Question

I built a DataSnap server with Delphi XE2 that implements TDSHTTPService. When the inbound request comes in, TIdIOHandler.InitComponent is called in a thread before execution is handed to the method called in TServerMethods. I do not have any Indy components in the server, so DataSnap is using Indy 10 under-the-hood.

.InitComponent() sets the IO handler’s max line length to a hard-coded value (FMaxLineLength := IdMaxLineLengthDefault;), which is 16384. I can’t find a way to increase the value. I even tried copying the IdIOHandler Unit to the project folder and changing the constant value. But it still picks up the IdIOHandler.dcu from the Indy 10 build, and ignores the copied file in my project folder. I also tried adding a TIdIOHandlerStream component to the server project and setting its MaxLineLength to no avail.

• Plan A = Properly set the MaxLineLength value in the DataSnap server.
• Plan B = Somehow compile a modified IdIOHandler.pas file into my project.

Are either of these possible? I’ve been working on this for hours and can’t find anything similar in all my searching, and can’t seem to make any headway by experimenting.

Answer 1

Short of removing the Delphi XE2 install of Indy 10 and downloading the source, tweaking the constant values and compiling / maintaining my own build forever going forward…, I solve the issue.

I created an additional method in the DataSnap server so that I could create a record in the database with a call to the first method, and then incrementally stream the rest of the data by passing it to the second method 16k at a time — buffering it in the DataSnap server until all parts are received. Then I update the record in the database with the fully buffered value from the DataSnap server.

Maybe not the most effective solution, but it works and it will scale as needed.