svn_1.4_releasenotes.html [plain text]
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style type="text/css"> /* <![CDATA[ */
@import "branding/css/tigris.css";
@import "branding/css/inst.css";
/* ]]> */</style>
<link rel="stylesheet" type="text/css" media="print"
href="branding/css/print.css"/>
<script type="text/javascript" src="branding/scripts/tigris.js"></script>
<title>Subversion 1.4 Release Notes</title>
</head>
<body>
<div class="app">
<h1 style="text-align: center">Subversion 1.4 Release Notes</h1>
<div class="h2" id="news" title="news">
<h2>What's New in Subversion 1.4</h2>
<ul>
<li><tt>svnsync</tt>, a new repository mirroring tool</li>
<li>Huge working-copy performance improvements</li>
<li>Support for BerkeleyDB 4.4 and its "auto recovery" feature</li>
<li>Size improvements to the binary delta algorithm</li>
<li>A handful of new command switches</li>
<li>Many improved APIs</li>
<li>More than 40 new bugfixes</li>
</ul>
<p>Details are described below.</p>
<p>Subversion 1.4 is a superset of all previous Subversion releases,
and is considered the current "best" release. Anything in 1.0.x,
1.1.x, 1.2.x or 1.3.x is also in 1.4, but 1.4 contains features and
bugfixes not present in any earlier release. The new features will
eventually be documented in a 1.4 version of the free Subversion book,
see <a
href="http://svnbook.red-bean.com">svnbook.red-bean.com</a>.</p>
</div> <!-- news -->
<div class="h2" id="compatibility" title="compatibility">
<h2>Compatibility Concerns</h2>
<p>Older clients and servers interoperate transparently with 1.4
servers and clients. Of course, some of the new 1.4 features may not
be available unless both client and server are the latest version.
There is <strong>no need</strong> to dump and reload your
repositories; Subversion 1.4 can read repositories created by earlier
versions. To upgrade an existing installation, just install the
newest libraries and binaries on top of the older ones.</p>
<p>Subversion 1.4 maintains API/ABI compatibility with earlier
releases, by only adding new functions. A program written to the 1.0,
1.1, 1.2 or 1.3 API can both compile and run using 1.4 libraries.
However, a program written for 1.4 cannot necessarily compile or run
against older libraries.</p>
<div class="h3" id="wc-format-change" title="wc-format-change">
<h3>Working Copy and Repository Format Changes</h3>
<p>Due to certain improvements and bugfixes made to the working copy
library, the version number of the working copy format has been
incremented. This means that Subversion clients earlier than 1.4 will
<em>not</em> be able to work with working copies produced by Subversion
1.4. Similarly, the repository format has changed as well, meaning
that pre-1.4 Subversion tools that normally access a repository
directly
(e.g. <tt>svnserve</tt>, <tt>mod_dav_svn</tt>, <tt>svnadmin</tt>)
won't be able to read a repository originally created by Subversion
1.4. </p>
<p><strong>WARNING:</strong> if a Subversion 1.4 client encounters a pre-1.4
working copy, it will <em>automatically</em> upgrade the working copy
format as soon as it touches it, making it unreadable by older
Subversion clients. If you are using several versions of Subversion
on your machine, you need to be careful about which version you use in
which working copy, to avoid accidentally upgrading the working copy
format. This "auto upgrade" feature, however, does <em>not</em> occur
with the new repository format. </p>
</div> <!-- wc-format-change -->
<div class="h3" id="output-changes" title="output-changes">
<h3>Command Line Output Changes</h3>
<p>Although the Subversion developers try hard to keep output from the
command line programs compatible between releases, new information
sometimes has to be added. This might break scripts that rely on the
exact format of the output. In 1.4, the following changes have been
made to the output:</p>
<ul>
<li><p>Conflict markers in files now match the file's defined eol-style.</p></li>
</ul>
</div> <!-- output-changes -->
</div> <!-- compatibility -->
<div class="h2" id="new-features" title="new-features">
<h2>New Features</h2>
<div class="h3" id="svnsync" title="svnsync">
<h3>svnsync (<em>some features require a 1.4 server</em>)</h3>
<p>A new tool — <a
href="http://svn.collab.net/repos/svn/trunk/notes/svnsync.txt"
><tt>svnsync</tt></a> — is now installed as part of the standard
distribution. This tool provides the ability to replicate history
from one repository to another. The replication can happen all at
once, or can be done incrementally through repeated 'sync' operations.
Because the tool uses the abstract network (RA) API, the source and
destination repositories can be either local, remote, or any
combination thereof.</p>
<p><em>Compatibility note</em>: in order to "push" information into a
destination repository, any version of the server will suffice. The
pushing is done through ordinary network commits. To "pull" history
from the source repository, however, requires a 1.4 (or later)
server.</p>
<p>Usage of this tool will be documented in the Subversion book soon,
but for now, running <tt>svnsync help</tt> should suffice; the number
of subcommands is very small, and the help system documents them
all.</p>
</div> <!-- svnsync -->
<div class="h3" id="wc-improvements" title="wc-improvements">
<h3>Working copy performance improvements (<em>client</em>)</h3>
<p>The way in which the Subversion client manages your working copy
has undergone radical changes. The <tt>.svn/entries</tt> file is no
longer XML, and the client has become smarter about the way it manages
and stores property metadata.</p>
<p>As a result, there are substantial performance improvements. The
new working copy format allows the client to more quickly search a
working copy, detect file modifications, manage property metadata, and
deal with large files. The overall disk footprint is smaller as well,
with fewer inodes being used. Additionally, a number of long standing
bugs related to merging and copying have been fixed.</p>
<p><strong>WARNING:</strong> A Subversion 1.4 client will upgrade
older working copies to the new format WITHOUT WARNING, rendering them
unreadable by older Subersion clients. See the section above, titled
'Working Copy Format Changes'.</p>
</div> <!-- wc-improvements -->
<div class="h3" id="bdb-4.4" title="bdb-4.4">
<h3>BerkeleyDB 4.4 and auto-recovery (<em>server</em>)</h3>
<p>A common problem with previous versions of Subversion is that
crashed server processes could leave BerkeleyDB-based repositories in
an unusable "wedged" state, requiring administrators to manually
intervene and bring back online. (Note: this is not due to bugs in
BerkeleyDB, but due to the unorthodox way in which Subversion uses
it!)</p>
<p>Subversion 1.4 can now be compiled against BerkeleyDB 4.4, which
has a new "auto-recovery" feature. If a Subversion server process
crashes and leaves the repository in an inconsistent state, the next
process which attempts to access the repository will notice the
problem, grab exclusive control of the repository, and automatically
recover it. In theory (and in our testing), this new feature makes
BerkeleyDB-based repositories just as wedge-proof as FSFS
repositories.</p>
<p><strong>WARNING:</strong> While upgrading to a new version of Berkeley DB
will not require you to dump and reload your repository, you
<em>will</em> still need to follow the Berkeley DB upgrade regimen to
ensure that your repository is accessible by the new version of those
libraries. Please see the <a
href="http://www.oracle.com/technology/documentation/berkeley-db/db/ref/upgrade/process.html"
>Upgrading Berkeley DB installations</a> chapter of the Berkeley DB
Reference Guide for instructions on upgrading Berkeley DB
environments.</p>
</div> <!-- bdb-4.4 -->
<div class="h3" id="svndiff1" title="svndiff1">
<h3>Binary Delta Encoding Improvements (<em>client and server</em>)</h3>
<p>Subversion uses the xdelta algorithm to compute differences between
strings of bytes. The output of this algorithm is stored in a custom
format called 'svndiff'. svndiff data is what's stored in the
repository to represent the difference between successive versions of
files, and svndiff data is also transmitted over the wire between
client and server (e.g. during updates and commits.)</p>
<p>In Subversion 1.4, the svndiff format has been improved to use much
less disk space — up to 50% less on plain text files in some
cases. Thus, if you choose to dump and reload your repository, the
new repository should be noticeably smaller on disk. (Make sure
to <tt>svnadmin create</tt> the new repository using svnadmin 1.4.)
Additionally, if a client and server are both version 1.4 , then
network traffic becomes smaller and faster.</p>
<p><strong>WARNING:</strong> A repository created by svnadmin 1.4 will not be
readable by earlier Subversion libraries or tools. However, in order
to experience the smaller data format, you'll have to dump and reload
your data. If you <em>don't</em> recreate your repository with
svnadmin 1.4, it will continue writing data in the older, larger
format, and will still be readable by older Subversion tools.</p>
</div> <!-- svndiff1 -->
<div class="h3" id="new-switches" title="new-switches">
<h3>New subcommand switches</h3>
This release of Subversion adds a few new switches and options to the
command line client. These are:
<dl>
<dt><tt>svn blame --force</tt></dt>
<dd>Displays the output of blame, even if the file is binary.</dd>
<dt><tt>svn merge/blame -x</tt></dt>
<dd>Merge and blame commands can now pass options to an external
diff3 program.</dd>
<dt><tt>svn diff/merge -c/--change</tt></dt>
<dd>You can now simply write -c N to view or merge a single
revision, instead of the cumbersome -r N-1:N.</dd>
<dt><tt>svn diff --summarize</tt></dt>
<dd>Prints only the list of changed files, in the output format
of 'svn status'. This lets you retrieve summaries of changes
directly from a repository, whereas 'svn status' operates only
on the local changes of your working copy.</dd>
<dt><tt>svn diff -x [-u | -b | -w | --ignore-eol-style]</tt></dt>
<dd>The diff engine internal to Subversion can now ignore
whitespace and eol-style when computing the diff.</dd>
</dl>
</div> <!-- new-switches -->
</div> <!-- new-features -->
<div class="h2" id="enhancements" title="enhancements">
<h2>Enhancements and Bugfixes</h2>
<div class="h3" id="svnserve" title="svnserve">
<h3>svnserve as native Windows service (<em>server</em>)</h3>
The <tt>svnserve</tt> server can now be run as a Windows service. This
allows svnserve to start automatically, at system boot time, without
having a user logged in and without the need for an external service
'wrapper' program. See <a
href="http://svn.collab.net/repos/svn/tags/1.4.0/notes/windows-service.txt"><tt>notes/windows-service.txt</tt></a>
for information on setting up <tt>svnserve</tt> as a Windows service.
</div> <!-- svnserve -->
<div class="h3" id="keychain" title="keychain">
<h3>OS X Keychain support (<em>client</em>)</h3>
On OS X, the <tt>svn</tt> client now caches passwords in Keychain,
rather than in <tt>~/.subversion/auth/</tt>.
</div> <!-- keychain -->
<div class="h3" id="apis" title="apis">
<h3>API improvements (<em>client and server</em>)</h3>
<p>If you develop a 3rd-party client application that uses Subversion
APIs, you may want to take notice of some new APIs:</p>
<ul>
<li>The RA replay API, used by <tt>svnsync</tt>, lets you retrieve
all the data associated with a set of revisions in a single
operation.</li>
<li>Many APIs have been revised to newer versions.</li>
</ul>
</div> <!-- apis -->
<div class="h3" id="bugfixes" title="bugfixes">
<h3>Other bugfixes (<em>client and server</em>)</h3>
<p>The usual slew of heretofore-unreleased bugfixes, more than 40
overall. See the
<a href="http://svn.collab.net/repos/svn/trunk/CHANGES">CHANGES</a>
file for full details.</p>
</div> <!-- bugfixes -->
</div> <!-- enhancements -->
<div class="h2" id="svn-1.2-deprecation" title="svn-1.2-deprecation">
<h2>Subversion 1.2.x series no longer supported</h2>
<p>The Subversion 1.2.x line is no longer supported. This doesn't
mean that your 1.2 installation is doomed; if it works well and is all
you need, that's fine. "No longer supported" just means we've stopped
accepting bug reports against 1.2.x versions, and will not make any
more 1.2.x bugfix releases, except perhaps for absolutely critical
security or data-loss bugs.</p>
</div> <!-- svn-1.2-deprecation -->
</div> <!-- app -->
</body>
</html>