Merge pull request #773 from gwenn/execute_batch

Implement our own sqlite3_exec

Cargo.toml

@@ -135,6 +135,10 @@ name = "vtab"
 name = "cache"
 harness = false
 
+[[bench]]
+name = "exec"
+harness = false
+
 [package.metadata.docs.rs]
 features = [ "backup", "blob", "chrono", "collation", "functions", "limits", "load_extension", "serde_json", "trace", "url", "vtab", "window", "modern_sqlite", "column_decltype" ]
 all-features = false

benches/exec.rs

@@ -0,0 +1,17 @@
+use bencher::{benchmark_group, benchmark_main, Bencher};
+use rusqlite::{Connection, NO_PARAMS};
+
+fn bench_execute(b: &mut Bencher) {
+    let db = Connection::open_in_memory().unwrap();
+    let sql = "PRAGMA user_version=1";
+    b.iter(|| db.execute(sql, NO_PARAMS).unwrap());
+}
+
+fn bench_execute_batch(b: &mut Bencher) {
+    let db = Connection::open_in_memory().unwrap();
+    let sql = "PRAGMA user_version=1";
+    b.iter(|| db.execute_batch(sql).unwrap());
+}
+
+benchmark_group!(exec_benches, bench_execute, bench_execute_batch);
+benchmark_main!(exec_benches);

src/inner_connection.rs

@@ -171,21 +171,6 @@ impl InnerConnection {
         }
     }
 
-    pub fn execute_batch(&mut self, sql: &str) -> Result<()> {
-        // use CString instead of SmallCString because it's probably big.
-        let c_sql = std::ffi::CString::new(sql)?;
-        unsafe {
-            let r = ffi::sqlite3_exec(
-                self.db(),
-                c_sql.as_ptr(),
-                None,
-                ptr::null_mut(),
-                ptr::null_mut(),
-            );
-            self.decode_result(r)
-        }
-    }
-
     #[cfg(feature = "load_extension")]
     pub fn enable_load_extension(&mut self, onoff: c_int) -> Result<()> {
         let r = unsafe { ffi::sqlite3_enable_load_extension(self.db, onoff) };
@@ -262,8 +247,17 @@ impl InnerConnection {
         // comment) then *ppStmt is set to NULL.
         let c_stmt: *mut ffi::sqlite3_stmt = c_stmt;
         let c_tail: *const c_char = c_tail;
-        // TODO ignore spaces, comments, ... at the end
-        let tail = !c_tail.is_null() && unsafe { c_tail != c_sql.offset(len as isize) };
+        let tail = if c_tail.is_null() {
+            0
+        } else {
+            // TODO nightly feature ptr_offset_from #41079
+            let n = (c_tail as isize) - (c_sql as isize);
+            if n <= 0 || n >= len as isize {
+                0
+            } else {
+                n as usize
+            }
+        };
         Ok(Statement::new(conn, unsafe {
             RawStatement::new(c_stmt, tail)
         }))

src/lib.rs

@@ -435,8 +435,6 @@ impl Connection {
     /// Convenience method to run multiple SQL statements (that cannot take any
     /// parameters).
     ///
-    /// Uses [sqlite3_exec](http://www.sqlite.org/c3ref/exec.html) under the hood.
-    ///
     /// ## Example
     ///
     /// ```rust,no_run
@@ -456,7 +454,19 @@ impl Connection {
     /// Will return `Err` if `sql` cannot be converted to a C-compatible string
     /// or if the underlying SQLite call fails.
     pub fn execute_batch(&self, sql: &str) -> Result<()> {
-        self.db.borrow_mut().execute_batch(sql)
+        let mut sql = sql;
+        while !sql.is_empty() {
+            let stmt = self.prepare(sql)?;
+            if !stmt.stmt.is_null() && stmt.step()? {
+                return Err(Error::ExecuteReturnedResults);
+            }
+            let tail = stmt.stmt.tail();
+            if tail == 0 || tail >= sql.len() {
+                break;
+            }
+            sql = &sql[tail..];
+        }
+        Ok(())
     }
 
     /// Convenience method to prepare and execute a single SQL statement.

src/pragma.rs

@@ -256,8 +256,7 @@ impl Connection {
         // The two syntaxes yield identical results.
         sql.push_equal_sign();
         sql.push_value(pragma_value)?;
-        self.execute(&sql, NO_PARAMS)?;
-        Ok(())
+        self.execute_batch(&sql)
     }
 
     /// Set a new value to `pragma_name` and return the updated value.

src/raw_statement.rs

@@ -12,7 +12,7 @@ use std::sync::Arc;
 #[derive(Debug)]
 pub struct RawStatement {
     ptr: *mut ffi::sqlite3_stmt,
-    tail: bool,
+    tail: usize,
     // Cached indices of named parameters, computed on the fly.
     cache: crate::util::ParamIndexCache,
     // Cached SQL (trimmed) that we use as the key when we're in the statement
@@ -29,7 +29,7 @@ pub struct RawStatement {
 }
 
 impl RawStatement {
-    pub unsafe fn new(stmt: *mut ffi::sqlite3_stmt, tail: bool) -> RawStatement {
+    pub unsafe fn new(stmt: *mut ffi::sqlite3_stmt, tail: usize) -> RawStatement {
         RawStatement {
             ptr: stmt,
             tail,
@@ -170,6 +170,10 @@ impl RawStatement {
 
     #[cfg(feature = "extra_check")]
     pub fn has_tail(&self) -> bool {
+        self.tail != 0
+    }
+
+    pub fn tail(&self) -> usize {
         self.tail
     }
 }

src/statement.rs

@@ -622,7 +622,7 @@ impl Statement<'_> {
     }
 
     fn finalize_(&mut self) -> Result<()> {
-        let mut stmt = unsafe { RawStatement::new(ptr::null_mut(), false) };
+        let mut stmt = unsafe { RawStatement::new(ptr::null_mut(), 0) };
         mem::swap(&mut stmt, &mut self.stmt);
         self.conn.decode_result(stmt.finalize())
     }
@@ -707,7 +707,7 @@ impl Statement<'_> {
     /// connection has closed is illegal, but `RawStatement` does not enforce
     /// this, as it loses our protective `'conn` lifetime bound.
     pub(crate) unsafe fn into_raw(mut self) -> RawStatement {
-        let mut stmt = RawStatement::new(ptr::null_mut(), false);
+        let mut stmt = RawStatement::new(ptr::null_mut(), 0);
         mem::swap(&mut stmt, &mut self.stmt);
         stmt
     }

src/transaction.rs

@@ -1,4 +1,4 @@
-use crate::{Connection, Result, NO_PARAMS};
+use crate::{Connection, Result};
 use std::ops::Deref;
 
 /// Options for transaction behavior. See [BEGIN
@@ -120,7 +120,7 @@ impl Transaction<'_> {
             TransactionBehavior::Immediate => "BEGIN IMMEDIATE",
             TransactionBehavior::Exclusive => "BEGIN EXCLUSIVE",
         };
-        conn.execute(query, NO_PARAMS).map(move |_| Transaction {
+        conn.execute_batch(query).map(move |_| Transaction {
             conn,
             drop_behavior: DropBehavior::Rollback,
         })
@@ -180,7 +180,7 @@ impl Transaction<'_> {
     }
 
     fn commit_(&mut self) -> Result<()> {
-        self.conn.execute("COMMIT", NO_PARAMS)?;
+        self.conn.execute_batch("COMMIT")?;
         Ok(())
     }
 
@@ -190,7 +190,7 @@ impl Transaction<'_> {
     }
 
     fn rollback_(&mut self) -> Result<()> {
-        self.conn.execute("ROLLBACK", NO_PARAMS)?;
+        self.conn.execute_batch("ROLLBACK")?;
         Ok(())
     }
 
@@ -238,7 +238,7 @@ impl Savepoint<'_> {
         name: T,
     ) -> Result<Savepoint<'_>> {
         let name = name.into();
-        conn.execute(&format!("SAVEPOINT {}", name), NO_PARAMS)
+        conn.execute_batch(&format!("SAVEPOINT {}", name))
             .map(|_| Savepoint {
                 conn,
                 name,
@@ -291,8 +291,7 @@ impl Savepoint<'_> {
     }
 
     fn commit_(&mut self) -> Result<()> {
-        self.conn
-            .execute(&format!("RELEASE {}", self.name), NO_PARAMS)?;
+        self.conn.execute_batch(&format!("RELEASE {}", self.name))?;
         self.committed = true;
         Ok(())
     }
@@ -305,8 +304,7 @@ impl Savepoint<'_> {
     /// rolled back, and can be rolled back again or committed.
     pub fn rollback(&mut self) -> Result<()> {
         self.conn
-            .execute(&format!("ROLLBACK TO {}", self.name), NO_PARAMS)?;
-        Ok(())
+            .execute_batch(&format!("ROLLBACK TO {}", self.name))
     }
 
     /// Consumes the savepoint, committing or rolling back according to the