Add a whole balance limit to UserDeposit

which is configurable at the deployment time.

Currently we keep the option of limiting deposits in all smart
contracts.

raiden_contracts/contracts/services/UserDeposit.sol

@@ -21,6 +21,11 @@ contract UserDeposit is Utils {
     mapping(address => uint256) public balances;
     mapping(address => WithdrawPlan) public withdraw_plans;
 
+    // The sum of all balances
+    uint256 public whole_balance = 0;
+    // Deposit limit for this whole contract
+    uint256 public whole_balance_limit;
+
     /*
      *  Structs
      */
@@ -51,14 +56,17 @@ contract UserDeposit is Utils {
 
     /// @notice Set the default values for the smart contract
     /// @param _token_address The address of the token to use for rewards
-    constructor(address _token_address)
+    constructor(address _token_address, uint256 _whole_balance_limit)
         public
     {
         // check token contract
         require(_token_address != address(0x0));
         require(contractExists(_token_address));
         token = Token(_token_address);
         require(token.totalSupply() > 0); // Check if the contract is indeed a token contract
+        // check and set the whole balance limit
+        require(_whole_balance_limit > 0);
+        whole_balance_limit = _whole_balance_limit;
     }
 
     /// @notice Specify trusted contracts. This has to be done outside of the
@@ -100,6 +108,13 @@ contract UserDeposit is Utils {
         balances[beneficiary] += added_deposit;
         total_deposit[beneficiary] += added_deposit;
         require(token.transferFrom(msg.sender, address(this), added_deposit));
+
+        // Update whole_balance, but take care against overflows.
+        require(whole_balance + added_deposit >= whole_balance);
+        whole_balance += added_deposit;
+
+        // Decline deposit if the whole balance is bigger than the limit.
+        require(whole_balance <= whole_balance_limit);
     }
 
     /// @notice Internally transfer deposits between two addresses.
@@ -161,6 +176,10 @@ contract UserDeposit is Utils {
         balances[msg.sender] -= withdrawable;
         require(token.transfer(msg.sender, withdrawable));
 
+        // Update whole_balance, but take care against underflows.
+        require(whole_balance - withdrawable <= whole_balance);
+        whole_balance -= withdrawable;
+
         emit BalanceReduced(msg.sender, balances[msg.sender]);
         delete withdraw_plans[msg.sender];
     }

raiden_contracts/data/source/services/UserDeposit.sol

@@ -21,6 +21,11 @@ contract UserDeposit is Utils {
     mapping(address => uint256) public balances;
     mapping(address => WithdrawPlan) public withdraw_plans;
 
+    // The sum of all balances
+    uint256 public whole_balance = 0;
+    // Deposit limit for this whole contract
+    uint256 public whole_balance_limit;
+
     /*
      *  Structs
      */
@@ -51,14 +56,17 @@ contract UserDeposit is Utils {
 
     /// @notice Set the default values for the smart contract
     /// @param _token_address The address of the token to use for rewards
-    constructor(address _token_address)
+    constructor(address _token_address, uint256 _whole_balance_limit)
         public
     {
         // check token contract
         require(_token_address != address(0x0));
         require(contractExists(_token_address));
         token = Token(_token_address);
         require(token.totalSupply() > 0); // Check if the contract is indeed a token contract
+        // check and set the whole balance limit
+        require(_whole_balance_limit > 0);
+        whole_balance_limit = _whole_balance_limit;
     }
 
     /// @notice Specify trusted contracts. This has to be done outside of the
@@ -100,6 +108,13 @@ contract UserDeposit is Utils {
         balances[beneficiary] += added_deposit;
         total_deposit[beneficiary] += added_deposit;
         require(token.transferFrom(msg.sender, address(this), added_deposit));
+
+        // Update whole_balance, but take care against overflows.
+        require(whole_balance + added_deposit >= whole_balance);
+        whole_balance += added_deposit;
+
+        // Decline deposit if the whole balance is bigger than the limit.
+        require(whole_balance <= whole_balance_limit);
     }
 
     /// @notice Internally transfer deposits between two addresses.
@@ -161,6 +176,10 @@ contract UserDeposit is Utils {
         balances[msg.sender] -= withdrawable;
         require(token.transfer(msg.sender, withdrawable));
 
+        // Update whole_balance, but take care against underflows.
+        require(whole_balance - withdrawable <= whole_balance);
+        whole_balance -= withdrawable;
+
         emit BalanceReduced(msg.sender, balances[msg.sender]);
         delete withdraw_plans[msg.sender];
     }

raiden_contracts/tests/fixtures/token.py

@@ -4,11 +4,19 @@
     CONTRACT_CUSTOM_TOKEN,
 )
 
-token_args = (10 ** 26, 18, CONTRACT_CUSTOM_TOKEN, 'TKN')
+
+@pytest.fixture(scope='session')
+def custom_token_total_supply():
+    return 10 ** 26
+
+
+@pytest.fixture(scope='session')
+def token_args(custom_token_total_supply):
+    return (custom_token_total_supply, 18, CONTRACT_CUSTOM_TOKEN, 'TKN')
 
 
 @pytest.fixture(scope='session')
-def custom_token_factory(deploy_tester_contract):
+def custom_token_factory(deploy_tester_contract, token_args):
     """A function that deploys a CustomToken contract"""
     def f():
         return deploy_tester_contract(
@@ -26,7 +34,7 @@ def custom_token(custom_token_factory):
 
 
 @pytest.fixture()
-def human_standard_token(deploy_token_contract):
+def human_standard_token(deploy_token_contract, token_args):
     """Deploy HumanStandardToken contract"""
     return deploy_token_contract(*token_args)
 

raiden_contracts/tests/fixtures/user_deposit.py

@@ -3,15 +3,22 @@
 from raiden_contracts.constants import CONTRACT_USER_DEPOSIT
 
 
+@pytest.fixture(scope='session')
+def user_deposit_whole_balance_limit(custom_token_total_supply):
+    return custom_token_total_supply // 100
+
+
 @pytest.fixture(scope='session')
 def uninitialized_user_deposit_contract(
         deploy_tester_contract,
         custom_token,
+        user_deposit_whole_balance_limit,
 ):
+    print(user_deposit_whole_balance_limit)
     return deploy_tester_contract(
         CONTRACT_USER_DEPOSIT,
         {},
-        [custom_token.address],
+        [custom_token.address, user_deposit_whole_balance_limit],
     )
 
 

raiden_contracts/tests/test_user_deposit_contract.py

@@ -42,6 +42,14 @@ def test_deposit(
     with pytest.raises(TransactionFailed):
         user_deposit_contract.functions.deposit(A, 21).transact({'from': A})
 
+    # Can't deposit more than the whole_balance_limit
+    limit = user_deposit_contract.functions.whole_balance_limit().call()
+    assert limit > 0
+    custom_token.functions.mint(limit + 1).transact({'from': A})
+    custom_token.functions.approve(user_deposit_contract.address, limit + 1).transact({'from': A})
+    with pytest.raises(TransactionFailed):
+        user_deposit_contract.functions.deposit(A, limit + 1).transact({'from': A})
+
 
 def test_transfer(
         uninitialized_user_deposit_contract,