Create backup.go

src/github.com/mattn/go-sqlite3/backup.go

@@ -0,0 +1,85 @@
+// Copyright (C) 2014 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package sqlite3
+
+/*
+#ifndef USE_LIBSQLITE3
+#include <sqlite3-binding.h>
+#else
+#include <sqlite3.h>
+#endif
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"runtime"
+	"unsafe"
+)
+
+// SQLiteBackup implement interface of Backup.
+type SQLiteBackup struct {
+	b *C.sqlite3_backup
+}
+
+// Backup make backup from src to dest.
+func (c *SQLiteConn) Backup(dest string, conn *SQLiteConn, src string) (*SQLiteBackup, error) {
+	destptr := C.CString(dest)
+	defer C.free(unsafe.Pointer(destptr))
+	srcptr := C.CString(src)
+	defer C.free(unsafe.Pointer(srcptr))
+
+	if b := C.sqlite3_backup_init(c.db, destptr, conn.db, srcptr); b != nil {
+		bb := &SQLiteBackup{b: b}
+		runtime.SetFinalizer(bb, (*SQLiteBackup).Finish)
+		return bb, nil
+	}
+	return nil, c.lastError()
+}
+
+// Step to backs up for one step. Calls the underlying `sqlite3_backup_step`
+// function.  This function returns a boolean indicating if the backup is done
+// and an error signalling any other error. Done is returned if the underlying
+// C function returns SQLITE_DONE (Code 101)
+func (b *SQLiteBackup) Step(p int) (bool, error) {
+	ret := C.sqlite3_backup_step(b.b, C.int(p))
+	if ret == C.SQLITE_DONE {
+		return true, nil
+	} else if ret != 0 && ret != C.SQLITE_LOCKED && ret != C.SQLITE_BUSY {
+		return false, Error{Code: ErrNo(ret)}
+	}
+	return false, nil
+}
+
+// Remaining return whether have the rest for backup.
+func (b *SQLiteBackup) Remaining() int {
+	return int(C.sqlite3_backup_remaining(b.b))
+}
+
+// PageCount return count of pages.
+func (b *SQLiteBackup) PageCount() int {
+	return int(C.sqlite3_backup_pagecount(b.b))
+}
+
+// Finish close backup.
+func (b *SQLiteBackup) Finish() error {
+	return b.Close()
+}
+
+// Close close backup.
+func (b *SQLiteBackup) Close() error {
+	ret := C.sqlite3_backup_finish(b.b)
+
+	// sqlite3_backup_finish() never fails, it just returns the
+	// error code from previous operations, so clean up before
+	// checking and returning an error
+	b.b = nil
+	runtime.SetFinalizer(b, nil)
+
+	if ret != 0 {
+		return Error{Code: ErrNo(ret)}
+	}
+	return nil
+}