Format of URLs
[Documentation for users]

FSVS can use more than one URL; the given URLs are overlaid according to their priority. More...

FSVS can use more than one URL; the given URLs are overlaid according to their priority.

For easier managing they get a name, and can optionally take a target revision.

Such an extended URL has the form

   ["name:"{name},]["target:"{t-rev},]["prio:"{prio},]URL

where URL is a standard URL known by subversion -- something like http://...., svn://... or svn+ssh://....

The arguments before the URL are optional and can be in any order; the URL must be last.

Example:

   name:perl,prio:5,svn://...

or, using abbreviations,

   N:perl,P:5,T:324,svn://...

Please mind that the full syntax is in lower case, whereas the abbreviations are capitalized!
Internally the : is looked for, and if the part before this character is a known keyword, it is used.
As soon as we find an unknown keyword we treat it as an URL, ie. stop processing.

The priority is in reverse numeric order - the lower the number, the higher the priority. (See url__current_has_precedence() )

Why a priority?

When we have to overlay several URLs, we have to know which URL takes precedence - in case the same entry is in more than one. (Which is not recommended!)

Why a name?

We need a name, so that the user can say "commit all outstanding changes to the repository at URL x", without having to remember the full URL. After all, this URL should already be known, as there's a list of URLs to update from.

You should only use alphanumeric characters and the underscore here; or, in other words, \w or [a-zA-Z0-9_]. (Whitespace, comma and semicolon get used as separators.)

What can I do with the target revision?

Using the target revision you can tell fsvs that it should use the given revision number as destination revision - so update would go there, but not further. Please note that the given revision number overrides the -r parameter; this sets the destination for all URLs.

The default target is HEAD.

Note:

In subversion you can enter URL@revision - this syntax may be implemented in fsvs too. (But it has the problem, that as soon as you have a @ in the URL, you must give the target revision every time!)

There's an additional internal number - why that?

This internal number is not for use by the user.
It is just used to have an unique identifier for an URL, without using the full string.

On my system the package names are on average 12.3 characters long (1024 packages with 12629 bytes, including newline):

   COLUMNS=200 dpkg-query -l | cut -c5- | cut -f1 -d" " | wc

So if we store an id of the url instead of the name, we have approx. 4 bytes per entry (length of strings of numbers from 1 to 1024). Whereas using the needs name 12.3 characters, that's a difference of 8.3 per entry.

Multiplied with 150 000 entries we get about 1MB difference in filesize of the dir-file. Not really small ...
And using the whole URL would inflate that much more.

Currently we use about 92 bytes per entry. So we'd (unnecessarily) increase the size by about 10%.

That's why there's an url_t::internal_number.