C#使用BerkeleyDB操作簡介(4)

五、遍歷

public List<IPut> Find()
{
List<IPut> custList = new List<IPut>();
using (DbBTreeCursor cursor = btree.OpenCursor(txn, DbFileCursor.CreateFlags.None))
{
IPut cust = null;
while (GetNextRecord(cursor, ref cust))
custList.Add(cust);
}
return custList;
}

private bool GetNextRecord(DbBTreeCursor cursor, ref IPut cust)
{
ReadStatus status;
keyStream.SetLength(keyStream.Capacity);
dataStream.SetLength(dataStream.Capacity);
DbEntry key = DbEntry.Out(keyStream.GetBuffer());
DbEntry data = DbEntry.Out(dataStream.GetBuffer());
do
{
status = cursor.Get(ref key, ref data, DbFileCursor.GetMode.Next, DbFileCursor.ReadFlags.None);
switch (status)
{
case ReadStatus.NotFound: return false;
case ReadStatus.KeyEmpty: continue; // skip deleted records
case ReadStatus.BufferSmall:
if (key.Buffer.Length < key.Size)
{
keyStream.SetLength(key.Size);
key = DbEntry.Out(keyStream.GetBuffer());
}
if (data.Buffer.Length < data.Size)
{
dataStream.SetLength(data.Size);
data = DbEntry.Out(dataStream.GetBuffer());
}
continue;
case ReadStatus.Success:
dataStream.Position = 0;
dataStream.SetLength(data.Size);
cust = (IPut)formatter.Deserialize(dataStream);
return true;
default:
return false;
}
} while (true);
}