Check that value is preserved in v_head

[v0d1ch]

Why

According to spec 5.5. rule 6 -> value is preserved there should be a validator check to make sure the head value is preserved. Note that checkAbort and checkFanout head transitions should not contain this check.

To check before merging:

• CHANGELOG is up to date
• Up to date with master

[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	2023-02-07 11:10:50.113544442 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	6e4ce2bd32260424babefe087c2a5ee0a414745fe0281d5608ae9bf8	5530
νCommit	03f2e29fd352f8c2961ad2f61d87a48f88bf01ea6c079b46a3184aee	2547
νHead	ee7104256459ac3b45f71a12cdad0156f78385b3fbf7afc64e38620b	9993

Cost of Init Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5017	10.77	4.27	0.49
2	5221	11.84	4.66	0.51
3	5427	14.16	5.56	0.54
5	5835	17.69	6.91	0.60
10	6861	28.99	11.30	0.77
45	14038	99.30	38.42	1.85

Cost of Commit Transaction

Currently only one UTxO per commit allowed (this is about to change soon)

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	630	21.10	8.53	0.41

Cost of CollectCom Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	13346	23.17	9.24	0.99
2	13697	38.77	15.61	1.18
3	14051	57.21	23.21	1.40
4	14331	76.79	31.33	1.63

Cost of Close Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	10590	17.97	6.95	0.81
2	10755	20.56	8.05	0.85
3	10921	22.77	9.00	0.88
5	11284	30.35	12.05	0.98
10	12148	52.00	20.66	1.25
19	13593	95.50	37.87	1.79

Cost of Contest Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	10618	18.59	7.16	0.82
2	10815	23.08	8.94	0.88
3	10949	23.69	9.33	0.89
5	11271	29.07	11.59	0.96
10	12139	50.08	19.98	1.23
19	13621	95.36	37.81	1.79

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	15122	28.55	12.06	1.13
2	15549	48.21	20.70	1.37
3	15547	60.18	25.56	1.50
4	15800	83.09	35.61	1.77
5	15592	95.37	40.58	1.90

Cost of FanOut Transaction

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

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	14873	10.65	4.61	0.92
2	14974	12.55	5.64	0.95
3	15077	14.20	6.57	0.98
5	15011	16.49	8.03	1.00
10	15326	24.87	12.73	1.12
20	15490	38.98	21.09	1.30
44	16355	75.59	42.24	1.79

[github-actions]

Test Results

274 tests   - 11   268 ✔️  - 11   11m 45s ⏱️ - 2m 23s
  93 suites  -   4       6 💤 ±  0 
    4 files    -   1       0 ❌ ±  0 

Results for commit 0ce2b93. ± Comparison against base commit 829332b.

This pull request removes 11 tests.

Hydra.TUI.Options ‑ parses --cardano-signing-key option
Hydra.TUI.Options ‑ parses --connect option
Hydra.TUI.Options ‑ parses --network-id option
Hydra.TUI.Options ‑ parses --node-socket 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.

[ch1bo]

Changes look good, but what happened to the close and contest benchmarks? Only 10 parties there is a bit odd..

[ch1bo]

Benchmarks show 45, but there might be some delta between the generators used in tx-cost and these tests here. It's fine to only bump it to 39, although we could try higher numbers to test the limits more often.

[ch1bo]

Now as we know why the close/contest is much smaller I can approve.