and convert from Mercurial to Mercurial.

Other configuration options supported:
 hg.saverev:: Store the original revision ID in changeset (forces target IDs to change). It takes a boolean argument and defaults to False.
 hg.startrev:: Convert the specified starting revision and its descendants. It takes a Mercurial revision identifier and defaults to 0.

=== Converting to Mercurial ===
The Mercurial back end supports the following configuration options:

 hg.usebranchnames:: Use named branches to record source branches (default: `true`)
 hg.clonebranches:: Create branches as clones of their parent branches. All branches will be created as subdirectories of the convert destination. (default: `false`)
 hg.tagsbranch:: Put tags on the given branch (default: `default`)

An example of using these settings in a ''`.hgrc`'' file is:


{{{#!wiki note
As thorough as the convert extension is, it cannot handle all cases, especially if those cases involve the conversion of a very non-standard repository layout. Please see ProblematicConversions for possible solutions.

== See also ==
 * RepositoryConversion for other tips and VCS systems
 * [[/Talk|Talk]] page

The writer is named Wen. Her friends say it's not good for her but what she loves doing is to camp but she's struggling to locate time for it. The task she is been occupying for decades can be a people manager and it is something she love. De may be the only place she's been residing in but now she is considering additional options. If you like to find out more check out his website: http://acguyfortlauderdale.com/

The writer is named Wen. Her friends say it's not good for her but what she loves doing is to camp but she's struggling to locate time for it. The task she is been occupying for decades can be a people manager and it is something she love. De may be the only place she's been residing in but now she is considering additional options. If you like to find out more check out his website: http://acguyfortlauderdale.com/

ConvertExtension (last edited 2015-02-11 17:56:41 by MadsKiilerich)