On 19 January 2011 16:23, la...@garfieldtech.com <la...@garfieldtech.com> wrote:
> On 1/19/11 10:09 AM, Adam Richardson wrote:
>>
>> On Wed, Jan 19, 2011 at 8:21 AM, Richard
>> Quadling<rquadl...@gmail.com>wrote:
>>
>>> On 19 January 2011 07:46, Adam Richardson<simples...@gmail.com>  wrote:
>>>>
>>>> On Wed, Jan 19, 2011 at 2:07 AM, Larry Garfield<la...@garfieldtech.com
>>>> wrote:
>>>>
>>>>> 3) Static analysis.  Instead of reflection, either tokenize or string
>>>
>>> parse
>>>>>
>>>>> all files to determine what classes implement what interfaces and then
>>>>> cache
>>>>> that information.  We are actually using this method now to locate
>>>
>>> classes,
>>>>>
>>>>> and it works surprisingly well.  Because we never parse code into
>>>>> memory
>>>
>>> it
>>>>>
>>>>> does not ever spike the memory usage.  However, it is impossible to
>>>>> determine
>>>>> if a class implements a given interface by static analysis unless it
>>>>> declare
>>>>> so itself with the implements keyword.  If it does so indirectly via
>>>>> inheritance, either via the class or via the interface, it would not
>>>
>>> find
>>>>>
>>>>> it.
>>>>> That necessitates that any "detectable" classes must explicitly
>>>
>>> themselves
>>>>>
>>>>> declare their interfaces, even if it is redundant to do so.  I don't
>>>
>>> like
>>>>>
>>>>> that
>>>>> approach, but it's the first one that strikes me as even viable.
>>>>>
>>>>
>>>> 4) Explicit declaration.  In this approach we detect nothing and rely on
>>>
>>> the
>>>>>
>>>>> plugin developer to do everything.  That is, they must provide
>>>>> somewhere
>>>>> (either in code or a configuration file) an index of all classes they
>>>>> offer,
>>>>> the interfaces they implement, and the file in which they live.  While
>>>
>>> this
>>>>>
>>>>> makes the implementation easy, it is a huge burden on the plugin
>>>
>>> developer
>>>>>
>>>>> and
>>>>> I'm quite sure they'll forget to do so or get it wrong on a regular
>>>
>>> basis.
>>>>>
>>>>
>>>> I'd suggest combining 3 and 4.  Build a tool that performs a static
>>>
>>> analysis
>>>>
>>>> of a group of files and make it easy for developers to use.  This tool
>>>
>>> would
>>>>
>>>> generate the explicit declarations your codebase would utilize when
>>>> answering such questions as "which classes implement interface foo".
>>>>  The
>>>> file the static analysis tool generates could be easily hand editable,
>>>> so
>>>> developers could tweak it if they see issues (just in case the static
>>>> analysis tool has bugs early on), or for small plugins, just quick crank
>>>
>>> out
>>>>
>>>> a couple lines by hand.
>>>>
>>>> As long as the static analysis tool builds a composite of class
>>>> hierarchy
>>>> established in all the files (project wide, at least in terms of the
>>>> plugin), you wouldn't have to double declare interfaces so they could be
>>>> detected.
>>>>
>>>> Adam
>
> That is essentially #3.  The static analysis results could easily be cached
> in a human-editable form, but in practice I don't think that will be viable.
>  The humans who will be running this system will largely be non-PHP-gurus so
> asking them to validate the accuracy of a giant PHP array dumped to a file
> is going to be a losing battle.  If we're actually building a full graph to
> determine indirect implementation that would then preclude pre-deriving
> information per-plugin and just shipping a manifest file with each plugin.
>  (I could be convinced of that as an approach, but that still doesn't solve
> the indirect implementation problem.)
>
>
>>> There is a pecl extension called inclued [1]&  [2] which could be used I
>>> think.
>>>
>>> It can be used to produce a list of all the relationships between
>>> included files, so a one off pass of all the class files (simply
>>> include them) and then retrieve the analysis from inclued.
>>>
>>> You can now build a class dependency tree from that data and cache it.
>>>
>>> Pretty much exactly what you need.
>>>
>>
>> Richard,
>>
>> While inclued performs a nice analysis of the files included at a given
>> stage of a script, I don't see that it performs a static analysis of the
>> PHP
>> contained within the files so Larry could use it to detect the interfaces
>> implemented in a given set of PHP files.
>>
>> I looked at the pages:
>> http://docs.php.net/manual/en/inclued.examples-implementation.php
>> http://docs.php.net/manual/en/function.inclued-get-data.php
>>
>> I'm curious about this feature myself, so if I missed something, please
>> let
>> me know.
>>
>> Thanks,
>>
>> Adam
>
> Yeah, inclued looks cool but it looks like a runtime analysis tool, not a
> static analysis tool.  That runs into the same problem as reflection where
> I'd have to include the whole code base in order to build up the indexes I
> need.
>
> --Larry Garfield
>
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>
>

You would only need to do analysis by reflection once per release
though? Just like you would do to build your documentation (using
something like phpdoc for example). You _do_ document your code don't
you???



-- 
Richard Quadling
Twitter : EE : Zend
@RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY

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