Few fixes in bench_fw to enable IndexFromCodec (#3383)

Summary:
Pull Request resolved: #3383

In this diff, I am fixing minor issues in bench_fw where either certain fields are not accessible when index is build from codec. It also requires index to be discovered using codec alias as index factory is not always available.

In subsequent diff internal to meta will have testcase that execute this path.

Reviewed By: algoriddle

Differential Revision: D56444641

fbshipit-source-id: b7af7e7bb47b20bbb5515a66f41dd24f42459d52

benchs/bench_fw/benchmark.py

@@ -208,9 +208,11 @@ def set_io(self, benchmark_io):
         self.io.distance_metric = self.distance_metric
         self.io.distance_metric_type = self.distance_metric_type
 
-    def get_index_desc(self, factory: str) -> Optional[IndexDescriptor]:
+    def get_index_desc(self, factory_or_codec: str) -> Optional[IndexDescriptor]:
         for desc in self.index_descs:
-            if desc.factory == factory:
+            if desc.factory == factory_or_codec:
+                return desc
+            if desc.codec_alias == factory_or_codec:
                 return desc
         return None
 
@@ -232,7 +234,7 @@ def range_search_reference(self, index, parameters, range_metric):
             parameters,
             radius=m_radius,
         )
-        flat = index.factory == "Flat"
+        flat = index.is_flat_index()
         (
             gt_radius,
             range_search_metric_function,
@@ -650,6 +652,7 @@ def benchmark(
                     f"Range index {index_desc.factory} has no radius_score"
                 )
             results["metrics"] = {}
+            self.build_index_wrapper(index_desc)
             for metric_key, range_metric in index_desc.range_metrics.items():
                 (
                     gt_radius,

benchs/bench_fw/descriptors.py

@@ -20,6 +20,7 @@ class IndexDescriptor:
     # but not both at the same time.
     path: Optional[str] = None
     factory: Optional[str] = None
+    codec_alias: Optional[str] = None
     construction_params: Optional[List[Dict[str, int]]] = None
     search_params: Optional[Dict[str, int]] = None
     # range metric definitions

benchs/bench_fw/index.py

@@ -495,7 +495,7 @@ def range_search(
         radius: Optional[float] = None,
     ):
         logger.info("range_search: begin")
-        if search_parameters is not None and search_parameters["snap"] == 1:
+        if search_parameters is not None and search_parameters.get("snap") == 1:
             query_vectors = self.snap(query_vectors)
         filename = (
             self.get_range_search_name(
@@ -776,6 +776,9 @@ def add_range_or_val(name, range):
             )
         return op
 
+    def is_flat_index(self):
+        return self.get_index_name().startswith("Flat")
+
 
 # IndexFromCodec, IndexFromQuantizer and IndexFromPreTransform
 # are used to wrap pre-trained Faiss indices (codecs)
@@ -807,6 +810,9 @@ def get_codec_name(self):
         name += Index.param_dict_list_to_name(self.construction_params)
         return name
 
+    def fetch_meta(self, dry_run=False):
+        return None, None
+
     def fetch_codec(self):
         codec = self.io.read_index(
             os.path.basename(self.path),
@@ -911,7 +917,7 @@ def fetch_codec(self, dry_run=False):
             assert codec_size is not None
             meta = {
                 "training_time": training_time,
-                "training_size": self.training_vectors.num_vectors,
+                "training_size": self.training_vectors.num_vectors if self.training_vectors else 0,
                 "codec_size": codec_size,
                 "sa_code_size": self.get_sa_code_size(codec),
                 "code_size": self.get_code_size(codec),