Allow commit txs with multiple UTxO

[ch1bo]

🔢 Extends the specification and the on-chain protocol to record any number of outputs committed in a commit tx into a Hydra head.

🔢 Changes (and simplifies) multiple call sites from Maybe Commit to [Commit].

🔢 Adds a mutation test where a commit is tried to be left out.

🔢 This theoretically increases the likelihood that some party locks up too many UTxO and makes the head not even abortable (see #699). Practically, this issue already exists with reference scripts and big datums.

🔢 Removes the MoreThanOneUTxOCommitted error as it's not needed anymore.

---

TODO:

• Update the spec / alternative version
  • Requires Open specification with change process #693
  • Do the update
  • Update the commitTx picture (needed?)
• Think about the fact that this makes the head not abortable more likely (see Always abortable Head #699)
  • While it's a bit simpler to shoot yourself in the foot, the risk is already there. Let's not worry and rather fix it with Always abortable Head #699 or so.
• Add/update tests which leverage the fact that there are now more than one committed UTxO (new mutations?)

• CHANGELOG updated
• Documentation updated
• Added and/or updated haddocks
• No new TODOs introduced or explained herafter

[github-actions]

Transactions Costs

Sizes and execution budgets for Hydra protocol transactions. Note that unlisted parameters are currently using arbitrary values and results are not fully deterministic and comparable to previous runs.

Metadata
Generated at	2023-05-26 10:49:57.567607076 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	2212a4ee618434b9b2f366d7c330dbdfb5c7072e793a850fd0de6ddd	4294
νCommit	69e1ccf9ad73dc6d37a5bc8de5aec86f3c4c1710fe5fd334e0e16b18	2124
νHead	8ae095dca4d14a1b8edffb37faa6c84ec60340fbf389a62f027e0b76	9355
μHead	33642a45c7fbb955ce1704ef09229bb211bf9af9980530db28c6aafe*	4148

• The minting policy hash is only usable for comparison. As the script is parameterized, the actual script is unique per Head.

Cost of Init Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	4742	14.66	5.78	0.52
2	4946	14.52	5.63	0.53
3	5149	17.99	6.98	0.57
5	5562	22.24	8.56	0.64
10	6587	35.05	13.43	0.82
37	12128	98.69	37.43	1.75

Cost of Commit Transaction

This is using ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	599	14.98	5.74	0.34
2	787	19.66	7.73	0.40
3	974	24.75	9.88	0.46
5	1350	36.15	14.59	0.61
10	2287	71.73	28.85	1.04
13	2838	98.11	39.18	1.35

Cost of CollectCom Transaction

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	814	27.63	10.73	0.49
2	114	1136	43.67	17.09	0.68
3	171	1457	61.71	24.31	0.89
4	227	1775	82.19	32.54	1.13

Cost of Close Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	639	18.58	8.31	0.39
2	805	19.97	9.56	0.42
3	977	21.37	10.82	0.44
5	1295	24.16	13.33	0.50
10	1471	25.68	11.14	0.50
50	8725	87.17	69.99	1.74

Cost of Contest Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	668	24.77	10.63	0.46
2	841	26.49	12.01	0.49
3	999	28.20	13.38	0.52
5	1343	31.63	16.12	0.58
10	2153	40.20	22.97	0.74
44	7765	98.03	69.37	1.78

Cost of Abort Transaction

Some variation because of random mixture of still initial and already committed outputs.

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	4713	19.19	7.79	0.57
2	5175	36.59	15.53	0.79
3	5355	49.09	20.77	0.93
4	5676	68.40	29.20	1.16
5	6136	95.88	41.39	1.49

Cost of FanOut Transaction

Involves spending head output and burning head tokens. Uses ada-only UTxO for better comparability.

Parties	UTxO	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
5	0	0	4764	8.66	3.57	0.46
5	1	57	4800	10.06	4.39	0.47
5	5	285	4944	15.64	7.69	0.55
5	10	569	5127	22.61	11.82	0.64
5	20	1139	5484	36.56	20.07	0.83
5	30	1710	5846	50.52	28.33	1.02
5	40	2274	6204	64.49	36.60	1.21
5	50	2847	6563	78.46	44.87	1.40
5	65	3697	7099	99.42	57.28	1.68

[github-actions]

Test Results

307 tests   - 11   301 ✔️  - 11   19m 32s ⏱️ +33s
104 suites  -   4       6 💤 ±  0 
    5 files    -   1       0 ❌ ±  0 

Results for commit 3e4eb95. ± Comparison against base commit ed0c22d.

This pull request removes 11 tests.

Hydra.TUI.Options ‑ parses --cardano-signing-key option
Hydra.TUI.Options ‑ parses --connect option
Hydra.TUI.Options ‑ parses --node-socket option
Hydra.TUI.Options ‑ parses --testnet-magic option
Hydra.TUI/end-to-end smoke tests ‑ display feedback long enough
Hydra.TUI/end-to-end smoke tests ‑ doesn't allow multiple initializations
Hydra.TUI/end-to-end smoke tests ‑ starts & renders
Hydra.TUI/end-to-end smoke tests ‑ supports the full Head life cycle
Hydra.TUI/end-to-end smoke tests ‑ supports the init & abort Head life cycle
Hydra.TUI/text rendering errors ‑ should show not enough fuel message and suggestion
…

♻️ This comment has been updated with latest results.

[ffakenz]

This looks very good! 💯

What is left for me is:

• a test to validate now multiple commits are allowed.
• have a mutation to validate if any of the multiple commits is not healthy.
• update api documentation to mention now we support multiple commits.
• maybe explain and mention the limits around this.

Also what is not clear to me is how, from API can I commit multiple UTxO.
Seems the user must provide a big one instead of multiple, is that intended?

[GeorgeFlerovsky]

This PR works well for us at hydra-auction. Very helpful and no issues. 🙏