70
70
The centralized model can have some drawbacks. A centralized RCS requires
71
71
that one is able to connect to the server whenever one wants to do version
72
control work. This can be a bit of a problem if your server on some other
73
machine on the internet and you are not. Or, worse yet, you ''are'' on the
72
control work. This can be a bit of a problem if your server is on some other
73
machine on the internet and you are not. Or, worse yet, you **are** on the
74
74
internet but the server is missing!
76
76
Decentralized Revision Control Systems (which I'll call DRCS after this
77
77
point) deal with this problem by keeping branches on the same machine as
78
the client. In Bazaar-NG's case, the branch is kept in the same place as
78
the client. In Bazaar's case, the branch is kept in the same place as
79
79
the code that is being version controlled. This allows the user to save
80
80
his changes (**commit**) whenever he wants -- even if he is offline. The
81
81
user only needs internet access when he wants to access the changes in
86
86
the changes for a directory such as file and subdirectory changes.
87
87
Performing this tracking by hand is a awkward process that over time
88
88
becomes unwieldy. That is, until one considers version control tools such
89
as Bazaar-NG. These tools automate the process of storing data by creating
89
as Bazaar. These tools automate the process of storing data by creating
90
90
a **revision** of the directory tree whenever the user asks.
92
Revision control software such as Bazaar-NG can do much more than just
93
storage and performing undo. For example, with Bazaar-NG developer can
94
take the modifications in one branch of software and apply them to
95
another, related, branch -- even if those changes exist in a branch owned
96
by somebody else. This allows developers to cooperate without giving write
92
Revision control software such as Bazaar can do much more than just
93
storage and performing undo. For example, with Bazaar a developer can
94
take the modifications in one branch of software and apply them to a
95
related branch -- even if those changes exist in a branch owned by
96
somebody else. This allows developers to cooperate without giving
97
write access to the repository.
99
Bazaar-NG remembers the ''ancestry'' of a revision: the previous revisions
99
Bazaar remembers the ''ancestry'' of a revision: the previous revisions
100
100
that it is based upon. A single revision may have more than one direct
101
101
descendant, each with different changes, representing a divergence in the
102
evolution of the tree. By branching, Bazaar-NG allows multiple people to
102
evolution of the tree. By branching, Bazaar allows multiple people to
103
103
cooperate on the evolution of a project, without all needing to work in
104
104
strict lock-step. Branching can be useful even for a single developer.
106
Introducing yourself to Bazaar-NG
107
=================================
106
Introducing yourself to Bazaar
107
==============================
109
Bazaar-NG installs a single new command, **bzr**. Everything else is a
110
subcommand of this. You can get some help with `bzr help`. There will be
109
Bazaar installs a single new command, **bzr**. Everything else is a
110
subcommand of this. You can get some help with ``bzr help``. Some arguments
111
are grouped in topics: ``bzr help topics`` to see which topics are available.
112
There will be more in the future.
113
114
One function of a version control system is to keep track of who changed
114
115
what. In a decentralized system, that requires an identifier for each
115
116
author that is globally unique. Most people already have one of these: an
116
117
email address. Bzr is smart enough to automatically generate an email
117
118
address by looking up your username and hostname. If you don't like the
118
guess that Bazaar-NG makes, then three options exist:
120
1. Setting the email address in the
121
``~/.bazaar/bazaar.conf`` by adding the following lines. Please note that
122
``[DEFAULT]`` is case sensitive::
119
guess that Bazaar makes, then three options exist:
121
1. Set an email address via ``bzr whoami``. This is the simplest way.
123
To set a global identity, use::
125
% bzr whoami 'Your Name <email@example.com>'
127
If you'd like to use a different address for a specific branch, enter
128
the branch folder and use::
130
% bzr whoami --branch 'Your Name <email@example.com>'
132
#. Setting the email address in the ``~/.bazaar/bazaar.conf`` [1]_ by adding the following lines.
133
Please note that ``[DEFAULT]`` is case sensitive::
125
135
email= Your Name <email@isp.com>
127
1. Override the previous setting on a
128
branch by branch basis by creating a branch section in
129
``~/.bazaar/branches.conf`` by adding the following lines::
131
[/the/directory/to/the/branch]
137
As above, you can override this settings on a branch by branch basis by
138
creating a branch section in ``~/.bazaar/locations.conf`` and adding the
140
[/the/path/to/the/branch]
132
141
email=Your Name <email@isp.com>
134
1. Overriding the two previous options by setting the global environment
135
variable ``$BZREMAIL`` or ``$EMAIL`` (``$BZREMAIL`` will take precedence)
136
to your full email address.
144
#. Overriding the two previous options by setting the global environment
145
variable ``$BZREMAIL`` or ``$EMAIL`` (``$BZREMAIL`` will take precedence)
146
to your full email address.
148
.. [1] On Windows, the users configuration files can be found in the
149
application data directory. So instead of ``~/.bazaar/branch.conf``
150
the configuration file can be found as:
151
``C:\Documents and Settings\<username>\Application Data\Bazaar\2.0\branch.conf``.
152
The same is true for ``locations.conf``, ``ignore``, and the
153
``plugins`` directory.
138
155
Creating a branch
139
156
=================
141
History is by default stored in the .bzr directory of the branch. There
142
will be a facility to store it in a separate repository, which may be
143
remote. We create a new branch by running **bzr init** in an existing
158
History is by default stored in the .bzr directory of the branch. In a
159
future version of Bazaar, there will be a facility to store it in a
160
separate repository, which may be remote. We create a new branch by
161
running ``bzr init`` in an existing directory::
180
197
containing control files. By default there is no separate repository or
181
198
database as used in svn or svk. You can choose to create a repository if
182
199
you want to (see the **bzr init-repo** command). You may wish to do this
183
if you have very large branches, or many branches of a moderate sized
200
if you have very large branches, or many branches of a moderately sized
186
203
You'll usually refer to branches on your computer's filesystem just by
187
204
giving the name of the directory containing the branch. bzr also supports
188
accessing branches over http, for example::
190
% bzr log http://bazaar-ng.org/bzr/bzr.dev/
192
By installing bzr plugins you can also access branches over the sftp or
205
accessing branches over http and sftp, for example::
207
% bzr log http://bazaar-vcs.org/bzr/bzr.dev/
208
% bzr log sftp://bazaar-vcs.org/bzr/bzr.dev/
210
By installing bzr plugins you can also access branches using the rsync
195
213
Reviewing changes
196
214
=================
472
If there is a conflict during a merge, 3 files with the same basename are
473
created. The filename of the common base is appended with .BASE, the
474
filename of the file containing your changes is appended .THIS and the
475
filename with the changes from the other tree is appended .OTHER.
476
Using a program such as kdiff3, you can now comfortably merge them into
477
one file. To commit you have to rename it to the original basename and
478
delete the other two files. As long as there exist files with .BASE, .THIS
479
or .OTHER the commit command will complain.
502
If there is a conflict during a merge, 3 files with the same basename
503
are created. The filename of the common base is appended with ".BASE",
504
the filename of the file containing your changes is appended with
505
".THIS" and the filename with the changes from the other tree is
506
appended with ".OTHER". Using a program such as kdiff3, you can now
507
comfortably merge them into one file. In order to commit you have to
508
rename the merged file (".THIS") to the original file name. To
509
complete the conflict resolution you must use the resolve command,
510
which will remove the ".OTHER" and ".BASE" files. As long as there
511
exist files with .BASE, .THIS or .OTHER the commit command will
516
% kdiff3 file.BASE file.OTHER file.THIS
481
520
[**TODO**: explain conflict markers within files]
489
528
directory. One can push a branch (or the changes for a branch) by one of
490
529
the following three methods:
492
* Rsync: rsync -avrz LOCALBRANCH servername.com/this/directory/here
531
* Rsync: rsync -avrz LOCALBRANCH servername.com/path/to/directory
494
533
(or any other tool for publishing a directory to a web site.)
496
* bzr push sftp://servername.com/this/directory/here
498
(The directory that must already exist)
500
* The push plugin that comes with BzrTools
535
* bzr push sftp://servername.com/path/to/directory
537
(The destination directory must already exist unless the
538
``--create-prefix`` option is used.)
540
* The rspush plugin that comes with BzrTools
543
Moving changes between trees
544
============================
546
It happens to the best of us: sometimes you'll make changes in the wrong
547
tree. Maybe because you've accidentally started work in the wrong directory,
548
maybe because as you're working, the change turns out to be bigger than you
549
expected, so you start a new branch for it.
551
To move your changes from one tree to another, use
556
% bzr merge --uncommitted OLDDIR
558
This will apply all of the uncommitted changes you made in OLDDIR to NEWDIR.
559
It will not apply committed changes, even if they could be applied to NEWDIR
560
with a regular merge. The changes will remain in OLDDIR, but you can use **bzr
561
revert OLDDIR** to remove them, once you're satisfied with NEWDIR.
563
NEWDIR does not have to be a copy of OLDDIR, but they should be related.
564
The more different they are, the greater the chance of conflicts.