Re: [Geotools-devel] GCExchange as a singleton

[Jesse E. <je...@re...>]

I like your proposal Martin but I have one concern:  The Readers and 
Writers have been given the responsibility for deciding how to use the 
Source object (This is written in the documentation for the Geotools 
GCExchange interface).  I am thinking that perhaps we can further 
separate the responsibilities. 

For example a reader/writer pair will know how to interpret a byte 
stream from an inputstream and write formatted data to a outputstream.  
A separate IOManager would be responsible for creating an input/output 
stream out of the Source Object.  A DBIOManager might be responsible for 
communication with a Database and a StreamIOManager would be responsible 
for communication with Files or streams. 

The GCExchange would create a Reader/Writer and pass to it the correct 
IOManager.  A GCExchange connected to a Database would pass its 
Readers/Writers an DBIOManager .

Jesse

Martin Desruisseaux wrote:

>My proposal is one singleton by database (exactly like database connection). In the case of file, we could see the whole file system as a kind of database. So there is one singleton for all GridCoverage reading from file or from InputStream.
>
>In other words, lets say:
>
>    ==> One root instance
>
>Point. This singleton is used for reading and writting any kind of GridCoverage from an InputStream / OutputStream, or a filename.
>
>For DataBase, all I propose to do is to create an other implementation of GridCoverageExchange, which is permanently connected to a database. When invoking getReader(source), it just gets the InputStream for this source from the database and pass it to the root GridCoverageExchange. That should be a easy to implement.
>
>    Martin.
>
>  
>