Remove the implementation of score-based block template construction

and the `-blockminsize` option.

Signed-off-by: Daira Emma Hopwood <daira@jacaranda.org>

doc/release-notes.md

@@ -52,6 +52,9 @@ We now use a new block template construction algorithm documented in
   "high priority" because they spent older inputs. The `-blockprioritysize` config
   option, which configured the portion of the block reserved for these transactions,
   has been removed and will now cause a warning if used.
+- The `-blockminsize` option, which configured the size of a portion of the block
+  to be filled regardless of transaction fees or priority, has also been removed
+  and will cause a warning if used.
 
 Removal of Priority Estimation
 ------------------------------

qa/rpc-tests/show_help.py

@@ -399,9 +399,6 @@ Node relay options:
 
 Block creation options:
 
-  -blockminsize=<n>
-       Set minimum block size in bytes (default: 0)
-
   -blockmaxsize=<n>
        Set maximum block size in bytes (default: 2000000)
 

src/init.cpp

@@ -500,7 +500,6 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-datacarriersize", strprintf(_("Maximum size of data in data carrier transactions we relay and mine (default: %u)"), MAX_OP_RETURN_RELAY));
 
     strUsage += HelpMessageGroup(_("Block creation options:"));
-    strUsage += HelpMessageOpt("-blockminsize=<n>", strprintf(_("Set minimum block size in bytes (default: %u)"), DEFAULT_BLOCK_MIN_SIZE));
     strUsage += HelpMessageOpt("-blockmaxsize=<n>", strprintf(_("Set maximum block size in bytes (default: %d)"), DEFAULT_BLOCK_MAX_SIZE));
     if (GetBoolArg("-help-debug", false))
         strUsage += HelpMessageOpt("-blockversion=<n>", strprintf("Override block version to test forking scenarios (default: %d)", (int)CBlock::CURRENT_VERSION));
@@ -1292,6 +1291,10 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
     }
 #endif
 
+    if (GetArg("-blockminsize", 0) != 0) {
+        InitWarning(_("The argument -blockminsize is no longer supported."));
+    }
+
     if (GetArg("-blockprioritysize", 0) != 0) {
         InitWarning(_("The argument -blockprioritysize is no longer supported."));
     }

src/miner.cpp

@@ -339,11 +339,6 @@ BlockAssembler::BlockAssembler(const CChainParams& _chainparams)
     nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
     // Limit to between 1K and MAX_BLOCK_SIZE-1K for sanity:
     nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
-
-    // 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:
-    nBlockMinSize = GetArg("-blockminsize", DEFAULT_BLOCK_MIN_SIZE);
-    nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
 }
 
 void BlockAssembler::resetBlock(const MinerAddress& minerAddress)
@@ -730,63 +725,6 @@ void BlockAssembler::addTransactions(
     }
 }
 
-void BlockAssembler::addScoreTxs()
-{
-    std::priority_queue<CTxMemPool::txiter, std::vector<CTxMemPool::txiter>, ScoreCompare> clearedTxs;
-    CTxMemPool::setEntries waitSet;
-    CTxMemPool::indexed_transaction_set::index<mining_score>::type::iterator mi = mempool.mapTx.get<mining_score>().begin();
-    CTxMemPool::txiter iter;
-    while (!blockFinished && (mi != mempool.mapTx.get<mining_score>().end() || !clearedTxs.empty()))
-    {
-        // If no txs that were previously postponed are available to try
-        // again, then try the next highest score tx
-        if (clearedTxs.empty()) {
-            iter = mempool.mapTx.project<0>(mi);
-            mi++;
-        }
-        // If a previously postponed tx is available to try again, then it
-        // has higher score than all untried so far txs
-        else {
-            iter = clearedTxs.top();
-            clearedTxs.pop();
-        }
-
-        // If tx already in block, skip  (added by addPriorityTxs)
-        if (inBlock.count(iter)) {
-            continue;
-        }
-
-        // If tx is dependent on other mempool txs which haven't yet been included
-        // then put it in the waitSet
-        if (isStillDependent(iter)) {
-            waitSet.insert(iter);
-            continue;
-        }
-
-        // If the fee rate is below the min fee rate for mining, then we're done
-        // adding txs based on score (fee rate)
-        if ((iter->GetModifiedFee() < ::minRelayTxFee.GetFee(iter->GetTxSize())) &&
-            (iter->GetModifiedFee() < DEFAULT_FEE) &&
-            (nBlockSize >= nBlockMinSize)) {
-            return;
-        }
-
-        // If this tx fits in the block add it, otherwise keep looping
-        if (TestForBlock(iter)) {
-            AddToBlock(iter);
-
-            // This tx was successfully added, so
-            // add transactions that depend on this one to the priority queue to try again
-            for (CTxMemPool::txiter child : mempool.GetMemPoolChildren(iter))
-            {
-                if (waitSet.count(child)) {
-                    clearedTxs.push(child);
-                    waitSet.erase(child);
-                }
-            }
-        }
-    }
-}
 
 //////////////////////////////////////////////////////////////////////////////
 //

src/miner.h

@@ -107,8 +107,8 @@ private:
     // A convenience pointer that always refers to the CBlock in pblocktemplate
     CBlock* pblock;
 
-    // Configuration parameters for the block size
-    unsigned int nBlockMaxSize, nBlockMinSize;
+    // Configuration parameter for the block size
+    unsigned int nBlockMaxSize;
 
     // Information on the current status of the block
     uint64_t nBlockSize;

src/policy/policy.h

@@ -15,9 +15,8 @@
 class CChainParams;
 class CCoinsViewCache;
 
-/** Default for -blockmaxsize and -blockminsize, which control the range of sizes the mining code will create **/
+/** Default for -blockmaxsize, which controls the maximum block size the mining code will create **/
 static const unsigned int DEFAULT_BLOCK_MAX_SIZE = MAX_BLOCK_SIZE;
-static const unsigned int DEFAULT_BLOCK_MIN_SIZE = 0;
 
 /** Maximum number of signature check operations in an IsStandard() P2SH script */
 static const unsigned int MAX_P2SH_SIGOPS = 15;