Make direct indexing mode configurable over RPC

[i-norden]

Make it possible to change which contracts/accounts we restrict statediffing to over RPC when doing direct indexing

[ashwinphatak]

Notes from discussion:

• API to Add/Append, Remove/Delete, Set, Clear watched addresses
• New table in ipld-eth-db to store watched addresses and status
• Handling uniswap like scenarios where Pool has events in the same block where it got created:
  • Watcher calls ipld-eth-server with contract address + creation block hash, which proxies the call to vulcanize/geth
  • vulcanize/geth starts watching the contract at current block hash
  • ipld-eth-server kicks off / tracks till completion the statediffing (eth_writeStateDiff) for missed blocks from (creation till addition), calling upstream process (vulcanize/geth for now, but eth-statediff-service cluster in the future)

[prathamesh0]

Tasks:

vulcanize-geth:

• An API to change watched addresses
• Use a map for watched addresses and pre-compute their hashes
• Tests

ipld-eth-db:

• Migration for a table that stores watched addresses
• Add column(s) to track watched address gap filling status
• Move the watched addresses table to a different schema
• Update UML
• Changes in pre- and post- migration sets
• Migrations should check and apply correct user permissions ipld-eth-db#42

ipld-eth-server:

• An API that proxies the call to change watched addresses to geth
• A service to fill indexing gap for watched addresses
• Tests:
  • API tests
  • Service tests

[ashwinphatak]

Changes:

• Remove slot based watching/params etc for current impl. Only watching of addresses will be supported. Implicitly, we watch all storage slots for an address.
• Goal: Make getStorageAt work for watched contracts

[prathamesh0]

The service to fill indexing gap for watched addresses has been extracted to a separate repository.

[i-norden]

Tracking remaining tasks separately: cerc-io/ipld-eth-db#81 cerc-io/ipld-eth-db#42