refactor(disk): consume in-crate pipnn module

Forward the disk feature to diskann/pipnn instead of depending on a separate crate. Consolidate duplicate pipeline builds and name adapter tests by the behavior they protect.

Author: SeliMeli

Cargo.lock

@@ -43,7 +43,6 @@ vfs = { workspace = true }
 
 # Optional dependencies
 opentelemetry = { workspace = true, optional = true }
-diskann-pipnn = { workspace = true, optional = true }
 
 [target.'cfg(target_os = "linux")'.dependencies]
 io-uring = "0.6.4"
@@ -84,7 +83,7 @@ proptest.workspace = true
 [features]
 default = []
 perf_test = ["dep:opentelemetry"]
-pipnn = ["dep:diskann-pipnn"]
+pipnn = ["diskann/pipnn"]
 virtual_storage = ["diskann-providers/virtual_storage"]
 experimental_diversity_search = [
     "diskann/experimental_diversity_search",

diskann-disk/Cargo.toml

@@ -15,7 +15,7 @@
 //! 5. serialize adjacency with the same header/layout used by Vamana.
 //!
 //! ```text
-//! dataset file ──> metadata check ──> MatrixView ──> diskann-pipnn ──> adjacency
+//! dataset file ──> metadata check ──> MatrixView ──> diskann::graph::pipnn ──> adjacency
 //!      │                                                              │
 //!      └──────────────────> sampled medoid ────────────────────────────┤
 //!                                                                     v
@@ -25,8 +25,8 @@
 //! There is no PiPNN-specific disk graph format. Keeping serialization here means
 //! search and loading cannot distinguish which builder produced the graph.
 
+use diskann::graph::pipnn::{PiPNNBuildContext, PiPNNConfig};
 use diskann::{utils::VectorRepr, ANNError, ANNResult};
-use diskann_pipnn::{PiPNNBuildContext, PiPNNConfig};
 use diskann_providers::{
     storage::{save_adjacency_graph, StorageReadProvider, StorageWriteProvider},
     utils::{find_medoid_with_sampling, RayonThreadPoolRef, MAX_MEDOID_SAMPLE_SIZE},
@@ -76,7 +76,7 @@ where
         builder.index_configuration.dist_metric,
         pool.as_rayon(),
     )?;
-    let adjacency = diskann_pipnn::build_graph(data.as_view(), &context)?;
+    let adjacency = diskann::graph::pipnn::build_graph(data.as_view(), &context)?;
 
     // Start-node policy belongs to the persisted index, not the core graph
     // constructor. Reuse the production sampled medoid implementation so the

diskann-disk/src/build/builder/build/pipnn.rs

@@ -88,7 +88,7 @@ fn builder<'a>(
 }
 
 #[test]
-fn pipnn_disk_build_rejects_configuration_dataset_mismatch() {
+fn disk_build_rejects_dataset_shape_mismatch() {
     let storage = VirtualStorageProvider::new_memory();
     write_data(&storage, 2, 8);
     let params = DiskIndexBuildParameters::new_pipnn(
@@ -107,7 +107,7 @@ fn pipnn_disk_build_rejects_configuration_dataset_mismatch() {
 }
 
 #[test]
-fn pipnn_graph_adapter_rejects_point_count_mismatch() {
+fn graph_adapter_rejects_point_count_mismatch() {
     let storage = VirtualStorageProvider::new_memory();
     write_data(&storage, 2, 8);
     let parameters = pipnn();
@@ -120,20 +120,7 @@ fn pipnn_graph_adapter_rejects_point_count_mismatch() {
 }
 
 #[test]
-fn pipnn_disk_build_uses_common_pipeline() {
-    let storage = VirtualStorageProvider::new_memory();
-    let (points, dimensions) = (256, 8);
-    write_data(&storage, points, dimensions);
-    let mut builder = builder(&storage, points, dimensions, 1.0, 1.2, pipnn());
-
-    builder.build().unwrap();
-
-    assert!(storage.exists(&get_disk_index_file("/index")));
-    assert!(storage.exists("/index_pq_compressed.bin"));
-}
-
-#[test]
-fn pipnn_graph_adapter_writes_real_point_header() {
+fn graph_adapter_writes_degree_medoid_and_frozen_count() {
     let storage = VirtualStorageProvider::new_memory();
     let (points, dimensions) = (256, 8);
     write_data(&storage, points, dimensions);
@@ -157,7 +144,7 @@ fn pipnn_graph_adapter_writes_real_point_header() {
 }
 
 #[test]
-fn explicit_pipnn_selection_is_not_replaced_by_memory_budget() {
+fn explicit_selection_ignores_the_vamana_memory_strategy() {
     let storage = VirtualStorageProvider::new_memory();
     let (points, dimensions) = (256, 8);
     write_data(&storage, points, dimensions);
@@ -176,10 +163,11 @@ fn explicit_pipnn_selection_is_not_replaced_by_memory_budget() {
     assert_eq!(builder.index_configuration.config.alpha(), 1.3);
     builder.build().unwrap();
     assert!(storage.exists(&get_disk_index_file("/index")));
+    assert!(storage.exists("/index_pq_compressed.bin"));
 }
 
 #[test]
-fn pipnn_disk_build_rejects_invalid_config() {
+fn builder_rejects_invalid_pipnn_config() {
     let storage = VirtualStorageProvider::new_memory();
     let invalid = PiPNNParameters {
         c_max: 0,

diskann-disk/src/build/builder/build/pipnn/tests.rs

@@ -46,7 +46,7 @@ impl Default for PiPNNParameters {
 }
 
 #[cfg(feature = "pipnn")]
-impl From<&PiPNNParameters> for diskann_pipnn::PiPNNConfig {
+impl From<&PiPNNParameters> for diskann::graph::pipnn::PiPNNConfig {
     fn from(config: &PiPNNParameters) -> Self {
         Self {
             c_max: config.c_max,

diskann-disk/src/build/configuration/build_algorithm.rs

@@ -196,7 +196,7 @@ impl DiskIndexBuildParameters {
     }
 
     #[cfg(feature = "pipnn")]
-    pub(crate) fn pipnn_config(&self) -> Option<diskann_pipnn::PiPNNConfig> {
+    pub(crate) fn pipnn_config(&self) -> Option<diskann::graph::pipnn::PiPNNConfig> {
         match &self.build_algorithm {
             BuildAlgorithm::PiPNN(config) => Some(config.into()),
             BuildAlgorithm::Vamana => None,
@@ -284,23 +284,4 @@ mod dataset_test {
         let chunks = NumPQChunks::new_with(64, 128).unwrap();
         assert_eq!(chunks.get(), 64);
     }
-
-    #[cfg(feature = "pipnn")]
-    #[test]
-    fn new_pipnn_uses_the_common_disk_pipeline_parameters() {
-        let pq = NumPQChunks::new_with(1, 128).unwrap();
-        let parameters = PiPNNParameters::default();
-        let config = diskann_pipnn::PiPNNConfig::from(&parameters);
-        let budget = MemoryBudget::try_from_gb(2.0).unwrap();
-        let params = DiskIndexBuildParameters::new_pipnn(budget, pq, parameters);
-
-        assert_eq!(params.pipnn_config(), Some(config));
-        assert_eq!(params.build_memory_limit(), budget);
-        assert_eq!(params.search_pq_chunks(), pq);
-        assert_eq!(
-            params.data_compression_chunk_vector_count(),
-            DEFAULT_DATA_COMPRESSION_CHUNK_VECTOR_COUNT
-        );
-        assert!(matches!(params.build_algorithm(), BuildAlgorithm::PiPNN(_)));
-    }
 }