[Proofs] Remove double administration of request end

The timestamp when proofs no longer are required was
stored in both the Marketplace and Proofs. It is now
only stored in the Marketplace.

contracts/Marketplace.sol

@@ -71,7 +71,6 @@ contract Marketplace is Collateral, Proofs {
     RequestContext storage context = _context(id);
     // set contract end time to `duration` from now (time request was created)
     context.endsAt = block.timestamp + request.ask.duration;
-    _setProofEnd(id, context.endsAt);
 
     requestsPerClient[request.client].add(RequestId.unwrap(id));
 
@@ -97,7 +96,7 @@ contract Marketplace is Collateral, Proofs {
 
     require(balanceOf(msg.sender) >= collateral, "Insufficient collateral");
 
-    _expectProofs(slotId, requestId, request.ask.proofProbability);
+    _expectProofs(slotId, request.ask.proofProbability);
     submitProof(slotId, proof);
 
     slot.host = msg.sender;
@@ -179,7 +178,6 @@ contract Marketplace is Collateral, Proofs {
       context.state == RequestState.Started
     ) {
       context.state = RequestState.Failed;
-      _setProofEnd(requestId, block.timestamp - 1);
       context.endsAt = block.timestamp - 1;
       emit RequestFailed(requestId);
 
@@ -322,12 +320,12 @@ contract Marketplace is Collateral, Proofs {
     return _timeout();
   }
 
-  function proofEnd(SlotId slotId) public view returns (uint256) {
+  function proofEnd(SlotId slotId) public view override returns (uint256) {
     return requestEnd(_slot(slotId).requestId);
   }
 
   function requestEnd(RequestId requestId) public view returns (uint256) {
-    uint256 end = _end(requestId);
+    uint256 end = _context(requestId).endsAt;
     if (_requestAcceptsProofs(requestId)) {
       return end;
     } else {

contracts/Proofs.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.8;
 
 import "./Requests.sol";
 
-contract Proofs {
+abstract contract Proofs {
   uint256 private immutable period;
   uint256 private immutable timeout;
   uint8 private immutable downtime;
@@ -17,8 +17,6 @@ contract Proofs {
 
   mapping(SlotId => bool) private slotIds;
   mapping(SlotId => uint256) private starts;
-  mapping(RequestId => uint256) private ends;
-  mapping(SlotId => RequestId) private requestForSlot;
   mapping(SlotId => uint256) private probabilities;
   mapping(SlotId => uint256) private markers;
   mapping(SlotId => uint256) private missed;
@@ -33,21 +31,9 @@ contract Proofs {
     return timeout;
   }
 
-  function _end(RequestId requestId) internal view returns (uint256) {
-    uint256 end = ends[requestId];
-    require(end > 0, "Proof ending doesn't exist");
-    return end;
-  }
-
-  function _requestId(SlotId id) internal view returns (RequestId) {
-    RequestId requestId = requestForSlot[id];
-    require(RequestId.unwrap(requestId) > 0, "request for slot doesn't exist");
-    return requestId;
-  }
-
-  function _end(SlotId id) internal view returns (uint256) {
-    return _end(_requestId(id));
-  }
+  // Override this to let the proving system know when proofs for a
+  // slot are no longer required.
+  function proofEnd(SlotId id) public view virtual returns (uint256);
 
   function missingProofs(SlotId slotId) public view returns (uint256) {
     return missed[slotId];
@@ -63,19 +49,13 @@ contract Proofs {
 
   /// @notice Informs the contract that proofs should be expected for id
   /// @dev Requires that the id is not already in use
-  /// @param id identifies the proof expectation, typically a slot id
   /// @param probability The probability that a proof should be expected
-  function _expectProofs(
-    SlotId id, // typically slot id
-    RequestId request, // typically request id, used so that the ending is global for all slots
-    uint256 probability
-  ) internal {
+  function _expectProofs(SlotId id, uint256 probability) internal {
     require(!slotIds[id], "Slot id already in use");
     slotIds[id] = true;
     starts[id] = block.timestamp;
     probabilities[id] = probability;
     markers[id] = uint256(blockhash(block.number - 1)) % period;
-    requestForSlot[id] = request;
   }
 
   function _unexpectProofs(SlotId id) internal {
@@ -122,7 +102,7 @@ contract Proofs {
     if (proofPeriod <= periodOf(starts[id])) {
       return (false, 0);
     }
-    uint256 end = _end(id);
+    uint256 end = proofEnd(id);
     if (proofPeriod >= periodOf(end)) {
       return (false, 0);
     }
@@ -171,16 +151,5 @@ contract Proofs {
     missed[id] += 1;
   }
 
-  /// @notice Sets the proof end time
-  /// @dev Can only be set once
-  /// @param ending the new end time (in seconds)
-  function _setProofEnd(RequestId request, uint256 ending) internal {
-    require(
-      ends[request] == 0 || ending < block.timestamp,
-      "End exists or must be past"
-    );
-    ends[request] = ending;
-  }
-
   event ProofSubmitted(SlotId id, bytes proof);
 }

contracts/TestProofs.sol

@@ -5,6 +5,8 @@ import "./Proofs.sol";
 
 // exposes internal functions of Proofs for testing
 contract TestProofs is Proofs {
+  mapping(SlotId => uint256) private ends;
+
   constructor(
     uint256 __period,
     uint256 __timeout,
@@ -16,6 +18,10 @@ contract TestProofs is Proofs {
 
   }
 
+  function proofEnd(SlotId slotId) public view override returns (uint256) {
+    return ends[slotId];
+  }
+
   function period() public view returns (uint256) {
     return _period();
   }
@@ -24,16 +30,8 @@ contract TestProofs is Proofs {
     return _timeout();
   }
 
-  function end(RequestId id) public view returns (uint256) {
-    return _end(id);
-  }
-
-  function expectProofs(
-    SlotId slot,
-    RequestId request,
-    uint256 _probability
-  ) public {
-    _expectProofs(slot, request, _probability);
+  function expectProofs(SlotId slot, uint256 _probability) public {
+    _expectProofs(slot, _probability);
   }
 
   function unexpectProofs(SlotId id) public {
@@ -60,7 +58,7 @@ contract TestProofs is Proofs {
     _markProofAsMissing(id, _period);
   }
 
-  function setProofEnd(RequestId id, uint256 ending) public {
-    _setProofEnd(id, ending);
+  function setProofEnd(SlotId id, uint256 end) public {
+    ends[id] = end;
   }
 }

test/Proofs.test.js

@@ -37,18 +37,18 @@ describe("Proofs", function () {
 
   describe("general", function () {
     beforeEach(async function () {
-      await proofs.setProofEnd(requestId, (await currentTime()) + duration)
+      await proofs.setProofEnd(slotId, (await currentTime()) + duration)
     })
 
     it("does not allow ids to be reused", async function () {
-      await proofs.expectProofs(slotId, requestId, probability)
-      await expect(
-        proofs.expectProofs(slotId, requestId, probability)
-      ).to.be.revertedWith("Slot id already in use")
+      await proofs.expectProofs(slotId, probability)
+      await expect(proofs.expectProofs(slotId, probability)).to.be.revertedWith(
+        "Slot id already in use"
+      )
     })
 
     it("requires proofs with an agreed upon probability", async function () {
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.expectProofs(slotId, probability)
       let amount = 0
       for (let i = 0; i < 100; i++) {
         if (await proofs.isProofRequired(slotId)) {
@@ -63,7 +63,7 @@ describe("Proofs", function () {
     it("requires no proofs in the start period", async function () {
       const startPeriod = Math.floor((await currentTime()) / period)
       const probability = 1
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.expectProofs(slotId, probability)
       while (Math.floor((await currentTime()) / period) == startPeriod) {
         expect(await proofs.isProofRequired(slotId)).to.be.false
         await advanceTime(Math.floor(period / 10))
@@ -72,14 +72,14 @@ describe("Proofs", function () {
 
     it("requires no proofs in the end period", async function () {
       const probability = 1
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.expectProofs(slotId, probability)
       await advanceTime(duration)
       expect(await proofs.isProofRequired(slotId)).to.be.false
     })
 
     it("requires no proofs after the end time", async function () {
       const probability = 1
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.expectProofs(slotId, probability)
       await advanceTime(duration + timeout)
       expect(await proofs.isProofRequired(slotId)).to.be.false
     })
@@ -89,7 +89,8 @@ describe("Proofs", function () {
       let id2 = hexlify(randomBytes(32))
       let id3 = hexlify(randomBytes(32))
       for (let slotId of [id1, id2, id3]) {
-        await proofs.expectProofs(slotId, requestId, probability)
+        await proofs.setProofEnd(slotId, (await currentTime()) + duration)
+        await proofs.expectProofs(slotId, probability)
       }
       let req1, req2, req3
       while (req1 === req2 && req2 === req3) {
@@ -119,8 +120,8 @@ describe("Proofs", function () {
     }
 
     beforeEach(async function () {
-      await proofs.setProofEnd(requestId, (await currentTime()) + duration)
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.setProofEnd(slotId, (await currentTime()) + duration)
+      await proofs.expectProofs(slotId, probability)
       await advanceTimeTo(periodEnd(periodOf(await currentTime())))
       await waitUntilProofWillBeRequired()
     })
@@ -153,8 +154,8 @@ describe("Proofs", function () {
     const proof = hexlify(randomBytes(42))
 
     beforeEach(async function () {
-      await proofs.setProofEnd(requestId, (await currentTime()) + duration)
-      await proofs.expectProofs(slotId, requestId, probability)
+      await proofs.setProofEnd(slotId, (await currentTime()) + duration)
+      await proofs.expectProofs(slotId, probability)
     })
 
     async function waitUntilProofIsRequired(slotId) {
@@ -273,35 +274,4 @@ describe("Proofs", function () {
       await expect(await proofs.isProofRequired(slotId)).to.be.false
     })
   })
-
-  describe("set proof end", function () {
-    const proof = hexlify(randomBytes(42))
-
-    it("fails to get proof end when proof ending doesn't exist", async function () {
-      await expect(proofs.end(requestId)).to.be.revertedWith(
-        "Proof ending doesn't exist"
-      )
-    })
-
-    it("sets proof end when proof ending doesn't already exist", async function () {
-      let ending = (await currentTime()) + duration
-      await expect(proofs.setProofEnd(requestId, ending)).not.to.be.reverted
-      await expect(await proofs.end(requestId)).to.equal(ending)
-    })
-
-    it("sets proof end when proof ending exists and ending set to past", async function () {
-      // let ending = (await currentTime()) + duration
-      // await proofs.setProofEnd(requestId, ending)
-      let past = (await currentTime()) - 1
-      await expect(proofs.setProofEnd(requestId, past)).not.to.be.reverted
-    })
-
-    it("fails when proof ending already exists and ending set to future", async function () {
-      let ending = (await currentTime()) + duration
-      await proofs.setProofEnd(requestId, ending)
-      await expect(proofs.setProofEnd(requestId, ending)).to.be.revertedWith(
-        "End exists or must be past"
-      )
-    })
-  })
 })