Struct DirectoryNamespaceBuilder 

pub struct DirectoryNamespaceBuilder { /* private fields */ }

Builder for creating a DirectoryNamespace.

This builder provides a fluent API for configuring and establishing connections to directory-based Lance namespaces.

Examples

// Create a local directory namespace
let namespace = DirectoryNamespaceBuilder::new("/path/to/data")
    .build()
    .await?;

// Create with custom storage options and session
let session = Arc::new(Session::default());
let namespace = DirectoryNamespaceBuilder::new("s3://bucket/path")
    .storage_option("region", "us-west-2")
    .storage_option("access_key_id", "key")
    .session(session)
    .build()
    .await?;

Implementations

impl DirectoryNamespaceBuilder

pub fn new(root: impl Into<String>) -> Self

Create a new DirectoryNamespaceBuilder with the specified root path.

Arguments

• root - Root directory path (local path or cloud URI like s3://bucket/path)

pub fn manifest_enabled(self, enabled: bool) -> Self

Enable or disable manifest-based listing.

When enabled (default), the namespace uses a __manifest table to track tables. When disabled, relies solely on directory scanning.

pub fn dir_listing_enabled(self, enabled: bool) -> Self

Enable or disable directory-based listing fallback.

When enabled (default), falls back to directory scanning for tables not in the manifest. When disabled, only consults the manifest table.

pub fn inline_optimization_enabled(self, enabled: bool) -> Self

Enable or disable inline optimization of the __manifest table.

When enabled (default), performs compaction and indexing on the __manifest table after every write operation to maintain optimal performance. When disabled, manual optimization must be performed separately.

pub fn from_properties( properties: HashMap<String, String>, session: Option<Arc<Session>>, ) -> Result<Self>

Create a DirectoryNamespaceBuilder from properties HashMap.

This method parses a properties map into builder configuration. It expects:

• root: The root directory path (required)
• manifest_enabled: Enable manifest-based table tracking (optional, default: true)
• dir_listing_enabled: Enable directory listing for table discovery (optional, default: true)
• inline_optimization_enabled: Enable inline optimization of __manifest table (optional, default: true)
• storage.*: Storage options (optional, prefix will be stripped)

Arguments

• properties - Configuration properties
• session - Optional Lance session to reuse object store registry

Returns

Returns a DirectoryNamespaceBuilder instance.

Errors

Returns an error if the root property is missing.

Examples

let mut properties = HashMap::new();
properties.insert("root".to_string(), "/path/to/data".to_string());
properties.insert("manifest_enabled".to_string(), "true".to_string());
properties.insert("dir_listing_enabled".to_string(), "false".to_string());
properties.insert("storage.region".to_string(), "us-west-2".to_string());

let namespace = DirectoryNamespaceBuilder::from_properties(properties, None)?
    .build()
    .await?;

pub fn storage_option( self, key: impl Into<String>, value: impl Into<String>, ) -> Self

Add a storage option.

Arguments

• key - Storage option key (e.g., “region”, “access_key_id”)
• value - Storage option value

pub fn storage_options(self, options: HashMap<String, String>) -> Self

Add multiple storage options.

Arguments

• options - HashMap of storage options to add

pub fn session(self, session: Arc<Session>) -> Self

Set the Lance session to use for this namespace.

When a session is provided, the namespace will reuse the session’s object store registry, allowing multiple namespaces and datasets to share the same underlying storage connections.

Arguments

• session - Arc-wrapped Lance session

pub async fn build(self) -> Result<DirectoryNamespace>

Build the DirectoryNamespace.

Returns

Returns a DirectoryNamespace instance.

Errors

Returns an error if:

• The root path is invalid
• Connection to the storage backend fails
• Storage options are invalid

Trait Implementations

impl Clone for DirectoryNamespaceBuilder

fn clone(&self) -> DirectoryNamespaceBuilder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DirectoryNamespaceBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.