From f224cb8eda74a166f0bb3020032026a8dec26466 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Tue, 10 Jan 2023 12:34:18 +0100
Subject: [PATCH] [Proofs] Remove double administration of request start

The timestamp when proofs start to be required was
stored in both the Marketplace and Proofs. It is now
only stored in the Marketplace.
---
 contracts/Marketplace.sol | 8 ++++++++
 contracts/Proofs.sol      | 8 +++++---
 contracts/TestProofs.sol  | 9 +++++++++
 test/Proofs.test.js       | 4 ++++
 4 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/contracts/Marketplace.sol b/contracts/Marketplace.sol
index 659102d..8e48671 100644
--- a/contracts/Marketplace.sol
+++ b/contracts/Marketplace.sol
@@ -320,10 +320,18 @@ contract Marketplace is Collateral, Proofs {
     return _timeout();
   }
 
+  function proofStart(SlotId slotId) public view override returns (uint256) {
+    return requestStart(_slot(slotId).requestId);
+  }
+
   function proofEnd(SlotId slotId) public view override returns (uint256) {
     return requestEnd(_slot(slotId).requestId);
   }
 
+  function requestStart(RequestId requestId) public view returns (uint256) {
+    return _context(requestId).startedAt;
+  }
+
   function requestEnd(RequestId requestId) public view returns (uint256) {
     uint256 end = _context(requestId).endsAt;
     if (_requestAcceptsProofs(requestId)) {
diff --git a/contracts/Proofs.sol b/contracts/Proofs.sol
index c9bd1f5..6df43b9 100644
--- a/contracts/Proofs.sol
+++ b/contracts/Proofs.sol
@@ -16,7 +16,6 @@ abstract contract Proofs {
   }
 
   mapping(SlotId => bool) private slotIds;
-  mapping(SlotId => uint256) private starts;
   mapping(SlotId => uint256) private probabilities;
   mapping(SlotId => uint256) private missed;
   mapping(SlotId => mapping(uint256 => bool)) private received;
@@ -30,6 +29,10 @@ abstract contract Proofs {
     return timeout;
   }
 
+  // Override this to let the proving system know when proofs for a
+  // slot are required.
+  function proofStart(SlotId id) public view virtual returns (uint256);
+
   // 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);
@@ -52,7 +55,6 @@ abstract contract Proofs {
   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;
   }
 
@@ -97,7 +99,7 @@ abstract contract Proofs {
     SlotId id,
     uint256 proofPeriod
   ) internal view returns (bool isRequired, uint8 pointer) {
-    if (proofPeriod <= periodOf(starts[id])) {
+    if (proofPeriod <= periodOf(proofStart(id))) {
       return (false, 0);
     }
     uint256 end = proofEnd(id);
diff --git a/contracts/TestProofs.sol b/contracts/TestProofs.sol
index 634d3b6..fe05c8a 100644
--- a/contracts/TestProofs.sol
+++ b/contracts/TestProofs.sol
@@ -5,6 +5,7 @@ import "./Proofs.sol";
 
 // exposes internal functions of Proofs for testing
 contract TestProofs is Proofs {
+  mapping(SlotId => uint256) private starts;
   mapping(SlotId => uint256) private ends;
 
   constructor(
@@ -18,6 +19,10 @@ contract TestProofs is Proofs {
 
   }
 
+  function proofStart(SlotId slotId) public view override returns (uint256) {
+    return starts[slotId];
+  }
+
   function proofEnd(SlotId slotId) public view override returns (uint256) {
     return ends[slotId];
   }
@@ -58,6 +63,10 @@ contract TestProofs is Proofs {
     _markProofAsMissing(id, _period);
   }
 
+  function setProofStart(SlotId id, uint256 start) public {
+    starts[id] = start;
+  }
+
   function setProofEnd(SlotId id, uint256 end) public {
     ends[id] = end;
   }
diff --git a/test/Proofs.test.js b/test/Proofs.test.js
index 3fda82d..978a2de 100644
--- a/test/Proofs.test.js
+++ b/test/Proofs.test.js
@@ -37,6 +37,7 @@ describe("Proofs", function () {
 
   describe("general", function () {
     beforeEach(async function () {
+      await proofs.setProofStart(slotId, await currentTime())
       await proofs.setProofEnd(slotId, (await currentTime()) + duration)
     })
 
@@ -89,6 +90,7 @@ describe("Proofs", function () {
       let id2 = hexlify(randomBytes(32))
       let id3 = hexlify(randomBytes(32))
       for (let slotId of [id1, id2, id3]) {
+        await proofs.setProofStart(slotId, await currentTime())
         await proofs.setProofEnd(slotId, (await currentTime()) + duration)
         await proofs.expectProofs(slotId, probability)
       }
@@ -120,6 +122,7 @@ describe("Proofs", function () {
     }
 
     beforeEach(async function () {
+      await proofs.setProofStart(slotId, await currentTime())
       await proofs.setProofEnd(slotId, (await currentTime()) + duration)
       await proofs.expectProofs(slotId, probability)
       await advanceTimeTo(periodEnd(periodOf(await currentTime())))
@@ -154,6 +157,7 @@ describe("Proofs", function () {
     const proof = hexlify(randomBytes(42))
 
     beforeEach(async function () {
+      await proofs.setProofStart(slotId, await currentTime())
       await proofs.setProofEnd(slotId, (await currentTime()) + duration)
       await proofs.expectProofs(slotId, probability)
     })