From 22401f17e026ead4bc3fe96967eec56a719a4f75 Mon Sep 17 00:00:00 2001
From: Andrew Chow <github@achow101.com>
Date: Thu, 25 Aug 2022 14:35:28 -0400
Subject: [PATCH] Implement LegacyScriptPubKeyMan::DeleteRecords

---
 src/wallet/scriptpubkeyman.cpp |  7 ++++++
 src/wallet/scriptpubkeyman.h   |  2 ++
 src/wallet/walletdb.cpp        | 40 ++++++++++++++++++++++++++++++++++
 src/wallet/walletdb.h          |  6 +++++
 4 files changed, 55 insertions(+)

diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index 3e6830a08da..41654579c6a 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -1964,6 +1964,13 @@ std::optional<MigrationData> LegacyScriptPubKeyMan::MigrateToDescriptor()
     return out;
 }
 
+bool LegacyScriptPubKeyMan::DeleteRecords()
+{
+    LOCK(cs_KeyStore);
+    WalletBatch batch(m_storage.GetDatabase());
+    return batch.EraseRecords(DBKeys::LEGACY_TYPES);
+}
+
 util::Result<CTxDestination> DescriptorScriptPubKeyMan::GetNewDestination(const OutputType type)
 {
     // Returns true if this descriptor supports getting new addresses. Conditions where we may be unable to fetch them (e.g. locked) are caught later
diff --git a/src/wallet/scriptpubkeyman.h b/src/wallet/scriptpubkeyman.h
index 19ec277c562..3ab489c3744 100644
--- a/src/wallet/scriptpubkeyman.h
+++ b/src/wallet/scriptpubkeyman.h
@@ -517,6 +517,8 @@ public:
     /** Get the DescriptorScriptPubKeyMans (with private keys) that have the same scriptPubKeys as this LegacyScriptPubKeyMan.
      * Does not modify this ScriptPubKeyMan. */
     std::optional<MigrationData> MigrateToDescriptor();
+    /** Delete all the records ofthis LegacyScriptPubKeyMan from disk*/
+    bool DeleteRecords();
 };
 
 /** Wraps a LegacyScriptPubKeyMan so that it can be returned in a new unique_ptr. Does not provide privkeys */
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 0d85652c0c0..30406a22f92 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -59,6 +59,7 @@ const std::string WALLETDESCRIPTORCKEY{"walletdescriptorckey"};
 const std::string WALLETDESCRIPTORKEY{"walletdescriptorkey"};
 const std::string WATCHMETA{"watchmeta"};
 const std::string WATCHS{"watchs"};
+const std::unordered_set<std::string> LEGACY_TYPES{CRYPTED_KEY, CSCRIPT, DEFAULTKEY, HDCHAIN, KEYMETA, KEY, OLD_KEY, POOL, WATCHMETA, WATCHS};
 } // namespace DBKeys
 
 //
@@ -1083,6 +1084,45 @@ bool WalletBatch::WriteWalletFlags(const uint64_t flags)
     return WriteIC(DBKeys::FLAGS, flags);
 }
 
+bool WalletBatch::EraseRecords(const std::unordered_set<std::string>& types)
+{
+    // Get cursor
+    if (!m_batch->StartCursor())
+    {
+        return false;
+    }
+
+    // Iterate the DB and look for any records that have the type prefixes
+    while (true)
+    {
+        // Read next record
+        CDataStream key(SER_DISK, CLIENT_VERSION);
+        CDataStream value(SER_DISK, CLIENT_VERSION);
+        bool complete;
+        bool ret = m_batch->ReadAtCursor(key, value, complete);
+        if (complete) {
+            break;
+        }
+        else if (!ret)
+        {
+            m_batch->CloseCursor();
+            return false;
+        }
+
+        // Make a copy of key to avoid data being deleted by the following read of the type
+        Span<const unsigned char> key_data = MakeUCharSpan(key);
+
+        std::string type;
+        key >> type;
+
+        if (types.count(type) > 0) {
+            m_batch->Erase(key_data);
+        }
+    }
+    m_batch->CloseCursor();
+    return true;
+}
+
 bool WalletBatch::TxnBegin()
 {
     return m_batch->TxnBegin();
diff --git a/src/wallet/walletdb.h b/src/wallet/walletdb.h
index a04ea598b65..6aa25fae038 100644
--- a/src/wallet/walletdb.h
+++ b/src/wallet/walletdb.h
@@ -84,6 +84,9 @@ extern const std::string WALLETDESCRIPTORCKEY;
 extern const std::string WALLETDESCRIPTORKEY;
 extern const std::string WATCHMETA;
 extern const std::string WATCHS;
+
+// Keys in this set pertain only to the legacy wallet (LegacyScriptPubKeyMan) and are removed during migration from legacy to descriptors.
+extern const std::unordered_set<std::string> LEGACY_TYPES;
 } // namespace DBKeys
 
 /* simple HD chain data model */
@@ -276,6 +279,9 @@ public:
     //! write the hdchain model (external chain child index counter)
     bool WriteHDChain(const CHDChain& chain);
 
+    //! Delete records of the given types
+    bool EraseRecords(const std::unordered_set<std::string>& types);
+
     bool WriteWalletFlags(const uint64_t flags);
     //! Begin a new transaction
     bool TxnBegin();