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From "" <>
Subject Re: [Lucene.Net] Roadmap
Date Mon, 21 Nov 2011 20:34:13 GMT


I'd say there not that hard to get wrong, the pattern for correctly 
implementing the IDisposable interface is well-established and has been 
common practice since .NET 1.0:

Additionally, I said protected virtual (as per the recommendation in the 
link above).

Also agreed on the use of iterators everywhere.  Foreach is your friend.

What would be even better in some cases, using "yield return", as I'm sure 
result sets don't need to be materialized everywhere as they are now.

- Nick


From: "Christopher Currens" <>

Sent: Monday, November 21, 2011 3:18 PM


Subject: Re: [Lucene.Net] Roadmap

Some of the Lucene classes have Dispose methods, well, ones that call Close 
(and that Close method may or may not call base.Close(), if needed or not). 
 Virtual dispose methods can be dangerous only in that they're easy to 
implement wrong.  However, it shouldn't be too bad, at least with a 
line-by-line port, as we would make the call to the base class whenever 
Lucene does, and that would (should) give us the same behavior, implemented 
properly.  I'm not aware of differences in the JVM, regarding inheritance 
and base methods being called automatically, particularly Close methods.

Slightly unrelated, another annoyance is the use of Java Iterators vs C# 
Enumerables.  A lot of our code is there simply because there are 
Iterators, but it could be converted to Enumerables. The whole HasNext, 
Next vs C#'s MoveNext(), Current is annoying, but it's used all over in the 
base code, and would have to be changed there as well.  Either way, I would 
like to push for that before 3.0.3 is relased.  IMO, small changes like 
this still keep the code similar to the line-by-line port, in that it 
doesn't add any difficulties in the porting process, but provides great 
benefits to the users of the code, to have a .NET centric API.  I don't 
think it would violate our project desciption we have listed on our 
Incubator page, either.


On Mon, Nov 21, 2011 at 12:03 PM, 
<> wrote:

+1 on the suggestion to move Close -> IDisposable; not being able to use

"using" is such a pain, and an eyesore on the code.

Although it will have to be done properly, and not just have Dispose call

Close (you should have proper protected virtual Dispose methods to take

inheritance into account, etc).

- Nick


From: "Christopher Currens" <>

Sent: Monday, November 21, 2011 2:56 PM


Subject: Re: [Lucene.Net] Roadmap

Regarding the 3.0.3 branch I started last week, I've put in a lot of late

nights and gotten far more done in a week and a half than I expected.  The

list of changes is very large, and fortunately, I've documented it in some

files that are in the branches root of certain projects.  I'll list what

changes have been made so far, and some of the concerns I have about them,

as well as what still needs to be done.  You can read them all in detail


the files that are in the branch.

All changes in 3.0.3 have been ported to the Lucene.Net and

Lucene.Net.Test, except BooleanClause, LockStressTest, MMapDirectory,

NIOFSDirectory, DummyConcurrentLock, NamedThreadFactory, and


MMapDirectory and NIOFSDirectory have never been ported in the first place

for 2.9.4, so I'm not worried about those.  LockStressTest is a

command-line tool, porting it should be easy, but not essential to a 3.0.3

release, IMO.  DummyConcurrentLock also seems unnecessary (and

non-portable) for .NET, since it's based around Java's Lock class and is

only used to bypass locking, which can be done by passing new Object() to

the method.

NamedThreadFactory I'm unsure about.  It's used in ParallelMultiSearcher

(in which I've opted to use the TPL), and seems to be only used for

debugging, possibly testing.  Either way, I'm not sure it's necessary.

Also, named threads would mean we probably would have to move the class

from the TPL, which greatly simplified the code and parallelization of it

all, as I can't see a way to Set names for a Task.  I suppose it might be

possible, as Tasks have unique Ids, and you could use a Dictionary to map

the thread's name to the ID in the factory, but you'd have to create a

helper function that would allow you to find a task by its name, which

seems more work than the resulting benefits.  VS2010 already has better

support for debugging tasks over threads (I used it when writing the

class), frankly, it's amazing how easy it was to debug.

Other than the above, the entire code base in the core dlls is at 3.0.3,

which is exciting, as I'm really hoping we can get Lucene.Net up to the

current version of Java's 3.x branch, and start working on a line-by-line

port of 4.0.  Tests need to be written for some of the collections I've

made that emulate Java's, to make sure they're even behaving the same way.

The good news is that all of the existing tests pass as a whole, so it

seems to be working, though I'd like the peace of mind of having tests for

them (being HashMap<TKey, TValue>, WeakDictionary<TKey, TValue> and

IdentityCollection<TKey, TValue>, it's quite possible any one of them


be completely wrong in how they were put together.)

I'd also like to finally formalize the way we use IDisposable in

Lucene.Net, by marking the Close functions as obsolete, moving the code

into Dispose, and eventually (or immediately) removing the Close


There's so much change to the API, that now would be a good time to make

that change if we wanted to.  I'm hesitant to move from a line-by-line


of Lucene.Net completely, but rather having it be close as possible.  The

main reason I feel this way, is when I was porting the Shingle namespace


Contrib.Analyzers, Troy has written it in a .Net way which different

GREATLY from java lucene, and it did make porting it considerably more

difficult; to keep the language to a minimum, I'm just going to say it was

a pain, a huge pain in fact.  I love the idea of moving to a more .NET

design, but I'd like to maintain a line-by-line port anyway, as I think

porting changes is far easier and quicker that way.  At this point, I'm

more interested in getting Lucene.Net to 4.0 and caught up to java, than I

am anything else, hence the extra amount of time I've put into this


over the past week and a half.  Though this isn't really a place for this


The larger area of difficult for the port, however, is the Contrib


There are two major problems with it that is slowing me down.  First,

there are a lot of classes that are outdated.  I've found versions of code

that still have the Apache 1.1 License attached to it, which makes the


quite old.  Also, it was almost impossible for me to port a lot of changes

in Contrib.Analyzers, since the code was so old and different from Java's


Second, we had almost no unit tests ported for any of the classes, which

means they have to be ported from scratch.

Third, there are a lot of contrib projects that have never been ported


from java.  That list includes: smartcn (I believe this is an intelligent

Chinese analyzer), benchmark, collation, db, lucli, memory, misc,

queryparser, remote, surround, swing, wikipedia, xml-query-parser.

However, it should be noted that I'm not even sure which, if any, SHOULD

be ported or even CAN be ported.

The progress on 3.0.3 Contrib is going steady, however.  The entire

Analyzers project (except for smartcn) has been ported, as well as the


for them, which all pass.  There were some minor exceptions, the

ThaiAnalyzer and hyphenation analyzers that could not be ported,

ThaiAnalyzer because it relies on BreakIterator, and there's no built-in

functionality to split a string by words based on a culture in .NET, and


third party library I could find that easily does it, and Hyphenation,

because it relies on SAX xml processing, which is also missing from .NET.

The FastVectorHighlighter project has also had all 3.0.3 changes ported to

the project and it's Tests, as well, all passing.  All other projects in

contrib have yet to be touched/ported.

You can find some of my notes scattered about in // TODO comments, but


centralized in the project directories:






If, and by if I mean when, you find porting errors, let me know and fix

them or have me fix them, or whatever you want to do.  The thing I worry

about the most are the tests for the collections I listed above, which I

will get around to writing soon.  I *have* found some porting issues in


core dll that didn't manifest themselves in the Lucene.Net.Test test


but did when I ported some of the tests for Contrib.Analyzers.  I have a

feeling they will be found slowly and surely, but I feel that they are few

and far between.

If anyone wants to help on this branch, I'd welcome it, we would just need

to coordinate who is working on what, so we aren't porting the same thing

and wasting time.



TL;DL: Lucene.Net/Lucene.Net.Tests have all been ported to 3.0.3 (with a

few very minor exceptions), Contrib.Analyzers/Contrib.Analyzer.Test have

all been ported to 3.0.3 (few minor exceptions),

FastVectorHighlighter/FastVectorHighlighter.Tests have all been ported to

3.0.3, and the rest of Contrib is going to be a pain.

On Sun, Nov 20, 2011 at 11:44 AM, Prescott Nasser



> Anyone have any thoughts on these items?




> My 2 cents is that after we get 2.9.4 out the door, we quickly release a

> 2.9.4g (Digy - you're probably most familiar with 2.9.4g, is there any


> that we should do to that to get it solid for a release?




> I'm still unsure the status of 3.0.3 or 4.0, but I'm thinking for the


> release in Q1 2012.








> >

> >

> > While you all take a look at the artifacts for a vote - I wanted to


> about the future roadmap and our releases -

> >

> >

> >

> > 2.9.4g is very stable - do we want to release this at some point?

> >

> > 3.0.3 - chris looks to be pretty active on this. Chris, can you fill


> in on what's the status of this branch?

> >

> > 4.0 - looks to be partially underway.

> >

> >

> >

> > I want to try and maybe build a better release schedule and begin

> filling out what needs to be done so people can easily jump in and help

> out. I noticed the 4.0 status page in the wiki - that's excellent

> >

> >

> >

> > ~P


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