/// <summary>
/// Read in all of the rows that have been cached
/// </summary>
/// <returns></returns>
public List <object[]> ReadCachedRows()
{
AssertMx.IsTrue(File.Exists(CacheFilePath), "CacheFilePath doesn't exist");
FileStream fs = File.Open(CacheFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
BinaryReader br = new BinaryReader(fs);
List <object[]> cachedRows = new List <object[]>(); // in-memory buffer list of rows
for (int ri = 0; ri < RowsWrittenToCache; ri++)
{
object[] vo = VoArray.ReadBinaryVoArray(br, VoaLength);
cachedRows.Add(vo);
}
br.Close(); // close reader and the underlying stream
return(cachedRows);
}
/// <summary>
/// Try to get the row at the given index from the buffer or cache
/// </summary>
/// <param name="ri"></param>
/// <returns></returns>
///
public object[] GetRow(
int ri)
{
object[] vo = null;
if (ri < 0 || ri >= TotalRowCount)
{
string msg = string.Format("Row {0} not in cache or buffer (cacheSize: {1}, bufferSize: {2})", ri, RowsWrittenToCache, RowBuffer.Count);
throw new InvalidDataException(msg);
}
// See if in buffer
if (ri >= RowsWrittenToCache)
{
vo = (object[])RowBuffer[ri - RowsWrittenToCache];
if (DebugCaching)
{
DebugLog.Message(string.Format("Row: {0} in Buffer (cacheSize: {1}, bufferSize: {2})", ri, RowsWrittenToCache, RowBuffer.Count));
}
return(vo);
}
// Get from cache
if (ri < CacheReaderPosition + 1) // if already read past this then close current cursor
{
CloseCacheReader();
}
if (CacheReader == null) // need to open reader?
{
AssertMx.IsNotNull(CacheWriter, "CacheWriter");
AssertMx.IsTrue(File.Exists(CacheFilePath), "CacheFilePath doesn't exist");
FileStream fs = File.Open(CacheFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
CacheReader = new BinaryReader(fs);
CacheReaderPosition = -1;
if (DebugCaching)
{
DebugLog.Message("Opening cache reader");
}
}
while (CacheReaderPosition + 1 <= ri) // read rows until we get the one we want
{
vo = VoArray.ReadBinaryVoArray(CacheReader, VoaLength);
CacheReaderPosition++;
}
CacheReaderPosition = ri;
if (DebugCaching)
{
DebugLog.Message(string.Format("Row: {0} in Cache (cacheSize: {1}, bufferSize: {2})", ri, RowsWrittenToCache, RowBuffer.Count));
}
return(vo);
}
