Introduce WalletDescriptor class

WalletDescriptor is a Descriptor with other wallet metadata

src/wallet/test/wallet_tests.cpp

@@ -637,4 +637,25 @@ BOOST_FIXTURE_TEST_CASE(dummy_input_size_test, TestChain100Setup)
     BOOST_CHECK_EQUAL(CalculateNestedKeyhashInputSize(true), DUMMY_NESTED_P2WPKH_INPUT_SIZE);
 }
 
+bool malformed_descriptor(std::ios_base::failure e)
+{
+    std::string s(e.what());
+    return s.find("Missing checksum") != std::string::npos;
+}
+
+BOOST_FIXTURE_TEST_CASE(wallet_descriptor_test, BasicTestingSetup)
+{
+    std::vector<unsigned char> malformed_record;
+    CVectorWriter vw(0, 0, malformed_record, 0);
+    vw << std::string("notadescriptor");
+    vw << (uint64_t)0;
+    vw << (int32_t)0;
+    vw << (int32_t)0;
+    vw << (int32_t)1;
+
+    VectorReader vr(0, 0, malformed_record, 0);
+    WalletDescriptor w_desc;
+    BOOST_CHECK_EXCEPTION(vr >> w_desc, std::ios_base::failure, malformed_descriptor);
+}
+
 BOOST_AUTO_TEST_SUITE_END()

src/wallet/walletutil.h

@@ -6,6 +6,7 @@
 #define BITCOIN_WALLET_WALLETUTIL_H
 
 #include <fs.h>
+#include <script/descriptor.h>
 
 #include <vector>
 
@@ -86,4 +87,41 @@ public:
     bool Exists() const;
 };
 
+/** Descriptor with some wallet metadata */
+class WalletDescriptor
+{
+public:
+    std::shared_ptr<Descriptor> descriptor;
+    uint64_t creation_time;
+    int32_t range_start; // First item in range; start of range, inclusive, i.e. [range_start, range_end). This never changes.
+    int32_t range_end; // Item after the last; end of range, exclusive, i.e. [range_start, range_end). This will increment with each TopUp()
+    int32_t next_index; // Position of the next item to generate
+    DescriptorCache cache;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        if (ser_action.ForRead()) {
+            std::string desc;
+            std::string error;
+            READWRITE(desc);
+            FlatSigningProvider keys;
+            descriptor = Parse(desc, keys, error, true);
+            if (!descriptor) {
+                throw std::ios_base::failure("Invalid descriptor: " + error);
+            }
+        } else {
+            READWRITE(descriptor->ToString());
+        }
+        READWRITE(creation_time);
+        READWRITE(next_index);
+        READWRITE(range_start);
+        READWRITE(range_end);
+    }
+
+    WalletDescriptor() {}
+    WalletDescriptor(std::shared_ptr<Descriptor> descriptor, uint64_t creation_time, int32_t range_start, int32_t range_end, int32_t next_index) : descriptor(descriptor), creation_time(creation_time), range_start(range_start), range_end(range_end), next_index(next_index) {}
+};
+
 #endif // BITCOIN_WALLET_WALLETUTIL_H