Ankr specific timestamp reader

[miohtama]

Block timestamps are needed for mass event ingestion with eth_getLogs. We need to map block number -> timestamp.

Currently we offer two ways to do it

• extract_timestamp_json_rpc - the naive method
  • Calls eth_getBlockByNumber for the range of all blocks (start, end) we need to get events from
  • Very slow, because to read just one uint64 timestamp avg. eth_getBlockByNumber returns 8 MB data and we often need to read 100 - 1,000 blocks once
  • Also often breaks QuickNode, because their API throttling limits is low
  • However it works on any EVM node
• GraphQL-based timestamp reading
  • Reads all timestamps for a block range in a single call... you can get 1,000s of timestamps with a single API request
  • Uses GoEthereum standard /grapql endpoint
  • Best for in-house hosted nodes
  • Does not work with any commercial SaaS node provider because they do not support /graphql

To be able to have commercial SaaS node providers as a fallback option for JSON-RPC, we need to be able to read block timestamps so that their nodes do not complain.

• Commercial SaaS vendors provide their incompatible proprietary APIs for tasks like reading multiple block headers
• This is exactly like of proprietary low-quality APIs you can think of

As first commercial SaaS vendor to pilot out we'd like to try Ankr
- ank_getBlocks proprietary API can read blocks in batch up to 20 blocks at a time
- Ankr claims to support up to API 1500 request/minute
- Ankr offer pay-as-you-go plan so it is easy get started with them

For the task

• Create reader/ankr.py module
• Create extract_timestamps_ankr_get_block method
• Create has_ankr_support method in eth_defi.chain
• Create AnkrReorganisationMonitor that is similar to GraphQLReorganisationMonitor - using the underlying extract_timestamps_ankr_get_block
• Add a compatibility check in create_reorganisation_monitor that will automatically create AnkrReorganisationMonitor if we are connected to Ankr node
• Create an integration test that take JSON_RPC_ANKR_PRIVATE as the environment variable input to test these against a live Ankr plan
  • See TVL tests for inspiration
  • See also test_chain

[AlexTheLion123]

Closed due to no longer working with Ankr