Implement evictions

[JoshOrndorff]

Solves #98. Second try at evictions after #52.

"Normally" UTXOs are consumed in a process called "redemption" where the transacting user supplies some kind of signature or other proof that satisfies the UTXO's Verifier. An eviction is a (new alternative) way to forcefully consume input data without satisfying the verifier. In some usecases this is desirable. For example incentivizing cleaning up old state. Or to make governance decisions enforceable.

Implementation

The changes revolve around this new enum:

/// An input can be consumed in two way. It can be redeemed normally (probably with some signature, or proof) or it 
/// can be evicted. This enum is isomorphic to `Option<Vec<u8>>` but has more meaningful names.
#[derive(Serialize, Deserialize, Encode, Decode, Debug, PartialEq, Eq, Clone, TypeInfo)]
pub enum RedemptionStrategy {
    /// The input is being consumed in the normal way with a signature or other proof provided by the spender.
    Redemption(Vec<u8>),
    /// The input is being forcefully evicted without satisfying its Verifier.
    Eviction,
}

This does not mean that any transaction can evict arbitrary storage. The ConstraintChecker will be informed about which inputs were evicted and it will enforce that evictions are only allowed in specific contexts (such as removing old votes after an election has been tallied).

Relationship with Peeks

Currently (both before and after this PR) all peeks are evictions. Peeks are evictions in the sense that anyone can peek at any data without needing to satisfy its verifier.

Now that I am focusing on evictions, it is clear that there are cases where it would be nice to require a redemption to peek at a UTXO. For example, this would make #186 much more parallelizable. I'll make a followup issue for this, but I don't see it as priority for now.

Must my Chain Allow Evictions?

No. In some chains, especially those serving communities strongly value property rights, evictions may never be desirable, and that is totally fine. It is straightforward to build a Tuxedo chain that has no eviction paths. But as a framework Tuxedo also supports chains that want to support evictions

[github-actions[bot]]

Coverage after merging joshy-evictions into main will be

61.56%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
tuxedo-core/aggregator/src
lib.rs	99.14%	100%	100%	99.11%	201, 22, 84
tuxedo-core/no_bound/src
clone_no_bound.rs	36.63%	100%	30%	37.36%	24, 32–39, 56, 59–72, 74–87, 89, 91–95, 98–99
debug_no_bound.rs	32.73%	100%	30%	33%	101–105, 108–109, 24, 32–42, 58, 60–78, 80–95, 97–99
default_no_bound.rs	19.11%	100%	16.67%	19.31%	100–122, 124–131, 133, 136–147, 151–157, 32–39, 51, 54–80, 83–88, 91–99
lib.rs	100%	100%	100%	100%
tuxedo-core/src
constraint_checker.rs	47.71%	100%	47.83%	47.67%	118–126, 132–137, 139–148, 150, 198–202, 205–210, 213–214
dynamic_typing.rs	83.33%	100%	70.59%	88.37%
executive.rs	92.17%	100%	93.60%	92%	127, 153, 193, 225, 254, 265, 316, 343, 394–399, 401, 411–412, 417–418, 420, 423–424, 427, 429–430, 433–434, 436, 440–461, 463, 467–468, 470–471, 473, 476–493, 55, 98
genesis.rs	43.69%	100%	42.86%	43.75%	102–103, 106, 158–160, 169, 36–49, 60, 62–65, 67–68, 70–72, 75–79, 81–83, 85–96, 98–99
inherents.rs	17.11%	100%	25%	15.63%	122–124, 151–158, 165–179, 185–203, 205–235, 56–58, 65–70, 72–80, 83, 85
types.rs	59.11%	100%	42.86%	65.43%	158, 160, 200–205, 82–86, 88–91, 93–99
utxo_set.rs	90.91%	100%	100%	88.89%	39–40
verifier.rs	42.86%	100%	32.50%	48.61%	106–108, 43–44, 46, 48–49, 54, 71, 78–80, 82–84
tuxedo-core/src/verifier
htlc.rs	77.96%	100%	44.93%	85.71%	107, 109, 115, 40, 42, 55, 57, 74–78, 91
multi_signature.rs	87.50%	100%	68.29%	91.16%	100–105, 45, 71
simple_signature.rs	76.87%	100%	58.33%	82.88%	65, 67, 78–82
tuxedo-parachain-core/register_validate_block/src
lib.rs	0%	100%	0%	0%	100–119, 12, 120–125, 128, 13, 130–131, 14–16, 18, 29–35, 38–46, 50, 54–56, 59–61, 64–66, 84–99
tuxedo-parachain-core/src
collation_api.rs	0%	100%	0%	0%	19–40
lib.rs	48.65%	100%	53.85%	45.83%	85–90, 94–96
relay_state_snapshot.rs	0%	100%	0%	0%	112, 128–140, 147–155, 157, 173–188, 193–202, 204–211, 223, 225, 227–233, 235–240, 242, 245–250, 252–257, 259–271, 274–286, 292–298, 303–310, 316–323, 330–337, 346–354, 362–370, 378–383, 389–394, 41, 54, 82
tests.rs	100%	100%	100%	100%
tuxedo-template-runtime/src
genesis.rs	84.81%	100%	88.89%	84.56%	23–45
lib.rs	5.87%	100%	14.63%	3.67%	100–104, 130, 135–137, 141–143, 205, 207, 209, 211, 213, 215, 217, 219, 222, 224, 227, 233, 242–249, 254, 263–284, 287–314, 317–436, 63–68, 99
wallet/src
amoeba.rs	0%	100%	0%	0%	100–106, 109–110, 112–118, 120–127, 19–48, 51–52, 54–99
cli.rs	0%	100%	0%	0%	100, 115, 119, 125, 128, 133, 144, 150, 17, 20, 22, 31, 36, 41, 48, 65, 77
keystore.rs	0%	100%	0%	0%	30–33, 38–45, 47–48, 51, 53–59, 65–73, 76–78, 80–82, 85–91, 93–94
main.rs	0%	100%	0%	0%	100–193, 196–203, 206–209, 211–213, 216–218, 220, 222, 225–231, 234–247, 250–253, 255–266, 268, 27–99
money.rs	0%	100%	0%	0%	100, 106–113, 115, 119–124, 128, 131, 133, 136–139, 141–142, 146, 150–153, 155, 160–166, 168–172, 175–176, 180–185, 187–188, 191–202, 204, 206, 22–23, 25–40, 43, 47–60, 63–69, 72–90, 94–99
output_filter.rs	100%	100%	100%	100%
rpc.rs	0%	100%	0%	0%	16–21, 24–26, 28–44, 47–53, 55–58, 60–61
sync.rs	0%	100%	0%	0%	103–106, 113–114, 116, 119–122, 127–129, 132–133, 136–141, 143–145, 148, 150–151, 156–159, 162–163, 170–174, 176–182, 185–187, 189–190, 193–194, 199–202, 205, 207–208, 213–216, 219, 221–222, 225–231, 233–234, 237–238, 241–242, 245–246, 250–256, 259–263, 266, 268, 271, 273, 277, 279–280, 283–284, 287–294, 296–297, 300–301, 303, 305–306, 310–312, 314–315, 317–318, 320–321, 324–326, 328–329, 331–332, 334–335, 339, 341–342, 346, 348–353, 356–357, 360–362, 365, 368–371, 373, 376–379, 382, 385–386, 389–390, 395–400, 402, 404, 409–412, 415–416, 419–424, 426, 429–430, 434–435, 437, 439–441, 443–446, 449–450, 46–50, 54, 57–58, 61, 63–77, 82–86, 88–89, 94–99
timestamp.rs	0%	100%	0%	0%	12–17, 20–27
wardrobe/amoeba/src
lib.rs	60.49%	100%	26.83%	71.90%	130, 148, 164, 194, 210, 83, 99
tests.rs	100%	100%	100%	100%
wardrobe/kitties/src
lib.rs	47.80%	100%	26.52%	57.19%	100, 102–103, 107–109, 117–119, 121–123, 127–129, 133–134, 137&nda © Githubissues. Githubissues is a development platform for aggregating issues.