fix: generated a custom key for the cache in blocks endpoint

[Imod7]

Issue

When we request a block in Sidecar with a query param set to a specific value, e.g. :
/blocks/1820744?extrinsicDocs=false : return block and show the docs in each extrinsic
and right away I request again the same block but now with the query param set to a different value, e.g. :
/blocks/1820744?extrinsicDocs=true : return block and do not show the docs in each extrinsic

the response is not updated so it still doesn't show me the docs in each extrinsic.

Root Cause

This happens because of how we cache the response. Wen we cache the block here we set the key in the cache "array" equal to the block hash. So when we request again the same block it will only check here if it finds this block hash and it will ignore the different query params. It will then find that this block was requested before and it will return the saved response. The problem is that this saved response has extrinsicDocs false so it will still not show me the docs.

Proposed Solution

Create a key that is a combination of the block hash (request param) and the query params of the request. This key will then be used to save/retrieve responses to/from the cache.

• The query params values were concatenated as 0 or 1s (since they are boolean indicating false or truevalues).

• For the generation of the key, only the query params

  • eventDocs
  • extrinsicDocs
  • checkFinalized,
  • noFees

  are used since those are the ones that can be changed by the user. The options queryFinalizedHead and omitFinalizedTag are not included since they depend on the params set above.

Testing

This solution was tested while running sidecar connected to Polkadot. For example, the requested block :

• http://127.0.0.1:8080/blocks/1820747?extrinsicDocs=false&eventDocs=true
  is updated when changing the query param extrinsicDocs and eventDocs to different boolean values.

[TarikGul]

LGTM great job!

[bee344]

Cool addition :)