Merge #15383: [rpc] mining: Omit uninitialized currentblockweight, currentblocktx

fa178a6385 [rpc] mining: Omit uninitialized currentblockweight, currentblocktx (MarcoFalke)

Pull request description:

  Previously we'd report "0", which could be mistaken for a valid number. E.g. the number of transactions is 0 or the block weight is 0, whatever that means.

Tree-SHA512: ee94ab203a329e272211b726f4c23edec4b09c650ec363b77fd59ad9264165d73064f78ebb9e11b5c2c543b73c157752410a307655560531c7d5444d203aa0ea

7 files changed, 62 insertions, 39 deletions

diff --git a/doc/release-notes.md b/doc/release-notes.md
index 113b8c07d0..a6408cf1e6 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -263,6 +263,9 @@ in the Low-level Changes section below.
 
 - See the [Mining](#mining) section for changes to `getblocktemplate`.
 
+- The `getmininginfo` RPC now omits `currentblockweight` and `currentblocktx`
+  when a block was never assembled via RPC on this node.
+
 - The `getrawtransaction` RPC & REST endpoints no longer check the
   unspent UTXO set for a transaction. The remaining behaviors are as
   follows: 1. If a blockhash is provided, check the corresponding block.
diff --git a/src/miner.cpp b/src/miner.cpp
index ef48a86e32..80a2f8f018 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -10,8 +10,8 @@
 #include <chainparams.h>
 #include <coins.h>
 #include <consensus/consensus.h>
-#include <consensus/tx_verify.h>
 #include <consensus/merkle.h>
+#include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <hash.h>
 #include <net.h>
@@ -21,22 +21,14 @@
 #include <primitives/transaction.h>
 #include <script/standard.h>
 #include <timedata.h>
-#include <util/system.h>
 #include <util/moneystr.h>
+#include <util/system.h>
 #include <validationinterface.h>
 
 #include <algorithm>
 #include <queue>
 #include <utility>
 
-// Unconfirmed transactions in the memory pool often depend on other
-// transactions in the memory pool. When we select transactions from the
-// pool, we select by highest fee rate of a transaction combined with all
-// its ancestors.
-
-uint64_t nLastBlockTx = 0;
-uint64_t nLastBlockWeight = 0;
-
 int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
 {
     int64_t nOldTime = pblock->nTime;
@@ -95,6 +87,9 @@ void BlockAssembler::resetBlock()
     nFees = 0;
 }
 
+Optional<int64_t> BlockAssembler::m_last_block_num_txs{nullopt};
+Optional<int64_t> BlockAssembler::m_last_block_weight{nullopt};
+
 std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& scriptPubKeyIn)
 {
     int64_t nTimeStart = GetTimeMicros();
@@ -147,8 +142,8 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
 
     int64_t nTime1 = GetTimeMicros();
 
-    nLastBlockTx = nBlockTx;
-    nLastBlockWeight = nBlockWeight;
+    m_last_block_num_txs = nBlockTx;
+    m_last_block_weight = nBlockWeight;
 
     // Create coinbase transaction.
     CMutableTransaction coinbaseTx;
diff --git a/src/miner.h b/src/miner.h
index 44c50b01ad..7c4c455072 100644
--- a/src/miner.h
+++ b/src/miner.h
@@ -1,17 +1,19 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_MINER_H
 #define BITCOIN_MINER_H
 
+#include <optional.h>
 #include <primitives/block.h>
 #include <txmempool.h>
 #include <validation.h>
 
-#include <stdint.h>
 #include <memory>
+#include <stdint.h>
+
 #include <boost/multi_index_container.hpp>
 #include <boost/multi_index/ordered_index.hpp>
 
@@ -159,6 +161,9 @@ public:
     /** Construct a new block template with coinbase to scriptPubKeyIn */
     std::unique_ptr<CBlockTemplate> CreateNewBlock(const CScript& scriptPubKeyIn);
 
+    static Optional<int64_t> m_last_block_num_txs;
+    static Optional<int64_t> m_last_block_weight;
+
 private:
     // utility functions
     /** Clear the block's state and prepare for assembling a new block */
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 66a3b1048e..6625a03bbd 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -187,36 +187,36 @@ static UniValue generatetoaddress(const JSONRPCRequest& request)
 
 static UniValue getmininginfo(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() != 0)
+    if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             RPCHelpMan{"getmininginfo",
                 "\nReturns a json object containing mining-related information.",
                 {},
                 RPCResult{
-            "{\n"
-            "  \"blocks\": nnn,             (numeric) The current block\n"
-            "  \"currentblockweight\": nnn, (numeric) The last block weight\n"
-            "  \"currentblocktx\": nnn,     (numeric) The last block transaction\n"
-            "  \"difficulty\": xxx.xxxxx    (numeric) The current difficulty\n"
-            "  \"networkhashps\": nnn,      (numeric) The network hashes per second\n"
-            "  \"pooledtx\": n              (numeric) The size of the mempool\n"
-            "  \"chain\": \"xxxx\",           (string) current network name as defined in BIP70 (main, test, regtest)\n"
-            "  \"warnings\": \"...\"          (string) any network and blockchain warnings\n"
-            "}\n"
+                    "{\n"
+                    "  \"blocks\": nnn,             (numeric) The current block\n"
+                    "  \"currentblockweight\": nnn, (numeric, optional) The block weight of the last assembled block (only present if a block was ever assembled)\n"
+                    "  \"currentblocktx\": nnn,     (numeric, optional) The number of block transactions of the last assembled block (only present if a block was ever assembled)\n"
+                    "  \"difficulty\": xxx.xxxxx    (numeric) The current difficulty\n"
+                    "  \"networkhashps\": nnn,      (numeric) The network hashes per second\n"
+                    "  \"pooledtx\": n              (numeric) The size of the mempool\n"
+                    "  \"chain\": \"xxxx\",           (string) current network name as defined in BIP70 (main, test, regtest)\n"
+                    "  \"warnings\": \"...\"          (string) any network and blockchain warnings\n"
+                    "}\n"
                 },
                 RPCExamples{
                     HelpExampleCli("getmininginfo", "")
             + HelpExampleRpc("getmininginfo", "")
                 },
             }.ToString());
-
+    }
 
     LOCK(cs_main);
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("blocks",           (int)chainActive.Height());
-    obj.pushKV("currentblockweight", (uint64_t)nLastBlockWeight);
-    obj.pushKV("currentblocktx",   (uint64_t)nLastBlockTx);
+    if (BlockAssembler::m_last_block_weight) obj.pushKV("currentblockweight", *BlockAssembler::m_last_block_weight);
+    if (BlockAssembler::m_last_block_num_txs) obj.pushKV("currentblocktx", *BlockAssembler::m_last_block_num_txs);
     obj.pushKV("difficulty",       (double)GetDifficulty(chainActive.Tip()));
     obj.pushKV("networkhashps",    getnetworkhashps(request));
     obj.pushKV("pooledtx",         (uint64_t)mempool.size());
diff --git a/src/validation.h b/src/validation.h
index 49f73e4c9b..1975846b69 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -14,8 +14,8 @@
 #include <coins.h>
 #include <crypto/common.h> // for ReadLE64
 #include <fs.h>
-#include <protocol.h> // For CMessageHeader::MessageStartChars
 #include <policy/feerate.h>
+#include <protocol.h> // For CMessageHeader::MessageStartChars
 #include <script/script_error.h>
 #include <sync.h>
 #include <versionbits.h>
@@ -152,8 +152,6 @@ extern CTxMemPool mempool;
 extern std::atomic_bool g_is_mempool_loaded;
 typedef std::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
 extern BlockMap& mapBlockIndex GUARDED_BY(cs_main);
-extern uint64_t nLastBlockTx;
-extern uint64_t nLastBlockWeight;
 extern const std::string strMessageMagic;
 extern Mutex g_best_block_mutex;
 extern std::condition_variable g_best_block_cv;
diff --git a/test/functional/mining_basic.py b/test/functional/mining_basic.py
index 5dafb11ac5..df8fe23a2e 100755
--- a/test/functional/mining_basic.py
+++ b/test/functional/mining_basic.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2014-2018 The Bitcoin Core developers
+# Copyright (c) 2014-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test mining RPCs
@@ -11,7 +11,10 @@
 import copy
 from decimal import Decimal
 
-from test_framework.blocktools import create_coinbase
+from test_framework.blocktools import (
+    create_coinbase,
+    TIME_GENESIS_BLOCK,
+)
 from test_framework.messages import (
     CBlock,
     CBlockHeader,
@@ -25,9 +28,11 @@ from test_framework.util import (
     assert_equal,
     assert_raises_rpc_error,
     bytes_to_hex_str as b2x,
+    connect_nodes_bi,
 )
 from test_framework.script import CScriptNum
 
+
 def assert_template(node, block, expect, rehash=True):
     if rehash:
         block.hashMerkleRoot = block.calc_merkle_root()
@@ -38,9 +43,22 @@ def assert_template(node, block, expect, rehash=True):
 class MiningTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
-        self.setup_clean_chain = False
+        self.setup_clean_chain = True
+
+    def mine_chain(self):
+        self.log.info('Create some old blocks')
+        for t in range(TIME_GENESIS_BLOCK, TIME_GENESIS_BLOCK + 200 * 600, 600):
+            self.nodes[0].setmocktime(t)
+            self.nodes[0].generate(1)
+        mining_info = self.nodes[0].getmininginfo()
+        assert_equal(mining_info['blocks'], 200)
+        assert_equal(mining_info['currentblocktx'], 0)
+        assert_equal(mining_info['currentblockweight'], 4000)
+        self.restart_node(0)
+        connect_nodes_bi(self.nodes, 0, 1)
 
     def run_test(self):
+        self.mine_chain()
         node = self.nodes[0]
 
         def assert_submitblock(block, result_str_1, result_str_2=None):
@@ -53,8 +71,8 @@ class MiningTest(BitcoinTestFramework):
         mining_info = node.getmininginfo()
         assert_equal(mining_info['blocks'], 200)
         assert_equal(mining_info['chain'], 'regtest')
-        assert_equal(mining_info['currentblocktx'], 0)
-        assert_equal(mining_info['currentblockweight'], 0)
+        assert 'currentblocktx' not in mining_info
+        assert 'currentblockweight' not in mining_info
         assert_equal(mining_info['difficulty'], Decimal('4.656542373906925E-10'))
         assert_equal(mining_info['networkhashps'], Decimal('0.003333333333333334'))
         assert_equal(mining_info['pooledtx'], 0)
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
index 6b47cae4c3..15f4502994 100644
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2015-2018 The Bitcoin Core developers
+# Copyright (c) 2015-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Utilities for manipulating blocks and transactions."""
@@ -43,9 +43,13 @@ from io import BytesIO
 
 MAX_BLOCK_SIGOPS = 20000
 
+# Genesis block time (regtest)
+TIME_GENESIS_BLOCK = 1296688602
+
 # From BIP141
 WITNESS_COMMITMENT_HEADER = b"\xaa\x21\xa9\xed"
 
+
 def create_block(hashprev, coinbase, ntime=None, *, version=1):
     """Create a block (with regtest difficulty)."""
     block = CBlock()