Minimal consensus/miner changes for 2mb block size bump.

src/consensus/consensus.h

@@ -6,10 +6,12 @@
 #ifndef BITCOIN_CONSENSUS_CONSENSUS_H
 #define BITCOIN_CONSENSUS_CONSENSUS_H
 
-/** The maximum allowed size for a serialized block, in bytes (network rule) */
-static const unsigned int MAX_BLOCK_SIZE = 1000000;
-/** The maximum allowed number of signature check operations in a block (network rule) */
-static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
+/** Block size limit, post-2MB fork */
+static const unsigned int MAX_BLOCK_SIZE = 2000000;
+/** The old block size limit */
+static const unsigned int OLD_MAX_BLOCK_SIZE = 1000000;
+/** pre-2MB-fork limit on signature operations in a block */
+static const unsigned int MAX_BLOCK_SIGOPS = OLD_MAX_BLOCK_SIZE/50;
 /** Coinbase transaction outputs can only be spent after this number of new blocks (network rule) */
 static const int COINBASE_MATURITY = 100;
 

src/main.cpp

@@ -2742,15 +2742,17 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bo
                              REJECT_INVALID, "bad-txns-duplicate", true);
     }
 
-    // All potential-corruption validation must be done before we do any
-    // transaction validation, as otherwise we may mark the header as invalid
-    // because we receive the wrong transactions for it.
-
     // Size limits
-    if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
+    unsigned int nSizeLimit = MaxBlockSize(block.nTime);
+
+    if (block.vtx.empty() || block.vtx.size() > nSizeLimit || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION) > nSizeLimit)
         return state.DoS(100, error("CheckBlock(): size limits failed"),
                          REJECT_INVALID, "bad-blk-length");
 
+    // All potential-corruption validation must be done before we do any
+    // transaction validation, as otherwise we may mark the header as invalid
+    // because we receive the wrong transactions for it.
+
     // First transaction must be coinbase, the rest must not be
     if (block.vtx.empty() || !block.vtx[0].IsCoinBase())
         return state.DoS(100, error("CheckBlock(): first tx is not coinbase"),
@@ -5217,6 +5219,14 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
      return strprintf("CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)", nBlocks, nSize, nHeightFirst, nHeightLast, DateTimeStrFormat("%Y-%m-%d", nTimeFirst), DateTimeStrFormat("%Y-%m-%d", nTimeLast));
  }
 
+/** Maximum size of a block */
+unsigned int MaxBlockSize(uint32_t nBLockTime)
+{
+    if (true) // TODO: activation condition
+        return MAX_BLOCK_SIZE;
+    return OLD_MAX_BLOCK_SIZE;
+}
+
 
 
 class CMainCleanup

src/main.h

@@ -492,4 +492,7 @@ extern CCoinsViewCache *pcoinsTip;
 /** Global variable that points to the active block tree (protected by cs_main) */
 extern CBlockTreeDB *pblocktree;
 
+/** Maximum size of a block */
+unsigned int MaxBlockSize(uint32_t nBlockTime);
+
 #endif // BITCOIN_MAIN_H

src/miner.cpp

@@ -116,21 +116,6 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
     pblocktemplate->vTxFees.push_back(-1); // updated at end
     pblocktemplate->vTxSigOps.push_back(-1); // updated at end
 
-    // Largest block you're willing to create:
-    unsigned int nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
-    // Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
-    nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
-
-    // How much of the block should be dedicated to high-priority transactions,
-    // included regardless of the fees they pay
-    unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
-    nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
-
-    // Minimum block size you want to create; block will be filled with free transactions
-    // until there are no more or the block reaches this size:
-    unsigned int nBlockMinSize = GetArg("-blockminsize", DEFAULT_BLOCK_MIN_SIZE);
-    nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
-
     // Collect memory pool transactions into the block
     CAmount nFees = 0;
 
@@ -142,6 +127,23 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast();
         CCoinsViewCache view(pcoinsTip);
 
+        unsigned int nSizeLimit = MaxBlockSize(nMedianTimePast);
+
+        // Largest block you're willing to create:
+        unsigned int nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
+        // Limit to betweeen 1K and max size-1K for sanity:
+        nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(nSizeLimit-1000), nBlockMaxSize));
+
+        // How much of the block should be dedicated to high-priority transactions,
+        // included regardless of the fees they pay
+        unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
+        nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
+
+        // Minimum block size you want to create; block will be filled with free transactions
+        // until there are no more or the block reaches this size:
+        unsigned int nBlockMinSize = GetArg("-blockminsize", DEFAULT_BLOCK_MIN_SIZE);
+        nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
+
         // Priority order to process transactions
         list<COrphan> vOrphan; // list memory doesn't move
         map<uint256, vector<COrphan*> > mapDependers;