Added docs and fixed a bug

[u/mrichter/AliRoot.git] / FMD / AliFMDRawWriter.cxx

diff --git a/FMD/AliFMDRawWriter.cxx b/FMD/AliFMDRawWriter.cxx
index 3c6222c16045c57e79bd74cb3287e80d4c1c1b1b..bdc65a44fdeab77c7cd03d0e966974739a95f3ab 100644 (file)
--- a/FMD/AliFMDRawWriter.cxx
+++ b/FMD/AliFMDRawWriter.cxx
@@ -19,13 +19,27 @@
 //
 // Class to write ADC values to a raw data file
 //
-#include "AliLog.h"            // ALILOG_H
+// This class writes FMD Raw data to a file.   The sample rate (number
+// of times the ALTRO ADC samples each pre-amp. channel - that is,
+// data from a single strip), can be set via SetSampleRate. 
+//
+// Zero-suppression can be enabled by calling SetThreshold with a
+// non-zero argument.   ADC values less than the value set will not be
+// written to output.   Note, that if you use zero-suppression, you
+// need to explicitly set the sample rate when reading back the data
+// with AliFMDRawReader. 
+// 
+// This class uses the AliAltroBuffer class to write the data in the
+// ALTRO format.  See the Exec member function for more information on
+// that format.  
+//
+#include <AliLog.h>            // ALILOG_H
+#include <AliLoader.h>         // ALILOADER_H
+#include <AliAltroBuffer.h>     // ALIALTROBUFFER_H
 #include "AliFMD.h"            // ALIFMD_H
 #include "AliFMDDigit.h"       // ALIFMDDIGIT_H
 #include "AliFMDRawWriter.h"   // ALIFMDRAWREADER_H 
-#include "AliAltroBuffer.h"     // ALIALTROBUFFER_H
-#include "AliLoader.h"         // ALILOADER_H
-#include "TArrayI.h"           // ROOT_TArrayI
+#include <TArrayI.h>           // ROOT_TArrayI
 #include <TClonesArray.h>      // ROOT_TClonesArray
 
 //____________________________________________________________________
@@ -37,6 +51,8 @@ AliFMDRawWriter::AliFMDRawWriter(AliFMD* fmd)
     fFMD(fmd)
 {
   SetSampleRate();
+  SetThreshold();
+  SetChannelsPerAltro();
 }
 
 
@@ -141,7 +157,7 @@ AliFMDRawWriter::Exec(Option_t*)
 
     // A buffer to hold 1 ALTRO channel - Normally, one ALTRO channel
     // holds 128 VA1_ALICE channels, sampled at a rate of `sampleRate' 
-    TArrayI channel(128 * sampleRate);
+    TArrayI channel(fChannelsPerAltro * sampleRate);
     
     // The Altro buffer 
     AliAltroBuffer* altro = 0;
@@ -178,10 +194,7 @@ AliFMDRawWriter::Exec(Option_t*)
          //    row       |     sector
          //    sector    |       ring
          // 
-         altro->WriteChannel(Int_t(startStrip), 
-                             Int_t(prevSector), 
-                             Int_t((prevRing == 'I' ? 0 : 1)), 
-                             channel.fN, channel.fArray, 0);
+         WriteChannel(altro, startStrip, prevSector, prevRing, channel);
          altro->Flush();
          altro->WriteDataHeader(kFALSE, kFALSE);
          delete altro;
@@ -212,27 +225,24 @@ AliFMDRawWriter::Exec(Option_t*)
          if (digit->Count3() >= 0) sampleRate = 3;
        }
 
-       channel.Set(128 * sampleRate);
+       channel.Set(fChannelsPerAltro * sampleRate);
        offset     = 0;
        prevRing   = ring;
        prevSector = sector;
        startStrip = strip;
       }
-      else if (offset == 128                        
+      else if (offset == fChannelsPerAltro
               || digit->Ring() != prevRing 
               || digit->Sector() != prevSector) {
        // Force a new Altro channel
        AliDebug(10, Form("Flushing channel to disk because %s",
-                         (offset == 128 ? "channel is full" :
+                         (offset == fChannelsPerAltro ? "channel is full" :
                           (ring != prevRing ? "new ring up" :
                            "new sector up"))));
        AliDebug(10, Form("New Channel: Write channel at %d Strip: %d "
                          "Sector: %d  Ring: %d", 
                          i, startStrip, prevSector, prevRing));
-       altro->WriteChannel(Int_t(startStrip), 
-                           Int_t(prevSector), 
-                           Int_t((prevRing == 'I' ? 0 : 1)), 
-                           channel.fN, channel.fArray, 0);
+       WriteChannel(altro, startStrip, prevSector, prevRing, channel);
        // Reset and update channel variables 
        channel.Reset(0);
        offset     = 0; 
@@ -260,6 +270,24 @@ AliFMDRawWriter::Exec(Option_t*)
   loader->UnloadDigits();
 }
 
+//____________________________________________________________________
+void
+AliFMDRawWriter::WriteChannel(AliAltroBuffer* altro, 
+                             UShort_t strip, UShort_t sector, Char_t ring, 
+                             const TArrayI& data) 
+{
+  // Write out one ALTRO channel to the data file. 
+  // Derived classes can overload this method to use a per-ALTRO
+  // threshold.   This implementation uses the common threshold set by
+  // SetThreshold. 
+  altro->WriteChannel(Int_t(strip), 
+                     Int_t(sector), 
+                     Int_t((ring == 'I' ? 0 : 1)), 
+                     data.fN, data.fArray, fThreshold);
+}
+
+  
+
 //____________________________________________________________________
 // 
 // EOF