in rally-custom/custom_tracks/opensearch/dense_vector/_tools/parse.py [0:0]
def to_json(f):
f.read(4) # the total number of vectors
f.read(4) # the vector dimension
for i in iterate(num_vectors):
vector = struct.unpack("f" * dims, f.read(dims * 4))
print(json.dumps({"vector": vector}, ensure_ascii=False))