feat: add list_indices to the async api (#1074)

python/src/index.rs

@@ -85,3 +85,25 @@ impl Index {
         })
     }
 }
+
+#[pyclass(get_all)]
+/// A description of an index currently configured on a column
+pub struct IndexConfig {
+    /// The type of the index
+    pub index_type: String,
+    /// The columns in the index
+    ///
+    /// Currently this is always a list of size 1.  In the future there may
+    /// be more columns to represent composite indices.
+    pub columns: Vec<String>,
+}
+
+impl From<lancedb::index::IndexConfig> for IndexConfig {
+    fn from(value: lancedb::index::IndexConfig) -> Self {
+        let index_type = format!("{:?}", value.index_type);
+        Self {
+            index_type,
+            columns: value.columns,
+        }
+    }
+}

python/src/lib.rs

@@ -14,7 +14,7 @@
 
 use connection::{connect, Connection};
 use env_logger::Env;
-use index::Index;
+use index::{Index, IndexConfig};
 use pyo3::{pymodule, types::PyModule, wrap_pyfunction, PyResult, Python};
 use table::Table;
 
@@ -33,6 +33,7 @@ pub fn _lancedb(_py: Python, m: &PyModule) -> PyResult<()> {
     m.add_class::<Connection>()?;
     m.add_class::<Table>()?;
     m.add_class::<Index>()?;
+    m.add_class::<IndexConfig>()?;
     m.add_function(wrap_pyfunction!(connect, m)?)?;
     m.add("__version__", env!("CARGO_PKG_VERSION"))?;
     Ok(())

python/src/table.rs

@@ -11,7 +11,10 @@ use pyo3::{
 };
 use pyo3_asyncio::tokio::future_into_py;
 
-use crate::{error::PythonErrorExt, index::Index};
+use crate::{
+    error::PythonErrorExt,
+    index::{Index, IndexConfig},
+};
 
 #[pyclass]
 pub struct Table {
@@ -127,6 +130,19 @@ impl Table {
         })
     }
 
+    pub fn list_indices(self_: PyRef<'_, Self>) -> PyResult<&PyAny> {
+        let inner = self_.inner_ref()?.clone();
+        future_into_py(self_.py(), async move {
+            Ok(inner
+                .list_indices()
+                .await
+                .infer_error()?
+                .into_iter()
+                .map(IndexConfig::from)
+                .collect::<Vec<_>>())
+        })
+    }
+
     pub fn __repr__(&self) -> String {
         match &self.inner {
             None => format!("ClosedTable({})", self.name),