Merge pull request #22 from jgallagher/load-extension

Add calls to load SQLite extensions

Cargo.toml

@@ -12,6 +12,12 @@ license = "MIT"
 [lib]
 name = "rusqlite"
 
+[features]
+load_extension = ["libsqlite3-sys/load_extension"]
+
 [dependencies]
 time = "~0.1.0"
 bitflags = "~0.1"
+
+[dependencies.libsqlite3-sys]
+path = "libsqlite3-sys"

build.rs

@@ -0,0 +1,5 @@
+extern crate "pkg-config" as pkg_config;
+
+fn main() {
+    pkg_config::find_library("sqlite3").unwrap();
+}

libsqlite3-sys/.gitignore

@@ -0,0 +1,3 @@
+/target/
+/doc/
+Cargo.lock

libsqlite3-sys/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "libsqlite3-sys"
+version = "0.0.9"
+authors = ["John Gallagher <jgallagher@bignerdranch.com>"]
+description = "Native bindings to the libsqlite3 library"
+license = "MIT"
+links = "sqlite3"
+build = "build.rs"
+
+[features]
+load_extension = []
+
+[build-dependencies]
+pkg-config = "~0.2"

libsqlite3-sys/build.rs

@@ -0,0 +1,5 @@
+extern crate "pkg-config" as pkg_config;
+
+fn main() {
+    pkg_config::find_library("sqlite3").unwrap();
+}

libsqlite3-sys/src/bindgen.rs

@@ -1,6 +1,5 @@
-#![allow(raw_pointer_derive)]
+#![allow(raw_pointer_derive, non_snake_case, non_camel_case_types)]
 /* Running `target/bindgen /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/include/sqlite3.h -I/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/6.0/include` */
-/* automatically generated by rust-bindgen */
 
 #[derive(Copy)]
 pub enum Struct_sqlite3 { }
@@ -521,7 +520,6 @@ pub struct Struct_sqlite3_rtree_geometry {
     pub xDelUser: ::std::option::Option<extern "C" fn
                                             (arg1: *mut ::libc::c_void)>,
 }
-#[link(name = "sqlite3")]
 extern "C" {
     pub static mut sqlite3_version: *const ::libc::c_char;
     pub static mut sqlite3_temp_directory: *mut ::libc::c_char;
@@ -1589,11 +1587,13 @@ extern "C" {
                                          pPrimaryKey: *mut ::libc::c_int,
                                          pAutoinc: *mut ::libc::c_int)
      -> ::libc::c_int;
+    #[cfg(feature = "load_extension")]
     pub fn sqlite3_load_extension(db: *mut sqlite3,
                                   zFile: *const ::libc::c_char,
                                   zProc: *const ::libc::c_char,
                                   pzErrMsg: *mut *mut ::libc::c_char)
      -> ::libc::c_int;
+    #[cfg(feature = "load_extension")]
     pub fn sqlite3_enable_load_extension(db: *mut sqlite3,
                                          onoff: ::libc::c_int)
      -> ::libc::c_int;

libsqlite3-sys/src/lib.rs

@@ -1,4 +1,10 @@
+#![feature(libc)]
+#![allow(non_snake_case)]
+
+extern crate libc;
+
 pub use self::bindgen::*;
+
 use std::mem;
 use libc::{c_int, c_void};
 
@@ -42,7 +48,7 @@ pub const SQLITE_NULL : c_int = 5;
 pub type SqliteDestructor = extern "C" fn(*mut c_void);
 
 pub fn SQLITE_TRANSIENT() -> SqliteDestructor {
-    unsafe { mem::transmute(-1is) }
+    unsafe { mem::transmute(-1isize) }
 }
 
 pub fn code_to_str(code: c_int) -> &'static str {

src/lib.rs

@@ -48,20 +48,21 @@
 //!     }
 //! }
 //! ```
-#![feature(unsafe_destructor, core, std_misc, libc, rustc_private, collections, hash)]
+#![feature(unsafe_destructor, core, std_misc, path, libc, rustc_private, collections)]
 #![cfg_attr(test, feature(test))]
 
 extern crate libc;
+extern crate "libsqlite3-sys" as ffi;
 #[macro_use] extern crate rustc_bitflags;
 
 use std::mem;
 use std::ptr;
 use std::fmt;
+use std::path::{Path};
 use std::error;
 use std::rc::{Rc};
 use std::cell::{RefCell, Cell};
-use std::ffi::{CString};
+use std::ffi::{CStr, CString};
-use std::ffi as std_ffi;
 use std::str;
 use libc::{c_int, c_void, c_char};
 
@@ -73,17 +74,17 @@ pub use transaction::{SqliteTransactionBehavior,
                       SqliteTransactionImmediate,
                       SqliteTransactionExclusive};
 
+#[cfg(feature = "load_extension")] pub use load_extension_guard::{SqliteLoadExtensionGuard};
+
 pub mod types;
 mod transaction;
-
+#[cfg(feature = "load_extension")] mod load_extension_guard;
-/// Automatically generated FFI bindings (via [bindgen](https://github.com/crabtw/rust-bindgen)).
-#[allow(dead_code,non_snake_case,non_camel_case_types)] pub mod ffi;
 
 /// A typedef of the result returned by many methods.
 pub type SqliteResult<T> = Result<T, SqliteError>;
 
 unsafe fn errmsg_to_string(errmsg: *const c_char) -> String {
-    let c_slice = std_ffi::c_str_to_bytes(&errmsg);
+    let c_slice = CStr::from_ptr(errmsg).to_bytes();
     let utf8_str = str::from_utf8(c_slice);
     utf8_str.unwrap_or("Invalid string encoding").to_string()
 }
@@ -123,6 +124,21 @@ impl SqliteError {
     }
 }
 
+fn str_to_cstring(s: &str) -> SqliteResult<CString> {
+    CString::new(s).map_err(|_| SqliteError{
+        code: ffi::SQLITE_MISUSE,
+        message: "Could not convert path to C-combatible string".to_string()
+    })
+}
+
+fn path_to_cstring(p: &Path) -> SqliteResult<CString> {
+    let s = try!(p.to_str().ok_or(SqliteError{
+        code: ffi::SQLITE_MISUSE,
+        message: "Could not convert path to UTF-8 string".to_string()
+    }));
+    str_to_cstring(s)
+}
+
 /// A connection to a SQLite database.
 ///
 /// ## Warning
@@ -322,6 +338,55 @@ impl SqliteConnection {
         db.close()
     }
 
+    /// Enable loading of SQLite extensions. Strongly consider using `SqliteLoadExtensionGuard`
+    /// instead of this function.
+    ///
+    /// ## Example
+    ///
+    /// ```rust,no_run
+    /// # use rusqlite::{SqliteConnection, SqliteResult};
+    /// # use std::path::{Path};
+    /// fn load_my_extension(conn: &SqliteConnection) -> SqliteResult<()> {
+    ///     try!(conn.load_extension_enable());
+    ///     try!(conn.load_extension(Path::new("my_sqlite_extension"), None));
+    ///     conn.load_extension_disable()
+    /// }
+    /// ```
+    #[cfg(feature = "load_extension")]
+    pub fn load_extension_enable(&self) -> SqliteResult<()> {
+        self.db.borrow_mut().enable_load_extension(1)
+    }
+
+    /// Disable loading of SQLite extensions.
+    ///
+    /// See `load_extension_enable` for an example.
+    #[cfg(feature = "load_extension")]
+    pub fn load_extension_disable(&self) -> SqliteResult<()> {
+        self.db.borrow_mut().enable_load_extension(0)
+    }
+
+    /// Load the SQLite extension at `dylib_path`. `dylib_path` is passed through to
+    /// `sqlite3_load_extension`, which may attempt OS-specific modifications if the file
+    /// cannot be loaded directly.
+    ///
+    /// If `entry_point` is `None`, SQLite will attempt to find the entry point. If it is not
+    /// `None`, the entry point will be passed through to `sqlite3_load_extension`.
+    ///
+    /// ## Example
+    ///
+    /// ```rust,no_run
+    /// # use rusqlite::{SqliteConnection, SqliteResult, SqliteLoadExtensionGuard};
+    /// # use std::path::{Path};
+    /// fn load_my_extension(conn: &SqliteConnection) -> SqliteResult<()> {
+    ///     let _guard = try!(SqliteLoadExtensionGuard::new(conn));
+    ///
+    ///     conn.load_extension(Path::new("my_sqlite_extension"), None)
+    /// }
+    #[cfg(feature = "load_extension")]
+    pub fn load_extension(&self, dylib_path: &Path, entry_point: Option<&str>) -> SqliteResult<()> {
+        self.db.borrow_mut().load_extension(dylib_path, entry_point)
+    }
+
     fn decode_result(&self, code: c_int) -> SqliteResult<()> {
         self.db.borrow_mut().decode_result(code)
     }
@@ -360,7 +425,7 @@ bitflags! {
 
 impl InnerSqliteConnection {
     fn open_with_flags(path: &str, flags: SqliteOpenFlags) -> SqliteResult<InnerSqliteConnection> {
-        let c_path = CString::from_slice(path.as_bytes());
+        let c_path = try!(str_to_cstring(path));
         unsafe {
             let mut db: *mut ffi::sqlite3 = mem::uninitialized();
             let r = ffi::sqlite3_open_v2(c_path.as_ptr(), &mut db, flags.bits(), ptr::null());
@@ -394,6 +459,16 @@ impl InnerSqliteConnection {
         }
     }
 
+    unsafe fn decode_result_with_errmsg(&self, code: c_int, errmsg: *mut c_char) -> SqliteResult<()> {
+        if code == ffi::SQLITE_OK {
+            Ok(())
+        } else {
+            let message = errmsg_to_string(&*errmsg);
+            ffi::sqlite3_free(errmsg as *mut c_void);
+            Err(SqliteError{ code: code, message: message })
+        }
+    }
+
     fn close(&mut self) -> SqliteResult<()> {
         let r = unsafe { ffi::sqlite3_close(self.db) };
         self.db = ptr::null_mut();
@@ -401,18 +476,33 @@ impl InnerSqliteConnection {
     }
 
     fn execute_batch(&mut self, sql: &str) -> SqliteResult<()> {
-        let c_sql = CString::from_slice(sql.as_bytes());
+        let c_sql = try!(str_to_cstring(sql));
         unsafe {
             let mut errmsg: *mut c_char = mem::uninitialized();
             let r = ffi::sqlite3_exec(self.db, c_sql.as_ptr(), None, ptr::null_mut(), &mut errmsg);
-            if r == ffi::SQLITE_OK {
+            self.decode_result_with_errmsg(r, errmsg)
-                Ok(())
-            } else {
-                let message = errmsg_to_string(&*errmsg);
-                ffi::sqlite3_free(errmsg as *mut c_void);
-                Err(SqliteError{ code: r, message: message })
         }
     }
+
+    #[cfg(feature = "load_extension")]
+    fn enable_load_extension(&mut self, onoff: c_int) -> SqliteResult<()> {
+        let r = unsafe { ffi::sqlite3_enable_load_extension(self.db, onoff) };
+        self.decode_result(r)
+    }
+
+    #[cfg(feature = "load_extension")]
+    fn load_extension(&self, dylib_path: &Path, entry_point: Option<&str>) -> SqliteResult<()> {
+        let dylib_str = try!(path_to_cstring(dylib_path));
+        unsafe {
+            let mut errmsg: *mut c_char = mem::uninitialized();
+            let r = if let Some(entry_point) = entry_point {
+                let c_entry = try!(str_to_cstring(entry_point));
+                ffi::sqlite3_load_extension(self.db, dylib_str.as_ptr(), c_entry.as_ptr(), &mut errmsg)
+            } else {
+                ffi::sqlite3_load_extension(self.db, dylib_str.as_ptr(), ptr::null(), &mut errmsg)
+            };
+            self.decode_result_with_errmsg(r, errmsg)
+        }
     }
 
     fn last_insert_rowid(&self) -> i64 {
@@ -425,7 +515,7 @@ impl InnerSqliteConnection {
                    conn: &'a SqliteConnection,
                    sql: &str) -> SqliteResult<SqliteStatement<'a>> {
         let mut c_stmt: *mut ffi::sqlite3_stmt = unsafe { mem::uninitialized() };
-        let c_sql = CString::from_slice(sql.as_bytes());
+        let c_sql = try!(str_to_cstring(sql));
         let r = unsafe {
             let len_with_nul = (sql.len() + 1) as c_int;
             ffi::sqlite3_prepare_v2(self.db, c_sql.as_ptr(), len_with_nul, &mut c_stmt,
@@ -705,6 +795,7 @@ impl<'stmt> SqliteRow<'stmt> {
 
 #[cfg(test)]
 mod test {
+    extern crate "libsqlite3-sys" as ffi;
     use super::*;
 
     fn checked_memory_handle() -> SqliteConnection {

src/load_extension_guard.rs

@@ -0,0 +1,34 @@
+use {SqliteResult, SqliteConnection};
+
+/// RAII guard temporarily enabling SQLite extensions to be loaded.
+///
+/// ## Example
+///
+/// ```rust,no_run
+/// # use rusqlite::{SqliteConnection, SqliteResult, SqliteLoadExtensionGuard};
+/// # use std::path::{Path};
+/// fn load_my_extension(conn: &SqliteConnection) -> SqliteResult<()> {
+///     let _guard = try!(SqliteLoadExtensionGuard::new(conn));
+///
+///     conn.load_extension(Path::new("my_sqlite_extension"), None)
+/// }
+/// ```
+pub struct SqliteLoadExtensionGuard<'conn> {
+    conn: &'conn SqliteConnection,
+}
+
+impl<'conn> SqliteLoadExtensionGuard<'conn> {
+    /// Attempt to enable loading extensions. Loading extensions will be disabled when this
+    /// guard goes out of scope. Cannot be meaningfully nested.
+    pub fn new(conn: &SqliteConnection) -> SqliteResult<SqliteLoadExtensionGuard> {
+        conn.load_extension_enable().map(|_| SqliteLoadExtensionGuard{ conn: conn })
+    }
+}
+
+#[unsafe_destructor]
+#[allow(unused_must_use)]
+impl<'conn> Drop for SqliteLoadExtensionGuard<'conn> {
+    fn drop(&mut self) {
+        self.conn.load_extension_disable();
+    }
+}

src/types.rs

@@ -55,12 +55,11 @@
 extern crate time;
 
 use libc::{c_int, c_double, c_char};
-use std::ffi as std_ffi;
+use std::ffi::{CStr};
-use std::ffi::{CString};
 use std::mem;
 use std::str;
 use super::ffi;
-use super::{SqliteResult, SqliteError};
+use super::{SqliteResult, SqliteError, str_to_cstring};
 
 const SQLITE_DATETIME_FMT: &'static str = "%Y-%m-%d %H:%M:%S";
 
@@ -90,8 +89,11 @@ raw_to_impl!(c_double, sqlite3_bind_double);
 
 impl<'a> ToSql for &'a str {
     unsafe fn bind_parameter(&self, stmt: *mut ffi::sqlite3_stmt, col: c_int) -> c_int {
-        let c_str = CString::from_slice(self.as_bytes());
+        if let Ok(c_str) = str_to_cstring(self) {
             ffi::sqlite3_bind_text(stmt, col, c_str.as_ptr(), -1, Some(ffi::SQLITE_TRANSIENT()))
+        } else {
+            ffi::SQLITE_MISUSE
+        }
     }
 }
 
@@ -177,8 +179,7 @@ impl FromSql for String {
         if c_text.is_null() {
             Ok("".to_string())
         } else {
-            let c_text = c_text as *const c_char;
+            let c_slice = CStr::from_ptr(c_text as *const c_char).to_bytes();
-            let c_slice = std_ffi::c_str_to_bytes(&c_text);
             let utf8_str = str::from_utf8(c_slice);
             utf8_str
                 .map(|s| { s.to_string() })