Move content previewing and encoding/decoding service to server/service option

[ikhoon]

Content previewing was implemented as a decorator to record the uncompressed content in conjunction with DecodingSevice and EncodingService. However, this approach may fail to capture the actual response sent over the wire. For example, a response generated by ServerErrorHandler cannot be previewed. Also, if a response is changed after ContentPreviewingService, the updated content is not reflected in RequestLog.responseContentPreview().

To address the limitation, we may need to configure ContentPreviewingFactory through server/service options (instead of using ContentPreviwingService) and record the previews internally at the Armeria transport layer. To recode decoded content consistently, compression/ decompression should also be configured via server/service options so that previewing happens after decompression and before compression.

decode request -> decompression -> content preview -> request decorators -> service -> 
response decorators -> server error handler -> content preview -> compression -> write response

API proposal:

// Migrate EncodingServiceBuilder into CompressionBuilder
Compression compression =
  Compression
     .builder()
     .encoderFactories(...)
     .encodableContentTypes(...)
     ...
     .build();
     
Server
  .builder()
  // Enabled by default
  .decompress(streamDecoderFactories)
  // 
  .compress(compression);
  .contentPreview(contentPreviewerFactory)
  .route().get("/get")
          // Apply response compression at the service level
          .compress(...)

[paka-jo]

Can I take this issue?

[ikhoon]

Unfortunately, I don't think it is a good issue for new contributors, as it touches a lot of internal core logic. Would you mind taking look at other issues?

[paka-jo]

Thanks for the guidance. I will look for other issues