Implement pipelined search a la PipeANN

.gitignore

@@ -333,4 +333,4 @@ target/
 *.info
 
 # ignore VS Code local history
-.history/
+.history/

diskann-benchmark/example/pipe-search.json

@@ -0,0 +1,79 @@
+{
+  "search_directories": [
+    "test_data/disk_index_search"
+  ],
+  "jobs": [
+    {
+      "type": "disk-index",
+      "content": {
+        "source": {
+          "disk-index-source": "Load",
+          "data_type": "float32",
+          "load_path": "test_data/disk_index_search/disk_index_sift_learn_R4_L50_A1.2_truth_search"
+        },
+        "search_phase": {
+          "queries": "disk_index_sample_query_10pts.fbin",
+          "groundtruth": "disk_index_10pts_idx_uint32_truth_search_res.bin",
+          "search_list": [10, 20, 40, 80],
+          "beam_width": 4,
+          "recall_at": 10,
+          "num_threads": 1,
+          "is_flat_search": false,
+          "distance": "squared_l2",
+          "vector_filters_file": null,
+          "search_mode": {
+            "mode": "BeamSearch"
+          }
+        }
+      }
+    },
+    {
+      "type": "disk-index",
+      "content": {
+        "source": {
+          "disk-index-source": "Load",
+          "data_type": "float32",
+          "load_path": "test_data/disk_index_search/disk_index_sift_learn_R4_L50_A1.2_truth_search"
+        },
+        "search_phase": {
+          "queries": "disk_index_sample_query_10pts.fbin",
+          "groundtruth": "disk_index_10pts_idx_uint32_truth_search_res.bin",
+          "search_list": [10, 20, 40, 80],
+          "beam_width": 4,
+          "recall_at": 10,
+          "num_threads": 1,
+          "is_flat_search": false,
+          "distance": "squared_l2",
+          "vector_filters_file": null,
+          "search_mode": {
+            "mode": "PipeSearch"
+          }
+        }
+      }
+    },
+    {
+      "type": "disk-index",
+      "content": {
+        "source": {
+          "disk-index-source": "Load",
+          "data_type": "float32",
+          "load_path": "test_data/disk_index_search/disk_index_sift_learn_R4_L50_A1.2_truth_search"
+        },
+        "search_phase": {
+          "queries": "disk_index_sample_query_10pts.fbin",
+          "groundtruth": "disk_index_10pts_idx_uint32_truth_search_res.bin",
+          "search_list": [10, 20, 40, 80],
+          "beam_width": 4,
+          "recall_at": 10,
+          "num_threads": 1,
+          "is_flat_search": false,
+          "distance": "squared_l2",
+          "vector_filters_file": null,
+          "search_mode": {
+            "mode": "PipeSearch"
+          }
+        }
+      }
+    }
+  ]
+}