Merge pull request #149 from jgallagher/gwenn-reset

Reset statements ASAP.

src/blob.rs

@@ -159,9 +159,8 @@ impl<'conn> io::Read for Blob<'conn> {
         if n <= 0 {
             return Ok(0);
         }
-        let rc = unsafe {
-            ffi::sqlite3_blob_read(self.blob, mem::transmute(buf.as_ptr()), n, self.pos)
-        };
+        let rc =
+            unsafe { ffi::sqlite3_blob_read(self.blob, mem::transmute(buf.as_ptr()), n, self.pos) };
         self.conn
             .decode_result(rc)
             .map(|_| {

src/convenient.rs

@@ -23,12 +23,14 @@ impl<'conn> Statement<'conn> {
     /// Return `true` if a query in the SQL statement it executes returns one or more rows
     /// and `false` if the SQL returns an empty set.
     pub fn exists(&mut self, params: &[&ToSql]) -> Result<bool> {
-        self.reset_if_needed();
         let mut rows = try!(self.query(params));
+        let exists = {
             match rows.next() {
-            Some(_) => Ok(true),
-            None => Ok(false),
+                Some(_) => true,
+                None => false,
             }
+        };
+        Ok(exists)
     }
 }
 

src/functions.rs

@@ -333,7 +333,9 @@ impl<'a> Context<'a> {
 ///
 /// `A` is the type of the aggregation context and `T` is the type of the final result.
 /// Implementations should be stateless.
-pub trait Aggregate<A, T> where T: ToResult {
+pub trait Aggregate<A, T>
+    where T: ToResult
+{
     /// Initializes the aggregation context. Will be called prior to the first call
     /// to `step()` to set up the context for an invocation of the function. (Note:
     /// `init()` will not be called if the there are no rows.)

src/lib.rs

@@ -708,7 +708,6 @@ pub type SqliteStatement<'conn> = Statement<'conn>;
 pub struct Statement<'conn> {
     conn: &'conn Connection,
     stmt: *mut ffi::sqlite3_stmt,
-    needs_reset: bool,
     column_count: c_int,
 }
 
@@ -717,7 +716,6 @@ impl<'conn> Statement<'conn> {
         Statement {
             conn: conn,
             stmt: stmt,
-            needs_reset: false,
             column_count: unsafe { ffi::sqlite3_column_count(stmt) },
         }
     }
@@ -826,13 +824,10 @@ impl<'conn> Statement<'conn> {
     ///
     /// Will return `Err` if binding parameters fails.
     pub fn query<'a>(&'a mut self, params: &[&ToSql]) -> Result<Rows<'a>> {
-        self.reset_if_needed();
-
         unsafe {
             try!(self.bind_parameters(params));
         }
 
-        self.needs_reset = true;
         Ok(Rows::new(self))
     }
 
@@ -906,15 +901,6 @@ impl<'conn> Statement<'conn> {
         Ok(())
     }
 
-    fn reset_if_needed(&mut self) {
-        if self.needs_reset {
-            unsafe {
-                ffi::sqlite3_reset(self.stmt);
-            };
-            self.needs_reset = false;
-        }
-    }
-
     fn finalize_(&mut self) -> Result<()> {
         let r = unsafe { ffi::sqlite3_finalize(self.stmt) };
         self.stmt = ptr::null_mut();
@@ -949,7 +935,8 @@ pub struct MappedRows<'stmt, F> {
     map: F,
 }
 
-impl<'stmt, T, F> Iterator for MappedRows<'stmt, F> where F: FnMut(&Row) -> T
+impl<'stmt, T, F> Iterator for MappedRows<'stmt, F>
+    where F: FnMut(&Row) -> T
 {
     type Item = Result<T>;
 
@@ -1015,17 +1002,15 @@ pub type SqliteRows<'stmt> = Rows<'stmt>;
 /// `min`/`max` (which could return a stale row unless the last row happened to be the min or max,
 /// respectively).
 pub struct Rows<'stmt> {
-    stmt: &'stmt Statement<'stmt>,
+    stmt: Option<&'stmt Statement<'stmt>>,
     current_row: Rc<Cell<c_int>>,
-    failed: bool,
 }
 
 impl<'stmt> Rows<'stmt> {
     fn new(stmt: &'stmt Statement<'stmt>) -> Rows<'stmt> {
         Rows {
-            stmt: stmt,
+            stmt: Some(stmt),
             current_row: Rc::new(Cell::new(0)),
-            failed: false,
         }
     }
 
@@ -1035,31 +1020,47 @@ impl<'stmt> Rows<'stmt> {
             None => Err(Error::QueryReturnedNoRows),
         }
     }
+
+    fn reset(&mut self) {
+        if let Some(stmt) = self.stmt.take() {
+            unsafe {
+                ffi::sqlite3_reset(stmt.stmt);
+            }
+        }
+    }
 }
 
 impl<'stmt> Iterator for Rows<'stmt> {
     type Item = Result<Row<'stmt>>;
 
     fn next(&mut self) -> Option<Result<Row<'stmt>>> {
-        if self.failed {
-            return None;
-        }
-        match unsafe { ffi::sqlite3_step(self.stmt.stmt) } {
+        self.stmt.and_then(|stmt| {
+            match unsafe { ffi::sqlite3_step(stmt.stmt) } {
                 ffi::SQLITE_ROW => {
                     let current_row = self.current_row.get() + 1;
                     self.current_row.set(current_row);
                     Some(Ok(Row {
-                    stmt: self.stmt,
+                        stmt: stmt,
                         current_row: self.current_row.clone(),
                         row_idx: current_row,
                     }))
                 }
-            ffi::SQLITE_DONE => None,
+                ffi::SQLITE_DONE => {
+                    self.reset();
+                    None
+                }
                 code => {
-                self.failed = true;
-                Some(Err(self.stmt.conn.decode_result(code).unwrap_err()))
+                    self.reset();
+                    Some(Err(stmt.conn.decode_result(code).unwrap_err()))
                 }
             }
+        })
+    }
+}
+
+impl<'stmt> Drop for Rows<'stmt> {
+    fn drop(&mut self) {
+        self.reset();
     }
 }
 

src/named_params.rs

@@ -113,10 +113,7 @@ impl<'conn> Statement<'conn> {
     ///
     /// Will return `Err` if binding parameters fails.
     pub fn query_named<'a>(&'a mut self, params: &[(&str, &ToSql)]) -> Result<Rows<'a>> {
-        self.reset_if_needed();
         try!(self.bind_parameters_named(params));
-
-        self.needs_reset = true;
         Ok(Rows::new(self))
     }
 
@@ -190,9 +187,8 @@ mod test {
         let mut stmt = db.prepare("INSERT INTO test (x, y) VALUES (:x, :y)").unwrap();
         stmt.execute_named(&[(":x", &"one")]).unwrap();
 
-        let result: Option<String> = db.query_row("SELECT y FROM test WHERE x = 'one'",
-                                                  &[],
-                                                  |row| row.get(0))
+        let result: Option<String> =
+            db.query_row("SELECT y FROM test WHERE x = 'one'", &[], |row| row.get(0))
                 .unwrap();
         assert!(result.is_none());
     }
@@ -207,9 +203,8 @@ mod test {
         stmt.execute_named(&[(":x", &"one")]).unwrap();
         stmt.execute_named(&[(":y", &"two")]).unwrap();
 
-        let result: String = db.query_row("SELECT x FROM test WHERE y = 'two'",
-                                          &[],
-                                          |row| row.get(0))
+        let result: String =
+            db.query_row("SELECT x FROM test WHERE y = 'two'", &[], |row| row.get(0))
                 .unwrap();
         assert_eq!(result, "one");
     }

src/trace.rs

@@ -4,7 +4,6 @@ use libc::{c_char, c_int, c_void};
 use std::ffi::{CStr, CString};
 use std::mem;
 use std::ptr;
-use std::str;
 use std::time::Duration;
 
 use super::ffi;