/// <summary>
/// Commits data buffered during recording to disk.
/// </summary>
/// <param name="streamID">ID of the stream in the database to be written to.</param>
/// <param name="indices">The indices of the new frames to be written.</param>
/// <param name="indicesCount">The number of the frames in the indices array to be written.</param>
/// <param name="buffer">The buffer where the data was buffered to.</param>
static internal void SaveBufferAndIndices( int streamID, Index[] indices, int indicesCount, byte[] buffer )
{
#region Save Buffer (saves the raw bytes into the RawStream table in the DB)
int offset;
try
{
SqlConnection conn = new SqlConnection(Constants.SQLConnectionString);
SqlCommand cmd = new SqlCommand( "AppendBuffer ", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter sqlStreamID = cmd.Parameters.Add( "@stream_id", SqlDbType.Int);
sqlStreamID.Direction = ParameterDirection.Input;
sqlStreamID.Value = streamID;
SqlParameter dataParam = cmd.Parameters.Add("@chunk", SqlDbType.Image);
dataParam.Direction = ParameterDirection.Input;
dataParam.Value = buffer;
dataParam.Size = indices[indicesCount-1].end + 1;
SqlParameter offsetParam = cmd.Parameters.Add( "@offset", SqlDbType.Int);
offsetParam.Direction = ParameterDirection.ReturnValue;
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
offset = (int)offsetParam.Value;
streamSizeDict[streamID] += (long)(indices[indicesCount - 1].end + 1);
}
catch( SqlException ex )
{
eventLog.WriteEntry(string.Format(CultureInfo.CurrentCulture, Strings.DatabaseOperationFailedError,
ex.ToString()), EventLogEntryType.Error, ArchiveServiceEventLog.ID.DBOpFailed );
throw;
}
#endregion
#region Build the index inserts
// lets do one big transaction to save on log writes etc.
StringBuilder sb = new StringBuilder("BEGIN TRANSACTION" , 50 + 125*indicesCount);
for ( int i = 0; i < indicesCount; i++)
{
sb.Append(" INSERT INTO Frame ( stream_id, raw_start, raw_end, frame_time ) VALUES (");
sb.Append( streamID);
sb.Append(" ,");
sb.Append( indices[i].start + offset);
sb.Append( ",");
sb.Append( indices[i].end + offset);
sb.Append( ",");
sb.Append ( indices[i].timestamp);
sb.Append( ") ");
}
sb.Append("COMMIT TRANSACTION");
string indexString = sb.ToString();
#endregion
#region Save the index inserts
int affected = ExecuteNonQuery( indexString );
if ( affected != indicesCount)
{
eventLog.WriteEntry(string.Format(CultureInfo.CurrentCulture, Strings.FailedToSaveAllIndices,
indicesCount, affected), EventLogEntryType.Error, ArchiveServiceEventLog.ID.IndiciesFailedToSave);
}
#endregion
}
public static void DirectWrite( FrameWithTicks frame, int streamID )
{
Trace.WriteLine(String.Format("BufferRecorder::DirectWrite called with frame of size {0} bytes and steamID {1}.",
frame.frame.Length, streamID));
Index ind = new Index();
ind.start = 0;
ind.end = frame.frame.Length-1;
ind.timestamp = frame.ticks;
DBHelper.SaveBufferAndIndices(streamID, new Index[]{ind}, 1, (byte[])frame.frame);
}
/// <summary>
/// Loads the next block of indexes into an array of indices.
/// </summary>
internal static bool LoadIndices(Index[] indices, long startingTick, int streamID, int maxBytes, out int indexCount)
{
SqlConnection conn = new SqlConnection(Constants.SQLConnectionString);
SqlCommand cmd = new SqlCommand("LoadIndices", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter stream_id = cmd.Parameters.Add("@stream_id", SqlDbType.Int);
stream_id.Direction = ParameterDirection.Input;
stream_id.Value = streamID;
SqlParameter starting_tick = cmd.Parameters.Add("@starting_tick", SqlDbType.BigInt);
starting_tick.Direction = ParameterDirection.Input;
starting_tick.Value = startingTick;
SqlParameter ending_tick = cmd.Parameters.Add("@count", SqlDbType.BigInt);
ending_tick.Direction = ParameterDirection.Input;
ending_tick.Value = indices.Length;
conn.Open();
SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.SequentialAccess);
int i = 0;
int quitCase = 1; // keep up with _why_ we exit this loop...
while (dr.Read())
{
indices[i].start = dr.GetInt32(0);
indices[i].end = dr.GetInt32(1);
indices[i].timestamp = dr.GetInt64(2);
// Check to make sure we have enough to fill our buffer
if( (indices[i].end - indices[0].start + 1) >= maxBytes )
{
quitCase = 0;
break;
}
i++;
// Make sure indices isn't full
if( i >= indices.Length )
{
quitCase = 2;
break;
}
}
// Close our connections
dr.Close();
conn.Close();
bool streamOutOfData = false;
indexCount = i;
// Now we do the appropriate follow-up based why we exited the loop
switch( quitCase )
{
case 0: // enough data to fill buffer. (note that 'i' is one less than it should be only in this case)
if( (indices[i].end - indices[0].start + 1) <= maxBytes )
indexCount = i + 1; // all the indices we parsed.
// else the last frame won't fit
Debug.Assert(indexCount > 0); // we can assert this because of the way maxBufferSize is calculated
break;
case 1: // we're out of data. Flag it.
streamOutOfData = true;
break;
default: // we have enough indices to fill the array
break;
}
return streamOutOfData;
}
public static void DirectWrite( FrameWithTicks frame, int streamID )
{
Index ind = new Index();
ind.start = 0;
ind.end = frame.frame.Length-1;
ind.timestamp = frame.ticks;
DBHelper.SaveBufferAndIndices(streamID, new Index[]{ind}, 1, (byte[])frame.frame);
}