Multiple storage contracts in solidity contract

contracts/StorageContracts.sol

@@ -4,19 +4,59 @@ pragma solidity ^0.8.0;
 import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
 
 contract StorageContracts {
-  uint public immutable duration; // contract duration in seconds
-  uint public immutable size; // storage size in bytes
-  bytes32 public immutable contentHash; // hash of data that is to be stored
-  uint public immutable price; // price in coins
-  address public immutable host; // host that provides storage
-  uint public immutable proofPeriod; // average time between proofs (in blocks)
-  uint public immutable proofTimeout; // proof has to be submitted before this
-  uint public immutable proofMarker; // indicates when a proof is required
 
-  mapping(uint => bool) proofReceived; // whether proof for a block was received
+  struct Contract {
-  uint public missingProofs;
+    bool initialized; // always true, except for empty contracts in mapping
+    uint duration; // contract duration in seconds
+    uint size; // storage size in bytes
+    bytes32 contentHash; // hash of data that is to be stored
+    uint price; // price in coins
+    address host; // host that provides storage
+    uint proofPeriod; // average time between proofs (in blocks)
+    uint proofTimeout; // proof has to be submitted before this
+    uint proofMarker; // indicates when a proof is required
+    mapping(uint => bool) proofReceived; // whether proof for block was received
+    uint missingProofs;
+  }
 
-  constructor(uint _duration,
+  uint numberOfContracts;
+  mapping(uint => Contract) contracts;
+
+  function duration(uint contractId) public view returns (uint) {
+    return contracts[contractId].duration;
+  }
+
+  function size(uint contractId) public view returns (uint) {
+    return contracts[contractId].size;
+  }
+
+  function contentHash(uint contractId) public view returns (bytes32) {
+    return contracts[contractId].contentHash;
+  }
+
+  function price(uint contractId) public view returns (uint) {
+    return contracts[contractId].price;
+  }
+
+  function host(uint contractId) public view returns (address) {
+    return contracts[contractId].host;
+  }
+
+  function proofPeriod(uint contractId) public view returns (uint) {
+    return contracts[contractId].proofPeriod;
+  }
+
+  function proofTimeout(uint contractId) public view returns (uint) {
+    return contracts[contractId].proofTimeout;
+  }
+
+  function missingProofs(uint contractId) public view returns (uint) {
+    return contracts[contractId].missingProofs;
+  }
+
+  function newContract(
+    uint contractId,
+    uint _duration,
     uint _size,
     bytes32 _contentHash,
     uint _price,
@@ -25,7 +65,9 @@ contract StorageContracts {
     uint _bidExpiry,
     address _host,
     bytes memory requestSignature,
-              bytes memory bidSignature)
+    bytes memory bidSignature
+  )
+    public
   {
     bytes32 requestHash = hashRequest(
       _duration,
@@ -39,14 +81,17 @@ contract StorageContracts {
     checkSignature(bidSignature, bidHash, _host);
     checkProofTimeout(_proofTimeout);
     checkBidExpiry(_bidExpiry);
-    duration = _duration;
+    checkId(contractId);
-    size = _size;
+    Contract storage c = contracts[contractId];
-    price = _price;
+    c.initialized = true;
-    contentHash = _contentHash;
+    c.duration = _duration;
-    host = _host;
+    c.size = _size;
-    proofPeriod = _proofPeriod;
+    c.price = _price;
-    proofTimeout = _proofTimeout;
+    c.contentHash = _contentHash;
-    proofMarker = uint(blockhash(block.number - 1)) % _proofPeriod;
+    c.host = _host;
+    c.proofPeriod = _proofPeriod;
+    c.proofTimeout = _proofTimeout;
+    c.proofMarker = uint(blockhash(block.number - 1)) % _proofPeriod;
   }
 
   // Creates hash for a storage request that can be used to check its signature.
@@ -103,31 +148,75 @@ contract StorageContracts {
     require(expiry > block.timestamp, "Bid expired");
   }
 
+  function checkId(uint contractId) internal view {
+    require(
+      !contracts[contractId].initialized,
+      "A contract with this id already exists"
+    );
+  }
+
   // Check whether a proof is required at the time of the block with the
   // specified block number. A proof has to be submitted within the proof
   // timeout for it to be valid. Whether a proof is required is determined
   // randomly, but on average it is once every proof period.
-  function isProofRequired(uint blocknumber) public view returns (bool) {
+  function isProofRequired(
+    uint contractId,
+    uint blocknumber
+  )
+    public view
+    returns (bool)
+  {
+    Contract storage c = contracts[contractId];
     bytes32 hash = blockhash(blocknumber);
-    return hash != 0 && uint(hash) % proofPeriod == proofMarker;
+    return hash != 0 && uint(hash) % c.proofPeriod == c.proofMarker;
   }
 
-  function isProofTimedOut(uint blocknumber) internal view returns (bool) {
+  function isProofTimedOut(
-    return block.number >= blocknumber + proofTimeout;
+    uint contractId,
+    uint blocknumber
+  )
+    internal view
+    returns (bool)
+  {
+    Contract storage c = contracts[contractId];
+    return block.number >= blocknumber + c.proofTimeout;
   }
 
-  function submitProof(uint blocknumber, bool proof) public {
+  function submitProof(
+    uint contractId,
+    uint blocknumber,
+    bool proof
+  )
+    public
+  {
+    Contract storage c = contracts[contractId];
     require(proof, "Invalid proof"); // TODO: replace bool by actual proof
-    require(isProofRequired(blocknumber), "No proof required for this block");
+    require(
-    require(!isProofTimedOut(blocknumber), "Proof not allowed after timeout");
+      isProofRequired(contractId, blocknumber),
-    require(!proofReceived[blocknumber], "Proof already submitted");
+      "No proof required for this block"
-    proofReceived[blocknumber] = true;
+    );
+    require(
+      !isProofTimedOut(contractId, blocknumber),
+      "Proof not allowed after timeout"
+    );
+    require(!c.proofReceived[blocknumber], "Proof already submitted");
+    c.proofReceived[blocknumber] = true;
   }
 
-  function markProofAsMissing(uint blocknumber) public {
+  function markProofAsMissing(uint contractId, uint blocknumber) public {
-    require(isProofTimedOut(blocknumber), "Proof has not timed out yet");
+    Contract storage c = contracts[contractId];
-    require(!proofReceived[blocknumber], "Proof was submitted, not missing");
+    require(
-    require(isProofRequired(blocknumber), "Proof was not required");
+      isProofTimedOut(contractId, blocknumber),
-    missingProofs += 1;
+      "Proof has not timed out yet"
+    );
+    require(
+      !c.proofReceived[blocknumber],
+      "Proof was submitted, not missing"
+    );
+    require(
+      isProofRequired(contractId, blocknumber),
+      "Proof was not required"
+    );
+    c.missingProofs += 1;
   }
 }

test/StorageContracts.test.js

@@ -11,15 +11,16 @@ describe("Storage Contracts", function () {
   const proofTimeout = 4 // 4 blocks ≈ 1 minute
   const price = 42
 
-  var StorageContracts
+  var contracts
   var client, host
   var bidExpiry
   var requestHash, bidHash
-  var contract
+  var id
 
   beforeEach(async function () {
     [client, host] = await ethers.getSigners()
-    StorageContracts = await ethers.getContractFactory("StorageContracts")
+    let StorageContracts = await ethers.getContractFactory("StorageContracts")
+    contracts = await StorageContracts.deploy()
     requestHash = hashRequest(
       duration,
       size,
@@ -29,12 +30,14 @@ describe("Storage Contracts", function () {
     )
     bidExpiry = Math.round(Date.now() / 1000) + 60 * 60 // 1 hour from now
     bidHash = hashBid(requestHash, bidExpiry, price)
+    id = Math.round(Math.random() * 99999999) // randomly chosen contract id
   })
 
   describe("when properly instantiated", function () {
 
     beforeEach(async function () {
-      contract = await StorageContracts.deploy(
+      await contracts.newContract(
+        id,
         duration,
         size,
         contentHash,
@@ -49,34 +52,63 @@ describe("Storage Contracts", function () {
     })
 
     it("has a duration", async function () {
-      expect(await contract.duration()).to.equal(duration)
+      expect(await contracts.duration(id)).to.equal(duration)
     })
 
     it("contains the size of the data that is to be stored", async function () {
-      expect(await contract.size()).to.equal(size)
+      expect(await contracts.size(id)).to.equal(size)
     })
 
     it("contains the hash of the data that is to be stored", async function () {
-      expect(await contract.contentHash()).to.equal(contentHash)
+      expect(await contracts.contentHash(id)).to.equal(contentHash)
     })
 
     it("has a price", async function () {
-      expect(await contract.price()).to.equal(price)
+      expect(await contracts.price(id)).to.equal(price)
     })
 
     it("knows the host that provides the storage", async function () {
-      expect(await contract.host()).to.equal(await host.getAddress())
+      expect(await contracts.host(id)).to.equal(await host.getAddress())
     })
 
     it("has an average time between proofs (in blocks)", async function (){
-      expect(await contract.proofPeriod()).to.equal(proofPeriod)
+      expect(await contracts.proofPeriod(id)).to.equal(proofPeriod)
     })
 
     it("has a proof timeout (in blocks)", async function (){
-      expect(await contract.proofTimeout()).to.equal(proofTimeout)
+      expect(await contracts.proofTimeout(id)).to.equal(proofTimeout)
     })
   })
 
+  it("cannot be created when contract id already used", async function () {
+    await contracts.newContract(
+      id,
+      duration,
+      size,
+      contentHash,
+      price,
+      proofPeriod,
+      proofTimeout,
+      bidExpiry,
+      await host.getAddress(),
+      await sign(client, requestHash),
+      await sign(host, bidHash)
+    )
+    await expect(contracts.newContract(
+      id,
+      duration,
+      size,
+      contentHash,
+      price,
+      proofPeriod,
+      proofTimeout,
+      bidExpiry,
+      await host.getAddress(),
+      await sign(client, requestHash),
+      await sign(host, bidHash)
+    )).to.be.revertedWith("A contract with this id already exists")
+  })
+
   it("cannot be created when client signature is invalid", async function () {
     let invalidHash = hashRequest(
       duration + 1,
@@ -86,7 +118,8 @@ describe("Storage Contracts", function () {
       proofTimeout
     )
     let invalidSignature = await sign(client, invalidHash)
-    await expect(StorageContract.deploy(
+    await expect(contracts.newContract(
+      id,
       duration,
       size,
       contentHash,
@@ -103,7 +136,8 @@ describe("Storage Contracts", function () {
   it("cannot be created when host signature is invalid", async function () {
     let invalidBid = hashBid(requestHash, bidExpiry, price - 1)
     let invalidSignature = await sign(host, invalidBid)
-    await expect(StorageContract.deploy(
+    await expect(contracts.newContract(
+      id,
       duration,
       size,
       contentHash,
@@ -127,7 +161,8 @@ describe("Storage Contracts", function () {
       invalidTimeout
     )
     bidHash = hashBid(requestHash, bidExpiry, price)
-    await expect(StorageContract.deploy(
+    await expect(contracts.newContract(
+      id,
       duration,
       size,
       contentHash,
@@ -144,7 +179,8 @@ describe("Storage Contracts", function () {
   it("cannot be created when bid has expired", async function () {
     let expired = Math.round(Date.now() / 1000) - 60 // 1 minute ago
     let bidHash = hashBid(requestHash, expired, price)
-    await expect(StorageContract.deploy(
+    await expect(contracts.newContract(
+      id,
       duration,
       size,
       contentHash,
@@ -168,8 +204,8 @@ describe("Storage Contracts", function () {
       return await ethers.provider.getBlockNumber() - 1
     }
 
-    async function mineUntilProofIsRequired() {
+    async function mineUntilProofIsRequired(id) {
-      while (!await contract.isProofRequired(await minedBlockNumber())) {
+      while (!await contracts.isProofRequired(id, await minedBlockNumber())) {
         mineBlock()
       }
     }
@@ -181,7 +217,8 @@ describe("Storage Contracts", function () {
     }
 
     beforeEach(async function () {
-      contract = await StorageContract.deploy(
+      await contracts.newContract(
+        id,
         duration,
         size,
         contentHash,
@@ -200,7 +237,7 @@ describe("Storage Contracts", function () {
       let proofs = 0
       for (i=0; i<blocks; i++) {
         await mineBlock()
-        if (await contract.isProofRequired(await minedBlockNumber())) {
+        if (await contracts.isProofRequired(id, await minedBlockNumber())) {
           proofs += 1
         }
       }
@@ -209,92 +246,92 @@ describe("Storage Contracts", function () {
     })
 
     it("requires no proof for blocks that are unavailable", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
       for (i=0; i<256; i++) { // only last 256 blocks are available in solidity
         mineBlock()
       }
-      expect(await contract.isProofRequired(blocknumber)).to.be.false
+      expect(await contracts.isProofRequired(id, blocknumber)).to.be.false
     })
 
     it("submits a correct proof", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
-      await contract.submitProof(blocknumber, true)
+      await contracts.submitProof(id, blocknumber, true)
     })
 
     it("fails proof submission when proof is incorrect", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
       await expect(
-        contract.submitProof(blocknumber, false)
+        contracts.submitProof(id, blocknumber, false)
       ).to.be.revertedWith("Invalid proof")
     })
 
     it("fails proof submission when proof was not required", async function () {
-      while (await contract.isProofRequired(await minedBlockNumber())) {
+      while (await contracts.isProofRequired(id, await minedBlockNumber())) {
         await mineBlock()
       }
       let blocknumber = await minedBlockNumber()
       await expect(
-        contract.submitProof(blocknumber, true)
+        contracts.submitProof(id, blocknumber, true)
       ).to.be.revertedWith("No proof required")
     })
 
     it("fails proof submission when proof is too late", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
       await mineUntilProofTimeout()
       await expect(
-        contract.submitProof(blocknumber, true)
+        contracts.submitProof(id, blocknumber, true)
       ).to.be.revertedWith("Proof not allowed after timeout")
     })
 
     it("fails proof submission when already submitted", async function() {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
-      await contract.submitProof(blocknumber, true)
+      await contracts.submitProof(id, blocknumber, true)
       await expect(
-        contract.submitProof(blocknumber, true)
+        contracts.submitProof(id, blocknumber, true)
       ).to.be.revertedWith("Proof already submitted")
     })
 
     it("marks a proof as missing", async function () {
-      expect(await contract.missingProofs()).to.equal(0)
+      expect(await contracts.missingProofs(id)).to.equal(0)
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
       await mineUntilProofTimeout()
-      await contract.markProofAsMissing(blocknumber)
+      await contracts.markProofAsMissing(id, blocknumber)
-      expect(await contract.missingProofs()).to.equal(1)
+      expect(await contracts.missingProofs(id)).to.equal(1)
     })
 
     it("does not mark a proof as missing before timeout", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
       await mineBlock()
       await expect(
-        contract.markProofAsMissing(blocknumber)
+        contracts.markProofAsMissing(id, blocknumber)
       ).to.be.revertedWith("Proof has not timed out yet")
     })
 
     it("does not mark a submitted proof as missing", async function () {
-      await mineUntilProofIsRequired()
+      await mineUntilProofIsRequired(id)
       let blocknumber = await minedBlockNumber()
-      await contract.submitProof(blocknumber, true)
+      await contracts.submitProof(id, blocknumber, true)
       await mineUntilProofTimeout()
       await expect(
-        contract.markProofAsMissing(blocknumber)
+        contracts.markProofAsMissing(id, blocknumber)
       ).to.be.revertedWith("Proof was submitted, not missing")
     })
 
     it("does not mark proof as missing when not required", async function () {
-      while (await contract.isProofRequired(await minedBlockNumber())) {
+      while (await contracts.isProofRequired(id, await minedBlockNumber())) {
         mineBlock()
       }
       let blocknumber = await minedBlockNumber()
       await mineUntilProofTimeout()
       await expect(
-        contract.markProofAsMissing(blocknumber)
+        contracts.markProofAsMissing(id, blocknumber)
       ).to.be.revertedWith("Proof was not required")
     })
   })
@@ -306,4 +343,3 @@ describe("Storage Contracts", function () {
 // TODO: only allow proofs after start of contract
 // TODO: payout
 // TODO: stake
-// TODO: multiple hosts in single contract