/// <summary>
/// Writes the media object to a stream.
/// </summary>
/// <param name="mediaId">The media id.</param>
/// <param name="output">The output.</param>
private void WriteMedia(int mediaId, Stream output)
{
using (NpgsqlConnection conn = FileHandlerHelpers.GetPgConnection())
{
int noid = 0;
using (NpgsqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = "SELECT data FROM \"MediaContent\" WHERE id=:id;";
cmd.Parameters.Add("id", mediaId);
noid = Convert.ToInt32(cmd.ExecuteScalar());
}
NpgsqlTransaction tran = conn.BeginTransaction();
LargeObjectManager lbm = new LargeObjectManager(conn);
LargeObject largeObject = lbm.Open(noid, LargeObjectManager.READWRITE);
largeObject.Seek(0);
int size = largeObject.Size();
byte[] buffer = new byte[size];
int read = 0;
int offset = 0;
while (offset < size)
{
read = largeObject.Read(buffer, offset, Math.Min(102400, size - offset));
output.Write(buffer, offset, read);
offset += 102400;
}
largeObject.Close();
tran.Commit();
}
}
private readonly int chunkSize = 204800; //200 KB
/// <summary>
/// Writes the content of a buffer into a LargeObject.
/// </summary>
/// <param name="buffer">The buffer.</param>
/// <param name="largeObject">The large object.</param>
/// <remarks>Documented by Dev02, 2008-08-08</remarks>
private void BufferToLargeObject(byte[] buffer, LargeObject largeObject)
{
largeObject.Seek(0);
int offset = 0;
int size = buffer.Length;
while (offset < size)
{
largeObject.Write(buffer, offset, Math.Min(chunkSize, size - offset));
offset += chunkSize;
}
}
/// <summary>
/// Gets the contents of a LargeObject into a buffer.
/// </summary>
/// <param name="largeObject">The large object.</param>
/// <returns></returns>
/// <remarks>Documented by Dev02, 2008-08-08</remarks>
private byte[] LargeObjectToBuffer(LargeObject largeObject)
{
largeObject.Seek(0);
int size = largeObject.Size();
byte[] buffer = new byte[size];
int offset = 0;
while (offset < size)
{
largeObject.Read(buffer, offset, Math.Min(chunkSize, size - offset));
offset += chunkSize;
}
return(buffer);
}
/// <summary>
/// Writes the content of a buffer into a LargeObject.
/// </summary>
/// <param name="buffer">The buffer.</param>
/// <param name="largeObject">The large object.</param>
/// <param name="rpu">The rpu.</param>
/// <param name="caller">The calling object.</param>
/// <remarks>Documented by Dev02, 2008-08-08</remarks>
private void BufferToLargeObject(byte[] buffer, LargeObject largeObject, StatusMessageReportProgress rpu, object caller)
{
largeObject.Seek(0);
int offset = 0;
int size = buffer.Length;
StatusMessageEventArgs args = new StatusMessageEventArgs(StatusMessageType.CreateMediaProgress, buffer.Length);
while (offset < size)
{
largeObject.Write(buffer, offset, Math.Min(chunkSize, size - offset));
offset += chunkSize;
args.Progress = offset;
if (rpu != null)
{
rpu(args, caller);
}
}
}