MapGuide RFC 73 - Batch processing of layers ¶

This page contains an change request (RFC) for the MapGuide Open Source project. More MapGuide RFCs can be found on the RFCs page.

Status ¶

RFC Template Version	(1.0)
Submission Date	(July 7, 2009)
Last Modified	(Christine Bao Tue July 7 02:22:17 2009)
Author	Christine Bao
RFC Status	adopted
Implementation Status	completed
Proposed Milestone	2.2
Assigned PSC guide(s)	Tom Fukushima
Voting History
+1	Tom, Kenneth, Paul, Trevor, Bruce
+0
-0
-1
no vote	Jason, Harris, Bob, Andy

Overview ¶

This RFC improves performance by getting batch layers in one request, instead of each layer in one request.

Motivation ¶

Currently MgMap is created on Web Extension side, and for each layer of this map it sends a request to get the resource content. This causes a lot of requests send to server again and again. To improve performance MgMap should get the layers in a single request, and use the batch processing result to create layer models. The more layers a map has, the better performance improvement is achieved.

Proposed Solution ¶

The possible solutions could be:

1. Add a new API of ResourceService to get a batch of resource contents for a collection of resource identifiers
   

PUBLISHED_API:
    ///////////////////////////////////////////////////////////////////////////
    /// \brief
    /// Gets the contents of the specified resources.
    ///
    /// \param resources
    /// Resource identifiers describing the resources.
    /// \param preProcessTags
    /// Pre-processing to apply to resource before returning content.  An empty
    /// string indicate no pre-processing. See MgResourcePreProcessingType for
    /// a list of supported pre-processing tags.
    ///
    /// \return
    /// MgStringCollection object representing the corresponding resource contents.
    ///
    /// \exception MgInvalidRepositoryTypeException
    /// \exception MgInvalidRepositoryNameException
    /// \exception MgInvalidResourcePathException
    /// \exception MgInvalidResourceNameException
    /// \exception MgInvalidResourceTypeException
    ///
    virtual MgStringCollection* GetResourceContents(MgStringCollection* resources,
        MgStringCollection* preProcessTags) = 0;

2. MgMap doesn't request the resource content of layers one by one, instead it forms a collection of layer resource ids, and use the new API to get a collection of layer definitions.

Implications ¶

This is new API only. There are no effects on existing applications. However, API documentation need to be updated.

Test Plan ¶

Test both Ajax viewer and Fusion viewer.

Funding/Resources ¶

Supplied by Autodesk.

Addendum ¶

Another APIs are added into MgLayerBase.

INTERNAL_API:
    //////////////////////////////////////////////////////////////////
    /// \brief
    /// Gets the layer's resource content.
    ///
    virtual STRING GetLayerResourceContent();

    //////////////////////////////////////////////////////////////////
    /// \brief
    /// Sets the resource content for this layer.
    ///
    virtual void SetLayerResourceContent(CREFSTRING resourceContent);