org.aspectj/docs/release/README-1.6.2.adoc

= AspectJ 1.6.2

_© Copyright 2008 Contributors. All rights reserved._

The main theme of AspectJ1.6.2 was improved IDE incremental performance
and a number of changes have gone in to improve how AspectJ and AJDT
communicate - greatly reducing the time taken to perform an incremental
compile (more details below). 1.6.2 also includes a number of fixes and
enhancements covering areas such as:

* better support for generics and intertype declarations
* better support for annotation style syntax
* improvements to ajdoc
* bringing the AspectJ structure model more in line with the JDT model

Many thanks to all the users that helped diagnose problems, provide
testcases and contribute fixes. In particular:

* Dave Whittaker - for generics and intertype declaration testing and
testcases
* Jason Naylor, Arturo Salazar - for ajdoc testcases, fixes and design
input
* Andrew Eisenberg - for helping shape the AJDT/AspectJ interface and
improving incremental

The complete list of issues resolved for AspectJ 1.6.2 (more than 60)
can be found with this bugzilla query:

* https://bugs.eclipse.org/bugs/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&product=AspectJ&target_milestone=1.6.2&long_desc_type=allwordssubstr&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&status_whiteboard_type=allwordssubstr&status_whiteboard=&keywords_type=allwords&keywords=&bug_status=RESOLVED&bug_status=VERIFIED&bug_status=CLOSED&emailtype1=substring&email1=&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=[Bugs
resolved]

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== Incremental compilation (https://bugs.eclipse.org/bugs/show_bug.cgi?id=247742[bug 247742], https://bugs.eclipse.org/bugs/show_bug.cgi?id=245566[bug 245566], https://bugs.eclipse.org/bugs/show_bug.cgi?id=243376[bug 243376])

Two main changes in this area.

* Better communication between AJDT and AspectJ. The interface between
the two has been modified so that AJDT can give more input to AspectJ
about what needs to be done for an incremental compile, rather than
having AspectJ discover it each time.
* Structure model changes. The AspectJ structure model (of types in a
project and the weaving amongst them) allows handles to be created for
every node, as a lightweight reference to the elements of the model.
These handles were similar to those that JDT uses for references to
elements of a project but not identical. Many many fixes have gone in to
bring the handle formats closer and closer. For example including src
folders as elements in the AspectJ model and using the fully correct set
of JDT delimiters throughout each handle. This means there is no longer
an expensive transformation cost in going from an AspectJ element to its
related JDT element and no need for AJDT to maintain a more JDT like
version of the AspectJ structure model. The imminent development builds
of AJDT will utilise these changes.

_What difference does it make?_

For every kind of build there are two numbers to take into account.
Firstly there is the time spent in the compiler (time spent compiling
and weaving), secondly there is the time spent in AJDT (time spent
communicating what happened back to the user via the problems view,
gutter annotations). Values for these times can be seen by opening the
'AJDT Event Trace View' in eclipse. The changes within AspectJ obviously
effect the time spent in the compiler and that is described as 'time
spent in AJDE' within the event trace view (AJDE being the compiler
wrapper invoked by AJDT).

For a 1000 source file AspectJ project, the times spent in AJDE have
changed as follows for a single whitespace change and save operation:

* For a sourcefile unaffected by aspects. Was 1828ms, now 75ms.
* For a sourcefile affected by some advice. Was 1844ms, now 90ms.
* For a sourcefile affected by lots of advice. Was 1937ms, now 188ms.

The AspectJ changes are done to support this, but we are still bedding
them down in AJDT. If you want to see numbers like those above you need
to install the latest AJDT dev builds for Eclipse 3.4 (an AJDT 1.6.1 dev
build from the dev update site:
https://download.eclipse.org/tools/ajdt/34/dev/update ) and then after
starting Eclipse, select 'Window>Preferences' and in the AspectJ tab
select 'Incremental Compiler Optimizations'. Let us know how you get on!
When it has had enough testing it will be made the default and then is
likely to be back ported to Eclipse 3.3 AJDT.

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