Added support for variable size channels.

DaqFileIO.cxx

@@ -2,7 +2,7 @@
 ///
 // DAQ low level IO Library
 // 
-// $Id: DaqFileIO.cxx,v 1.9 2005/03/14 23:05:04 yiannis Exp $
+// $Id: DaqFileIO.cxx,v 1.10 2005/03/22 20:12:17 yiannis Exp $
 // Date: March, 2005
 // Author: Yiannis Papelis
 //
@@ -982,8 +982,24 @@ CDaqLowLevelIo::CheckIntegrity(
 			}
 			else {
 				CDaqChannelInfo& ch = m_Channels[chId];
-				int  skip = ch.GetRecSize();
-				fseek(m_pFile, skip, SEEK_CUR);
+				int              skip;
+
+				if ( ch.IsVarLen() ) {
+					int actCount;
+
+					if ( fread(&actCount, sizeof(int), 1, m_pFile) != 1 ) {
+						sprintf(buf, "Could not read var size channel length; chId=%d, ofs=%d, abort",
+							chId, ftell(m_pFile));
+						m_LastError = buf;
+						(*m_UserErrorFunc)(m_Filename.c_str(), buf);
+						return false;
+					}
+					skip = ch.GetItemSize() * actCount;
+				}
+				else {
+					skip = ch.GetRecSize();				
+				}
+				if ( skip ) fseek(m_pFile, skip, SEEK_CUR);			// save a system call if 0
 			}
 			ch++;
 
@@ -1235,9 +1251,24 @@ CDaqLowLevelIo::LowLevelDataRead(
 				m_LastError = buf;
 				return false;
 			}
-
 			CDaqChannelInfo& ch = m_Channels[chId];
-			int              size = ch.GetRecSize();
+			int size;
+
+			if ( ch.IsVarLen() ) {
+				int actCount;
+
+				if ( fread(&actCount, sizeof(int), 1, m_pFile) != 1 ) {
+					sprintf(buf, "Could not read var size channel length; chId=%d, ofs=%d, abort",
+						chId, ftell(m_pFile));
+					m_LastError = buf;
+					(*m_UserErrorFunc)(m_Filename.c_str(), buf);
+					return false;
+				}
+				size = ch.GetItemSize() * actCount;
+			}
+			else {
+				size = ch.GetRecSize();
+			}
 			if ( needChan[chId] != -1 ) {	// it is -1 when we don't need it
 				CDaqBuffer&  daqBuf = userStorage[needChan[chId]];
 
@@ -1247,6 +1278,7 @@ CDaqLowLevelIo::LowLevelDataRead(
 					return false;
 				}
 
+				if ( size > 0 ) {
 					size_t n = fread(pTempSpace, size, 1, m_pFile);
 					if ( n != 1 ) {
 						sprintf(buf, "read data for channel %d near frame %d failed",
@@ -1254,12 +1286,21 @@ CDaqLowLevelIo::LowLevelDataRead(
 						m_LastError = buf;
 						return false;
 					}
-				daqBuf.Append(pTempSpace, size, ch.GetItemCount());
+				}
+
+				// for variable size records, 'size' may be less than the full size for the channel
+				// The shorter storage used in the DAQ is transparent to the user so we fill
+				// the rest of the space (that didn't get read from the file with zeros.
+				int fullSize = ch.GetRecSize();
+				if ( fullSize  != size ) {
+					memset(((char *)pTempSpace) + size, 0, fullSize - size);
+				}
+				daqBuf.Append(pTempSpace, fullSize, ch.GetItemCount());
 				if ( pFrameList ) (*pFrameList)[needChan[chId]].push_back(curFrame);
 			}
 			else {
 				// skip the data
-				fseek(m_pFile, size, SEEK_CUR);
+				if ( size ) fseek(m_pFile, size, SEEK_CUR);
 			}
 		}
 	}
@@ -1785,7 +1826,23 @@ CDaqLowLevelIo::ReadDataForOneFrame(
 		}
 
 		CDaqChannelInfo& ch   = m_Channels[chId];
-		int              size = ch.GetRecSize();
+		int              size;
+
+		if ( ch.IsVarLen() ) {
+			int actCount;
+			if ( fread(&actCount, sizeof(int), 1, m_pFile) != 1 ) {
+				sprintf(buf, "Could not read var size channel length; chId=%d, ofs=%d, abort",
+					chId, ftell(m_pFile));
+				m_LastError = buf;
+				(*m_UserErrorFunc)(m_Filename.c_str(), buf);
+				return eDAQ_READ_ERROR;
+			}
+			size = ch.GetItemSize() * actCount;
+		}
+		else {
+			size = ch.GetRecSize();
+		}
+
 		if ( needChannel[chId] != -1 ) {	// it is -1 when we don't need it
 			CDaqBuffer&  daqBuf = storage[needChannel[chId]];
 
@@ -1795,13 +1852,20 @@ CDaqLowLevelIo::ReadDataForOneFrame(
 				return eDAQ_READ_INTERNAL_ERROR;
 			}
 
+			if ( size > 0 ) {
 				size_t n = fread(pTempSpace, size, 1, m_pFile);
 				if ( n != 1 ) {
 					sprintf(buf, "read data for channel %d failed", chId);
 					m_LastError = buf;
 					return eDAQ_READ_ERROR;
 				}
-			daqBuf.Replace(pTempSpace, size, ch.GetItemCount());
+			}
+
+			int fullSize = ch.GetRecSize();
+			if ( fullSize != size ) {
+				memset(((char *)pTempSpace) + size, 0, fullSize - size);
+			}
+			daqBuf.Replace(pTempSpace, fullSize, ch.GetItemCount());
 			gotData[chId] = true;
 		}
 		else {