Initial Vexta Core v0.1.0 release

src/wallet/sqlite.h

@@ -0,0 +1,120 @@
+// Copyright (c) 2020 The DigiByte Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef DIGIBYTE_WALLET_SQLITE_H
+#define DIGIBYTE_WALLET_SQLITE_H
+
+#include <wallet/db.h>
+
+#include <sqlite3.h>
+
+struct bilingual_str;
+class SQLiteDatabase;
+
+/** RAII class that provides access to a WalletDatabase */
+class SQLiteBatch : public DatabaseBatch
+{
+private:
+    SQLiteDatabase& m_database;
+
+    bool m_cursor_init = false;
+
+    sqlite3_stmt* m_read_stmt{nullptr};
+    sqlite3_stmt* m_insert_stmt{nullptr};
+    sqlite3_stmt* m_overwrite_stmt{nullptr};
+    sqlite3_stmt* m_delete_stmt{nullptr};
+    sqlite3_stmt* m_cursor_stmt{nullptr};
+
+    void SetupSQLStatements();
+
+    bool ReadKey(CDataStream&& key, CDataStream& value) override;
+    bool WriteKey(CDataStream&& key, CDataStream&& value, bool overwrite = true) override;
+    bool EraseKey(CDataStream&& key) override;
+    bool HasKey(CDataStream&& key) override;
+
+public:
+    explicit SQLiteBatch(SQLiteDatabase& database);
+    ~SQLiteBatch() override { Close(); }
+
+    /* No-op. See comment on SQLiteDatabase::Flush */
+    void Flush() override {}
+
+    void Close() override;
+
+    bool StartCursor() override;
+    bool ReadAtCursor(CDataStream& key, CDataStream& value, bool& complete) override;
+    void CloseCursor() override;
+    bool TxnBegin() override;
+    bool TxnCommit() override;
+    bool TxnAbort() override;
+};
+
+/** An instance of this class represents one SQLite3 database.
+ **/
+class SQLiteDatabase : public WalletDatabase
+{
+private:
+    const bool m_mock{false};
+
+    const std::string m_dir_path;
+
+    const std::string m_file_path;
+
+    void Cleanup() noexcept;
+
+public:
+    SQLiteDatabase() = delete;
+
+    /** Create DB handle to real database */
+    SQLiteDatabase(const fs::path& dir_path, const fs::path& file_path, bool mock = false);
+
+    ~SQLiteDatabase();
+
+    bool Verify(bilingual_str& error);
+
+    /** Open the database if it is not already opened */
+    void Open() override;
+
+    /** Close the database */
+    void Close() override;
+
+    /* These functions are unused */
+    void AddRef() override { assert(false); }
+    void RemoveRef() override { assert(false); }
+
+    /** Rewrite the entire database on disk */
+    bool Rewrite(const char* skip = nullptr) override;
+
+    /** Back up the entire database to a file.
+     */
+    bool Backup(const std::string& dest) const override;
+
+    /** No-ops
+     *
+     * SQLite always flushes everything to the database file after each transaction
+     * (each Read/Write/Erase that we do is its own transaction unless we called
+     * TxnBegin) so there is no need to have Flush or Periodic Flush.
+     *
+     * There is no DB env to reload, so ReloadDbEnv has nothing to do
+     */
+    void Flush() override {}
+    bool PeriodicFlush() override { return false; }
+    void ReloadDbEnv() override {}
+
+    void IncrementUpdateCounter() override { ++nUpdateCounter; }
+
+    std::string Filename() override { return m_file_path; }
+    std::string Format() override { return "sqlite"; }
+
+    /** Make a SQLiteBatch connected to this database */
+    std::unique_ptr<DatabaseBatch> MakeBatch(bool flush_on_close = true) override;
+
+    sqlite3* m_db{nullptr};
+};
+
+std::unique_ptr<SQLiteDatabase> MakeSQLiteDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error);
+
+std::string SQLiteDatabaseVersion();
+
+#endif // DIGIBYTE_WALLET_SQLITE_H