DataLiteCore swift package

Sources/DataLiteCore/Enums/JournalMode.swift

@@ -0,0 +1,82 @@
+import Foundation
+
+/// Represents the journal modes available for an SQLite database.
+///
+/// The journal mode determines how the database handles transactions and how it
+/// maintains the journal for rollback and recovery. For more details, refer to
+/// [Journal Mode Pragma](https://www.sqlite.org/pragma.html#pragma_journal_mode).
+public enum JournalMode: String, SQLiteRawRepresentable {
+    /// DELETE journal mode.
+    ///
+    /// This is the default behavior. The rollback journal is deleted at the conclusion
+    /// of each transaction. The delete operation itself causes the transaction to commit.
+    /// For more details, refer to the
+    /// [Atomic Commit In SQLite](https://www.sqlite.org/atomiccommit.html).
+    case delete
+    
+    /// TRUNCATE journal mode.
+    ///
+    /// In this mode, the rollback journal is truncated to zero length at the end of each transaction
+    /// instead of being deleted. On many systems, truncating a file is much faster than deleting it
+    /// because truncating does not require modifying the containing directory.
+    case truncate
+    
+    /// PERSIST journal mode.
+    ///
+    /// In this mode, the rollback journal is not deleted at the end of each transaction. Instead,
+    /// the header of the journal is overwritten with zeros. This prevents other database connections
+    /// from rolling the journal back. The PERSIST mode is useful as an optimization on platforms
+    /// where deleting or truncating a file is more expensive than overwriting the first block of a file
+    /// with zeros. For additional configuration, refer to
+    /// [journal_size_limit](https://www.sqlite.org/pragma.html#pragma_journal_size_limit).
+    case persist
+    
+    /// MEMORY journal mode.
+    ///
+    /// In this mode, the rollback journal is stored entirely in volatile RAM rather than on disk.
+    /// This saves disk I/O but at the expense of database safety and integrity. If the application
+    /// crashes during a transaction, the database file will likely become corrupt.
+    case memory
+    
+    /// Write-Ahead Logging (WAL) journal mode.
+    ///
+    /// This mode uses a write-ahead log instead of a rollback journal to implement transactions.
+    /// The WAL mode is persistent, meaning it stays in effect across multiple database connections
+    /// and persists even after closing and reopening the database. For more details, refer to the
+    /// [Write-Ahead Logging](https://www.sqlite.org/wal.html).
+    case wal
+    
+    /// OFF journal mode.
+    ///
+    /// In this mode, the rollback journal is completely disabled, meaning no rollback journal is ever created.
+    /// This disables SQLite's atomic commit and rollback capabilities. The `ROLLBACK` command will no longer work
+    /// and behaves in an undefined way. Applications must avoid using the `ROLLBACK` command when the journal mode is OFF.
+    /// If the application crashes in the middle of a transaction, the database file will likely become corrupt,
+    /// as there is no way to unwind partially completed operations. For example, if a duplicate entry causes a
+    /// `CREATE UNIQUE INDEX` statement to fail halfway through, it will leave behind a partially created index,
+    /// resulting in a corrupted database state.
+    case off
+    
+    public var rawValue: String {
+        switch self {
+        case .delete:       "DELETE"
+        case .truncate:     "TRUNCATE"
+        case .persist:      "PERSIST"
+        case .memory:       "MEMORY"
+        case .wal:          "WAL"
+        case .off:          "OFF"
+        }
+    }
+    
+    public init?(rawValue: String) {
+        switch rawValue.uppercased() {
+        case "DELETE":      self = .delete
+        case "TRUNCATE":    self = .truncate
+        case "PERSIST":     self = .persist
+        case "MEMORY":      self = .memory
+        case "WAL":         self = .wal
+        case "OFF":         self = .off
+        default:            return nil
+        }
+    }
+}