go-sqlite3-hak5/backup.go

86 lines
2.2 KiB
Go

// Copyright (C) 2019 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 (destConn *SQLiteConn) Backup(dest string, srcConn *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(destConn.db, destptr, srcConn.db, srcptr); b != nil {
bb := &SQLiteBackup{b: b}
runtime.SetFinalizer(bb, (*SQLiteBackup).Finish)
return bb, nil
}
return nil, destConn.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
}