FIX #245 - Set required DirectML session options (memory_pattern + sequential execution)

Cargo.toml

@@ -57,6 +57,7 @@ nomic-v2-moe = ["dep:candle-core", "dep:candle-nn", "hf-hub"]
 image-models = ["dep:image"]
 mkl = ["qwen3", "nomic-v2-moe", "dep:intel-mkl-src", "candle-nn/mkl", "candle-core/mkl"]
 accelerate = ["qwen3", "nomic-v2-moe", "dep:accelerate-src", "candle-core/accelerate", "candle-nn/accelerate"]
+directml = ["ort/directml"]
 cuda = ["qwen3", "nomic-v2-moe", "candle-core/cuda", "candle-nn/cuda"]
 cudnn = ["qwen3", "nomic-v2-moe", "candle-core/cudnn", "candle-nn/cudnn", "cuda"]
 metal = ["qwen3", "nomic-v2-moe", "candle-core/metal", "candle-nn/metal"]

README.md

@@ -292,6 +292,29 @@ println!("Rerank result: {:?}", results);
 
 Alternatively, local model files can be used for inference via the `try_new_from_user_defined(...)` methods of respective structs.
 
+### DirectML (Windows)
+
+To run models on a GPU via DirectML on Windows, enable the `directml` feature:
+
+```toml
+[dependencies]
+fastembed = { version = "5", features = ["directml"] }
+```
+
+Then pass a DirectML execution provider when initializing a model:
+
+```rust
+use fastembed::{TextEmbedding, InitOptions, EmbeddingModel};
+use ort::ep::DirectML;
+
+let model = TextEmbedding::try_new(
+    InitOptions::new(EmbeddingModel::AllMiniLML6V2)
+        .with_execution_providers(vec![DirectML::default().into()]),
+)?;
+```
+
+When DirectML is detected, fastembed automatically disables memory pattern optimization and parallel execution on the ONNX Runtime session, as required by the DirectML execution provider.
+
 ## LICENSE
 
 [Apache 2.0](https://github.com/Anush008/fastembed-rs/blob/main/LICENSE)

src/image_embedding/impl.rs

@@ -59,11 +59,25 @@ impl ImageEmbedding {
             .get(&model_file_name)
             .context(format!("Failed to retrieve {}", model_file_name))?;
 
-        let session = Session::builder()?
+        #[cfg(feature = "directml")]
+        let has_directml = execution_providers
+            .iter()
+            .any(|ep| ep.downcast_ref::<ort::ep::DirectML>().is_some());
+        #[cfg(not(feature = "directml"))]
+        let has_directml = false;
+
+        let mut builder = Session::builder()?
             .with_execution_providers(execution_providers)?
             .with_optimization_level(GraphOptimizationLevel::Level3)?
-            .with_intra_threads(threads)?
-            .commit_from_file(model_file_reference)?;
+            .with_intra_threads(threads)?;
+
+        if has_directml {
+            builder = builder
+                .with_memory_pattern(false)?
+                .with_parallel_execution(false)?;
+        }
+
+        let session = builder.commit_from_file(model_file_reference)?;
 
         Ok(Self::new(preprocessor, session))
     }
@@ -83,11 +97,25 @@ impl ImageEmbedding {
 
         let preprocessor = Compose::from_bytes(model.preprocessor_file)?;
 
-        let session = Session::builder()?
+        #[cfg(feature = "directml")]
+        let has_directml = execution_providers
+            .iter()
+            .any(|ep| ep.downcast_ref::<ort::ep::DirectML>().is_some());
+        #[cfg(not(feature = "directml"))]
+        let has_directml = false;
+
+        let mut builder = Session::builder()?
             .with_execution_providers(execution_providers)?
             .with_optimization_level(GraphOptimizationLevel::Level3)?
-            .with_intra_threads(threads)?
-            .commit_from_memory(&model.onnx_file)?;
+            .with_intra_threads(threads)?;
+
+        if has_directml {
+            builder = builder
+                .with_memory_pattern(false)?
+                .with_parallel_execution(false)?;
+        }
+
+        let session = builder.commit_from_memory(&model.onnx_file)?;
 
         Ok(Self::new(preprocessor, session))
     }

src/text_embedding/impl.rs

@@ -70,11 +70,25 @@ impl TextEmbedding {
         // prioritise loading pooling config if available, if not (thanks qdrant!), look for it in hardcoded
         let post_processing = TextEmbedding::get_default_pooling_method(&model_name);
 
-        let session = Session::builder()?
+        #[cfg(feature = "directml")]
+        let has_directml = execution_providers
+            .iter()
+            .any(|ep| ep.downcast_ref::<ort::ep::DirectML>().is_some());
+        #[cfg(not(feature = "directml"))]
+        let has_directml = false;
+
+        let mut builder = Session::builder()?
             .with_execution_providers(execution_providers)?
             .with_optimization_level(GraphOptimizationLevel::Level3)?
-            .with_intra_threads(threads)?
-            .commit_from_file(model_file_reference)?;
+            .with_intra_threads(threads)?;
+
+        if has_directml {
+            builder = builder
+                .with_memory_pattern(false)?
+                .with_parallel_execution(false)?;
+        }
+
+        let session = builder.commit_from_file(model_file_reference)?;
 
         let tokenizer = load_tokenizer_hf_hub(model_repo, max_length)?;
         Ok(Self::new(
@@ -100,12 +114,25 @@ impl TextEmbedding {
 
         let threads = available_parallelism()?.get();
 
+        #[cfg(feature = "directml")]
+        let has_directml = execution_providers
+            .iter()
+            .any(|ep| ep.downcast_ref::<ort::ep::DirectML>().is_some());
+        #[cfg(not(feature = "directml"))]
+        let has_directml = false;
+
         let session = {
             let mut session_builder = Session::builder()?
                 .with_execution_providers(execution_providers)?
                 .with_optimization_level(GraphOptimizationLevel::Level3)?
                 .with_intra_threads(threads)?;
 
+            if has_directml {
+                session_builder = session_builder
+                    .with_memory_pattern(false)?
+                    .with_parallel_execution(false)?;
+            }
+
             for external_initializer_file in model.external_initializers {
                 session_builder = session_builder.with_external_initializer_file_in_memory(
                     external_initializer_file.file_name,