add errror text to python exceptions

python/cuvs/cuvs/common/CMakeLists.txt

@@ -13,7 +13,7 @@
 # =============================================================================
 
 # Set the list of Cython files to build
-set(cython_sources cydlpack.pyx)
+set(cython_sources cydlpack.pyx exceptions.pyx)
 set(linked_libraries cuvs::cuvs cuvs_c)
 
 # Build all of the Cython targets

python/cuvs/cuvs/common/c_api.pxd

@@ -30,3 +30,4 @@ cdef extern from "cuvs/core/c_api.h":
     cuvsError_t cuvsResourcesCreate(cuvsResources_t* res)
     cuvsError_t cuvsResourcesDestroy(cuvsResources_t res)
     cuvsError_t cuvsStreamSet(cuvsResources_t res, cudaStream_t stream)
+    const char * cuvsGetLastErrorText()

python/cuvs/cuvs/common/exceptions.pyx

@@ -0,0 +1,37 @@
+#
+# Copyright (c) 2024, NVIDIA CORPORATION.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# cython: language_level=3
+
+from cuvs.common.c_api cimport cuvsError_t, cuvsGetLastErrorText
+
+
+class CuvsException(Exception):
+    pass
+
+
+def get_last_error_text():
+    """ returns the last error description from the cuvs c-api """
+    cdef const char* c_err = cuvsGetLastErrorText()
+    if c_err is NULL:
+        return
+    cdef bytes err = c_err
+    return err.decode("utf8")
+
+
+def check_cuvs(status: cuvsError_t):
+    """ Converts a status code into an exception """
+    if status == cuvsError_t.CUVS_ERROR:
+        raise CuvsException(get_last_error_text())

python/cuvs/cuvs/neighbors/cagra/cagra.pyx

@@ -52,6 +52,8 @@ from cuvs.common.c_api cimport (
     cuvsResourcesCreate,
 )
 
+from cuvs.common.exceptions import check_cuvs
+
 
 cdef class IndexParams:
     """
@@ -124,19 +126,13 @@ cdef class Index:
     cdef bool trained
 
     def __cinit__(self):
-        cdef cuvsError_t index_create_status
-        index_create_status = cuvsCagraIndexCreate(&self.index)
         self.trained = False
-
-        if index_create_status == cuvsError_t.CUVS_ERROR:
-            raise RuntimeError("Failed to create index.")
+        check_cuvs(cuvsCagraIndexCreate(&self.index))
 
     def __dealloc__(self):
         cdef cuvsError_t index_destroy_status
         if self.index is not NULL:
-            index_destroy_status = cuvsCagraIndexDestroy(self.index)
-            if index_destroy_status == cuvsError_t.CUVS_ERROR:
-                raise Exception("Failed to deallocate index.")
+            check_cuvs(cuvsCagraIndexDestroy(self.index))
 
     @property
     def trained(self):
@@ -203,9 +199,7 @@ def build_index(IndexParams index_params, dataset, resources=None):
     cdef cuvsResources_t res_
     cdef cuvsError_t cstat
 
-    cstat = cuvsResourcesCreate(&res_)
-    if cstat == cuvsError_t.CUVS_ERROR:
-        raise RuntimeError("Error creating Device Reources.")
+    check_cuvs(cuvsResourcesCreate(&res_))
 
     cdef Index idx = Index()
     cdef cuvsError_t build_status
@@ -214,17 +208,13 @@ def build_index(IndexParams index_params, dataset, resources=None):
     cdef cuvsCagraIndexParams* params = index_params.params
 
     with cuda_interruptible():
-        build_status = cuvsCagraBuild(
+        check_cuvs(cuvsCagraBuild(
             res_,
             params,
             dataset_dlpack,
             idx.index
-        )
-
-        if build_status == cuvsError_t.CUVS_ERROR:
-            raise RuntimeError("Index failed to build.")
-        else:
-            idx.trained = True
+        ))
+        idx.trained = True
 
     return idx
 
@@ -451,9 +441,7 @@ def search(SearchParams search_params,
     cdef cuvsResources_t res_
     cdef cuvsError_t cstat
 
-    cstat = cuvsResourcesCreate(&res_)
-    if cstat == cuvsError_t.CUVS_ERROR:
-        raise RuntimeError("Error creating Device Reources.")
+    check_cuvs(cuvsResourcesCreate(&res_))
 
     # todo(dgd): we can make the check of dtype a parameter of wrap_array
     # in RAFT to make this a single call
@@ -487,16 +475,13 @@ def search(SearchParams search_params,
         cydlpack.dlpack_c(distances_cai)
 
     with cuda_interruptible():
-        search_status = cuvsCagraSearch(
+        check_cuvs(cuvsCagraSearch(
             res_,
             params,
             index.index,
             queries_dlpack,
             neighbors_dlpack,
             distances_dlpack
-        )
-
-        if search_status == cuvsError_t.CUVS_ERROR:
-            raise RuntimeError("Search failed.")
+        ))
 
     return (distances, neighbors)

rust/cuvs/src/cagra/index_params.rs

@@ -69,7 +69,7 @@ impl fmt::Debug for IndexParams {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         // custom debug trait here, default value will show the pointer address
         // for the inner params object which isn't that useful.
-        write!(f, "IndexParams {{ params: {:?} }}", unsafe { *self.0 })
+        write!(f, "IndexParams({:?})", unsafe { *self.0 })
     }
 }