/// <summary>
/// Upgrade datafile from v6 to new v7 format used in LiteDB 3
/// </summary>
public static bool Upgrade(string filename, string password = null, bool backup = true, int batchSize = 5000)
{
// if not exists, just exit
if (!File.Exists(filename))
{
return(false);
}
// use a temp file to copy/convert data from
var tempFile = FileHelper.GetTempFile(filename);
// open file as stream and test if is V6
using (var stream = new FileStream(filename, System.IO.FileMode.Open, FileAccess.Read))
{
using (IDbReader reader = new LiteDB_V6.DbReader())
{
if (reader.Initialize(stream, password) == false)
{
return(false);
}
// open new datafile to copy data from
using (var engine = new LiteEngine(tempFile, false))
{
foreach (var col in reader.GetCollections())
{
// first, create all unique indexes
foreach (var field in reader.GetUniqueIndexes(col))
{
engine.EnsureIndex(col, field, true);
}
// now bulk copy documents
var docs = reader.GetDocuments(col);
engine.InsertBulk(col, docs, batchSize);
// just clear pages/cache
engine.Rollback();
}
}
}
}
// if backup, move current file to new -bkp
if (backup)
{
File.Move(filename, FileHelper.GetTempFile(filename, "-bkp"));
}
else
{
File.Delete(filename);
}
// move temp file to original filename
File.Move(tempFile, filename);
return(true);
}
/// <summary>
/// Reduce disk size re-arranging unused spaces. Can change password. If temporary disk was not provided, use MemoryStream temp disk
/// </summary>
public long Shrink(string password = null, IDiskService temp = null)
{
var originalSize = _disk.FileLength;
// if temp disk are not passed, use memory stream disk
temp = temp ?? new StreamDiskService(new MemoryStream());
using (_locker.Reserved())
using (_locker.Exclusive())
using (var engine = new LiteEngine(temp, password))
{
// read all collection
foreach (var collectionName in this.GetCollectionNames())
{
// first create all user indexes (exclude _id index)
foreach (var index in this.GetIndexes(collectionName).Where(x => x.Field != "_id"))
{
engine.EnsureIndex(collectionName, index.Field, index.Unique);
}
// now copy documents
var docs = this.Find(collectionName, Query.All());
engine.InsertBulk(collectionName, docs);
}
// copy user version
engine.UserVersion = this.UserVersion;
// set current disk size to exact new disk usage
_disk.SetLength(temp.FileLength);
// read new header page to start copy
var header = BasePage.ReadPage(temp.ReadPage(0)) as HeaderPage;
// copy (as is) all pages from temp disk to original disk
for (uint i = 0; i <= header.LastPageID; i++)
{
var page = temp.ReadPage(i);
_disk.WritePage(i, page);
}
// create/destroy crypto class
_crypto = password == null ? null : new AesEncryption(password, header.Salt);
// initialize all services again (crypto can be changed)
this.InitializeServices();
// return how many bytes are reduced
return(originalSize - temp.FileLength);
}
}
