move-only: unittest: add test/util/chainstate.h

and move `CreateAndActivateUTXOSnapshot()` into it for reuse
in future test modules.

1 files changed, 54 insertions, 0 deletions

diff --git a/src/test/util/chainstate.h b/src/test/util/chainstate.h
new file mode 100644
index 0000000000..38a6be7e9a
--- /dev/null
+++ b/src/test/util/chainstate.h
@@ -0,0 +1,54 @@
+// Copyright (c) 2021 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_TEST_UTIL_CHAINSTATE_H
+#define BITCOIN_TEST_UTIL_CHAINSTATE_H
+
+#include <clientversion.h>
+#include <fs.h>
+#include <node/context.h>
+#include <node/utxo_snapshot.h>
+#include <rpc/blockchain.h>
+#include <validation.h>
+
+#include <univalue.h>
+
+#include <boost/test/unit_test.hpp>
+
+auto NoMalleation = [](CAutoFile& file, SnapshotMetadata& meta){};
+
+/**
+ * Create and activate a UTXO snapshot, optionally providing a function to
+ * malleate the snapshot.
+ */
+template<typename F = decltype(NoMalleation)>
+static bool
+CreateAndActivateUTXOSnapshot(NodeContext& node, const fs::path root, F malleation = NoMalleation)
+{
+    // Write out a snapshot to the test's tempdir.
+    //
+    int height;
+    WITH_LOCK(::cs_main, height = node.chainman->ActiveHeight());
+    fs::path snapshot_path = root / tfm::format("test_snapshot.%d.dat", height);
+    FILE* outfile{fsbridge::fopen(snapshot_path, "wb")};
+    CAutoFile auto_outfile{outfile, SER_DISK, CLIENT_VERSION};
+
+    UniValue result = CreateUTXOSnapshot(node, node.chainman->ActiveChainstate(), auto_outfile);
+    BOOST_TEST_MESSAGE(
+        "Wrote UTXO snapshot to " << snapshot_path.make_preferred().string() << ": " << result.write());
+
+    // Read the written snapshot in and then activate it.
+    //
+    FILE* infile{fsbridge::fopen(snapshot_path, "rb")};
+    CAutoFile auto_infile{infile, SER_DISK, CLIENT_VERSION};
+    SnapshotMetadata metadata;
+    auto_infile >> metadata;
+
+    malleation(auto_infile, metadata);
+
+    return node.chainman->ActivateSnapshot(auto_infile, metadata, /*in_memory*/ true);
+}
+
+
+#endif // BITCOIN_TEST_UTIL_CHAINSTATE_H