<title>Unversioned Content</title>
<h1 align="center">Unversioned Content</h1>

"Unversioned content" or "unversioned files" are
files stored in a Fossil repository without history.
Only the newest version of each unversioned file is retained.

Though history is omitted, unversioned content is synced between
repositories.  In the event of a conflict during a sync, the most recent
version of each unversioned file is retained and older versions are discarded.

Unversioned files are useful for storing ephemeral content such as builds
or frequently changing web pages.
The [https://fossil-scm.org/home/uv/download.html|download] page of
the self-hosting Fossil repository is stored as unversioned
content, for example.

<h2>Accessing Unversioned Files</h2>

Unversioned files are <u>not</u> a part of a check-out.
Unversioned files are intended to be accessible as web pages using
URLs of the form:  "http://domain/cgi-script/<b>uv</b>/<i>FILENAME</i>".
In other words, the URI method "<b>uv</b>" (short for "unversioned")
followed by the name of the unversioned file will retrieve the content
of the file.  The MIME type is inferred from the filename suffix.

The content of unversioned files can also be retrieved using the
[/help?cmd=unversioned|fossil unvers cat <i>FILENAME</i>] command.

A list of all unversioned files on a server can be seen using
the [/help?cmd=/uvlist|/uvlist] URL.  ([/uvlist|example]).

<h2>Syncing Unversioned Files</h2>

Unversioned content is synced between repositories, though not by default.
Special commands or command-line options are required.
Unversioned content can be synced using the following commands:

<blockquote><pre>
fossil sync <b>-u</b>
fossil clone <b>-u</b> <i>URL local-repo-name</i>
fossil unversioned sync
</pre></blockquote>

The [/help?cmd=sync|fossil sync] and [/help?cmd=clone|fossil clone]
commands will synchronize unversioned content if and only if the
"-u" (or "--unversioned") command-line option is supplied.  The
[/help?cmd=unversioned|fossil unversioned sync] command will synchronize the
unversioned content without synchronizing anything else.

Notice that the "-u" option does not work on
[/help?cmd=push|fossil push] or [/help?cmd=pull|fossil pull].
The "-u" option is only available on "sync" and "clone".

A rough equivalent of an unversioned pull would be the
[/help?cmd=unversioned|fossil unversioned revert] command.  The
"unversioned revert"
command causes the unversioned content on the local repository to overwritten
by the unversioned content found on the remote repository.

<h2>Implementation Details</h2>

<i>(This section outlines the current implementation of unversioned
files.  This is not an interface spec and hence subject to change.)</i>

Unversioned content is stored in the repository in the
"unversioned" table:

<blockquote><pre>
CREATE TABLE unversioned(
  uvid INTEGER PRIMARY KEY AUTOINCREMENT,  -- unique ID for this file
  name TEXT UNIQUE,       -- Name of the file
  rcvid INTEGER,          -- From whence this file was received
  mtime DATETIME,         -- Last change (seconds since 1970)
  hash TEXT,              -- SHA1 hash of uncompressed content
  sz INTEGER,             -- Size of uncompressed content
  encoding INT,           -- 0: plaintext  1: zlib compressed
  content BLOB            -- File content
);
</pre></blockquote>

If there are no unversioned files in the repository, then the
"unversioned" table does not necessarily exist.
A simple way to purge all unversioned content from a repository
is to run:

<blockquote><pre>
fossil sql "DROP TABLE unversioned; VACUUM;"
</pre></blockquote>

No delta compression is performed on unversioned files, since there is no
history to delta against.

Unversioned content is exchanged between servers as whole, uncompressed
files (though the content does get compressed when the overall HTTP message
payload is compressed).  SHA1 hash exchanges are used to avoid sending
content over the wire unnecessarily.  See the
[./sync.wiki|synchronization protocol documentation] for further
information.
