[ALICE3] Add possibility to use generic geometry (#13086)

Author: njacazio

ALICE3/Core/FastTracker.cxx

@@ -30,6 +30,7 @@ namespace fastsim
 
 void FastTracker::AddLayer(TString name, float r, float z, float x0, float xrho, float resRPhi, float resZ, float eff, int type)
 {
+  LOG(debug) << "Adding layer " << name << " r=" << r << " z=" << z << " x0=" << x0 << " xrho=" << xrho << " resRPhi=" << resRPhi << " resZ=" << resZ << " eff=" << eff << " type=" << type;
   DetLayer newLayer(name, r, z, x0, xrho, resRPhi, resZ, eff, type);
   // Check that efficient layers are not inert layers
   if (newLayer.getEfficiency() > 0.0f && newLayer.isInert()) {
@@ -232,6 +233,56 @@ void FastTracker::AddTPC(float phiResMean, float zResMean)
   }
 }
 
+void FastTracker::AddGenericDetector(std::string filename, o2::ccdb::BasicCCDBManager* ccdbManager)
+{
+  LOG(info) << " Adding generic detector from file " << filename;
+  // If the filename starts with ccdb: then take the file from the ccdb
+  if (filename.rfind("ccdb:", 0) == 0) {
+    std::string ccdbPath = filename.substr(5); // remove "ccdb:" prefix
+    if (ccdbManager == nullptr) {
+      LOG(fatal) << "CCDB manager is null, cannot retrieve file " << ccdbPath;
+      return;
+    }
+    const std::string outPath = "/tmp/DetGeo/";
+    filename = Form("%s/%s/snapshot.root", outPath.c_str(), ccdbPath.c_str());
+    std::ifstream checkFile(filename); // Check if file already exists
+    if (!checkFile.is_open()) {        // File does not exist, retrieve from CCDB
+      LOG(info) << " --- CCDB source detected for detector geometry " << filename;
+      std::map<std::string, std::string> metadata;
+      ccdbManager->getCCDBAccessor().retrieveBlob(ccdbPath, outPath, metadata, 1);
+      // Add CCDB handling logic here if needed
+      LOG(info) << " --- Now retrieving geometry configuration from CCDB to: " << filename;
+    } else { // File exists, proceed to load
+      LOG(info) << " --- Geometry configuration file already exists: " << filename << ". Skipping download.";
+      checkFile.close();
+    }
+    AddGenericDetector(filename, nullptr);
+    return;
+  }
+
+  std::ifstream infile(filename);
+  if (!infile.is_open()) {
+    LOG(fatal) << "Could not open detector configuration file: " << filename;
+    return;
+  }
+
+  std::string line;
+  while (std::getline(infile, line)) {
+    if (line.empty() || line[0] == '#')
+      continue; // skip comments and empty lines
+    std::istringstream iss(line);
+    std::string name;
+    float r, z, x0, xrho, resRPhi, resZ, eff;
+    int type;
+    if (!(iss >> name >> r >> z >> x0 >> xrho >> resRPhi >> resZ >> eff >> type)) {
+      LOG(error) << "Malformed line in detector config: " << line;
+      continue;
+    }
+    AddLayer(name.c_str(), r, z, x0, xrho, resRPhi, resZ, eff, type);
+  }
+  infile.close();
+}
+
 float FastTracker::Dist(float z, float r)
 {
   // porting of DetektorK::Dist

ALICE3/Core/FastTracker.h

@@ -14,9 +14,10 @@
 
 #include "DetLayer.h"
 
-#include "ReconstructionDataFormats/Track.h"
+#include <CCDB/BasicCCDBManager.h>
+#include <ReconstructionDataFormats/Track.h>
 
-#include <fairlogger/Logger.h> // not a system header but megalinter thinks so
+#include <fairlogger/Logger.h>
 
 #include <string>
 #include <vector>
@@ -61,6 +62,17 @@ class FastTracker
   void AddSiliconALICE3v2(std::vector<float> pixelResolution);
   void AddSiliconALICE3(float scaleX0VD, std::vector<float> pixelResolution);
   void AddTPC(float phiResMean, float zResMean);
+  /**
+   * @brief Adds a generic detector configuration from the specified file.
+   *
+   * This function loads and integrates a detector configuration into the tracker
+   * using the provided filename. The file should contain the necessary parameters
+   * and settings for the detector to be added.
+   *
+   * @param filename Path to the configuration file describing the detector.
+   * @param ccdbManager Pointer to a BasicCCDBManager instance for database access (if needed).
+   */
+  void AddGenericDetector(std::string filename, o2::ccdb::BasicCCDBManager* ccdbManager = nullptr);
 
   void Print();