github.com/insionng/yougam@v0.0.0-20170714101924-2bc18d833463/libraries/mattn/go-sqlite3/backup.go (about)

     1  // Copyright (C) 2014 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
     2  //
     3  // Use of this source code is governed by an MIT-style
     4  // license that can be found in the LICENSE file.
     5  
     6  package sqlite3
     7  
     8  /*
     9  #include <sqlite3-binding.h>
    10  #include <stdlib.h>
    11  */
    12  import "C"
    13  import (
    14  	"runtime"
    15  	"unsafe"
    16  )
    17  
    18  type SQLiteBackup struct {
    19  	b *C.sqlite3_backup
    20  }
    21  
    22  func (c *SQLiteConn) Backup(dest string, conn *SQLiteConn, src string) (*SQLiteBackup, error) {
    23  	destptr := C.CString(dest)
    24  	defer C.free(unsafe.Pointer(destptr))
    25  	srcptr := C.CString(src)
    26  	defer C.free(unsafe.Pointer(srcptr))
    27  
    28  	if b := C.sqlite3_backup_init(c.db, destptr, conn.db, srcptr); b != nil {
    29  		bb := &SQLiteBackup{b: b}
    30  		runtime.SetFinalizer(bb, (*SQLiteBackup).Finish)
    31  		return bb, nil
    32  	}
    33  	return nil, c.lastError()
    34  }
    35  
    36  // Backs up for one step. Calls the underlying `sqlite3_backup_step` function.
    37  // This function returns a boolean indicating if the backup is done and
    38  // an error signalling any other error. Done is returned if the underlying C
    39  // function returns SQLITE_DONE (Code 101)
    40  func (b *SQLiteBackup) Step(p int) (bool, error) {
    41  	ret := C.sqlite3_backup_step(b.b, C.int(p))
    42  	if ret == C.SQLITE_DONE {
    43  		return true, nil
    44  	} else if ret != 0 && ret != C.SQLITE_LOCKED && ret != C.SQLITE_BUSY {
    45  		return false, Error{Code: ErrNo(ret)}
    46  	}
    47  	return false, nil
    48  }
    49  
    50  func (b *SQLiteBackup) Remaining() int {
    51  	return int(C.sqlite3_backup_remaining(b.b))
    52  }
    53  
    54  func (b *SQLiteBackup) PageCount() int {
    55  	return int(C.sqlite3_backup_pagecount(b.b))
    56  }
    57  
    58  func (b *SQLiteBackup) Finish() error {
    59  	return b.Close()
    60  }
    61  
    62  func (b *SQLiteBackup) Close() error {
    63  	ret := C.sqlite3_backup_finish(b.b)
    64  	if ret != 0 {
    65  		return Error{Code: ErrNo(ret)}
    66  	}
    67  	b.b = nil
    68  	runtime.SetFinalizer(b, nil)
    69  	return nil
    70  }