feat(fast-usdc): deposit, withdraw liquidity in exchange for shares #10400
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,239 @@ | ||
| import { | ||
| AmountMath, | ||
| AmountShape, | ||
| PaymentShape, | ||
| RatioShape, | ||
| } from '@agoric/ertp'; | ||
| import { | ||
| makeRecorderTopic, | ||
| TopicsRecordShape, | ||
| } from '@agoric/zoe/src/contractSupport/topics.js'; | ||
| import { depositToSeat } from '@agoric/zoe/src/contractSupport/zoeHelpers.js'; | ||
| import { SeatShape } from '@agoric/zoe/src/typeGuards.js'; | ||
| import { M } from '@endo/patterns'; | ||
| import { Fail, q } from '@endo/errors'; | ||
| import { | ||
| depositCalc, | ||
| makeParity, | ||
| withdrawCalc, | ||
| withFees, | ||
| } from '../pool-share-math.js'; | ||
| import { makeProposalShapes } from '../type-guards.js'; | ||
|
|
||
| /** | ||
| * @import {Zone} from '@agoric/zone'; | ||
| * @import {Remote, TypedPattern} from '@agoric/internal' | ||
| * @import {StorageNode} from '@agoric/internal/src/lib-chainStorage.js' | ||
| * @import {MakeRecorderKit, RecorderKit} from '@agoric/zoe/src/contractSupport/recorder.js' | ||
| * @import {USDCProposalShapes, ShareWorth} from '../pool-share-math.js' | ||
| */ | ||
|
|
||
| const { add, isEqual } = AmountMath; | ||
|
|
||
| /** @param {Brand} brand */ | ||
| const makeDust = brand => AmountMath.make(brand, 1n); | ||
|
|
||
| /** | ||
| * Use of pool-share-math in offer handlers below assumes that | ||
| * the pool balance represented by the USDC allocation in poolSeat | ||
| * is the same as the pool balance represented by the numerator | ||
| * of shareWorth. | ||
| * | ||
| * Well, almost: they're the same modulo the dust used | ||
| * to initialize shareWorth with a non-zero denominator. | ||
| * | ||
| * @param {ZCFSeat} poolSeat | ||
| * @param {ShareWorth} shareWorth | ||
| * @param {Brand} USDC | ||
| */ | ||
| const checkPoolBalance = (poolSeat, shareWorth, USDC) => { | ||
| const available = poolSeat.getAmountAllocated('USDC', USDC); | ||
| const dust = makeDust(USDC); | ||
| isEqual(add(available, dust), shareWorth.numerator) || | ||
| Fail`🚨 pool balance ${q(available)} inconsistent with shareWorth ${q(shareWorth)}`; | ||
| }; | ||
|
|
||
| /** | ||
| * @param {Zone} zone | ||
| * @param {ZCF} zcf | ||
| * @param {Brand<'nat'>} USDC | ||
| * @param {{ | ||
| * makeRecorderKit: MakeRecorderKit; | ||
| * }} tools | ||
| */ | ||
| export const prepareLiquidityPoolKit = (zone, zcf, USDC, tools) => { | ||
| return zone.exoClassKit( | ||
| 'Liquidity Pool', | ||
| { | ||
| feeSink: M.interface('feeSink', { | ||
| receive: M.call(AmountShape, PaymentShape).returns(M.promise()), | ||
| }), | ||
| external: M.interface('external', { | ||
| publishShareWorth: M.call().returns(), | ||
| }), | ||
| depositHandler: M.interface('depositHandler', { | ||
| handle: M.call(SeatShape, M.any()).returns(M.promise()), | ||
| }), | ||
| withdrawHandler: M.interface('withdrawHandler', { | ||
| handle: M.call(SeatShape, M.any()).returns(M.promise()), | ||
| }), | ||
| public: M.interface('public', { | ||
| makeDepositInvitation: M.call().returns(M.promise()), | ||
| makeWithdrawInvitation: M.call().returns(M.promise()), | ||
| getPublicTopics: M.call().returns(TopicsRecordShape), | ||
| }), | ||
| }, | ||
| /** | ||
| * @param {ZCFMint<'nat'>} shareMint | ||
| * @param {Remote<StorageNode>} node | ||
| */ | ||
| (shareMint, node) => { | ||
turadg marked this conversation as resolved.
Show resolved
Hide resolved
|
||
| const { brand: PoolShares } = shareMint.getIssuerRecord(); | ||
|
There was a problem hiding this comment. nit: should we call it There was a problem hiding this comment. hardly a nit! the keys of I'll follow up with product. There was a problem hiding this comment. I suppose the name here is local to this contract. But I'm also working on the core-eval (#10301), which will put a name in There was a problem hiding this comment.
Here's the current list of brands in agoricNames, I think the abbreviations are generally for vbank brands. Using the more verbose style would be appropriate here, in part to convey it's not a vbank brand. There was a problem hiding this comment. not a vbank brand? why not? we don't want folks sending it over IBC to trade on the open market for some reason? There was a problem hiding this comment. I think we punted on it being a vbank brand, but with the option to make it one later. That suggests that the name be amenable to vbank. But ay you also point out, it's easy to change later. We can defer to milestone 3: #10432 |
||
| const proposalShapes = makeProposalShapes({ USDC, PoolShares }); | ||
| const shareWorth = makeParity(makeDust(USDC), PoolShares); | ||
| const { zcfSeat: poolSeat } = zcf.makeEmptySeatKit(); | ||
| const shareWorthRecorderKit = tools.makeRecorderKit(node, RatioShape); | ||
| return { | ||
| shareMint, | ||
| shareWorth, | ||
| poolSeat, | ||
| PoolShares, | ||
| proposalShapes, | ||
| shareWorthRecorderKit, | ||
| }; | ||
| }, | ||
| { | ||
| feeSink: { | ||
| /** | ||
| * @param {Amount<'nat'>} amount | ||
| * @param {Payment<'nat'>} payment | ||
| */ | ||
| async receive(amount, payment) { | ||
| const { poolSeat, shareWorth } = this.state; | ||
| const { external } = this.facets; | ||
| await depositToSeat( | ||
| zcf, | ||
| poolSeat, | ||
| harden({ USDC: amount }), | ||
| harden({ USDC: payment }), | ||
| ); | ||
| this.state.shareWorth = withFees(shareWorth, amount); | ||
| external.publishShareWorth(); | ||
| }, | ||
| }, | ||
|
|
||
| external: { | ||
| publishShareWorth() { | ||
| const { shareWorth } = this.state; | ||
| const { recorder } = this.state.shareWorthRecorderKit; | ||
| // Consumers of this .write() are off-chain / outside the VM. | ||
|
|
||
| // And there's no way to recover from a failed write. | ||
| // So don't await. | ||
| void recorder.write(shareWorth); | ||
| }, | ||
| }, | ||
|
|
||
| depositHandler: { | ||
| /** @param {ZCFSeat} lp */ | ||
| async handle(lp) { | ||
| const { shareWorth, shareMint, poolSeat } = this.state; | ||
| const { external } = this.facets; | ||
|
|
||
| /** @type {USDCProposalShapes['deposit']} */ | ||
| // @ts-expect-error ensured by proposalShape | ||
| const proposal = lp.getProposal(); | ||
| checkPoolBalance(poolSeat, shareWorth, USDC); | ||
| const post = depositCalc(shareWorth, proposal); | ||
|
|
||
| // COMMIT POINT | ||
turadg marked this conversation as resolved.
Show resolved
Hide resolved
|
||
|
|
||
| try { | ||
| const mint = shareMint.mintGains(post.payouts); | ||
| this.state.shareWorth = post.shareWorth; | ||
| zcf.atomicRearrange( | ||
| harden([ | ||
| // zoe guarantees lp has proposal.give allocated | ||
| [lp, poolSeat, proposal.give], | ||
| // mintGains() above establishes that mint has post.payouts | ||
|
|
||
| [mint, lp, post.payouts], | ||
| ]), | ||
| ); | ||
| lp.exit(); | ||
| mint.exit(); | ||
| } catch (cause) { | ||
| const reason = Error('🚨 cannot commit deposit', { cause }); | ||
| console.error(reason.message, cause); | ||
| zcf.shutdownWithFailure(reason); | ||
| } | ||
| external.publishShareWorth(); | ||
| }, | ||
| }, | ||
| withdrawHandler: { | ||
| /** @param {ZCFSeat} lp */ | ||
| async handle(lp) { | ||
| const { shareWorth, shareMint, poolSeat } = this.state; | ||
| const { external } = this.facets; | ||
|
|
||
| /** @type {USDCProposalShapes['withdraw']} */ | ||
| // @ts-expect-error ensured by proposalShape | ||
| const proposal = lp.getProposal(); | ||
| const { zcfSeat: burn } = zcf.makeEmptySeatKit(); | ||
| checkPoolBalance(poolSeat, shareWorth, USDC); | ||
| const post = withdrawCalc(shareWorth, proposal); | ||
|
|
||
| // COMMIT POINT | ||
|
|
||
| try { | ||
| this.state.shareWorth = post.shareWorth; | ||
| zcf.atomicRearrange( | ||
| harden([ | ||
| // zoe guarantees lp has proposal.give allocated | ||
| [lp, burn, proposal.give], | ||
| // checkPoolBalance() + withdrawCalc() guarantee poolSeat has enough | ||
| [poolSeat, lp, post.payouts], | ||
| ]), | ||
| ); | ||
| shareMint.burnLosses(proposal.give, burn); | ||
| lp.exit(); | ||
| burn.exit(); | ||
| } catch (cause) { | ||
| const reason = Error('🚨 cannot commit withdraw', { cause }); | ||
| console.error(reason.message, cause); | ||
| zcf.shutdownWithFailure(reason); | ||
| } | ||
| external.publishShareWorth(); | ||
| }, | ||
| }, | ||
| public: { | ||
| makeDepositInvitation() { | ||
| return zcf.makeInvitation( | ||
| this.facets.depositHandler, | ||
| 'Deposit', | ||
| undefined, | ||
| this.state.proposalShapes.deposit, | ||
| ); | ||
| }, | ||
| makeWithdrawInvitation() { | ||
| return zcf.makeInvitation( | ||
| this.facets.withdrawHandler, | ||
| 'Withdraw', | ||
| undefined, | ||
| this.state.proposalShapes.withdraw, | ||
| ); | ||
| }, | ||
| getPublicTopics() { | ||
|
There was a problem hiding this comment. I was surprised to see Consider making this public facet be its own There was a problem hiding this comment. Good idea, but after looking into it, I'd like to postpone this until we get more pieces of the contract together. I started on it, but the LP exo isn't available until after remote calls, which would mean doing the same gymnastics for the public facet. |
||
| const { shareWorthRecorderKit } = this.state; | ||
| return { | ||
| shareWorth: makeRecorderTopic('shareWorth', shareWorthRecorderKit), | ||
| }; | ||
| }, | ||
| }, | ||
| }, | ||
| { | ||
| finish: ({ facets: { external } }) => { | ||
| void external.publishShareWorth(); | ||
| }, | ||
| }, | ||
| ); | ||
| }; | ||
| harden(prepareLiquidityPoolKit); | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
assertPoolBalanceThere was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
assertFoo(x)usually means: assert thatxis aFoo.The
atomicRearranges that follow the call todepositCalc/withdrawCalcassume that the pool balance represented by thepoolSeatUSDC allocation is the same as the pool balance represented by the numerator ofshareWorth. When I first added this check, my tests failed; they differ by the dust used to make the initial shareworth denominator non-zero.The fact that this answer didn't come in the form of a pointer to existing docs says I should add more.
In flight in what sense? Its only use is in normal straight-line synchronous offer handlers: gather all the relevant info in one place and compute the outcome, synchronously. Things happening outside this vat may happen causally before or after, or in an incomparable causal order. In any case, the local computation does what it does.