Index.load function exhibits unexpected behavior with filename:str argument

[JF235]

The Index.load function is producing an error when called with a file name instead of a file object.

Expected behaviour

Output:

# For Case 2.
[ 1 22 43 93 36]
[0.   0.08 0.11 0.31 0.32]

Actual behaviour

Output:

# For Case 1.
RuntimeError: Index seems to be corrupted or unsupported. 
Advancing to the next linked list requires 13312 additional bytes (from position 13337), 
but index data only has 13575 bytes in total.

Perhaps there is some detail I missed, but I couldn't find information about this in the Python API documentation.

Steps to reproduce the behaviour

• Python: 3.12.0
• voyager: 2.0.9
• Windows, x86_64

import numpy as np
from voyager import Index, Space

n = 100
q = 1
index = Index(Space.Euclidean, num_dimensions=5, random_seed=21)
np.random.seed(42)
data = np.random.rand(n, 5)
index.add_items(data)

index.save("output_file.voy")

# Case 1.
# cp = Index.load("output_file.voy")
#  => RuntimeError: Index seems to be corrupted or unsupported. 
# Advancing to the next linked list requires 13312 additional bytes (from position 13337),
# but index data only has 13575 bytes in total.


# Case 2.
with open("output_file.voy", "rb") as f:
    cp = Index.load(f)

neighbors, distances = cp.query(data[q], k=5)
print(neighbors) # => [ 1 22 43 93 36]
print(np.round(distances, 2)) # => [0.   0.08 0.11 0.31 0.32]

[JF235]

It seems to be a manifestation of the #40. Maybe a problem with Windows?