🎯 Cadence VM (execution environment) goals - Q1 2025

[j1010001]

Previous goal tracker: #6577

### Planned
- [ ] https://github.com/onflow/flow-go/issues/6897
- [ ] https://github.com/onflow/flow-evm-gateway/issues/700
- [ ] https://github.com/onflow/flow-go/issues/6887
- [ ] https://github.com/onflow/flow-go/issues/6558
- [ ] https://github.com/onflow/flow-execution-effort-estimation/issues/9
- [ ] https://github.com/onflow/flow-go/issues/5598
- [ ] https://github.com/onflow/flow-go/issues/6938
- [ ] https://github.com/onflow/flow-go/issues/6973

### Stretch goals
- [ ] https://github.com/onflow/flow-go/issues/6895
- [ ] https://github.com/onflow/atree/issues/341
- [ ] #6788
- [ ] https://github.com/onflow/atree/issues/443
- [ ] https://github.com/onflow/flow-go/issues/6628
- [ ] https://github.com/onflow/flow-go/issues/6959

### Unplanned work
- [ ] https://github.com/onflow/cadence-internal/issues/286
- [ ] https://github.com/onflow/flow-go/issues/6928
- [x] Add features, smoke test, and release Atree v0.9.0 (+8360 lines of code)
- [ ] Leo - Review dapper's NBA topshot solidity contract which will be deployed to Flow EVM
- [ ] https://github.com/onflow/flow-go/issues/7221

[fxamacker]

I added atree v0.9.0 to unplanned work because it required +8360 lines of code, weeks of testing, and it isn't mentioned in sprint kickoffs or release notes of packages using it (as of Feb 11).

@j1010001 as raised in our Thursday Jan 23 meeting, this was a part of higher priority unplanned work.
From Dec 20 to Jan 22:

• ~30 days (worked on weekends too) for unplanned higher priority work
• ~2 days for my OKRs (New Trie Research, Atree Refactoring)
• 2 days off (postponed approved end-of-year time off, not taken yet as of Feb 11)

Higher priority work in private repos: I examined and reviewed thousands of lines of code in a repo where I'm not a codeowner, debugged+identified+fixed security bug, contributed ~9500 lines of code that got ported to 2 public repos, helped improve integration tests, ran 40+ smoke tests to reduce risk of regressions, etc.

Non-urgent PR reviews for teammates were also affected by this unplanned higher priority work.

[zhangchiqing]

I was asked to review NBA topshot solidity contract which will be deployed to Flow EVM

https://flow-foundation.slack.com/archives/C07HCF7M6UR/p1739294310155879

[fxamacker]

I completed an approved OKR-Q1 task that isn't listed here and it also isn't listed at Cadence Language Goals.

• CCF Specification Release (OKR-Q1)

CCF 1.0.0 specification released on March 31, 2025 (release notes).

CCF is a binary data format defined in ccf_specs.md at onflow/ccf.

BTW, CCF README summarizes CCF specs and highlights a useful tip: CCF-based protocols can specify using CBOR Sequences (RFC 8742) to have the first data item contain metadata (e.g., version number and data item count).

[fxamacker]

Added #7221 to unplanned list here (it started on March 18 as onflow/atree#539). It will fix build issues for external projects (e.g., reported by Anchorage Digital) that depend on newer version of fxamacker/cbor than we're using at onflow.

Code changes are mostly at fxamacker/cbor feature/stream-mode branch. So changes to each onflow repo can be tiny:

• PR onflow/atree#542 bump to latest branch v2.4-> v2.8 (+3 -3)
  • PR fxamacker/cbor#640 update branch v2.4->v2.7 (+15,260 −4,371)
  • PR fxamacker/cbor#650 update branch v2.7->v2.8 (+2,328 −952)

We need to update several onflow repos and run various tests before merging the version bump to main branches. Some repos may need tests not mentioned at atree (e.g., backward compatibility test for network messages).

Until we upgrade, additional external projects may run into build issues. By upgrading, we will also gain bug fixes, optimizations, features, etc. in fxamacker/cbor v2.5-v2.8.

NOTE: Except for the stream-mode branch, all the implementation and PR reviews for fxamacker/cbor v2.5-v2.8 were done during weekends and holidays because of higher priority work during weekdays.