Created a function to read the groundtruth

Author: AntonisZks

main2.cpp

@@ -97,16 +97,57 @@ void saveGroundtruthToFile(const std::vector<std::vector<float>>& distances, con
   file.close();
 }
 
+/**
+ * @brief Read the groundtruth distances from a binary file.
+ * 
+ * This function reads the groundtruth distances from a binary file. The file format consists of the following:
+ * - The number of query vectors (4 bytes)
+ * - For each query vector:
+ *   - The number of distances (4 bytes)
+ *   - The computed distances (4 bytes each)
+ * 
+ * @param filename The name of the input file to read the distances from
+ * 
+ * @return A 2D vector containing the read distances for each query vector
+ */
+std::vector<std::vector<float>> readGroundtruthFromFile(const std::string& filename) {
+  std::ifstream file(filename, std::ios::binary);
+
+  if (!file.is_open()) {
+    std::cerr << "Error opening file: " << filename << std::endl;
+    return {};
+  }
+
+  // Read the number of query vectors from the file
+  uint32_t num_queries;
+  file.read(reinterpret_cast<char*>(&num_queries), sizeof(num_queries));
+
+  std::vector<std::vector<float>> distances(num_queries);
+
+  // Read the distances for each query vector
+  for (auto& query_distances : distances) {
+    uint32_t num_distances;
+    file.read(reinterpret_cast<char*>(&num_distances), sizeof(num_distances));
+    query_distances.resize(num_distances);
+    file.read(reinterpret_cast<char*>(query_distances.data()), num_distances * sizeof(float));
+  }
+
+  file.close();
+  return distances;
+}
 
 int main(int argc, char* argv[]) {
 
   std::vector<BaseDataVector<float>> base_vectors = ReadFilteredBaseVectorFile("data/Dummy/dummy-data.bin");
   std::vector<QueryDataVector<float>> query_vectors = ReadFilteredQueryVectorFile("data/Dummy/dummy-queries.bin");
 
   // Compute the distance vector, and save the computed distances to a file
-  std::vector<std::vector<float>> distances = computeGroundtruth(base_vectors, query_vectors, 100);
+  std::vector<std::vector<float>> distances = computeGroundtruth(base_vectors, query_vectors, 1000);
   saveGroundtruthToFile(distances, "data/Dummy/dummy-groundtruth.bin");
-  
+
+  // Example usage of readGroundtruthFromFile
+  std::vector<std::vector<float>> read_distances = readGroundtruthFromFile("data/Dummy/dummy-groundtruth.bin");
+
   return 0;
 
 }