feat: move to timestamp-based period on mini TWAP

panoptic-labs · Sep 19, 2023 · b2c71fe · b2c71fe
1 parent 0c4f905
commit b2c71fe
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Showing 2 changed files with 22 additions and 18 deletions.
diff --git a/contracts/PanopticPool.sol b/contracts/PanopticPool.sol
@@ -155,6 +155,9 @@ contract PanopticPool is ERC1155Holder, Multicall {
     /// May be configurable on a pool-by-pool basis in the future, but hardcoded for now
     uint32 internal constant TWAP_WINDOW = 600;
 
+    // The minimum amount of time, in seconds, permitted between mini/median TWAP updates.
+    uint256 internal constant MEDIAN_PERIOD = 60;
+
     /// @dev The maximum allowed ratio for a single chunk, defined as: shortLiquidity / netLiquidity
     /// The long premium spread multiplier that corresponds with the MAX_SPREAD value depends on VEGOID,
     /// which can be explored in this calculator: https://www.desmos.com/calculator/mdeqob2m04
@@ -180,8 +183,8 @@ contract PanopticPool is ERC1155Holder, Multicall {
 
     /// @notice Mini-median storage slot
     /// @dev The data for the last 8 interactions is stored as such:
-    /// LAST UPDATED BLOCK NUMBER (32 bits)
-    /// [BLOCK.NUMBER]
+    /// LAST UPDATED BLOCK TIMESTAMP (40 bits)
+    /// [BLOCK.TIMESTAMP]
     // (00000000000000000000000000000000) // dynamic
     //
     /// @dev ORDERING of tick indices least --> greatest (24 bits)
@@ -210,9 +213,6 @@ contract PanopticPool is ERC1155Holder, Multicall {
     // [Constants.MAX_V3POOL_TICK] [2]
     // 000011011000100111101001
     //
-    /// @dev [TickMath.MAX_TICK] [2]
-    /// 000011011000100111101001
-    //
     ///  @dev [CURRENT TICK] [4]
     /// (000000000000000000000000) // dynamic
     //
@@ -296,7 +296,7 @@ contract PanopticPool is ERC1155Holder, Multicall {
 
         unchecked {
             s_miniMedian =
-                (uint256(block.number) << 216) +
+                (uint256(block.timestamp) << 216) +
                 // magic number which adds (7,5,3,1,0,2,4,6) order and minTick in positions 7, 5, 3 and maxTick in 6, 4, 2
                 // see comment on s_miniMedian initialization for format of this magic number
                 (uint256(0xF590A6F276170D89E9F276170D89E9F276170D89E9000000000000)) +
@@ -1574,8 +1574,8 @@ contract PanopticPool is ERC1155Holder, Multicall {
     function updateMedian(int24 currentTick) internal {
         uint256 oldMedianData = s_miniMedian;
         unchecked {
-            // only proceed if last block is more than 1 min old (ie. 5 blocks or older)
-            if (block.number > uint256(uint40(oldMedianData >> 216)) + 4) {
+            // only proceed if last entry is at least MEDIAN_PERIOD seconds old
+            if (block.timestamp >= uint256(uint40(oldMedianData >> 216)) + MEDIAN_PERIOD) {
                 uint24 orderMap = uint24(oldMedianData >> 192);
 
                 uint24 newOrderMap;
@@ -1601,9 +1601,8 @@ contract PanopticPool is ERC1155Holder, Multicall {
 
                     newOrderMap = newOrderMap + ((rank + 1) << (3 * (i + shift - 1)));
                 }
-
                 s_miniMedian =
-                    (block.number << 216) +
+                    (block.timestamp << 216) +
                     (uint256(newOrderMap) << 192) +
                     uint256(uint192(oldMedianData << 24)) +
                     uint256(uint24(currentTick));

diff --git a/test/foundry/core/PanopticPool.t.sol b/test/foundry/core/PanopticPool.t.sol
@@ -4993,7 +4993,7 @@ contract PanopticPoolTest is PositionUtils {
     ) public {
         for (uint256 i = 0; i < 50; ++i) {
             pokeTicks[i] = bound(pokeTicks[i], TickMath.MIN_TICK, TickMath.MAX_TICK);
-            blockTimes[i] = bound(blockTimes[i], 0, type(uint32).max);
+            blockTimes[i] = bound(blockTimes[i], 0, 21990232555);
         }
 
         _initWorldAtTick(x, int24(pokeTicks[0]));
@@ -5012,10 +5012,10 @@ contract PanopticPoolTest is PositionUtils {
             0
         ];
 
-        uint256 lastBlockNumber = block.number;
+        uint256 lastTimestamp = block.timestamp;
 
         for (uint256 i = 1; i < 10; ++i) {
-            vm.roll(block.number + blockTimes[i]);
+            vm.warp(block.timestamp + blockTimes[i]);
 
             UniPoolPriceMock(address(pool)).updatePrice(int24(pokeTicks[i]));
 
@@ -5025,12 +5025,17 @@ contract PanopticPoolTest is PositionUtils {
             expectedArray[8] = int24(pokeTicks[i]);
             (priceArray, medianTick) = pp.getPriceArray();
             for (uint256 j = 0; j < 8; ++j) {
-                // only shift array if an update occured, i.e more than 5 blocks passed since the last update
-                expectedArray[j] = block.number > lastBlockNumber + 4
+                console2.log(expectedArray[j]);
+                console2.log(expectedArray[j+1]);
+                console2.log(priceArray[j]);
+                console2.log(block.timestamp);
+                console2.log(lastTimestamp);
+                // only shift array if an update occured, i.e more than 60 seconds passed since the last update
+                expectedArray[j] = block.timestamp >= lastTimestamp + 60
                     ? expectedArray[j + 1]
                     : expectedArray[j];
-
                 assertEq(priceArray[j], expectedArray[j]);
+                if (priceArray[j] != expectedArray[j]) revert();
             }
 
             // sort the array using quicksort and verify correctness of the median
@@ -5039,8 +5044,8 @@ contract PanopticPoolTest is PositionUtils {
             assertEq(medianTick, (sortedPriceArray[3] + sortedPriceArray[4]) / 2);
 
             // bump last updated block number if an update occured
-            if (block.number > lastBlockNumber + 4) {
-                lastBlockNumber = block.number;
+            if (block.timestamp >= lastTimestamp + 60) {
+                lastTimestamp = block.timestamp;
             }
         }
     }