Merge #15741: Batch write imported stuff in importmulti

0db94e55d wallet: Pass WalletBatch to CWallet::UnsetWalletFlag (João Barbosa)
6cb888b37 Apply the batch treatment to CWallet::SetAddressBook via ImportScriptPubKeys (Ben Woosley)
6154a09e0 Move some of ProcessImport into CWallet::Import* (Ben Woosley)
ccb26cf34 Batch writes for importmulti (Andrew Chow)
d6576e349 Have WalletBatch automatically flush every 1000 updates (Andrew Chow)
366fe0be0 Add AddWatchOnlyWithDB, AddKeyOriginWithDB, AddCScriptWithDB functions (Andrew Chow)

Pull request description:

  Instead of writing each item to the wallet database individually, do them in batches so that the import runs faster.

  This was tested by importing a ranged descriptor for 10,000 keys.

  Current master

  ```
  $ time src/bitcoin-cli -regtest -rpcwallet=importbig importmulti '[{"desc": "sh(wpkh([73111820/44h/1h/0h]tpubDDoT2SgEjaU5rerQpfcRDWPAcwyZ5g7xxHgVAfPwidgPDKVjm89d6jJ8AQotp35Np3m6VaysfUY1C2g68wFqUmraGbzhSsMF9YBuTGxpBaW/1/*))#3w7php47", "range": [0, 10000], "timestamp": "now", "internal": true, "keypool": false, "watchonly": true}]'
  ...

  real	7m45.29s
  ```

  This PR:

  ```
  $ time src/bitcoin-cli -regtest -rpcwallet=importbig4 importmulti '[{"desc": "pkh([73111820/44h/1h/0h]tpubDDoT2SgEjaU5rerQpfcRDWPAcwyZ5g7xxHgVAfPwidgPDKVjm89d6jJ8AQotp35Np3m6VaysfUY1C2g68wFqUmraGbzhSsMF9YBuTGxpBaW/1/*)#v65yjgmc", "range": [0, 10000], "timestamp": "now", "internal": true, "keypool": false, "watchonly": true}]'
  ...

  real	3.93s
  ```

  Fixes #15739

ACKs for commit 0db94e:
  jb55:
    utACK 0db94e5
  ariard:
    Tested ACK 0db94e5
  Empact:
    re-utACK https://github.com/bitcoin/bitcoin/pull/15741/commits/0db94e55dcbbfc741df463c404818d9033b4fff1 only change is re the privacy of `UnsetWalletFlagWithDB` and `AddCScriptWithDB`.

Tree-SHA512: 3481308a64c99b6129f7bd328113dc291fe58743464628931feaebdef0e6ec770ddd5c19e4f9fbc1249a200acb04aaf62a8d914d53b0a29ac1e557576659c0cc

5 files changed, 163 insertions, 89 deletions

diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 546e3d54eb..8633d8701b 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -607,7 +607,9 @@ void BerkeleyBatch::Flush()
     if (fReadOnly)
         nMinutes = 1;
 
-    env->dbenv->txn_checkpoint(nMinutes ? gArgs.GetArg("-dblogsize", DEFAULT_WALLET_DBLOGSIZE) * 1024 : 0, nMinutes, 0);
+    if (env) { // env is nullptr for dummy databases (i.e. in tests). Don't actually flush if env is nullptr so we don't segfault
+        env->dbenv->txn_checkpoint(nMinutes ? gArgs.GetArg("-dblogsize", DEFAULT_WALLET_DBLOGSIZE) * 1024 : 0, nMinutes, 0);
+    }
 }
 
 void BerkeleyDatabase::IncrementUpdateCounter()
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index d428fac728..ee1b792f9b 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1273,55 +1273,17 @@ static UniValue ProcessImport(CWallet * const pwallet, const UniValue& data, con
 
         // All good, time to import
         pwallet->MarkDirty();
-        for (const auto& entry : import_data.import_scripts) {
-            if (!pwallet->HaveCScript(CScriptID(entry)) && !pwallet->AddCScript(entry)) {
-                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding script to wallet");
-             }
-         }
-         for (const auto& entry : privkey_map) {
-             const CKey& key = entry.second;
-             CPubKey pubkey = key.GetPubKey();
-             const CKeyID& id = entry.first;
-             assert(key.VerifyPubKey(pubkey));
-             pwallet->mapKeyMetadata[id].nCreateTime = timestamp;
-             // If the private key is not present in the wallet, insert it.
-             if (!pwallet->HaveKey(id) && !pwallet->AddKeyPubKey(key, pubkey)) {
-                 throw JSONRPCError(RPC_WALLET_ERROR, "Error adding key to wallet");
-             }
-             pwallet->UpdateTimeFirstKey(timestamp);
+        if (!pwallet->ImportScripts(import_data.import_scripts)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding script to wallet");
         }
-        for (const auto& entry : import_data.key_origins) {
-            pwallet->AddKeyOrigin(entry.second.first, entry.second.second);
+        if (!pwallet->ImportPrivKeys(privkey_map, timestamp)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding key to wallet");
         }
-        for (const CKeyID& id : ordered_pubkeys) {
-            auto entry = pubkey_map.find(id);
-            if (entry == pubkey_map.end()) {
-                continue;
-            }
-             const CPubKey& pubkey = entry->second;
-             CPubKey temp;
-             if (!pwallet->GetPubKey(id, temp) && !pwallet->AddWatchOnly(GetScriptForRawPubKey(pubkey), timestamp)) {
-                throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
-            }
-            pwallet->mapKeyMetadata[id].nCreateTime = timestamp;
-
-            // Add to keypool only works with pubkeys
-            if (add_keypool) {
-                pwallet->AddKeypoolPubkey(pubkey, internal);
-            }
+        if (!pwallet->ImportPubKeys(ordered_pubkeys, pubkey_map, import_data.key_origins, add_keypool, internal, timestamp)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
         }
-
-        for (const CScript& script : script_pub_keys) {
-            if (!have_solving_data || !::IsMine(*pwallet, script)) { // Always call AddWatchOnly for non-solvable watch-only, so that watch timestamp gets updated
-                if (!pwallet->AddWatchOnly(script, timestamp)) {
-                    throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
-                }
-            }
-            CTxDestination dest;
-            ExtractDestination(script, dest);
-            if (!internal && IsValidDestination(dest)) {
-                pwallet->SetAddressBook(dest, label, "receive");
-            }
+        if (!pwallet->ImportScriptPubKeys(label, script_pub_keys, have_solving_data, internal, timestamp)) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
         }
 
         result.pushKV("success", UniValue(true));
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 260617c666..e86147b5d0 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -320,7 +320,7 @@ bool CWallet::AddKeyPubKeyWithDB(WalletBatch& batch, const CKey& secret, const C
                                                  secret.GetPrivKey(),
                                                  mapKeyMetadata[pubkey.GetID()]);
     }
-    UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
+    UnsetWalletFlagWithDB(batch, WALLET_FLAG_BLANK_WALLET);
     return true;
 }
 
@@ -362,12 +362,6 @@ void CWallet::LoadScriptMetadata(const CScriptID& script_id, const CKeyMetadata&
     m_script_metadata[script_id] = meta;
 }
 
-// Writes a keymetadata for a public key. overwrite specifies whether to overwrite an existing metadata for that key if there exists one.
-bool CWallet::WriteKeyMetadata(const CKeyMetadata& meta, const CPubKey& pubkey, const bool overwrite)
-{
-    return WalletBatch(*database).WriteKeyMetadata(meta, pubkey, overwrite);
-}
-
 void CWallet::UpgradeKeyMetadata()
 {
     AssertLockHeld(cs_wallet);
@@ -376,7 +370,6 @@ void CWallet::UpgradeKeyMetadata()
     }
 
     std::unique_ptr<WalletBatch> batch = MakeUnique<WalletBatch>(*database);
-    size_t cnt = 0;
     for (auto& meta_pair : mapKeyMetadata) {
         CKeyMetadata& meta = meta_pair.second;
         if (!meta.hd_seed_id.IsNull() && !meta.has_key_origin && meta.hdKeypath != "s") { // If the hdKeypath is "s", that's the seed and it doesn't have a key origin
@@ -399,10 +392,6 @@ void CWallet::UpgradeKeyMetadata()
             CPubKey pubkey;
             if (GetPubKey(meta_pair.first, pubkey)) {
                 batch->WriteKeyMetadata(meta, pubkey, true);
-                if (++cnt % 1000 == 0) {
-                    // avoid creating overlarge in-memory batches in case the wallet contains large amounts of keys
-                    batch.reset(new WalletBatch(*database));
-                }
             }
         }
     }
@@ -433,10 +422,16 @@ void CWallet::UpdateTimeFirstKey(int64_t nCreateTime)
 
 bool CWallet::AddCScript(const CScript& redeemScript)
 {
+    WalletBatch batch(*database);
+    return AddCScriptWithDB(batch, redeemScript);
+}
+
+bool CWallet::AddCScriptWithDB(WalletBatch& batch, const CScript& redeemScript)
+{
     if (!CCryptoKeyStore::AddCScript(redeemScript))
         return false;
-    if (WalletBatch(*database).WriteCScript(Hash160(redeemScript), redeemScript)) {
-        UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
+    if (batch.WriteCScript(Hash160(redeemScript), redeemScript)) {
+        UnsetWalletFlagWithDB(batch, WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
@@ -457,20 +452,32 @@ bool CWallet::LoadCScript(const CScript& redeemScript)
     return CCryptoKeyStore::AddCScript(redeemScript);
 }
 
-bool CWallet::AddWatchOnly(const CScript& dest)
+bool CWallet::AddWatchOnlyWithDB(WalletBatch &batch, const CScript& dest)
 {
     if (!CCryptoKeyStore::AddWatchOnly(dest))
         return false;
     const CKeyMetadata& meta = m_script_metadata[CScriptID(dest)];
     UpdateTimeFirstKey(meta.nCreateTime);
     NotifyWatchonlyChanged(true);
-    if (WalletBatch(*database).WriteWatchOnly(dest, meta)) {
-        UnsetWalletFlag(WALLET_FLAG_BLANK_WALLET);
+    if (batch.WriteWatchOnly(dest, meta)) {
+        UnsetWalletFlagWithDB(batch, WALLET_FLAG_BLANK_WALLET);
         return true;
     }
     return false;
 }
 
+bool CWallet::AddWatchOnlyWithDB(WalletBatch &batch, const CScript& dest, int64_t create_time)
+{
+    m_script_metadata[CScriptID(dest)].nCreateTime = create_time;
+    return AddWatchOnlyWithDB(batch, dest);
+}
+
+bool CWallet::AddWatchOnly(const CScript& dest)
+{
+    WalletBatch batch(*database);
+    return AddWatchOnlyWithDB(batch, dest);
+}
+
 bool CWallet::AddWatchOnly(const CScript& dest, int64_t nCreateTime)
 {
     m_script_metadata[CScriptID(dest)].nCreateTime = nCreateTime;
@@ -1543,9 +1550,15 @@ void CWallet::SetWalletFlag(uint64_t flags)
 
 void CWallet::UnsetWalletFlag(uint64_t flag)
 {
+    WalletBatch batch(*database);
+    UnsetWalletFlagWithDB(batch, flag);
+}
+
+void CWallet::UnsetWalletFlagWithDB(WalletBatch& batch, uint64_t flag)
+{
     LOCK(cs_wallet);
     m_wallet_flags &= ~flag;
-    if (!WalletBatch(*database).WriteWalletFlags(m_wallet_flags))
+    if (!batch.WriteWalletFlags(m_wallet_flags))
         throw std::runtime_error(std::string(__func__) + ": writing wallet flags failed");
 }
 
@@ -1606,6 +1619,80 @@ bool CWallet::DummySignTx(CMutableTransaction &txNew, const std::vector<CTxOut>
     return true;
 }
 
+bool CWallet::ImportScripts(const std::set<CScript> scripts)
+{
+    WalletBatch batch(*database);
+    for (const auto& entry : scripts) {
+        if (!HaveCScript(CScriptID(entry)) && !AddCScriptWithDB(batch, entry)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool CWallet::ImportPrivKeys(const std::map<CKeyID, CKey>& privkey_map, const int64_t timestamp)
+{
+    WalletBatch batch(*database);
+    for (const auto& entry : privkey_map) {
+        const CKey& key = entry.second;
+        CPubKey pubkey = key.GetPubKey();
+        const CKeyID& id = entry.first;
+        assert(key.VerifyPubKey(pubkey));
+        mapKeyMetadata[id].nCreateTime = timestamp;
+        // If the private key is not present in the wallet, insert it.
+        if (!HaveKey(id) && !AddKeyPubKeyWithDB(batch, key, pubkey)) {
+            return false;
+        }
+        UpdateTimeFirstKey(timestamp);
+    }
+    return true;
+}
+
+bool CWallet::ImportPubKeys(const std::vector<CKeyID>& ordered_pubkeys, const std::map<CKeyID, CPubKey>& pubkey_map, const std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>>& key_origins, const bool add_keypool, const bool internal, const int64_t timestamp)
+{
+    WalletBatch batch(*database);
+    for (const auto& entry : key_origins) {
+        AddKeyOriginWithDB(batch, entry.second.first, entry.second.second);
+    }
+    for (const CKeyID& id : ordered_pubkeys) {
+        auto entry = pubkey_map.find(id);
+        if (entry == pubkey_map.end()) {
+            continue;
+        }
+        const CPubKey& pubkey = entry->second;
+        CPubKey temp;
+        if (!GetPubKey(id, temp) && !AddWatchOnlyWithDB(batch, GetScriptForRawPubKey(pubkey), timestamp)) {
+            return false;
+        }
+        mapKeyMetadata[id].nCreateTime = timestamp;
+
+        // Add to keypool only works with pubkeys
+        if (add_keypool) {
+            AddKeypoolPubkeyWithDB(pubkey, internal, batch);
+            NotifyCanGetAddressesChanged();
+        }
+    }
+    return true;
+}
+
+bool CWallet::ImportScriptPubKeys(const std::string& label, const std::set<CScript>& script_pub_keys, const bool have_solving_data, const bool internal, const int64_t timestamp)
+{
+    WalletBatch batch(*database);
+    for (const CScript& script : script_pub_keys) {
+        if (!have_solving_data || !::IsMine(*this, script)) { // Always call AddWatchOnly for non-solvable watch-only, so that watch timestamp gets updated
+            if (!AddWatchOnlyWithDB(batch, script, timestamp)) {
+                return false;
+            }
+        }
+        CTxDestination dest;
+        ExtractDestination(script, dest);
+        if (!internal && IsValidDestination(dest)) {
+            SetAddressBookWithDB(batch, dest, label, "receive");
+        }
+    }
+    return true;
+}
+
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *wallet, bool use_max_sig)
 {
     std::vector<CTxOut> txouts;
@@ -3149,8 +3236,7 @@ DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx>& vWtx)
     return DBErrors::LOAD_OK;
 }
 
-
-bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& strPurpose)
+bool CWallet::SetAddressBookWithDB(WalletBatch& batch, const CTxDestination& address, const std::string& strName, const std::string& strPurpose)
 {
     bool fUpdated = false;
     {
@@ -3163,9 +3249,15 @@ bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& s
     }
     NotifyAddressBookChanged(this, address, strName, ::IsMine(*this, address) != ISMINE_NO,
                              strPurpose, (fUpdated ? CT_UPDATED : CT_NEW) );
-    if (!strPurpose.empty() && !WalletBatch(*database).WritePurpose(EncodeDestination(address), strPurpose))
+    if (!strPurpose.empty() && !batch.WritePurpose(EncodeDestination(address), strPurpose))
         return false;
-    return WalletBatch(*database).WriteName(EncodeDestination(address), strName);
+    return batch.WriteName(EncodeDestination(address), strName);
+}
+
+bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& strPurpose)
+{
+    WalletBatch batch(*database);
+    return SetAddressBookWithDB(batch, address, strName, strPurpose);
 }
 
 bool CWallet::DelAddressBook(const CTxDestination& address)
@@ -3315,13 +3407,6 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
     return true;
 }
 
-void CWallet::AddKeypoolPubkey(const CPubKey& pubkey, const bool internal)
-{
-    WalletBatch batch(*database);
-    AddKeypoolPubkeyWithDB(pubkey, internal, batch);
-    NotifyCanGetAddressesChanged();
-}
-
 void CWallet::AddKeypoolPubkeyWithDB(const CPubKey& pubkey, const bool internal, WalletBatch& batch)
 {
     LOCK(cs_wallet);
@@ -4443,12 +4528,12 @@ bool CWallet::GetKeyOrigin(const CKeyID& keyID, KeyOriginInfo& info) const
     return true;
 }
 
-bool CWallet::AddKeyOrigin(const CPubKey& pubkey, const KeyOriginInfo& info)
+bool CWallet::AddKeyOriginWithDB(WalletBatch& batch, const CPubKey& pubkey, const KeyOriginInfo& info)
 {
     LOCK(cs_wallet);
     std::copy(info.fingerprint, info.fingerprint + 4, mapKeyMetadata[pubkey.GetID()].key_origin.fingerprint);
     mapKeyMetadata[pubkey.GetID()].key_origin.path = info.path;
     mapKeyMetadata[pubkey.GetID()].has_key_origin = true;
     mapKeyMetadata[pubkey.GetID()].hdKeypath = WriteHDKeypath(info.path);
-    return WriteKeyMetadata(mapKeyMetadata[pubkey.GetID()], pubkey, true);
+    return batch.WriteKeyMetadata(mapKeyMetadata[pubkey.GetID()], pubkey, true);
 }
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 5e3bbe2f37..87aff09039 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -775,6 +775,26 @@ private:
      * nTimeFirstKey more intelligently for more efficient rescans.
      */
     bool AddWatchOnly(const CScript& dest) override EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool AddWatchOnlyWithDB(WalletBatch &batch, const CScript& dest) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+
+    /** Add a KeyOriginInfo to the wallet */
+    bool AddKeyOriginWithDB(WalletBatch& batch, const CPubKey& pubkey, const KeyOriginInfo& info);
+
+    //! Adds a key to the store, and saves it to disk.
+    bool AddKeyPubKeyWithDB(WalletBatch &batch,const CKey& key, const CPubKey &pubkey) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+
+    //! Adds a watch-only address to the store, and saves it to disk.
+    bool AddWatchOnlyWithDB(WalletBatch &batch, const CScript& dest, int64_t create_time) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+
+    void AddKeypoolPubkeyWithDB(const CPubKey& pubkey, const bool internal, WalletBatch& batch);
+
+    bool SetAddressBookWithDB(WalletBatch& batch, const CTxDestination& address, const std::string& strName, const std::string& strPurpose);
+
+    //! Adds a script to the store and saves it to disk
+    bool AddCScriptWithDB(WalletBatch& batch, const CScript& script);
+
+    //! Unsets a wallet flag and saves it to disk
+    void UnsetWalletFlagWithDB(WalletBatch& batch, uint64_t flag);
 
     /** Interface for accessing chain state. */
     interfaces::Chain* m_chain;
@@ -833,8 +853,6 @@ public:
     // Map from Script ID to key metadata (for watch-only keys).
     std::map<CScriptID, CKeyMetadata> m_script_metadata GUARDED_BY(cs_wallet);
 
-    bool WriteKeyMetadata(const CKeyMetadata& meta, const CPubKey& pubkey, bool overwrite);
-
     typedef std::map<unsigned int, CMasterKey> MasterKeyMap;
     MasterKeyMap mapMasterKeys;
     unsigned int nMasterKeyMaxID = 0;
@@ -930,7 +948,6 @@ public:
     CPubKey GenerateNewKey(WalletBatch& batch, bool internal = false) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
-    bool AddKeyPubKeyWithDB(WalletBatch &batch,const CKey& key, const CPubKey &pubkey) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)
     bool LoadKey(const CKey& key, const CPubKey &pubkey) { return CCryptoKeyStore::AddKeyPubKey(key, pubkey); }
     //! Load metadata (used by LoadWallet)
@@ -1049,6 +1066,11 @@ public:
     bool DummySignTx(CMutableTransaction &txNew, const std::vector<CTxOut> &txouts, bool use_max_sig = false) const;
     bool DummySignInput(CTxIn &tx_in, const CTxOut &txout, bool use_max_sig = false) const;
 
+    bool ImportScripts(const std::set<CScript> scripts) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool ImportPrivKeys(const std::map<CKeyID, CKey>& privkey_map, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool ImportPubKeys(const std::vector<CKeyID>& ordered_pubkeys, const std::map<CKeyID, CPubKey>& pubkey_map, const std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>>& key_origins, const bool add_keypool, const bool internal, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    bool ImportScriptPubKeys(const std::string& label, const std::set<CScript>& script_pub_keys, const bool have_solving_data, const bool internal, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+
     CFeeRate m_pay_tx_fee{DEFAULT_PAY_TX_FEE};
     unsigned int m_confirm_target{DEFAULT_TX_CONFIRM_TARGET};
     bool m_spend_zero_conf_change{DEFAULT_SPEND_ZEROCONF_CHANGE};
@@ -1070,8 +1092,6 @@ public:
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    void AddKeypoolPubkey(const CPubKey& pubkey, const bool internal);
-    void AddKeypoolPubkeyWithDB(const CPubKey& pubkey, const bool internal, WalletBatch& batch);
 
     /**
      * Reserves a key from the keypool and sets nIndex to its index
@@ -1288,9 +1308,6 @@ public:
 
     /** Implement lookup of key origin information through wallet key metadata. */
     bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override;
-
-    /** Add a KeyOriginInfo to the wallet */
-    bool AddKeyOrigin(const CPubKey& pubkey, const KeyOriginInfo& info);
 };
 
 /**
diff --git a/src/wallet/walletdb.h b/src/wallet/walletdb.h
index 0532a55ff5..d4a3bba97a 100644
--- a/src/wallet/walletdb.h
+++ b/src/wallet/walletdb.h
@@ -143,9 +143,11 @@ public:
 };
 
 /** Access to the wallet database.
- * This represents a single transaction at the
- * database. It will be committed when the object goes out of scope.
- * Optionally (on by default) it will flush to disk as well.
+ * Opens the database and provides read and write access to it. Each read and write is its own transaction.
+ * Multiple operation transactions can be started using TxnBegin() and committed using TxnCommit()
+ * Otherwise the transaction will be committed when the object goes out of scope.
+ * Optionally (on by default) it will flush to disk on close.
+ * Every 1000 writes will automatically trigger a flush to disk.
  */
 class WalletBatch
 {
@@ -157,6 +159,9 @@ private:
             return false;
         }
         m_database.IncrementUpdateCounter();
+        if (m_database.nUpdateCounter % 1000 == 0) {
+            m_batch.Flush();
+        }
         return true;
     }
 
@@ -167,6 +172,9 @@ private:
             return false;
         }
         m_database.IncrementUpdateCounter();
+        if (m_database.nUpdateCounter % 1000 == 0) {
+            m_batch.Flush();
+        }
         return true;
     }