Fixing index_prefix_path bug in python for StaticMemoryIndex (#491)

* Fixing the same bug I had in static disk index inside of static memory index as well.

* Unit tests and a better understanding of why the unit tests were successful despite this bug

pyproject.toml

@@ -11,7 +11,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "diskannpy"
-version = "0.7.0rc1"
+version = "0.7.0rc2"
 
 description = "DiskANN Python extension module"
 readme = "python/README.md"

python/src/_static_disk_index.py

@@ -79,9 +79,9 @@ def __init__(
           does not exist, you are required to provide it.
         - **index_prefix**: The prefix of the index files. Defaults to "ann".
         """
-        index_prefix = _valid_index_prefix(index_directory, index_prefix)
+        index_prefix_path = _valid_index_prefix(index_directory, index_prefix)
         vector_dtype, metric, _, _ = _ensure_index_metadata(
-            index_prefix,
+            index_prefix_path,
             vector_dtype,
             distance_metric,
             1,  # it doesn't matter because we don't need it in this context anyway
@@ -101,7 +101,7 @@ def __init__(
             _index = _native_dap.StaticDiskFloatIndex
         self._index = _index(
             distance_metric=dap_metric,
-            index_path_prefix=index_prefix,
+            index_path_prefix=index_prefix_path,
             num_threads=num_threads,
             num_nodes_to_cache=num_nodes_to_cache,
             cache_mechanism=cache_mechanism,

python/src/_static_memory_index.py

@@ -77,22 +77,22 @@ def __init__(
           does not exist, you are required to provide it.
         - **enable_filters**: Indexes built with filters can also be used for filtered search.
         """
-        index_prefix = _valid_index_prefix(index_directory, index_prefix)
+        index_prefix_path = _valid_index_prefix(index_directory, index_prefix)
         self._labels_map = {}
         self._labels_metadata = {}
         if enable_filters:
             try:
-                with open(index_prefix + "_labels_map.txt", "r") as labels_map_if:
+                with open(f"{index_prefix_path}_labels_map.txt", "r") as labels_map_if:
                     for line in labels_map_if:
                         (key, val) = line.split("\t")
                         self._labels_map[key] = int(val)
-                with open(f"{index_prefix}_label_metadata.json", "r") as labels_metadata_if:
+                with open(f"{index_prefix_path}_label_metadata.json", "r") as labels_metadata_if:
                     self._labels_metadata = json.load(labels_metadata_if)
             except: # noqa: E722
                 # exceptions are basically presumed to be either file not found or file not formatted correctly
                 raise RuntimeException("Filter labels file was unable to be processed.")
         vector_dtype, metric, num_points, dims = _ensure_index_metadata(
-            index_prefix,
+            index_prefix_path,
             vector_dtype,
             distance_metric,
             1,  # it doesn't matter because we don't need it in this context anyway
@@ -119,7 +119,7 @@ def __init__(
             distance_metric=dap_metric,
             num_points=num_points,
             dimensions=dims,
-            index_path=os.path.join(index_directory, index_prefix),
+            index_path=index_prefix_path,
             num_threads=num_threads,
             initial_search_complexity=initial_search_complexity,
         )

python/tests/test_static_disk_index.py

@@ -3,6 +3,7 @@
 
 import shutil
 import unittest
+from pathlib import Path
 from tempfile import mkdtemp
 
 import diskannpy as dap
@@ -165,4 +166,33 @@ def test_zero_threads(self):
                 k = 5
                 ids, dists = index.batch_search(
                     query_vectors, k_neighbors=k, complexity=5, beam_width=2, num_threads=0
-                )
+                )
+
+    def test_relative_paths(self):
+        # Issue 483 and 491 both fixed errors that were somehow slipping past our unit tests
+        # os.path.join() acts as a semi-merge if you give it two paths that look absolute.
+        # since our unit tests are using absolute paths via tempfile.mkdtemp(), the double os.path.join() was never
+        # caught by our tests, but was very easy to trip when using relative paths
+        rel_dir = "tmp"
+        Path(rel_dir).mkdir(exist_ok=True)
+        try:
+            tiny_index_vecs = random_vectors(20, 10, dtype=np.float32, seed=12345)
+            dap.build_disk_index(
+                data=tiny_index_vecs,
+                distance_metric="l2",
+                index_directory=rel_dir,
+                graph_degree=16,
+                complexity=32,
+                search_memory_maximum=0.00003,
+                build_memory_maximum=1,
+                num_threads=0,
+                pq_disk_bytes=0,
+            )
+            index = dap.StaticDiskIndex(
+                index_directory=rel_dir,
+                num_threads=16,
+                num_nodes_to_cache=10,
+            )
+
+        finally:
+            shutil.rmtree(rel_dir, ignore_errors=True)

python/tests/test_static_memory_index.py

@@ -5,6 +5,7 @@
 import shutil
 import unittest
 
+from pathlib import Path
 from tempfile import mkdtemp
 
 import diskannpy as dap
@@ -191,6 +192,33 @@ def test_zero_threads(self):
                 k = 5
                 ids, dists = index.batch_search(query_vectors, k_neighbors=k, complexity=5, num_threads=0)
 
+    def test_relative_paths(self):
+        # Issue 483 and 491 both fixed errors that were somehow slipping past our unit tests
+        # os.path.join() acts as a semi-merge if you give it two paths that look absolute.
+        # since our unit tests are using absolute paths via tempfile.mkdtemp(), the double os.path.join() was never
+        # caught by our tests, but was very easy to trip when using relative paths
+        rel_dir = "tmp"
+        Path(rel_dir).mkdir(exist_ok=True)
+        try:
+            tiny_index_vecs = random_vectors(20, 10, dtype=np.float32, seed=12345)
+            dap.build_memory_index(
+                data=tiny_index_vecs,
+                distance_metric="l2",
+                index_directory=rel_dir,
+                graph_degree=16,
+                complexity=32,
+                num_threads=0,
+            )
+            index = dap.StaticMemoryIndex(
+                index_directory=rel_dir,
+                num_threads=0,
+                initial_search_complexity=32,
+            )
+
+        finally:
+            shutil.rmtree(rel_dir, ignore_errors=True)
+
+
 
 class TestFilteredStaticMemoryIndex(unittest.TestCase):
     def test_simple_scenario(self):