On 14/01/10 00:43, Emmanuel Lcharny wrote:
[...]
Well, I don't really think that it's anything but implementation
dependent, so from the API POV, it's irrelevant. As soon as we add the
valueof() methods, those who want to add a cache can do it.
It's very relevant from an API POV. Being future proof is an essential
part of any API. Client applications will need to be modified if a
valueOf constructor is added at a later date in order to take advantage
of any potential perf improvements. By including the valueOf initially
applications can choose to use the constructor knowing that they will
inherit any future improvements such as caching.
If for learnability reasons we decide that a DN(String) constructor is
required then so be it, but it should include Javadoc recommending that
users use the valueOf constructor in preference.
I don't know why I raised this point...
The base constructor we can have are probably something like:
DN()
DN(String dnStr)
DN( RDN... rdns)
DN( RDN rdn, DN parent)
I like the DN( RDN rdn, DN parent) constructor - we support this via
an instance method called DN.child(RDN). I think I prefer the
constructor approach since it is not clear from our "child" method
whether or not it modifies this DN or creates a new DN. A
constructor is more obvious. You may want to have a concatenation
constructor DN(DN child, DN parent) for constructing DNs of entries
within a subtree using a relative DN (or "local name").
Why not a DN(DN child, DN parent) constructor two. It does not hurt
and can help.
OK.
One thing that is a bit tricky is whether or not the API should order
RDN parameters in little-endian (LDAP World) order or big-endian
(everyone else outside of LDAP) order. I think first time users may
be surprised by LDAP's unnatural little endian ordering.
I think we should keep the LDAP order when using DN( RDN...)
constructor. For instance, if we want to create "dc=example, dc=org",
that would be :
DN( "dc=example", "dc=org") (here, I use the String, but you should
read RDN)
Ok, fair enough.
Also, I strongly believe that DNs and RDNs and AVAs should be
immutable objects (as well as any other low level API type). What do
you think?
DN and RDN should be immutable, sure. AVA, I have some doubt.
If AVA is mutable then it is impossible for DN and RDN to be immutable
unless they do defensive copies which will be a bit annoying.
Also, on the subject of AVAs - we have the AVA type as an inner class
in RDN. I'm not particularly happy with this this, but less happy
with it being a standalone class since AVAs are only used in RDNs and
may introduce confusion elsewhere. For example, filters also use
attribute value assertions but these are not the same type of object
as an AVA even if they have the same name. For example, AVAs (in
RDNs) do not allow attribute options or matching rules to be specified.
I don't really like inner classes in this case for two reasons :
- It will be a big class, and the RN class while be hundreds of line
long. Not cool
- If we just use an Inner class just because we want to hide it from
the other classes, then I think it's probably better to have it
package protected (ie, no qualifier for this class).
If it's package protected then the class will not be part of the public
API. I'm not sure that I understand?
I agree about inner classes. They look even uglier in the API Javadoc...
Matt
