1 files changed, 221 insertions, 0 deletions
diff --git a/src/node/mempool_persist.cpp b/src/node/mempool_persist.cpp
new file mode 100644
index 0000000000..a265c2e12d
--- /dev/null
+++ b/src/node/mempool_persist.cpp
@@ -0,0 +1,221 @@
+// 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 <node/mempool_persist.h>
+
+#include <clientversion.h>
+#include <consensus/amount.h>
+#include <logging.h>
+#include <primitives/transaction.h>
+#include <random.h>
+#include <serialize.h>
+#include <streams.h>
+#include <sync.h>
+#include <txmempool.h>
+#include <uint256.h>
+#include <util/fs.h>
+#include <util/fs_helpers.h>
+#include <util/signalinterrupt.h>
+#include <util/time.h>
+#include <validation.h>
+
+#include <cstdint>
+#include <cstdio>
+#include <exception>
+#include <functional>
+#include <map>
+#include <memory>
+#include <set>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+using fsbridge::FopenFn;
+
+namespace node {
+
+static const uint64_t MEMPOOL_DUMP_VERSION_NO_XOR_KEY{1};
+static const uint64_t MEMPOOL_DUMP_VERSION{2};
+
+bool LoadMempool(CTxMemPool& pool, const fs::path& load_path, Chainstate& active_chainstate, ImportMempoolOptions&& opts)
+{
+    if (load_path.empty()) return false;
+
+    AutoFile file{opts.mockable_fopen_function(load_path, "rb")};
+    if (file.IsNull()) {
+        LogInfo("Failed to open mempool file. 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;
+    const auto now{NodeClock::now()};
+
+    try {
+        uint64_t version;
+        file >> version;
+        std::vector<std::byte> xor_key;
+        if (version == MEMPOOL_DUMP_VERSION_NO_XOR_KEY) {
+            // Leave XOR-key empty
+        } else if (version == MEMPOOL_DUMP_VERSION) {
+            file >> xor_key;
+        } else {
+            return false;
+        }
+        file.SetXor(xor_key);
+        uint64_t total_txns_to_load;
+        file >> total_txns_to_load;
+        uint64_t txns_tried = 0;
+        LogInfo("Loading %u mempool transactions from file...\n", total_txns_to_load);
+        int next_tenth_to_report = 0;
+        while (txns_tried < total_txns_to_load) {
+            const int percentage_done(100.0 * txns_tried / total_txns_to_load);
+            if (next_tenth_to_report < percentage_done / 10) {
+                LogInfo("Progress loading mempool transactions from file: %d%% (tried %u, %u remaining)\n",
+                        percentage_done, txns_tried, total_txns_to_load - txns_tried);
+                next_tenth_to_report = percentage_done / 10;
+            }
+            ++txns_tried;
+
+            CTransactionRef tx;
+            int64_t nTime;
+            int64_t nFeeDelta;
+            file >> TX_WITH_WITNESS(tx);
+            file >> nTime;
+            file >> nFeeDelta;
+
+            if (opts.use_current_time) {
+                nTime = TicksSinceEpoch<std::chrono::seconds>(now);
+            }
+
+            CAmount amountdelta = nFeeDelta;
+            if (amountdelta && opts.apply_fee_delta_priority) {
+                pool.PrioritiseTransaction(tx->GetHash(), amountdelta);
+            }
+            if (nTime > TicksSinceEpoch<std::chrono::seconds>(now - pool.m_opts.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 (active_chainstate.m_chainman.m_interrupt)
+                return false;
+        }
+        std::map<uint256, CAmount> mapDeltas;
+        file >> mapDeltas;
+
+        if (opts.apply_fee_delta_priority) {
+            for (const auto& i : mapDeltas) {
+                pool.PrioritiseTransaction(i.first, i.second);
+            }
+        }
+
+        std::set<uint256> unbroadcast_txids;
+        file >> unbroadcast_txids;
+        if (opts.apply_unbroadcast_set) {
+            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) {
+        LogInfo("Failed to deserialize mempool data on file: %s. Continuing anyway.\n", e.what());
+        return false;
+    }
+
+    LogInfo("Imported mempool transactions from file: %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();
+
+    AutoFile file{mockable_fopen_function(dump_path + ".new", "wb")};
+    if (file.IsNull()) {
+        return false;
+    }
+
+    try {
+        const uint64_t version{pool.m_opts.persist_v1_dat ? MEMPOOL_DUMP_VERSION_NO_XOR_KEY : MEMPOOL_DUMP_VERSION};
+        file << version;
+
+        std::vector<std::byte> xor_key(8);
+        if (!pool.m_opts.persist_v1_dat) {
+            FastRandomContext{}.fillrand(xor_key);
+            file << xor_key;
+        }
+        file.SetXor(xor_key);
+
+        uint64_t mempool_transactions_to_write(vinfo.size());
+        file << mempool_transactions_to_write;
+        LogInfo("Writing %u mempool transactions to file...\n", mempool_transactions_to_write);
+        for (const auto& i : vinfo) {
+            file << TX_WITH_WITNESS(*(i.tx));
+            file << int64_t{count_seconds(i.m_time)};
+            file << int64_t{i.nFeeDelta};
+            mapDeltas.erase(i.tx->GetHash());
+        }
+
+        file << mapDeltas;
+
+        LogInfo("Writing %d unbroadcast transactions to file.\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();
+
+        LogInfo("Dumped mempool: %.3fs to copy, %.3fs to dump, %d bytes dumped to file\n",
+                  Ticks<SecondsDouble>(mid - start),
+                  Ticks<SecondsDouble>(last - mid),
+                  fs::file_size(dump_path));
+    } catch (const std::exception& e) {
+        LogInfo("Failed to dump mempool: %s. Continuing anyway.\n", e.what());
+        return false;
+    }
+    return true;
+}
+
+} // namespace node