Compression in a REST Web services client

Send and receive compressed requests from a REST Web services client.

When you create a low-level Web service and do not have any stubs created by fglrestful, you need to manage it by setting the HTTP headers.

Send a compressed request

The method used to set up the client for sending a compressed request depends on whether the Genero Web Services client is a high-level or low-level Web services client. A high-level client is a Genero Web services client using the GWS REST high-level framework that includes the stub files created by the fglrestful tool. A low-level client is a Genero Web services client that does not utilize stub files created by the fglrestful tool.

Regardless of the type of client, the server must be set up to handle such compression; otherwise, the request will be rejected.

Send a compressed request from a high-level client

In the stub file, an Endpoint variable of type tGlobalEndpointType is defined as public.

Set the variable Binding.CompressRequest to either "gzip" or "deflate".

LET clientStub.Endpoint.Binding.CompressRequest = "gzip"

The Binding.CompressRequest variable is defined in the stub file.

TYPE tGlobalEndpointType RECORD # REST Endpoint
      Address RECORD 
         Uri STRING 
      END RECORD,
      Binding RECORD 
         Version STRING, # HTTP Version (1.0 or 1.1)
         ConnectionTimeout INTEGER,
         ReadWriteTimeout INTEGER, 
         CompressRequest STRING 
      END RECORD
END RECORD

Send a compressed request from a low-level client

Set the Content-Encoding field in the request header to either "gzip" or "deflate".

This example sets the Content-Encoding field to "gzip", where the request is a com.HttpRequest object.

CALL request.setHeader("Content-Encoding","gzip")

Accept a compressed response

A Genero Web services client can accept a compressed request if it sets the Accept-Encoding field in the header to "gzip, deflate". These values represent supported compression schema names (called content-coding tokens) separated by commas.

This example sets the Accept-Encoding field with the setHeader method, where the request is a com.HttpRequest object.

CALL request.setHeader("Accept-Encoding","gzip, deflate")