Feature request - Fetch code_hash without the entire ABI

[nsjames]

Some ABIs are massive ( system for instance is 1.3mb ) and take a good 1-3 seconds to fetch.
If there was a way to fetch only the hash of the contract without the rest of the ABI it would allow signature providers a way to cache ABIs locally and only re-cache if the code hash changes.

eosjs doesn't propagate the code abi to the signature provider so it has to be double fetched ( once for eosjs and once for the signature app ) to parse data and retrieve ricardian contracts which adds between 2 - 6 seconds per contract from the moment a user clicks a button to sign to the time the transaction parameters + ricardians can be displayed to them.

[nsjames]

[nsjames]

Actually seeing as how getting only the hash is supported in cleos, I'm moving this ticket to eosjs itself for support there.

EOSIO/eosjs#206

[nsjames]

Reopening as it seems the RPC doesn't have an option for code_hash only
https://github.com/EOSIO/eos/blob/master/plugins/chain_plugin/chain_plugin.cpp#L952

[jcalfee]

Did you see this: #566

Looks like get_abi was added about 2 weeks ago.. so that will help greatly. I was foced to fetch code and the ABI at the same time. I'll update to use get_abi on this ticket.

It will not tell me if it was modified though so I will have to keep re-fetching..

[nsjames]

Yeah I saw that one last night too, which is massively faster than get_code, but doesn't include the hash :(

[jcalfee]

I suggest adding abi_hash:

   fc::sha256 abi_hash;

Then add optional<abi_hash> abi_hash to get_abi's parameters and result:

   struct get_abi_params {
      name account_name;
      optional<abi_hash> abi_hash;
   };

   struct get_abi_results {
      name                   account_name;
      optional<abi_def>      abi;
      optional<abi_hash>     abi_hash;
   };

• The abi_hash is the sha256 hash of the binary abi_def serialization
• If an ABI exists for the account its hash is always returned.
• If a hash was provided in the request and it matches the current ABI, the ABI hash is returned but the abi is not.
• If a hash was provided in the request and the ABI does not exist (was probably removed) neither hash nor ABI are returned.

[taokayan]

Can you get it once then store the result somewhere else? As code and abi are not frequently changed?

[nsjames]

@tbfleming

[ScottSallinen]

For getting just the code hash, see this PR:
#5434

[jcalfee]

Great .. I'll have it in eosjs for the next release.

[tbfleming]

@jcalfee I added your abi_hash caching idea to #5375's get_raw_abi

[jgiszczak]

The get_code_hash API has been available since the v1.3.0 release on 2018 September 18.