Move {Load,Dump}Mempool to kernel namespace

Also:
1. Add the newly introduced kernel/mempool_persist.cpp to IWYU CI script
2. Add chrono mapping for iwyu

11 files changed, 238 insertions, 158 deletions

diff --git a/ci/test/06_script_b.sh b/ci/test/06_script_b.sh
index e1032ba6bd..77358f93d9 100755
--- a/ci/test/06_script_b.sh
+++ b/ci/test/06_script_b.sh
@@ -41,6 +41,7 @@ if [ "${RUN_TIDY}" = "true" ]; then
   CI_EXEC "python3 ${DIR_IWYU}/include-what-you-use/iwyu_tool.py"\
           " src/compat"\
           " src/init"\
+          " src/kernel/mempool_persist.cpp"\
           " src/policy/feerate.cpp"\
           " src/policy/packages.cpp"\
           " src/policy/settings.cpp"\
diff --git a/contrib/devtools/iwyu/bitcoin.core.imp b/contrib/devtools/iwyu/bitcoin.core.imp
index ce7786f58c..919ffab102 100644
--- a/contrib/devtools/iwyu/bitcoin.core.imp
+++ b/contrib/devtools/iwyu/bitcoin.core.imp
@@ -3,4 +3,5 @@
   { include: [ "<bits/termios-c_lflag.h>", private, "<termios.h>", public ] },
   { include: [ "<bits/termios-struct.h>", private, "<termios.h>", public ] },
   { include: [ "<bits/termios-tcflow.h>", private, "<termios.h>", public ] },
+  { include: [ "<bits/chrono.h>", private, "<chrono>", public ] },
 ]
diff --git a/src/Makefile.am b/src/Makefile.am
index 1ba76ac5e7..c2148936af 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -177,6 +177,7 @@ BITCOIN_CORE_H = \
   kernel/context.h \
   kernel/mempool_limits.h \
   kernel/mempool_options.h \
+  kernel/mempool_persist.h \
   key.h \
   key_io.h \
   logging.h \
@@ -368,6 +369,7 @@ libbitcoin_node_a_SOURCES = \
   kernel/checks.cpp \
   kernel/coinstats.cpp \
   kernel/context.cpp \
+  kernel/mempool_persist.cpp \
   mapport.cpp \
   mempool_args.cpp \
   net.cpp \
@@ -884,6 +886,7 @@ libbitcoinkernel_la_SOURCES = \
   kernel/checks.cpp \
   kernel/coinstats.cpp \
   kernel/context.cpp \
+  kernel/mempool_persist.cpp \
   key.cpp \
   logging.cpp \
   node/blockstorage.cpp \
diff --git a/src/init.cpp b/src/init.cpp
index c46205d583..6cc42c5319 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -10,6 +10,7 @@
 #include <init.h>
 
 #include <kernel/checks.h>
+#include <kernel/mempool_persist.h>
 
 #include <addrman.h>
 #include <banman.h>
@@ -104,6 +105,8 @@
 #include <zmq/zmqrpc.h>
 #endif
 
+using kernel::DumpMempool;
+
 using node::CacheSizes;
 using node::CalculateCacheSizes;
 using node::ChainstateLoadVerifyError;
diff --git a/src/kernel/mempool_persist.cpp b/src/kernel/mempool_persist.cpp
new file mode 100644
index 0000000000..1a1cf2bbdc
--- /dev/null
+++ b/src/kernel/mempool_persist.cpp
@@ -0,0 +1,189 @@
+// Copyright (c) 2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <kernel/mempool_persist.h>
+
+#include <clientversion.h>
+#include <consensus/amount.h>
+#include <fs.h>
+#include <logging.h>
+#include <primitives/transaction.h>
+#include <serialize.h>
+#include <shutdown.h>
+#include <streams.h>
+#include <sync.h>
+#include <txmempool.h>
+#include <uint256.h>
+#include <util/system.h>
+#include <util/time.h>
+#include <validation.h>
+
+#include <chrono>
+#include <cstdint>
+#include <cstdio>
+#include <exception>
+#include <functional>
+#include <map>
+#include <memory>
+#include <set>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+using fsbridge::FopenFn;
+
+namespace kernel {
+
+static const uint64_t MEMPOOL_DUMP_VERSION = 1;
+
+bool LoadMempool(CTxMemPool& pool, const fs::path& load_path, CChainState& active_chainstate, FopenFn mockable_fopen_function)
+{
+    if (load_path.empty()) return false;
+
+    FILE* filestr{mockable_fopen_function(load_path, "rb")};
+    CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
+    if (file.IsNull()) {
+        LogPrintf("Failed to open mempool file from disk. Continuing anyway.\n");
+        return false;
+    }
+
+    int64_t count = 0;
+    int64_t expired = 0;
+    int64_t failed = 0;
+    int64_t already_there = 0;
+    int64_t unbroadcast = 0;
+    auto now = NodeClock::now();
+
+    try {
+        uint64_t version;
+        file >> version;
+        if (version != MEMPOOL_DUMP_VERSION) {
+            return false;
+        }
+        uint64_t num;
+        file >> num;
+        while (num) {
+            --num;
+            CTransactionRef tx;
+            int64_t nTime;
+            int64_t nFeeDelta;
+            file >> tx;
+            file >> nTime;
+            file >> nFeeDelta;
+
+            CAmount amountdelta = nFeeDelta;
+            if (amountdelta) {
+                pool.PrioritiseTransaction(tx->GetHash(), amountdelta);
+            }
+            if (nTime > TicksSinceEpoch<std::chrono::seconds>(now - pool.m_expiry)) {
+                LOCK(cs_main);
+                const auto& accepted = AcceptToMemoryPool(active_chainstate, tx, nTime, /*bypass_limits=*/false, /*test_accept=*/false);
+                if (accepted.m_result_type == MempoolAcceptResult::ResultType::VALID) {
+                    ++count;
+                } else {
+                    // mempool may contain the transaction already, e.g. from
+                    // wallet(s) having loaded it while we were processing
+                    // mempool transactions; consider these as valid, instead of
+                    // failed, but mark them as 'already there'
+                    if (pool.exists(GenTxid::Txid(tx->GetHash()))) {
+                        ++already_there;
+                    } else {
+                        ++failed;
+                    }
+                }
+            } else {
+                ++expired;
+            }
+            if (ShutdownRequested())
+                return false;
+        }
+        std::map<uint256, CAmount> mapDeltas;
+        file >> mapDeltas;
+
+        for (const auto& i : mapDeltas) {
+            pool.PrioritiseTransaction(i.first, i.second);
+        }
+
+        std::set<uint256> unbroadcast_txids;
+        file >> unbroadcast_txids;
+        unbroadcast = unbroadcast_txids.size();
+        for (const auto& txid : unbroadcast_txids) {
+            // Ensure transactions were accepted to mempool then add to
+            // unbroadcast set.
+            if (pool.get(txid) != nullptr) pool.AddUnbroadcastTx(txid);
+        }
+    } catch (const std::exception& e) {
+        LogPrintf("Failed to deserialize mempool data on disk: %s. Continuing anyway.\n", e.what());
+        return false;
+    }
+
+    LogPrintf("Imported mempool transactions from disk: %i succeeded, %i failed, %i expired, %i already there, %i waiting for initial broadcast\n", count, failed, expired, already_there, unbroadcast);
+    return true;
+}
+
+bool DumpMempool(const CTxMemPool& pool, const fs::path& dump_path, FopenFn mockable_fopen_function, bool skip_file_commit)
+{
+    auto start = SteadyClock::now();
+
+    std::map<uint256, CAmount> mapDeltas;
+    std::vector<TxMempoolInfo> vinfo;
+    std::set<uint256> unbroadcast_txids;
+
+    static Mutex dump_mutex;
+    LOCK(dump_mutex);
+
+    {
+        LOCK(pool.cs);
+        for (const auto &i : pool.mapDeltas) {
+            mapDeltas[i.first] = i.second;
+        }
+        vinfo = pool.infoAll();
+        unbroadcast_txids = pool.GetUnbroadcastTxs();
+    }
+
+    auto mid = SteadyClock::now();
+
+    try {
+        FILE* filestr{mockable_fopen_function(dump_path + ".new", "wb")};
+        if (!filestr) {
+            return false;
+        }
+
+        CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
+
+        uint64_t version = MEMPOOL_DUMP_VERSION;
+        file << version;
+
+        file << (uint64_t)vinfo.size();
+        for (const auto& i : vinfo) {
+            file << *(i.tx);
+            file << int64_t{count_seconds(i.m_time)};
+            file << int64_t{i.nFeeDelta};
+            mapDeltas.erase(i.tx->GetHash());
+        }
+
+        file << mapDeltas;
+
+        LogPrintf("Writing %d unbroadcast transactions to disk.\n", unbroadcast_txids.size());
+        file << unbroadcast_txids;
+
+        if (!skip_file_commit && !FileCommit(file.Get()))
+            throw std::runtime_error("FileCommit failed");
+        file.fclose();
+        if (!RenameOver(dump_path + ".new", dump_path)) {
+            throw std::runtime_error("Rename failed");
+        }
+        auto last = SteadyClock::now();
+
+        LogPrintf("Dumped mempool: %gs to copy, %gs to dump\n",
+                  Ticks<SecondsDouble>(mid - start),
+                  Ticks<SecondsDouble>(last - mid));
+    } catch (const std::exception& e) {
+        LogPrintf("Failed to dump mempool: %s. Continuing anyway.\n", e.what());
+        return false;
+    }
+    return true;
+}
+
+} // namespace kernel
diff --git a/src/kernel/mempool_persist.h b/src/kernel/mempool_persist.h
new file mode 100644
index 0000000000..9a15ec6dca
--- /dev/null
+++ b/src/kernel/mempool_persist.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2022 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_KERNEL_MEMPOOL_PERSIST_H
+#define BITCOIN_KERNEL_MEMPOOL_PERSIST_H
+
+#include <fs.h>
+
+class CChainState;
+class CTxMemPool;
+
+namespace kernel {
+
+/** Dump the mempool to disk. */
+bool DumpMempool(const CTxMemPool& pool, const fs::path& dump_path,
+                 fsbridge::FopenFn mockable_fopen_function = fsbridge::fopen,
+                 bool skip_file_commit = false);
+
+/** Load the mempool from disk. */
+bool LoadMempool(CTxMemPool& pool, const fs::path& load_path,
+                 CChainState& active_chainstate,
+                 fsbridge::FopenFn mockable_fopen_function = fsbridge::fopen);
+
+} // namespace kernel
+
+
+#endif // BITCOIN_KERNEL_MEMPOOL_PERSIST_H
diff --git a/src/rpc/mempool.cpp b/src/rpc/mempool.cpp
index 7f4ff47941..3b53ec82e4 100644
--- a/src/rpc/mempool.cpp
+++ b/src/rpc/mempool.cpp
@@ -5,6 +5,8 @@
 
 #include <rpc/blockchain.h>
 
+#include <kernel/mempool_persist.h>
+
 #include <chainparams.h>
 #include <core_io.h>
 #include <fs.h>
@@ -19,6 +21,8 @@
 #include <univalue.h>
 #include <util/moneystr.h>
 
+using kernel::DumpMempool;
+
 using node::DEFAULT_MAX_RAW_TX_FEE_RATE;
 using node::MempoolPath;
 using node::ShouldPersistMempool;
diff --git a/src/test/fuzz/validation_load_mempool.cpp b/src/test/fuzz/validation_load_mempool.cpp
index 357d8a9987..90c1a71d9f 100644
--- a/src/test/fuzz/validation_load_mempool.cpp
+++ b/src/test/fuzz/validation_load_mempool.cpp
@@ -2,6 +2,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <kernel/mempool_persist.h>
+
 #include <chainparamsbase.h>
 #include <mempool_args.h>
 #include <node/mempool_persist_args.h>
@@ -17,6 +19,8 @@
 #include <cstdint>
 #include <vector>
 
+using kernel::DumpMempool;
+
 using node::MempoolPath;
 
 namespace {
diff --git a/src/validation.cpp b/src/validation.cpp
index 510071de22..6840753cd4 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -5,6 +5,9 @@
 
 #include <validation.h>
 
+#include <kernel/coinstats.h>
+#include <kernel/mempool_persist.h>
+
 #include <arith_uint256.h>
 #include <chain.h>
 #include <chainparams.h>
@@ -19,7 +22,6 @@
 #include <flatfile.h>
 #include <fs.h>
 #include <hash.h>
-#include <kernel/coinstats.h>
 #include <logging.h>
 #include <logging/timer.h>
 #include <node/blockstorage.h>
@@ -64,6 +66,7 @@
 using kernel::CCoinsStats;
 using kernel::CoinStatsHashType;
 using kernel::ComputeUTXOStats;
+using kernel::LoadMempool;
 
 using fsbridge::FopenFn;
 using node::BLOCKFILE_CHUNK_SIZE;
@@ -4640,157 +4643,6 @@ bool CChainState::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
     return ret;
 }
 
-static const uint64_t MEMPOOL_DUMP_VERSION = 1;
-
-bool LoadMempool(CTxMemPool& pool, const fs::path& load_path, CChainState& active_chainstate, FopenFn mockable_fopen_function)
-{
-    if (load_path.empty()) return false;
-
-    FILE* filestr{mockable_fopen_function(load_path, "rb")};
-    CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
-    if (file.IsNull()) {
-        LogPrintf("Failed to open mempool file from disk. Continuing anyway.\n");
-        return false;
-    }
-
-    int64_t count = 0;
-    int64_t expired = 0;
-    int64_t failed = 0;
-    int64_t already_there = 0;
-    int64_t unbroadcast = 0;
-    auto now = NodeClock::now();
-
-    try {
-        uint64_t version;
-        file >> version;
-        if (version != MEMPOOL_DUMP_VERSION) {
-            return false;
-        }
-        uint64_t num;
-        file >> num;
-        while (num) {
-            --num;
-            CTransactionRef tx;
-            int64_t nTime;
-            int64_t nFeeDelta;
-            file >> tx;
-            file >> nTime;
-            file >> nFeeDelta;
-
-            CAmount amountdelta = nFeeDelta;
-            if (amountdelta) {
-                pool.PrioritiseTransaction(tx->GetHash(), amountdelta);
-            }
-            if (nTime > TicksSinceEpoch<std::chrono::seconds>(now - pool.m_expiry)) {
-                LOCK(cs_main);
-                const auto& accepted = AcceptToMemoryPool(active_chainstate, tx, nTime, /*bypass_limits=*/false, /*test_accept=*/false);
-                if (accepted.m_result_type == MempoolAcceptResult::ResultType::VALID) {
-                    ++count;
-                } else {
-                    // mempool may contain the transaction already, e.g. from
-                    // wallet(s) having loaded it while we were processing
-                    // mempool transactions; consider these as valid, instead of
-                    // failed, but mark them as 'already there'
-                    if (pool.exists(GenTxid::Txid(tx->GetHash()))) {
-                        ++already_there;
-                    } else {
-                        ++failed;
-                    }
-                }
-            } else {
-                ++expired;
-            }
-            if (ShutdownRequested())
-                return false;
-        }
-        std::map<uint256, CAmount> mapDeltas;
-        file >> mapDeltas;
-
-        for (const auto& i : mapDeltas) {
-            pool.PrioritiseTransaction(i.first, i.second);
-        }
-
-        std::set<uint256> unbroadcast_txids;
-        file >> unbroadcast_txids;
-        unbroadcast = unbroadcast_txids.size();
-        for (const auto& txid : unbroadcast_txids) {
-            // Ensure transactions were accepted to mempool then add to
-            // unbroadcast set.
-            if (pool.get(txid) != nullptr) pool.AddUnbroadcastTx(txid);
-        }
-    } catch (const std::exception& e) {
-        LogPrintf("Failed to deserialize mempool data on disk: %s. Continuing anyway.\n", e.what());
-        return false;
-    }
-
-    LogPrintf("Imported mempool transactions from disk: %i succeeded, %i failed, %i expired, %i already there, %i waiting for initial broadcast\n", count, failed, expired, already_there, unbroadcast);
-    return true;
-}
-
-bool DumpMempool(const CTxMemPool& pool, const fs::path& dump_path, FopenFn mockable_fopen_function, bool skip_file_commit)
-{
-    auto start = SteadyClock::now();
-
-    std::map<uint256, CAmount> mapDeltas;
-    std::vector<TxMempoolInfo> vinfo;
-    std::set<uint256> unbroadcast_txids;
-
-    static Mutex dump_mutex;
-    LOCK(dump_mutex);
-
-    {
-        LOCK(pool.cs);
-        for (const auto &i : pool.mapDeltas) {
-            mapDeltas[i.first] = i.second;
-        }
-        vinfo = pool.infoAll();
-        unbroadcast_txids = pool.GetUnbroadcastTxs();
-    }
-
-    auto mid = SteadyClock::now();
-
-    try {
-        FILE* filestr{mockable_fopen_function(dump_path + ".new", "wb")};
-        if (!filestr) {
-            return false;
-        }
-
-        CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
-
-        uint64_t version = MEMPOOL_DUMP_VERSION;
-        file << version;
-
-        file << (uint64_t)vinfo.size();
-        for (const auto& i : vinfo) {
-            file << *(i.tx);
-            file << int64_t{count_seconds(i.m_time)};
-            file << int64_t{i.nFeeDelta};
-            mapDeltas.erase(i.tx->GetHash());
-        }
-
-        file << mapDeltas;
-
-        LogPrintf("Writing %d unbroadcast transactions to disk.\n", unbroadcast_txids.size());
-        file << unbroadcast_txids;
-
-        if (!skip_file_commit && !FileCommit(file.Get()))
-            throw std::runtime_error("FileCommit failed");
-        file.fclose();
-        if (!RenameOver(dump_path + ".new", dump_path)) {
-            throw std::runtime_error("Rename failed");
-        }
-        auto last = SteadyClock::now();
-
-        LogPrintf("Dumped mempool: %gs to copy, %gs to dump\n",
-                  Ticks<SecondsDouble>(mid - start),
-                  Ticks<SecondsDouble>(last - mid));
-    } catch (const std::exception& e) {
-        LogPrintf("Failed to dump mempool: %s. Continuing anyway.\n", e.what());
-        return false;
-    }
-    return true;
-}
-
 //! Guess how far we are in the verification process at the given block index
 //! require cs_main if pindex has not been validated yet (because nChainTx might be unset)
 double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex *pindex) {
diff --git a/src/validation.h b/src/validation.h
index df4fc77980..f89d42e310 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1012,12 +1012,6 @@ bool DeploymentEnabled(const ChainstateManager& chainman, DEP dep)
     return DeploymentEnabled(chainman.GetConsensus(), dep);
 }
 
-/** Dump the mempool to disk. */
-bool DumpMempool(const CTxMemPool& pool, const fs::path& dump_path, fsbridge::FopenFn mockable_fopen_function = fsbridge::fopen, bool skip_file_commit = false);
-
-/** Load the mempool from disk. */
-bool LoadMempool(CTxMemPool& pool, const fs::path& load_path, CChainState& active_chainstate, fsbridge::FopenFn mockable_fopen_function = fsbridge::fopen);
-
 /**
  * Return the expected assumeutxo value for a given height, if one exists.
  *
diff --git a/test/lint/lint-circular-dependencies.py b/test/lint/lint-circular-dependencies.py
index 5d157eb4b1..f44ed8f7c7 100755
--- a/test/lint/lint-circular-dependencies.py
+++ b/test/lint/lint-circular-dependencies.py
@@ -22,6 +22,7 @@ EXPECTED_CIRCULAR_DEPENDENCIES = (
     "wallet/fees -> wallet/wallet -> wallet/fees",
     "wallet/wallet -> wallet/walletdb -> wallet/wallet",
     "kernel/coinstats -> validation -> kernel/coinstats",
+    "kernel/mempool_persist -> validation -> kernel/mempool_persist",
 )
 
 CODE_DIR = "src"