Partial CSV virtual table implementation.

Cargo.toml

@@ -19,6 +19,7 @@ blob = []
 functions = []
 trace = []
 vtab = []
+csvtab = ["csv"]
 
 [dependencies]
 time = "~0.1.0"
@@ -34,6 +35,10 @@ regex = "~0.1.41"
 path = "libsqlite3-sys"
 version = "0.4.0"
 
+[dependencies.csv]
+version = "~0.14.3"
+optional = true
+
 [[test]]
 name = "config_log"
 harness = false

src/error.rs

@@ -66,6 +66,12 @@ pub enum Error {
     #[cfg(feature = "functions")]
     #[allow(dead_code)]
     UserFunctionError(Box<error::Error + Send + Sync>),
+
+    /// An error case available for implementors of custom modules (e.g.,
+    /// `create_module`).
+    #[cfg(feature = "vtab")]
+    #[allow(dead_code)]
+    ModuleError(String),
 }
 
 impl From<str::Utf8Error> for Error {
@@ -107,6 +113,8 @@ impl fmt::Display for Error {
             &Error::InvalidFunctionParameterType => write!(f, "Invalid function parameter type"),
             #[cfg(feature = "functions")]
             &Error::UserFunctionError(ref err) => err.fmt(f),
+            #[cfg(feature = "vtab")]
+            &Error::ModuleError(ref desc) => write!(f, "{}", desc),
         }
     }
 }
@@ -137,6 +145,8 @@ impl error::Error for Error {
             &Error::InvalidFunctionParameterType => "invalid function parameter type",
             #[cfg(feature = "functions")]
             &Error::UserFunctionError(ref err) => err.description(),
+            #[cfg(feature = "vtab")]
+            &Error::ModuleError(ref desc) => desc,
         }
     }
 
@@ -160,6 +170,8 @@ impl error::Error for Error {
             &Error::InvalidFunctionParameterType => None,
             #[cfg(feature = "functions")]
             &Error::UserFunctionError(ref err) => Some(&**err),
+            #[cfg(feature = "vtab")]
+            &Error::ModuleError(_) => None,
         }
     }
 }

src/vtab/csvtab.rs

@@ -0,0 +1,114 @@
+//! CSV Virtual Table
+extern crate csv;
+use std::fs::File;
+use std::mem;
+use libc;
+
+use {Connection, Error, Result};
+use ffi;
+use vtab::declare_vtab;
+
+use self::csv::Reader;
+
+pub fn load_module(conn: &Connection) -> Result<()> {
+    let aux: Option<()> = None;
+    conn.create_module("csv", &CSV_MODULE, aux)
+}
+
+init_module!(CSV_MODULE, CSVTab, CSVTabCursor,
+    csv_create, csv_best_index, csv_destroy,
+    csv_open, csv_close,
+    csv_filter, csv_next, csv_eof,
+    csv_column, csv_rowid);
+
+#[repr(C)]
+struct CSVTab {
+    /// Base class
+    base: ffi::sqlite3_vtab,
+    reader: csv::Reader<File>,
+    offset_first_row: u64,
+}
+
+impl CSVTab {
+    fn create(db: *mut ffi::sqlite3,
+              aux: *mut libc::c_void,
+              _argc: libc::c_int,
+              _argv: *const *const libc::c_char)
+              -> Result<CSVTab> {
+        let reader = try!(csv::Reader::from_file("FIXME"));
+        let vtab = CSVTab {
+            base: Default::default(),
+            reader: reader,
+            offset_first_row: 0,
+        };
+        unimplemented!();
+        try!(declare_vtab(db, "CREATE TABLE x FIXME"));
+        Ok(vtab)
+    }
+
+    fn best_index(&self, _info: *mut ffi::sqlite3_index_info) {}
+
+    fn open(&self) -> Result<CSVTabCursor> {
+        Ok(CSVTabCursor::new())
+    }
+}
+
+
+#[repr(C)]
+struct CSVTabCursor {
+    /// Base class
+    base: ffi::sqlite3_vtab_cursor,
+    /// Current cursor position
+    row_number: usize,
+}
+
+impl CSVTabCursor {
+    fn new() -> CSVTabCursor {
+        CSVTabCursor {
+            base: Default::default(),
+            row_number: 0,
+        }
+    }
+
+    fn vtab(&self) -> &mut CSVTab {
+        unsafe { &mut *(self.base.pVtab as *mut CSVTab) }
+    }
+
+    fn filter(&mut self) -> Result<()> {
+        {
+            let vtab = self.vtab();
+            vtab.reader.seek(vtab.offset_first_row); // FIXME Result ignore
+        }
+        self.row_number = 0;
+        self.next()
+    }
+    fn next(&mut self) -> Result<()> {
+        let vtab = self.vtab();
+        if vtab.reader.done() {
+            return Err(Error::SqliteFailure(ffi::Error::new(ffi::SQLITE_ERROR), None));
+        }
+        unimplemented!();
+        // self.row_number = self.row_number + 1;
+        Ok(())
+    }
+    fn eof(&self) -> bool {
+        let vtab = self.vtab();
+        unsafe { (*vtab).reader.done() }
+    }
+    fn column(&self, ctx: *mut ffi::sqlite3_context, _i: libc::c_int) -> Result<()> {
+        let vtab = self.vtab();
+        unimplemented!();
+        // TODO.set_result(ctx);
+        Ok(())
+    }
+    fn rowid(&self) -> Result<i64> {
+        Ok(self.row_number as i64)
+    }
+}
+
+impl From<csv::Error> for Error {
+    fn from(err: csv::Error) -> Error {
+        use std::error::Error as StdError;
+        Error::ModuleError(String::from(err.description()))
+    }
+}

src/vtab/int_array.rs

@@ -1,5 +1,4 @@
 //! Int array virtual table.
-use std::error::Error as StdError;
 use std::cell::RefCell;
 use std::default::Default;
 use std::mem;
@@ -8,12 +7,11 @@ use libc;
 
 use {Connection, Error, Result};
 use ffi;
-use functions::ToResult;
+use vtab::declare_vtab;
-use vtab::{declare_vtab, mprintf};
 
 pub fn create_int_array(conn: &Connection, name: &str) -> Result<Rc<RefCell<Vec<i64>>>> {
     let array = Rc::new(RefCell::new(Vec::new()));
-    try!(conn.create_module(name, &INT_ARRAY_MODULE, array.clone()));
+    try!(conn.create_module(name, &INT_ARRAY_MODULE, Some(array.clone())));
     try!(conn.execute_batch(&format!("CREATE VIRTUAL TABLE temp.{0} USING {0}",
                                      escape_quote(name.to_string()))));
     Ok(array)
@@ -60,11 +58,10 @@ impl IntArrayVTab {
         Ok(vtab)
     }
 
-    fn best_index(&self, _info: *mut ffi::sqlite3_index_info) {
+    fn best_index(&self, _info: *mut ffi::sqlite3_index_info) {}
-    }
 
-    fn open(&self) -> IntArrayVTabCursor {
+    fn open(&self) -> Result<IntArrayVTabCursor> {
-        IntArrayVTabCursor::new()
+        Ok(IntArrayVTabCursor::new())
     }
 }
 
@@ -84,35 +81,36 @@ impl IntArrayVTabCursor {
         }
     }
 
-    fn vtab(&self) -> *mut IntArrayVTab {
+    fn vtab(&self) -> &mut IntArrayVTab {
-        self.base.pVtab as *mut IntArrayVTab
+        unsafe { &mut *(self.base.pVtab as *mut IntArrayVTab) }
     }
 
-    fn filter(&mut self) -> libc::c_int {
+    fn filter(&mut self) -> Result<()> {
         self.i = 0;
-        ffi::SQLITE_OK
+        Ok(())
     }
-    fn next(&mut self) -> libc::c_int {
+    fn next(&mut self) -> Result<()> {
         self.i = self.i + 1;
-        ffi::SQLITE_OK
+        Ok(())
     }
     fn eof(&self) -> bool {
         let vtab = self.vtab();
         unsafe {
-            let array = (*(*vtab).array).borrow();
+            let array = (*vtab.array).borrow();
             self.i >= array.len()
         }
     }
-    fn column(&self, ctx: *mut ffi::sqlite3_context, _i: libc::c_int) -> libc::c_int {
+    fn column(&self, ctx: *mut ffi::sqlite3_context, _i: libc::c_int) -> Result<()> {
+        use functions::ToResult;
         let vtab = self.vtab();
         unsafe {
-            let array = (*(*vtab).array).borrow();
+            let array = (*vtab.array).borrow();
             array[self.i].set_result(ctx);
         }
-        ffi::SQLITE_OK
+        Ok(())
     }
-    fn rowid(&self) -> i64 {
+    fn rowid(&self) -> Result<i64> {
-        self.i as i64
+        Ok(self.i as i64)
     }
 }
 

src/vtab/mod.rs

@@ -1,8 +1,8 @@
 //! Create virtual tables.
 //! (See http://sqlite.org/vtab.html)
-use std::error::Error as StdError;
 use std::ffi::CString;
 use std::mem;
+use std::ptr;
 use libc;
 
 use {Connection, Error, Result, InnerConnection, str_to_cstring};
@@ -29,7 +29,7 @@ use ffi;
 //
 // let stmt = conn.prepare("SELECT ... FROM foo WHERE ...");
 // \-> vtab.xbestindex
-// stmt.quey().next();
+// stmt.query().next();
 // \-> vtab.xopen
 //  |-> let cursor: Cursor = ...; // on the heap
 //  |-> cursor.xfilter or xnext
@@ -42,7 +42,7 @@ impl Connection {
     pub fn create_module<A>(&self,
                             module_name: &str,
                             module: *const ffi::sqlite3_module,
-                            aux: A)
+                            aux: Option<A>)
                             -> Result<()> {
         self.db
             .borrow_mut()
@@ -54,16 +54,27 @@ impl InnerConnection {
     fn create_module<A>(&mut self,
                         module_name: &str,
                         module: *const ffi::sqlite3_module,
-                        aux: A)
+                        aux: Option<A>)
                         -> Result<()> {
-        let boxed_aux: *mut A = Box::into_raw(Box::new(aux));
         let c_name = try!(str_to_cstring(module_name));
-        let r = unsafe {
+        let r = match aux {
+            Some(aux) => {
+                let boxed_aux: *mut A = Box::into_raw(Box::new(aux));
+                unsafe {
                     ffi::sqlite3_create_module_v2(self.db(),
                                                   c_name.as_ptr(),
                                                   module,
                                                   mem::transmute(boxed_aux),
                                                   Some(mem::transmute(free_boxed_value::<A>)))
+                }
+            }
+            None => unsafe {
+                ffi::sqlite3_create_module_v2(self.db(),
+                                              c_name.as_ptr(),
+                                              module,
+                                              ptr::null_mut(),
+                                              None)
+            },
         };
         self.decode_result(r)
     }
@@ -125,27 +136,25 @@ unsafe extern "C" fn $create(db: *mut ffi::sqlite3,
                               pp_vtab: *mut *mut ffi::sqlite3_vtab,
                               err_msg: *mut *mut libc::c_char)
                               -> libc::c_int {
+    use std::error::Error as StdError;
+    use vtab::mprintf;
     match $vtab::create(db, aux, argc, argv) {
         Ok(vtab) => {
             let boxed_vtab: *mut $vtab = Box::into_raw(Box::new(vtab));
             *pp_vtab = boxed_vtab as *mut ffi::sqlite3_vtab;
             ffi::SQLITE_OK
         }
-        Err(err) => {
+        Err(Error::SqliteFailure(err, s)) => {
-            match err {
-                Error::SqliteFailure(err, s) => {
             if let Some(s) = s {
                 *err_msg = mprintf(&s);
             }
             err.extended_code
-                }
+        },
-                _ => {
+        Err(err) => {
             *err_msg = mprintf(err.description());
             ffi::SQLITE_ERROR
         }
     }
-        }
-    }
 }
 unsafe extern "C" fn $best_index(vtab: *mut ffi::sqlite3_vtab,
                                   info: *mut ffi::sqlite3_index_info)
@@ -163,15 +172,28 @@ unsafe extern "C" fn $destroy(vtab: *mut ffi::sqlite3_vtab) -> libc::c_int {
 unsafe extern "C" fn $open(vtab: *mut ffi::sqlite3_vtab,
                             pp_cursor: *mut *mut ffi::sqlite3_vtab_cursor)
                             -> libc::c_int {
-    let vtab = vtab as *mut $vtab;
+    use vtab::set_err_msg;
-    let cursor = (*vtab).open();
+    let vt = vtab as *mut $vtab;
+    match (*vt).open() {
+        Ok(cursor) => {
             let boxed_cursor: *mut $cursor = Box::into_raw(Box::new(cursor));
             *pp_cursor = boxed_cursor as *mut ffi::sqlite3_vtab_cursor;
             ffi::SQLITE_OK
+        },
+        Err(Error::SqliteFailure(err, s)) => {
+            if let Some(err_msg) = s {
+                set_err_msg(vtab, &err_msg);
+            }
+            err.extended_code
+        }
+        Err(_) => {
+            ffi::SQLITE_ERROR
+        }
+    }
 }
 unsafe extern "C" fn $close(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    let cr = cursor as *mut $cursor;
-    let _: Box<$cursor> = Box::from_raw(mem::transmute(cursor));
+    let _: Box<$cursor> = Box::from_raw(mem::transmute(cr));
     ffi::SQLITE_OK
 }
 
@@ -181,35 +203,70 @@ unsafe extern "C" fn $filter(cursor: *mut ffi::sqlite3_vtab_cursor,
                               _argc: libc::c_int,
                               _argv: *mut *mut ffi::sqlite3_value)
                               -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    use vtab::cursor_error;
-    (*cursor).filter()
+    let cr = cursor as *mut $cursor;
+    cursor_error(cursor, (*cr).filter())
 }
 unsafe extern "C" fn $next(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    use vtab::cursor_error;
-    (*cursor).next()
+    let cr = cursor as *mut $cursor;
+    cursor_error(cursor, (*cr).next())
 }
 unsafe extern "C" fn $eof(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    let cr = cursor as *mut $cursor;
-    (*cursor).eof() as libc::c_int
+    (*cr).eof() as libc::c_int
 }
 unsafe extern "C" fn $column(cursor: *mut ffi::sqlite3_vtab_cursor,
                               ctx: *mut ffi::sqlite3_context,
                               i: libc::c_int)
                               -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    use vtab::cursor_error;
-    (*cursor).column(ctx, i)
+    let cr = cursor as *mut $cursor;
+    cursor_error(cursor, (*cr).column(ctx, i))
 }
 unsafe extern "C" fn $rowid(cursor: *mut ffi::sqlite3_vtab_cursor,
                              p_rowid: *mut ffi::sqlite3_int64)
                              -> libc::c_int {
-    let cursor = cursor as *mut $cursor;
+    use vtab::cursor_error;
-    *p_rowid = (*cursor).rowid();
+    let cr = cursor as *mut $cursor;
+    match (*cr).rowid() {
+        Ok(rowid) => {
+            *p_rowid = rowid;
             ffi::SQLITE_OK
+        },
+        err => cursor_error(cursor, err)
+    }
 }
     }
 }
 
+pub unsafe fn cursor_error<T>(cursor: *mut ffi::sqlite3_vtab_cursor,
+                              result: Result<T>)
+                              -> libc::c_int {
+    match result {
+        Ok(_) => ffi::SQLITE_OK,
+        Err(Error::SqliteFailure(err, s)) => {
+            if let Some(err_msg) = s {
+                set_err_msg((*cursor).pVtab, &err_msg);
+            }
+            err.extended_code
+        }
+        Err(_) => {
+            // TODO errMsg
+            ffi::SQLITE_ERROR
+        }
+    }
+}
+
+unsafe fn set_err_msg(vtab: *mut ffi::sqlite3_vtab, err_msg: &str) {
+    if !(*vtab).zErrMsg.is_null() {
+        ffi::sqlite3_free((*vtab).zErrMsg as *mut libc::c_void);
+    }
+    (*vtab).zErrMsg = mprintf(err_msg);
+}
+
 unsafe fn result_error(ctx: *mut ffi::sqlite3_context, err: Error) -> libc::c_int {
+    use std::error::Error as StdError;
     match err {
         Error::SqliteFailure(err, s) => {
             ffi::sqlite3_result_error_code(ctx, err.extended_code);
@@ -236,3 +293,4 @@ pub fn mprintf(err_msg: &str) -> *mut ::libc::c_char {
 }
 
 pub mod int_array;
+#[cfg(feature = "csvtab")]pub mod csvtab;