Merge pull request #21 from stainless-steel/connection-flags

Introduce connection flags

src/connection.rs

@@ -12,35 +12,26 @@ pub struct Connection {
     phantom: PhantomData<ffi::sqlite3>,
 }
 
+/// Flags for opening a database connection.
+#[derive(Clone, Copy, Debug)]
+pub struct OpenFlags(c_int);
+
 unsafe impl Send for Connection {}
 
 impl Connection {
-    /// Open a connection to a new or existing database.
+    /// Open a read-write connection to a new or existing database.
     pub fn open<T: AsRef<Path>>(path: T) -> Result<Connection> {
-        let mut raw = 0 as *mut _;
-        unsafe {
-            ok!(ffi::sqlite3_open_v2(
-                path_to_cstr!(path.as_ref()).as_ptr(),
-                &mut raw,
-                ffi::SQLITE_OPEN_CREATE | ffi::SQLITE_OPEN_READWRITE,
-                0 as *const _,
-            ));
-        }
-        Ok(Connection {
-            raw: raw,
-            busy_callback: None,
-            phantom: PhantomData,
-        })
+        Connection::open_with_flags(path, OpenFlags::new().set_create().set_read_write())
     }
 
-    /// Open a read-only connection to an existing database.
-    pub fn open_readonly<T: AsRef<Path>>(path: T) -> Result<Connection> {
+    /// Open a database connection with specific flags.
+    pub fn open_with_flags<T: AsRef<Path>>(path: T, flags: OpenFlags) -> Result<Connection> {
         let mut raw = 0 as *mut _;
         unsafe {
             ok!(ffi::sqlite3_open_v2(
                 path_to_cstr!(path.as_ref()).as_ptr(),
                 &mut raw,
-                ffi::SQLITE_OPEN_READONLY,
+                flags.0,
                 0 as *const _,
             ));
         }
@@ -166,6 +157,48 @@ impl Drop for Connection {
     }
 }
 
+impl OpenFlags {
+    /// Create flags for opening a database connection.
+    #[inline]
+    pub fn new() -> Self {
+        OpenFlags(0)
+    }
+
+    /// Create the database if it does not already exist.
+    pub fn set_create(mut self) -> Self {
+        self.0 |= ffi::SQLITE_OPEN_CREATE;
+        self
+    }
+
+    /// Open the database in the serialized [threading mode][1].
+    ///
+    /// [1]: https://www.sqlite.org/threadsafe.html
+    pub fn set_full_mutex(mut self) -> Self {
+        self.0 |= ffi::SQLITE_OPEN_FULLMUTEX;
+        self
+    }
+
+    /// Opens the database in the multi-thread [threading mode][1].
+    ///
+    /// [1]: https://www.sqlite.org/threadsafe.html
+    pub fn set_no_mutex(mut self) -> Self {
+        self.0 |= ffi::SQLITE_OPEN_NOMUTEX;
+        self
+    }
+
+    /// Open the database for reading only.
+    pub fn set_read_only(mut self) -> Self {
+        self.0 |= ffi::SQLITE_OPEN_READONLY;
+        self
+    }
+
+    /// Open the database for reading and writing.
+    pub fn set_read_write(mut self) -> Self {
+        self.0 |= ffi::SQLITE_OPEN_READWRITE;
+        self
+    }
+}
+
 extern "C" fn busy_callback<F>(callback: *mut c_void, attempts: c_int) -> c_int
 where
     F: FnMut(usize) -> bool,

src/lib.rs

@@ -294,21 +294,16 @@ mod cursor;
 mod statement;
 
 pub use connection::Connection;
+pub use connection::OpenFlags;
 pub use cursor::Cursor;
 pub use statement::{Bindable, Readable, State, Statement};
 
-/// Open a connection to a new or existing database.
+/// Open a read-write connection to a new or existing database.
 #[inline]
 pub fn open<T: AsRef<std::path::Path>>(path: T) -> Result<Connection> {
     Connection::open(path)
 }
 
-/// Open a read-only connection to an existing database.
-#[inline]
-pub fn open_readonly<T: AsRef<std::path::Path>>(path: T) -> Result<Connection> {
-    Connection::open_readonly(path)
-}
-
 /// Return the version number of SQLite.
 ///
 /// For instance, the version `3.8.11.1` corresponds to the integer `3008011`.

tests/lib.rs

@@ -1,7 +1,7 @@
 extern crate sqlite;
 extern crate temporary;
 
-use sqlite::{Connection, State, Type, Value};
+use sqlite::{Connection, OpenFlags, State, Type, Value};
 use std::path::Path;
 
 macro_rules! ok(($result:expr) => ($result.unwrap()));
@@ -40,6 +40,22 @@ fn connection_iterate() {
     assert!(done);
 }
 
+#[test]
+fn connection_open_with_flags() {
+    use temporary::Directory;
+
+    let directory = ok!(Directory::new("sqlite"));
+    let path = directory.path().join("database.sqlite3");
+    setup_users(&path);
+
+    let flags = OpenFlags::new().set_read_only();
+    let connection = ok!(Connection::open_with_flags(path, flags));
+    match connection.execute("INSERT INTO users VALUES (2, 'Bob', NULL, NULL)") {
+        Err(_) => {}
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn connection_set_busy_handler() {
     use std::thread;