Add OpenAI ArXiv Dataset (#299)

* added openai arxiv dataset

* added comment describing dataset

benchmark/datasets.py

@@ -619,6 +619,50 @@ def get_dataset(self):
     def distance(self):
         return "ip"
 
+'''
+The OpenAI-ArXiv dataset consists of 2321096 1536-dimensional OpenAI ada-002 
+embeddings of the abstracts of ArXiv papers, with 20000 queries drawn from the same source. 
+The ArXiv dataset was released by Cornell University and can be found here:
+https://www.kaggle.com/datasets/Cornell-University/arxiv
+'''
+class OpenAIArXivDataset(DatasetCompetitionFormat):
+    def __init__(self, nb=2321096):
+        self.nb = nb
+        self.d = 1536
+        self.nq = 20000
+        self.dtype = "float32"
+        self.ds_fn =  "openai_base.bin"
+        self.qs_fn = "openai_query.bin"
+        self.gt_fn = (
+            "openai-2M" if self.nb == 2321096 else
+            "openai-100K" if self.nb == 100000 else
+            None
+        )
+        self.basedir = os.path.join(BASEDIR, "OpenAIArXiv")
+        self.base_url = "https://comp21storage.z5.web.core.windows.net/arxiv-openaiv2-2M"
+
+        self.private_qs_url = None
+        self.private_gt_url = None
+
+    def prepare(self, skip_data=False, original_size=2321096):
+        return super().prepare(skip_data, 2321096)
+
+    def get_dataset_fn(self):
+        fn = os.path.join(self.basedir, self.ds_fn)
+        if self.nb != 2321096:
+            fn += '.crop_nb_%d' % self.nb
+        if os.path.exists(fn):
+            return fn
+        else:
+            raise RuntimeError("file %s not found" %fn)
+
+    def get_dataset(self):
+        slice = next(self.get_dataset_iterator(bs=self.nb))
+        return sanitize(slice)
+
+    def distance(self):
+        return "euclidean"
+
 class RandomClusteredDS(DatasetCompetitionFormat):
     def __init__(self, basedir="random-clustered"):
         self.nb = 10000
@@ -1264,6 +1308,9 @@ def short_name(self):
     'msmarco-10M': lambda : MSMarcoWebSearchDataset(10000000),
     'msmarco-1M': lambda : MSMarcoWebSearchDataset(1000000),
 
+    'openai-2M': lambda : OpenAIArXivDataset(2321096),
+    'openai-100K': lambda : OpenAIArXivDataset(100000),
+
     'random-xs': lambda : RandomDS(10000, 1000, 20),
     'random-s': lambda : RandomDS(100000, 1000, 50),