wallet: add experimental SQLite record store

1 files changed, 254 insertions, 0 deletions

diff --git a/src/wallet_sqlite.cpp b/src/wallet_sqlite.cpp
new file mode 100644
index 0000000..4104ac6
--- /dev/null
+++ b/src/wallet_sqlite.cpp
@@ -0,0 +1,254 @@
+// Copyright (c) 2026 Bitflash developers
+// Distributed under the MIT/X11 software license.
+
+#include "headers.h"
+#include "wallet_sqlite.h"
+
+static void SetSQLiteError(sqlite3* pdb, const string& strContext,
+                           string& strError)
+{
+    if (pdb)
+        strError = strContext + ": " + sqlite3_errmsg(pdb);
+    else
+        strError = strContext;
+}
+
+CWalletDBSQLite::CWalletDBSQLite() : pdb(NULL)
+{
+}
+
+CWalletDBSQLite::~CWalletDBSQLite()
+{
+    Close();
+}
+
+bool CWalletDBSQLite::Open(const string& strPath, string& strError)
+{
+    Close();
+
+    int ret = sqlite3_open_v2(strPath.c_str(), &pdb,
+                              SQLITE_OPEN_READWRITE |
+                              SQLITE_OPEN_CREATE |
+                              SQLITE_OPEN_FULLMUTEX,
+                              NULL);
+    if (ret != SQLITE_OK)
+    {
+        SetSQLiteError(pdb, "cannot open SQLite wallet", strError);
+        Close();
+        return false;
+    }
+
+    sqlite3_busy_timeout(pdb, 5000);
+
+    if (!Exec("PRAGMA journal_mode=WAL;", strError))
+    {
+        Close();
+        return false;
+    }
+    if (!Exec("PRAGMA synchronous=FULL;", strError))
+    {
+        Close();
+        return false;
+    }
+    if (!InitSchema(strError))
+    {
+        Close();
+        return false;
+    }
+    return true;
+}
+
+void CWalletDBSQLite::Close()
+{
+    if (pdb)
+    {
+        sqlite3_close(pdb);
+        pdb = NULL;
+    }
+}
+
+bool CWalletDBSQLite::BeginTransaction(string& strError)
+{
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+    return Exec("BEGIN IMMEDIATE;", strError);
+}
+
+bool CWalletDBSQLite::CommitTransaction(string& strError)
+{
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+    return Exec("COMMIT;", strError);
+}
+
+bool CWalletDBSQLite::RollbackTransaction(string& strError)
+{
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+    return Exec("ROLLBACK;", strError);
+}
+
+bool CWalletDBSQLite::Exec(const char* pszSql, string& strError)
+{
+    char* pszErr = NULL;
+    int ret = sqlite3_exec(pdb, pszSql, NULL, NULL, &pszErr);
+    if (ret != SQLITE_OK)
+    {
+        if (pszErr)
+        {
+            strError = pszErr;
+            sqlite3_free(pszErr);
+        }
+        else
+            SetSQLiteError(pdb, "SQLite exec failed", strError);
+        return false;
+    }
+    return true;
+}
+
+bool CWalletDBSQLite::InitSchema(string& strError)
+{
+    return Exec("CREATE TABLE IF NOT EXISTS wallet_records ("
+                "key BLOB PRIMARY KEY NOT NULL,"
+                "value BLOB NOT NULL"
+                ");",
+                strError) &&
+           Exec("PRAGMA user_version=1;", strError);
+}
+
+bool CWalletDBSQLite::WriteRecord(const vector<unsigned char>& vchKey,
+                                  const vector<unsigned char>& vchValue,
+                                  string& strError)
+{
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+    if (vchKey.empty())
+    {
+        strError = "SQLite wallet record key is empty";
+        return false;
+    }
+
+    sqlite3_stmt* stmt = NULL;
+    const char* pszSql =
+        "INSERT OR REPLACE INTO wallet_records(key, value) VALUES(?, ?);";
+    int ret = sqlite3_prepare_v2(pdb, pszSql, -1, &stmt, NULL);
+    if (ret != SQLITE_OK)
+    {
+        SetSQLiteError(pdb, "cannot prepare SQLite wallet write", strError);
+        return false;
+    }
+
+    ret = sqlite3_bind_blob(stmt, 1, &vchKey[0], (int)vchKey.size(),
+                            SQLITE_TRANSIENT);
+    if (ret == SQLITE_OK)
+        ret = sqlite3_bind_blob(stmt, 2,
+                                vchValue.empty() ? NULL : &vchValue[0],
+                                (int)vchValue.size(),
+                                SQLITE_TRANSIENT);
+    if (ret == SQLITE_OK)
+        ret = sqlite3_step(stmt);
+
+    bool fOk = (ret == SQLITE_DONE);
+    if (!fOk)
+        SetSQLiteError(pdb, "cannot write SQLite wallet record", strError);
+    sqlite3_finalize(stmt);
+    return fOk;
+}
+
+bool CWalletDBSQLite::ReadRecord(const vector<unsigned char>& vchKey,
+                                 vector<unsigned char>& vchValueRet,
+                                 string& strError)
+{
+    vchValueRet.clear();
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+    if (vchKey.empty())
+    {
+        strError = "SQLite wallet record key is empty";
+        return false;
+    }
+
+    sqlite3_stmt* stmt = NULL;
+    const char* pszSql = "SELECT value FROM wallet_records WHERE key = ?;";
+    int ret = sqlite3_prepare_v2(pdb, pszSql, -1, &stmt, NULL);
+    if (ret != SQLITE_OK)
+    {
+        SetSQLiteError(pdb, "cannot prepare SQLite wallet read", strError);
+        return false;
+    }
+
+    ret = sqlite3_bind_blob(stmt, 1, &vchKey[0], (int)vchKey.size(),
+                            SQLITE_TRANSIENT);
+    if (ret != SQLITE_OK)
+    {
+        SetSQLiteError(pdb, "cannot bind SQLite wallet key", strError);
+        sqlite3_finalize(stmt);
+        return false;
+    }
+
+    ret = sqlite3_step(stmt);
+    if (ret == SQLITE_ROW)
+    {
+        const unsigned char* pch =
+            (const unsigned char*)sqlite3_column_blob(stmt, 0);
+        int nBytes = sqlite3_column_bytes(stmt, 0);
+        if (nBytes > 0 && pch)
+            vchValueRet.assign(pch, pch + nBytes);
+        sqlite3_finalize(stmt);
+        return true;
+    }
+
+    if (ret == SQLITE_DONE)
+        strError = "SQLite wallet record not found";
+    else
+        SetSQLiteError(pdb, "cannot read SQLite wallet record", strError);
+    sqlite3_finalize(stmt);
+    return false;
+}
+
+bool CWalletDBSQLite::CountRecords(int& nRecordsRet, string& strError)
+{
+    nRecordsRet = 0;
+    if (!pdb)
+    {
+        strError = "SQLite wallet is not open";
+        return false;
+    }
+
+    sqlite3_stmt* stmt = NULL;
+    int ret = sqlite3_prepare_v2(pdb,
+                                 "SELECT COUNT(*) FROM wallet_records;",
+                                 -1, &stmt, NULL);
+    if (ret != SQLITE_OK)
+    {
+        SetSQLiteError(pdb, "cannot prepare SQLite wallet count", strError);
+        return false;
+    }
+
+    ret = sqlite3_step(stmt);
+    if (ret != SQLITE_ROW)
+    {
+        SetSQLiteError(pdb, "cannot count SQLite wallet records", strError);
+        sqlite3_finalize(stmt);
+        return false;
+    }
+
+    nRecordsRet = sqlite3_column_int(stmt, 0);
+    sqlite3_finalize(stmt);
+    return true;
+}