Removed index_shard_and_quantize OIVFBBS (#3291)

Summary:
This PR removes the unused method `index_shard_and_quantize` in OIVFBBS.

Pull Request resolved: #3291

Reviewed By: algoriddle, junjieqi

Differential Revision: D54901824

Pulled By: mlomeli1

fbshipit-source-id: f723aa386b91417f697b24b620618b864329ef6d

Author: mlomeli1

demos/offline_ivf/offline_ivf.py

@@ -227,64 +227,6 @@ def _iterate_transformed(self, ds, start, batch_size, dt):
             for buffer in ds.iterate(start, batch_size, dt):
                 yield buffer
 
-    def index_shard_and_quantize(self):
-        assert os.path.exists(self.index_template_file)
-        index = faiss.read_index(self.index_template_file)
-        index_ivf = faiss.downcast_index(faiss.extract_index_ivf(index))
-        assert self.nprobe <= index_ivf.quantizer.ntotal, (
-            f"the number of vectors {index_ivf.quantizer.ntotal} is not enough"
-            f" to retrieve {self.nprobe} neighbours, check."
-        )
-
-        if is_pretransform_index(index):
-            d = index.chain.at(0).d_out
-        else:
-            d = self.input_d
-        for i in range(0, self.nshards):
-            sfn = f"{self.index_shard_prefix}{i}"
-            cqfn = f"{self.coarse_quantization_prefix}{i}"  # fixme
-            if os.path.exists(sfn) or os.path.exists(cqfn):
-                logging.info(f"skipping shard: {i}")
-                continue
-            try:
-                with open(cqfn, "xb") as cqf:
-                    index.reset()
-                    start = i * self.shard_size
-                    j = 0
-                    quantizer = faiss.index_cpu_to_all_gpus(
-                        index_ivf.quantizer
-                    )
-                    for xb_j in tqdm(
-                        self._iterate_transformed(
-                            self.xb_ds,
-                            start,
-                            EMBEDDINGS_BATCH_SIZE,
-                            np.float32,
-                        ),
-                        file=sys.stdout,
-                    ):
-                        assert xb_j.shape[1] == d
-                        _, I = quantizer.search(xb_j, self.nprobe)
-                        assert np.amin(I) >= 0, f"{I}"
-                        assert np.amax(I) < index_ivf.nlist
-                        cqf.write(I)
-                        self._index_add_core_wrapper(  # fixme
-                            index_ivf,
-                            xb_j,
-                            np.arange(start + j, start + j + xb_j.shape[0]),
-                            I[:, 0],
-                        )
-                        j += xb_j.shape[0]
-                        assert j <= self.shard_size
-                        if j == self.shard_size:
-                            break
-                logging.info(f"writing {sfn}...")
-                faiss.write_index(index, sfn)
-            except FileExistsError:
-                logging.info(f"skipping shard: {i}")
-                continue
-        logging.info("done")
-
     def index_shard(self):
         assert os.path.exists(self.index_template_file)
         index = faiss.read_index(self.index_template_file)