ColumnBlob API, error handling.

api.go

@@ -28,6 +28,7 @@ func newConn(module api.Module) *Conn {
 			malloc:        getFun("malloc"),
 			free:          getFun("free"),
 			destructor:    uint64(destructor),
+			errcode:       getFun("sqlite3_errcode"),
 			errstr:        getFun("sqlite3_errstr"),
 			errmsg:        getFun("sqlite3_errmsg"),
 			erroff:        getFun("sqlite3_error_offset"),
@@ -59,6 +60,7 @@ type sqliteAPI struct {
 	malloc        api.Function
 	free          api.Function
 	destructor    uint64
+	errcode       api.Function
 	errstr        api.Function
 	errmsg        api.Function
 	erroff        api.Function

conn.go

@@ -141,31 +141,33 @@ func (c *Conn) error(rc uint64) error {
 		return nil
 	}
 
-	serr := Error{
+	err := Error{
 		Code:         ErrorCode(rc),
 		ExtendedCode: ExtendedErrorCode(rc),
 	}
 
+	if err.Code == NOMEM || err.ExtendedCode == IOERR_NOMEM {
+		panic(oomErr)
+	}
+
 	var r []uint64
 
-	// string
-	r, _ = c.api.errstr.Call(c.ctx, rc)
-	if r != nil {
-		serr.str = c.getString(uint32(r[0]), 512)
-	}
-
-	// message
+	// Do this first, sqlite3_errmsg is guaranteed to never change the value of the error code.
 	r, _ = c.api.errmsg.Call(c.ctx, uint64(c.handle))
 	if r != nil {
-		serr.msg = c.getString(uint32(r[0]), 512)
+		err.msg = c.getString(uint32(r[0]), 512)
 	}
 
-	switch serr.msg {
-	case "not an error", serr.str:
-		serr.msg = ""
+	r, _ = c.api.errstr.Call(c.ctx, rc)
+	if r != nil {
+		err.str = c.getString(uint32(r[0]), 512)
 	}
 
-	return &serr
+	if err.msg == err.str {
+		err.msg = ""
+
+	}
+	return &err
 }
 
 func (c *Conn) free(ptr uint32) {

stmt.go

@@ -149,7 +149,11 @@ func (s *Stmt) ColumnText(col int) string {
 
 	ptr := uint32(r[0])
 	if ptr == 0 {
-		// handle error
+		r, err = s.c.api.errcode.Call(s.c.ctx, uint64(s.handle))
+		if err != nil {
+			panic(err)
+		}
+		s.err = s.c.error(r[0])
 		return ""
 	}
 
@@ -166,7 +170,7 @@ func (s *Stmt) ColumnText(col int) string {
 	return string(mem)
 }
 
-func (s *Stmt) ColumnBlob(col int, buf []byte) int {
+func (s *Stmt) ColumnBlob(col int, buf []byte) []byte {
 	r, err := s.c.api.columnBlob.Call(s.c.ctx,
 		uint64(s.handle), uint64(col))
 	if err != nil {
@@ -175,8 +179,12 @@ func (s *Stmt) ColumnBlob(col int, buf []byte) int {
 
 	ptr := uint32(r[0])
 	if ptr == 0 {
-		// handle error
-		return 0
+		r, err = s.c.api.errcode.Call(s.c.ctx, uint64(s.handle))
+		if err != nil {
+			panic(err)
+		}
+		s.err = s.c.error(r[0])
+		return nil
 	}
 
 	r, err = s.c.api.columnBytes.Call(s.c.ctx,
@@ -189,5 +197,5 @@ func (s *Stmt) ColumnBlob(col int, buf []byte) int {
 	if !ok {
 		panic(rangeErr)
 	}
-	return copy(mem, buf)
+	return append(buf[0:0], mem...)
 }