Move MAX_MONEY into a core chain parameter

Enables support for blockchains whose MAX_MONEY does not match Bitcoin.

Author: Ross Nicoll

bitcoin/core/__init__.py

@@ -24,12 +24,15 @@
 
 # Core definitions
 COIN = 100000000
-MAX_MONEY = 21000000 * COIN
 MAX_BLOCK_SIZE = 1000000
 MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50
 
-def MoneyRange(nValue):
-    return 0 <= nValue <= MAX_MONEY
+def MoneyRange(nValue, params=None):
+    global coreparams
+    if not params:
+      params = coreparams
+
+    return 0 <= nValue <= params.MAX_MONEY
 
 def _py2_x(h):
     """Convert a hex string to bytes"""
@@ -537,12 +540,14 @@ def GetHash(self):
 
 class CoreChainParams(object):
     """Define consensus-critical parameters of a given instance of the Bitcoin system"""
+    MAX_MONEY = None
     GENESIS_BLOCK = None
     PROOF_OF_WORK_LIMIT = None
     SUBSIDY_HALVING_INTERVAL = None
     NAME = None
 
 class CoreMainParams(CoreChainParams):
+    MAX_MONEY = 21000000 * COIN
     NAME = 'mainnet'
     GENESIS_BLOCK = CBlock.deserialize(x('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'))
     SUBSIDY_HALVING_INTERVAL = 210000
@@ -586,6 +591,7 @@ def CheckTransaction(tx):
 
     Raises CheckTransactionError
     """
+    global coreparams
 
     if not tx.vin:
         raise CheckTransactionError("CheckTransaction() : vin empty")
@@ -601,7 +607,7 @@ def CheckTransaction(tx):
     for txout in tx.vout:
         if txout.nValue < 0:
             raise CheckTransactionError("CheckTransaction() : txout.nValue negative")
-        if txout.nValue > MAX_MONEY:
+        if txout.nValue > coreparams.MAX_MONEY:
             raise CheckTransactionError("CheckTransaction() : txout.nValue too high")
         nValueOut += txout.nValue
         if not MoneyRange(nValueOut):
@@ -737,7 +743,6 @@ def CheckBlock(block, fCheckPoW = True, fCheckMerkleRoot = True, cur_time=None):
         'Hash',
         'Hash160',
         'COIN',
-        'MAX_MONEY',
         'MAX_BLOCK_SIZE',
         'MAX_BLOCK_SIGOPS',
         'MoneyRange',

bitcoin/tests/test_core.py

@@ -32,6 +32,21 @@ def T(value, expected):
         T(1001000000, '10.01')
         T(1012345678, '10.12345678')
 
+class Test_Money(unittest.TestCase):
+    def test_MoneyRange(self):
+        self.assertFalse(MoneyRange(-1))
+        self.assertTrue(MoneyRange(0))
+        self.assertTrue(MoneyRange(100000))
+        self.assertTrue(MoneyRange(21000000 * COIN)) # Maximum money on Bitcoin network
+        self.assertFalse(MoneyRange(21000001 * COIN))
+
+    def test_MoneyRangeCustomParams(self):
+        highMaxParamsType = type(str('CoreHighMainParams'), (CoreMainParams,object), {'MAX_MONEY': 22000000 * COIN })
+        highMaxParams = highMaxParamsType()
+        self.assertTrue(MoneyRange(21000001 * COIN, highMaxParams))
+        self.assertTrue(MoneyRange(22000000 * COIN, highMaxParams))
+        self.assertFalse(MoneyRange(22000001 * COIN, highMaxParams))
+
 class Test_CBlockHeader(unittest.TestCase):
     def test_serialization(self):
         genesis = CBlockHeader(nVersion=1,