Merge branch 'master' into savepoint-improvements

src/lib.rs

@@ -55,6 +55,7 @@
 
 extern crate libc;
 extern crate libsqlite3_sys as ffi;
+extern crate lru_cache;
 #[macro_use]
 extern crate bitflags;
 #[cfg(test)]
@@ -76,24 +77,32 @@ use libc::{c_int, c_char};
 
 use types::{ToSql, FromSql};
 use error::{error_from_sqlite_code, error_from_handle};
+use raw_statement::RawStatement;
+use cache::StatementCache;
 
 pub use transaction::{SqliteTransaction, Transaction, TransactionBehavior};
 pub use error::{SqliteError, Error};
+pub use cache::CachedStatement;
 
 #[cfg(feature = "load_extension")]
 pub use load_extension_guard::{SqliteLoadExtensionGuard, LoadExtensionGuard};
 
 pub mod types;
 mod transaction;
+mod cache;
 mod named_params;
 mod error;
 mod convenient;
+mod raw_statement;
 #[cfg(feature = "load_extension")]mod load_extension_guard;
 #[cfg(feature = "trace")]pub mod trace;
 #[cfg(feature = "backup")]pub mod backup;
 #[cfg(feature = "functions")]pub mod functions;
 #[cfg(feature = "blob")]pub mod blob;
 
+// Number of cached prepared statements we'll hold on to.
+const STATEMENT_CACHE_DEFAULT_CAPACITY: usize = 16;
+
 /// Old name for `Result`. `SqliteResult` is deprecated.
 pub type SqliteResult<T> = Result<T>;
 
@@ -146,6 +155,7 @@ pub type SqliteConnection = Connection;
 /// A connection to a SQLite database.
 pub struct Connection {
     db: RefCell<InnerConnection>,
+    cache: StatementCache,
     path: Option<PathBuf>,
 }
 
@@ -190,6 +200,7 @@ impl Connection {
         InnerConnection::open_with_flags(&c_path, flags).map(|db| {
             Connection {
                 db: RefCell::new(db),
+                cache: StatementCache::with_capacity(STATEMENT_CACHE_DEFAULT_CAPACITY),
                 path: Some(path.as_ref().to_path_buf()),
             }
         })
@@ -208,6 +219,7 @@ impl Connection {
         InnerConnection::open_with_flags(&c_memory, flags).map(|db| {
             Connection {
                 db: RefCell::new(db),
+                cache: StatementCache::with_capacity(STATEMENT_CACHE_DEFAULT_CAPACITY),
                 path: None,
             }
         })
@@ -647,7 +659,7 @@ impl InnerConnection {
                                     &mut c_stmt,
                                     ptr::null_mut())
         };
-        self.decode_result(r).map(|_| Statement::new(conn, c_stmt))
+        self.decode_result(r).map(|_| Statement::new(conn, RawStatement::new(c_stmt)))
     }
 
     fn changes(&mut self) -> c_int {
@@ -668,25 +680,23 @@ pub type SqliteStatement<'conn> = Statement<'conn>;
 /// A prepared statement.
 pub struct Statement<'conn> {
     conn: &'conn Connection,
-    stmt: *mut ffi::sqlite3_stmt,
-    column_count: c_int,
+    stmt: RawStatement,
 }
 
 impl<'conn> Statement<'conn> {
-    fn new(conn: &Connection, stmt: *mut ffi::sqlite3_stmt) -> Statement {
+    fn new(conn: &Connection, stmt: RawStatement) -> Statement {
         Statement {
             conn: conn,
             stmt: stmt,
-            column_count: unsafe { ffi::sqlite3_column_count(stmt) },
         }
     }
 
     /// Get all the column names in the result set of the prepared statement.
     pub fn column_names(&self) -> Vec<&str> {
-        let n = self.column_count;
+        let n = self.column_count();
         let mut cols = Vec::with_capacity(n as usize);
         for i in 0..n {
-            let slice = unsafe { CStr::from_ptr(ffi::sqlite3_column_name(self.stmt, i)) };
+            let slice = self.stmt.column_name(i);
             let s = str::from_utf8(slice.to_bytes()).unwrap();
             cols.push(s);
         }
@@ -695,7 +705,7 @@ impl<'conn> Statement<'conn> {
 
     /// Return the number of columns in the result set returned by the prepared statement.
     pub fn column_count(&self) -> i32 {
-        self.column_count
+        self.stmt.column_count()
     }
 
     /// Returns the column index in the result set for a given column name.
@@ -705,10 +715,9 @@ impl<'conn> Statement<'conn> {
     /// Will return an `Error::InvalidColumnName` when there is no column with the specified `name`.
     pub fn column_index(&self, name: &str) -> Result<i32> {
         let bytes = name.as_bytes();
-        let n = self.column_count;
+        let n = self.column_count();
         for i in 0..n {
-            let slice = unsafe { CStr::from_ptr(ffi::sqlite3_column_name(self.stmt, i)) };
-            if bytes == slice.to_bytes() {
+            if bytes == self.stmt.column_name(i).to_bytes() {
                 return Ok(i);
             }
         }
@@ -739,18 +748,16 @@ impl<'conn> Statement<'conn> {
     /// Will return `Err` if binding parameters fails, the executed statement returns rows (in
     /// which case `query` should be used instead), or the underling SQLite call fails.
     pub fn execute(&mut self, params: &[&ToSql]) -> Result<c_int> {
-        unsafe {
-            try!(self.bind_parameters(params));
-            self.execute_()
-        }
+        try!(self.bind_parameters(params));
+        self.execute_()
     }
 
-    unsafe fn execute_(&mut self) -> Result<c_int> {
-        let r = ffi::sqlite3_step(self.stmt);
-        ffi::sqlite3_reset(self.stmt);
+    fn execute_(&mut self) -> Result<c_int> {
+        let r = self.stmt.step();
+        self.stmt.reset();
         match r {
             ffi::SQLITE_DONE => {
-                if self.column_count == 0 {
+                if self.column_count() == 0 {
                     Ok(self.conn.changes())
                 } else {
                     Err(Error::ExecuteReturnedResults)
@@ -785,10 +792,7 @@ impl<'conn> Statement<'conn> {
     ///
     /// Will return `Err` if binding parameters fails.
     pub fn query<'a>(&'a mut self, params: &[&ToSql]) -> Result<Rows<'a>> {
-        unsafe {
-            try!(self.bind_parameters(params));
-        }
-
+        try!(self.bind_parameters(params));
         Ok(Rows::new(self))
     }
 
@@ -849,32 +853,39 @@ impl<'conn> Statement<'conn> {
         self.finalize_()
     }
 
-    unsafe fn bind_parameters(&mut self, params: &[&ToSql]) -> Result<()> {
-        assert!(params.len() as c_int == ffi::sqlite3_bind_parameter_count(self.stmt),
+    fn bind_parameters(&mut self, params: &[&ToSql]) -> Result<()> {
+        assert!(params.len() as c_int == self.stmt.bind_parameter_count(),
                 "incorrect number of parameters to query(): expected {}, got {}",
-                ffi::sqlite3_bind_parameter_count(self.stmt),
+                self.stmt.bind_parameter_count(),
                 params.len());
 
         for (i, p) in params.iter().enumerate() {
-            try!(self.conn.decode_result(p.bind_parameter(self.stmt, (i + 1) as c_int)));
+            try!(unsafe {
+                self.conn.decode_result(p.bind_parameter(self.stmt.ptr(), (i + 1) as c_int))
+            });
         }
 
         Ok(())
     }
 
     fn finalize_(&mut self) -> Result<()> {
-        let r = unsafe { ffi::sqlite3_finalize(self.stmt) };
-        self.stmt = ptr::null_mut();
-        self.conn.decode_result(r)
+        let mut stmt = RawStatement::new(ptr::null_mut());
+        mem::swap(&mut stmt, &mut self.stmt);
+        self.conn.decode_result(stmt.finalize())
+    }
+}
+
+impl<'conn> Into<RawStatement> for Statement<'conn> {
+    fn into(mut self) -> RawStatement {
+        let mut stmt = RawStatement::new(ptr::null_mut());
+        mem::swap(&mut stmt, &mut self.stmt);
+        stmt
     }
 }
 
 impl<'conn> fmt::Debug for Statement<'conn> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let sql = unsafe {
-            let c_slice = CStr::from_ptr(ffi::sqlite3_sql(self.stmt)).to_bytes();
-            str::from_utf8(c_slice)
-        };
+        let sql = str::from_utf8(self.stmt.sql().to_bytes());
         f.debug_struct("Statement")
             .field("conn", self.conn)
             .field("stmt", &self.stmt)
@@ -984,9 +995,7 @@ impl<'stmt> Rows<'stmt> {
 
     fn reset(&mut self) {
         if let Some(stmt) = self.stmt.take() {
-            unsafe {
-                ffi::sqlite3_reset(stmt.stmt);
-            }
+            stmt.stmt.reset();
         }
     }
 }
@@ -996,7 +1005,7 @@ impl<'stmt> Iterator for Rows<'stmt> {
 
     fn next(&mut self) -> Option<Result<Row<'stmt>>> {
         self.stmt.and_then(|stmt| {
-            match unsafe { ffi::sqlite3_step(stmt.stmt) } {
+            match stmt.stmt.step() {
                 ffi::SQLITE_ROW => {
                     let current_row = self.current_row.get() + 1;
                     self.current_row.set(current_row);
@@ -1091,8 +1100,8 @@ impl<'stmt> Row<'stmt> {
         unsafe {
             let idx = try!(idx.idx(self.stmt));
 
-            if T::column_has_valid_sqlite_type(self.stmt.stmt, idx) {
-                FromSql::column_result(self.stmt.stmt, idx)
+            if T::column_has_valid_sqlite_type(self.stmt.stmt.ptr(), idx) {
+                FromSql::column_result(self.stmt.stmt.ptr(), idx)
             } else {
                 Err(Error::InvalidColumnType)
             }
@@ -1115,7 +1124,7 @@ pub trait RowIndex {
 impl RowIndex for i32 {
     #[inline]
     fn idx(&self, stmt: &Statement) -> Result<i32> {
-        if *self < 0 || *self >= stmt.column_count {
+        if *self < 0 || *self >= stmt.column_count() {
             Err(Error::InvalidColumnIndex(*self))
         } else {
             Ok(*self)