/// <summary>
/// Reads and inserts all key value pairs into current prefix from stream
/// </summary>
/// <param name="transaction">transaction where to import all data</param>
/// <param name="stream">where to read it from</param>
public static void Import(IKeyValueDBTransaction transaction, Stream stream)
{
if (transaction == null)
{
throw new ArgumentNullException("transaction");
}
if (stream == null)
{
throw new ArgumentNullException("stream");
}
if (!stream.CanRead)
{
throw new ArgumentException("stream must be readable", "stream");
}
var tempbuf = new byte[4096];
if (stream.Read(tempbuf, 0, 16) != 16)
{
throw new EndOfStreamException();
}
if (tempbuf[0] != 'B' || tempbuf[1] != 'T' || tempbuf[2] != 'D' || tempbuf[3] != 'B' || tempbuf[4] != 'E' || tempbuf[5] != 'X' || tempbuf[6] != 'P' || tempbuf[7] != '1')
{
throw new BTDBException("Invalid header (it should start with BTDBEXP1)");
}
var keyValuePairs = PackUnpack.UnpackInt64LE(tempbuf, 8);
if (keyValuePairs < 0)
{
throw new BTDBException("Negative number of key value pairs");
}
for (var kv = 0; kv < keyValuePairs; kv++)
{
if (stream.Read(tempbuf, 0, 4) != 4)
{
throw new EndOfStreamException();
}
var keySize = PackUnpack.UnpackInt32LE(tempbuf, 0);
if (keySize < 0)
{
throw new BTDBException("Negative key size");
}
if (keySize > tempbuf.Length)
{
tempbuf = new byte[keySize];
}
if (stream.Read(tempbuf, 0, keySize) != keySize)
{
throw new EndOfStreamException();
}
transaction.CreateKey(tempbuf);
if (stream.Read(tempbuf, 0, 8) != 8)
{
throw new EndOfStreamException();
}
var valueSize = PackUnpack.UnpackInt64LE(tempbuf, 0);
if (valueSize < 0)
{
throw new BTDBException("Negative value size");
}
if (valueSize <= tempbuf.Length)
{
if (stream.Read(tempbuf, 0, (int)valueSize) != valueSize)
{
throw new EndOfStreamException();
}
transaction.SetValue(tempbuf, 0, (int)valueSize);
}
else
{
transaction.SetValueSize(valueSize);
long pos = 0;
while (pos < valueSize)
{
int toRead = (int)Math.Min(valueSize - pos, tempbuf.Length);
if (stream.Read(tempbuf, 0, toRead) != toRead)
{
throw new EndOfStreamException();
}
transaction.WriteValue(pos, toRead, tempbuf, 0);
pos += toRead;
}
}
}
}
