From 83d1a07fe3084eb4b17ca9d1c9a57902b24638e7 Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Fri, 23 Feb 2024 16:54:35 -0800
Subject: [PATCH 01/12] remove extraneous line + add natspec

---
 src/pumps/MultiFlowPump.sol | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 23a62765..91f99b9a 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -94,7 +94,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             capExponent = ((deltaTimestamp - 1) / capInterval + 1);
         }
 
-        (numberOfReserves, pumpState.lastTimestamp, pumpState.lastReserves) = slot.readLastReserves();
         pumpState.lastReserves = _capReserves(msg.sender, pumpState.lastReserves, reserves, capExponent, crp);
 
         // Read: Cumulative & EMA Reserves
@@ -202,6 +201,17 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         cappedReserves = _capReserves(well, cappedReserves, currentReserves, capExponent, crp);
     }
 
+    /**
+     * @notice Cap `reserves` to have at most a maximum % increase/decrease in rate and a maximum % increase/decrease in total liquidity
+     * in relation to `lastReserves` based on the parameters defined in `crp` and the time passed since the last update, which is used
+     * to calculate `capExponent`.
+     * @param well The address of the Well
+     * @param lastReserves The last capped reserves.
+     * @param reserves The current reserves being capped.
+     * @param capExponent The exponent to raise the all % changes to.
+     * @param crp The parameters for capping reserves. See {CapReservesParameters}.
+     * @return cappedReserves The current reserves capped to the maximum % changes defined by `crp`.
+     */
     function _capReserves(
         address well,
         uint256[] memory lastReserves,

From a20420ab8b72d6d1af242800c1b2cae300f2bc9f Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Fri, 23 Feb 2024 16:56:53 -0800
Subject: [PATCH 02/12] remove commented out line

---
 src/pumps/MultiFlowPump.sol | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 91f99b9a..ba9cf0ff 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -557,7 +557,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         uint256 lpTokenSupply,
         bytes memory data
     ) internal view returns (uint256[] memory underlyingAmounts) {
-        // return wf.calcLPTokenUnderlying(lpTokenAmount, reserves, lpTokenSupply, data);
         try wf.calcLPTokenUnderlying(lpTokenAmount, reserves, lpTokenSupply, data) returns (
             uint256[] memory _underlyingAmounts
         ) {

From 3a6ed099127c827354e6381f5637c68c37d8c29b Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Fri, 23 Feb 2024 16:58:05 -0800
Subject: [PATCH 03/12] remove TODO

---
 src/pumps/MultiFlowPump.sol | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index ba9cf0ff..15399d72 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -279,7 +279,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 crv.ratios[i] = crv.rLimit;
                 crv.ratios[j] = CAP_PRECISION;
                 // Use a minimum of 1 for reserve. Geometric means will be set to 0 if a reserve is 0.
-                // TODO: Make sure this works.
                 uint256 cappedReserveI =
                     Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, i, crv.ratios, data), 1);
                 cappedReserves[j] = Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, j, crv.ratios, data), 1);

From 8b439efb84fa92484b7b4edbe391c96d75f61c96 Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sat, 24 Feb 2024 14:16:38 -0800
Subject: [PATCH 04/12] ratio -> rate

---
 src/pumps/MultiFlowPump.sol | 6 +++---
 test/pumps/PumpHelpers.sol  | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 15399d72..d6519322 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -234,11 +234,11 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         cappedReserves = _capLpTokenSupply(lastReserves, cappedReserves, capExponent, crp, mfpWf, wf.data, true);
 
         if (cappedReserves.length == 0) {
-            cappedReserves = _capRatios(lastReserves, reserves, capExponent, crp, mfpWf, wf.data);
+            cappedReserves = _capRates(lastReserves, reserves, capExponent, crp, mfpWf, wf.data);
 
             cappedReserves = _capLpTokenSupply(lastReserves, cappedReserves, capExponent, crp, mfpWf, wf.data, false);
         } else {
-            cappedReserves = _capRatios(lastReserves, cappedReserves, capExponent, crp, mfpWf, wf.data);
+            cappedReserves = _capRates(lastReserves, cappedReserves, capExponent, crp, mfpWf, wf.data);
         }
     }
 
@@ -252,7 +252,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
     /**
      * @dev Cap the change in ratio of `reserves` to a maximum % change from `lastReserves`.
      */
-    function _capRatios(
+    function _capRates(
         uint256[] memory lastReserves,
         uint256[] memory reserves,
         uint256 capExponent,
diff --git a/test/pumps/PumpHelpers.sol b/test/pumps/PumpHelpers.sol
index e88fc773..8e0d6990 100644
--- a/test/pumps/PumpHelpers.sol
+++ b/test/pumps/PumpHelpers.sol
@@ -72,7 +72,7 @@ function encodePumpData(
     data = abi.encode(alpha, capInterval, crp);
 }
 
-function mockPumpData() view returns (bytes memory data) {
+function mockPumpData() pure returns (bytes memory data) {
     bytes16[][] memory maxRatioChanges = new bytes16[][](2);
     maxRatioChanges[0] = new bytes16[](2);
     maxRatioChanges[1] = new bytes16[](2);

From e697188b91b09b22b48eb20d9a5fffc3dda5415b Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sat, 24 Feb 2024 14:53:30 -0800
Subject: [PATCH 05/12] ratio -> rate p2

---
 src/pumps/MultiFlowPump.sol       |  2 +-
 test/pumps/Pump.CapReserves.t.sol | 22 +++++++++++-----------
 test/pumps/PumpHelpers.sol        | 14 ++++++--------
 3 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index d6519322..9a97e4cd 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -52,7 +52,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
     }
 
     struct CapReservesParameters {
-        bytes16[][] maxRatioChanges;
+        bytes16[][] maxRateChanges;
         bytes16 maxLpSupplyIncrease;
         bytes16 maxLpSupplyDecrease;
     }
diff --git a/test/pumps/Pump.CapReserves.t.sol b/test/pumps/Pump.CapReserves.t.sol
index 3df75ca9..e06d7aa4 100644
--- a/test/pumps/Pump.CapReserves.t.sol
+++ b/test/pumps/Pump.CapReserves.t.sol
@@ -21,7 +21,7 @@ contract CapBalanceTest is TestHelper, MultiFlowPump {
 
     uint256[] lastReserves;
     uint256[] reserves;
-    bytes16[][] maxRatioChanges;
+    bytes16[][] maxRateChanges;
     bytes16 maxLpSupplyIncrease;
     bytes16 maxLpSupplyDecrease;
     // uint256 MAX_RESERVE = 1e30;
@@ -39,13 +39,13 @@ contract CapBalanceTest is TestHelper, MultiFlowPump {
         maxLpSupplyIncrease = from18(0.05e18);
         maxLpSupplyDecrease = from18(0.04761904762e18);
 
-        maxRatioChanges = new bytes16[][](2);
-        maxRatioChanges[0] = new bytes16[](2);
-        maxRatioChanges[1] = new bytes16[](2);
-        maxRatioChanges[0][1] = from18(0.05e18);
-        maxRatioChanges[1][0] = from18(0.05e18);
+        maxRateChanges = new bytes16[][](2);
+        maxRateChanges[0] = new bytes16[](2);
+        maxRateChanges[1] = new bytes16[](2);
+        maxRateChanges[0][1] = from18(0.05e18);
+        maxRateChanges[1][0] = from18(0.05e18);
 
-        crp = MultiFlowPump.CapReservesParameters(maxRatioChanges, maxLpSupplyIncrease, maxLpSupplyDecrease);
+        crp = MultiFlowPump.CapReservesParameters(maxRateChanges, maxLpSupplyIncrease, maxLpSupplyDecrease);
 
         wf = new ConstantProduct2();
 
@@ -72,7 +72,7 @@ contract CapBalanceTest is TestHelper, MultiFlowPump {
             lastReserves,
             reserves,
             1, // capExponent
-            CapReservesParameters(maxRatioChanges, maxLpSupplyIncrease, maxLpSupplyDecrease)
+            CapReservesParameters(maxRateChanges, maxLpSupplyIncrease, maxLpSupplyDecrease)
         );
 
         assertEq(cappedReserves[0], 101);
@@ -174,8 +174,8 @@ contract CapBalanceTest is TestHelper, MultiFlowPump {
 
         (uint256 i, uint256 j) = lastReserves[0] > lastReserves[1] ? (0, 1) : (1, 0);
 
-        uint256 rIJMax = lastReserves[i] * (1e18 + to18(maxRatioChanges[i][j])) / lastReserves[j];
-        uint256 rIJMin = lastReserves[i] * 1e18 / (1 + to18(maxRatioChanges[i][j])) / lastReserves[j];
+        uint256 rIJMax = lastReserves[i] * (1e18 + to18(maxRateChanges[i][j])) / lastReserves[j];
+        uint256 rIJMin = lastReserves[i] * 1e18 / (1 + to18(maxRateChanges[i][j])) / lastReserves[j];
         uint256 rIJCapped = cappedReserves[i] * 1e18 / cappedReserves[j];
         console.log("Max R: %s", rIJMax);
         console.log("Min R: %s", rIJMin);
@@ -271,7 +271,7 @@ contract CapBalanceTest is TestHelper, MultiFlowPump {
         uint256 r = mfpWf.calcRate(_reserves, i, j, _wf.data);
         if (r < rLast) {
             ratioDigits = rLast.mulDiv(
-                ABDKMathQuad.ONE.div(ABDKMathQuad.ONE.add(_crp.maxRatioChanges[j][i])).powu(capExponent).to128x128()
+                ABDKMathQuad.ONE.div(ABDKMathQuad.ONE.add(_crp.maxRateChanges[j][i])).powu(capExponent).to128x128()
                     .toUint256(),
                 CAP_PRECISION2
             );
diff --git a/test/pumps/PumpHelpers.sol b/test/pumps/PumpHelpers.sol
index 8e0d6990..24dca9d3 100644
--- a/test/pumps/PumpHelpers.sol
+++ b/test/pumps/PumpHelpers.sol
@@ -73,15 +73,13 @@ function encodePumpData(
 }
 
 function mockPumpData() pure returns (bytes memory data) {
-    bytes16[][] memory maxRatioChanges = new bytes16[][](2);
-    maxRatioChanges[0] = new bytes16[](2);
-    maxRatioChanges[1] = new bytes16[](2);
-    maxRatioChanges[0][1] = from18(0.5e18);
-    maxRatioChanges[1][0] = from18(0.5e18);
+    bytes16[][] memory maxRateChanges = new bytes16[][](2);
+    maxRateChanges[0] = new bytes16[](2);
+    maxRateChanges[1] = new bytes16[](2);
+    maxRateChanges[0][1] = from18(0.5e18);
+    maxRateChanges[1][0] = from18(0.5e18);
 
     data = encodePumpData(
-        from18(0.9e18),
-        12,
-        MultiFlowPump.CapReservesParameters(maxRatioChanges, from18(0.5e18), from18(0.4761904762e18))
+        from18(0.9e18), 12, MultiFlowPump.CapReservesParameters(maxRateChanges, from18(0.5e18), from18(0.4761904762e18))
     );
 }

From 09ab092239fc5fee1e82aa09eb3366f694cdae3b Mon Sep 17 00:00:00 2001
From: publius <beanstalk.publius@protonmail.com>
Date: Sat, 24 Feb 2024 14:55:00 -0800
Subject: [PATCH 06/12] Ratio -> Rate p3

---
 src/pumps/MultiFlowPump.sol | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 9a97e4cd..b321d569 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -242,7 +242,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         }
     }
 
-    struct CapRatiosVariables {
+    struct CapRatesVariables {
         uint256 r;
         uint256 rLast;
         uint256 rLimit;
@@ -261,16 +261,16 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         bytes memory data
     ) internal view returns (uint256[] memory cappedReserves) {
         cappedReserves = reserves;
-        // Part 1: Cap Ratios
+        // Part 1: Cap Rates
         // Use the larger reserve as the numerator for the ratio to maximize precision
         (uint256 i, uint256 j) = lastReserves[0] > lastReserves[1] ? (0, 1) : (1, 0);
-        CapRatiosVariables memory crv;
+        CapRatesVariables memory crv;
         crv.rLast = mfpWf.calcRate(lastReserves, i, j, data);
         crv.r = mfpWf.calcRate(cappedReserves, i, j, data);
 
         // If the ratio increased, check that it didn't increase above the max.
         if (crv.r > crv.rLast) {
-            bytes16 tempExp = ABDKMathQuad.ONE.add(crp.maxRatioChanges[i][j]).powu(capExponent);
+            bytes16 tempExp = ABDKMathQuad.ONE.add(crp.maxRateChanges[i][j]).powu(capExponent);
             crv.rLimit = tempExp.cmp(MAX_CONVERT_TO_128x128) != -1
                 ? crv.rLimit = type(uint256).max
                 : crv.rLast.mulDivOrMax(tempExp.to128x128().toUint256(), CAP_PRECISION2);
@@ -287,7 +287,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             // If the ratio decreased, check that it didn't decrease below the max.
         } else if (crv.r < crv.rLast) {
             crv.rLimit = crv.rLast.mulDiv(
-                ABDKMathQuad.ONE.div(ABDKMathQuad.ONE.add(crp.maxRatioChanges[j][i])).powu(capExponent).to128x128()
+                ABDKMathQuad.ONE.div(ABDKMathQuad.ONE.add(crp.maxRateChanges[j][i])).powu(capExponent).to128x128()
                     .toUint256(),
                 CAP_PRECISION2
             );

From b88d7f29f595648a4f2f04d362d4c5a92ec7cebb Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sat, 24 Feb 2024 14:55:21 -0800
Subject: [PATCH 07/12] add documentation around cap order

---
 src/pumps/MultiFlowPump.sol | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index b321d569..4a42e943 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -224,15 +224,13 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             revert TooManyTokens();
         }
 
-        cappedReserves = new uint256[](2);
-        cappedReserves[0] = reserves[0];
-        cappedReserves[1] = reserves[1];
-
         Call memory wf = IWell(well).wellFunction();
         IMultiFlowPumpWellFunction mfpWf = IMultiFlowPumpWellFunction(wf.target);
 
-        cappedReserves = _capLpTokenSupply(lastReserves, cappedReserves, capExponent, crp, mfpWf, wf.data, true);
+        // The order that the LP token supply and the rates are capped are dependent upon the values of the reserves to maximize precision.
+        cappedReserves = _capLpTokenSupply(lastReserves, reserves, capExponent, crp, mfpWf, wf.data, true);
 
+        // If `_capLpTokenSupply` returns an empty array, then the rates should be capped first.
         if (cappedReserves.length == 0) {
             cappedReserves = _capRates(lastReserves, reserves, capExponent, crp, mfpWf, wf.data);
 

From 80ed67dbb116650af353e99dd7b7b288b3affcdc Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sat, 24 Feb 2024 15:02:26 -0800
Subject: [PATCH 08/12] add calcCapExponent

---
 src/pumps/MultiFlowPump.sol | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 4a42e943..d80a9b8b 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -91,7 +91,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             alphaN = alpha.powu(deltaTimestamp);
             deltaTimestampBytes = deltaTimestamp.fromUInt();
             // Round up in case capInterval > block time to guarantee capExponent > 0 if time has passed since the last update.
-            capExponent = ((deltaTimestamp - 1) / capInterval + 1);
+            capExponent = calcCapExponent(deltaTimestamp, capInterval);
         }
 
         pumpState.lastReserves = _capReserves(msg.sender, pumpState.lastReserves, reserves, capExponent, crp);
@@ -197,7 +197,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             return cappedReserves;
         }
 
-        uint256 capExponent = ((deltaTimestamp - 1) / capInterval + 1);
+        uint256 capExponent = calcCapExponent(deltaTimestamp, capInterval);
         cappedReserves = _capReserves(well, cappedReserves, currentReserves, capExponent, crp);
     }
 
@@ -393,7 +393,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             }
             return emaReserves;
         }
-        uint256 capExponent = ((deltaTimestamp - 1) / capInterval + 1);
+        uint256 capExponent = calcCapExponent(deltaTimestamp, capInterval);
         lastReserves = _capReserves(well, lastReserves, reserves, capExponent, crp);
         bytes16 alphaN = alpha.powu(deltaTimestamp);
         for (uint256 i; i < numberOfReserves; ++i) {
@@ -455,7 +455,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             return cumulativeReserves;
         }
         bytes16 deltaTimestampBytes = deltaTimestamp.fromUInt();
-        uint256 capExponent = ((deltaTimestamp - 1) / capInterval + 1);
+        uint256 capExponent = calcCapExponent(deltaTimestamp, capInterval);
         lastReserves = _capReserves(well, lastReserves, reserves, capExponent, crp);
         // Currently, there is so support for overflow.
         for (uint256 i; i < cumulativeReserves.length; ++i) {
@@ -488,6 +488,13 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
 
     //////////////////// HELPERS ////////////////////
 
+    /**
+     * @dev Calculate the cap exponent for a given `deltaTimestamp` and `capInterval`.
+     */
+    function calcCapExponent(uint256 deltaTimestamp, uint256 capInterval) internal pure returns (uint256 capExponent) {
+        capExponent = ((deltaTimestamp - 1) / capInterval + 1);
+    }
+
     /**
      * @dev Convert an `address` into a `bytes32` by zero padding the right 12 bytes.
      */

From 4a2f50ee54b42155085ec2f01baadb63bc41eccc Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sat, 24 Feb 2024 15:05:41 -0800
Subject: [PATCH 09/12] move struct up

---
 src/pumps/MultiFlowPump.sol | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index d80a9b8b..fb3875e6 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -57,6 +57,13 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         bytes16 maxLpSupplyDecrease;
     }
 
+    struct CapRatesVariables {
+        uint256 r;
+        uint256 rLast;
+        uint256 rLimit;
+        uint256[] ratios;
+    }
+
     //////////////////// PUMP ////////////////////
 
     /**
@@ -240,13 +247,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         }
     }
 
-    struct CapRatesVariables {
-        uint256 r;
-        uint256 rLast;
-        uint256 rLimit;
-        uint256[] ratios;
-    }
-
     /**
      * @dev Cap the change in ratio of `reserves` to a maximum % change from `lastReserves`.
      */

From c37e6fc1e4895ae40647fb82cca69c69ee1a2b68 Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sun, 25 Feb 2024 11:10:34 -0800
Subject: [PATCH 10/12] move enforce min of 1

---
 src/pumps/MultiFlowPump.sol | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index fb3875e6..c3d028ac 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -330,8 +330,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 // If `_capLpTokenSupply` decreases the reserves, cap the ratio first, to maximize precision.
                 if (returnIfBelowMin) return new uint256[](0);
                 cappedReserves = tryCalcLPTokenUnderlying(mfpWf, maxLpTokenSupply, cappedReserves, lpTokenSupply, data);
-                if (cappedReserves[0] == 0) cappedReserves[0] = 1;
-                if (cappedReserves[1] == 0) cappedReserves[1] = 1;
             }
             // If LP Token Suppply decreased, check that it didn't increase below the min.
         } else if (lpTokenSupply < lastLpTokenSupply) {
@@ -339,8 +337,6 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 * (ABDKMathQuad.ONE.sub(crp.maxLpSupplyDecrease)).powu(capExponent).to128x128().toUint256() / CAP_PRECISION2;
             if (lpTokenSupply < minLpTokenSupply) {
                 cappedReserves = tryCalcLPTokenUnderlying(mfpWf, minLpTokenSupply, cappedReserves, lpTokenSupply, data);
-                if (cappedReserves[0] == 0) cappedReserves[0] = 1;
-                if (cappedReserves[1] == 0) cappedReserves[1] = 1;
             }
         }
     }
@@ -553,6 +549,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
     /**
      * @dev Assumes that if `calcLPTokenUnderlying` fails, it fails because of overflow.
      * If the call fails, returns the maximum possible return value for `calcLPTokenUnderlying`.
+     * Also, enforces a minimum of 1 for each reserve.
      */
     function tryCalcLPTokenUnderlying(
         IMultiFlowPumpWellFunction wf,
@@ -565,6 +562,11 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             uint256[] memory _underlyingAmounts
         ) {
             underlyingAmounts = _underlyingAmounts;
+            for (uint256 i; i < underlyingAmounts.length; ++i) {
+                if (underlyingAmounts[i] == 0) {
+                    underlyingAmounts[i] = 1;
+                }
+            }
         } catch {
             underlyingAmounts = new uint256[](reserves.length);
             for (uint256 i; i < reserves.length; ++i) {

From f46d5ff41b35131b2ad1cfb8c0b180e343c66aa3 Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sun, 25 Feb 2024 11:12:30 -0800
Subject: [PATCH 11/12] mulDiv

---
 src/pumps/MultiFlowPump.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index c3d028ac..60b38661 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -272,7 +272,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             crv.rLimit = tempExp.cmp(MAX_CONVERT_TO_128x128) != -1
                 ? crv.rLimit = type(uint256).max
                 : crv.rLast.mulDivOrMax(tempExp.to128x128().toUint256(), CAP_PRECISION2);
-            if (cappedReserves[i] * CAP_PRECISION / cappedReserves[j] > crv.rLimit) {
+            if (cappedReserves[i].mulDiv(CAP_PRECISION, cappedReserves[j]) > crv.rLimit) {
                 crv.ratios = new uint256[](2);
                 crv.ratios[i] = crv.rLimit;
                 crv.ratios[j] = CAP_PRECISION;
@@ -289,7 +289,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                     .toUint256(),
                 CAP_PRECISION2
             );
-            if (cappedReserves[i] * CAP_PRECISION / cappedReserves[j] < crv.rLimit) {
+            if (cappedReserves[i].mulDiv(CAP_PRECISION, cappedReserves[j]) < crv.rLimit) {
                 crv.ratios = new uint256[](2);
                 crv.ratios[i] = crv.rLimit;
                 crv.ratios[j] = CAP_PRECISION;

From c13a263ec9f1c62c1fd5482808156b4f342d88df Mon Sep 17 00:00:00 2001
From: brendan <brendangsanderson@gmail.com>
Date: Sun, 25 Feb 2024 12:39:29 -0800
Subject: [PATCH 12/12] add calcReservesAtRatioSwap

---
 src/pumps/MultiFlowPump.sol | 41 ++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/src/pumps/MultiFlowPump.sol b/src/pumps/MultiFlowPump.sol
index 60b38661..ea29f6e7 100644
--- a/src/pumps/MultiFlowPump.sol
+++ b/src/pumps/MultiFlowPump.sol
@@ -273,14 +273,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 ? crv.rLimit = type(uint256).max
                 : crv.rLast.mulDivOrMax(tempExp.to128x128().toUint256(), CAP_PRECISION2);
             if (cappedReserves[i].mulDiv(CAP_PRECISION, cappedReserves[j]) > crv.rLimit) {
-                crv.ratios = new uint256[](2);
-                crv.ratios[i] = crv.rLimit;
-                crv.ratios[j] = CAP_PRECISION;
-                // Use a minimum of 1 for reserve. Geometric means will be set to 0 if a reserve is 0.
-                uint256 cappedReserveI =
-                    Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, i, crv.ratios, data), 1);
-                cappedReserves[j] = Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, j, crv.ratios, data), 1);
-                cappedReserves[i] = cappedReserveI;
+                calcReservesAtRatioSwap(mfpWf, crv.rLimit, cappedReserves, i, j, data);
             }
             // If the ratio decreased, check that it didn't decrease below the max.
         } else if (crv.r < crv.rLast) {
@@ -290,14 +283,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 CAP_PRECISION2
             );
             if (cappedReserves[i].mulDiv(CAP_PRECISION, cappedReserves[j]) < crv.rLimit) {
-                crv.ratios = new uint256[](2);
-                crv.ratios[i] = crv.rLimit;
-                crv.ratios[j] = CAP_PRECISION;
-                // Use a minimum of 1 for reserve. Geometric means will be set to 0 if a reserve is 0.
-                uint256 cappedReserveI =
-                    Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, i, crv.ratios, data), 1);
-                cappedReserves[j] = Math.max(tryCalcReserveAtRatioSwap(mfpWf, cappedReserves, j, crv.ratios, data), 1);
-                cappedReserves[i] = cappedReserveI;
+                calcReservesAtRatioSwap(mfpWf, crv.rLimit, cappedReserves, i, j, data);
             }
         }
     }
@@ -487,10 +473,31 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
     /**
      * @dev Calculate the cap exponent for a given `deltaTimestamp` and `capInterval`.
      */
-    function calcCapExponent(uint256 deltaTimestamp, uint256 capInterval) internal pure returns (uint256 capExponent) {
+    function calcCapExponent(uint256 deltaTimestamp, uint256 capInterval) private pure returns (uint256 capExponent) {
         capExponent = ((deltaTimestamp - 1) / capInterval + 1);
     }
 
+    /**
+     * @dev Calculates the capped reserves given a rate limit.
+     */
+    function calcReservesAtRatioSwap(
+        IMultiFlowPumpWellFunction mfpWf,
+        uint256 rLimit,
+        uint256[] memory reserves,
+        uint256 i,
+        uint256 j,
+        bytes memory data
+    ) private view returns (uint256[] memory) {
+        uint256[] memory ratios = new uint256[](2);
+        ratios[i] = rLimit;
+        ratios[j] = CAP_PRECISION;
+        // Use a minimum of 1 for reserve. Geometric means will be set to 0 if a reserve is 0.
+        uint256 cappedReserveI = Math.max(tryCalcReserveAtRatioSwap(mfpWf, reserves, i, ratios, data), 1);
+        reserves[j] = Math.max(tryCalcReserveAtRatioSwap(mfpWf, reserves, j, ratios, data), 1);
+        reserves[i] = cappedReserveI;
+        return reserves;
+    }
+
     /**
      * @dev Convert an `address` into a `bytes32` by zero padding the right 12 bytes.
      */