Struct RelationStore 

pub struct RelationStore { /* private fields */ }

Storage for named relations as GPU buffers

RelationStore manages a collection of named relations, each stored as a CudaBuffer. It provides CRUD operations for relation management during query execution.

Thread Safety

This implementation is NOT thread-safe. It is designed for single-threaded runtime execution in the MVP.

Example

use xlog_runtime::RelationStore;
use xlog_cuda::CudaBuffer;
use xlog_core::Schema;

let mut store = RelationStore::new(provider);

// Add a relation
store.put("edge", buffer);

// Check if relation exists
if store.contains("edge") {
    let edge = store.get("edge").unwrap();
}

// Remove a relation
let removed = store.remove("edge");

Implementations

impl RelationStore

pub fn new(provider: Arc<CudaKernelProvider>) -> Self

Create a new empty relation store

pub fn get(&self, name: &str) -> Option<&CudaBuffer>

Get a reference to a relation by name

Arguments

• name - The name of the relation

Returns

Some(&CudaBuffer) if the relation exists, None otherwise

pub fn get_mut(&mut self, name: &str) -> Option<&mut CudaBuffer>

Get a mutable reference to a relation by name

Arguments

• name - The name of the relation

Returns

Some(&mut CudaBuffer) if the relation exists, None otherwise

pub fn get_with_version(&self, name: &str) -> Option<(&CudaBuffer, u64)>

Get a relation by name along with its current version.

pub fn version(&self, name: &str) -> Option<u64>

Get the current version for a relation.

pub fn put(&mut self, name: &str, buffer: CudaBuffer)

Store a relation with the given name

If a relation with the same name already exists, it will be replaced.

Arguments

• name - The name of the relation
• buffer - The GPU buffer containing the relation data

pub fn get_or_insert_empty( &mut self, name: &str, schema: &Schema, ) -> Result<&CudaBuffer>

Get a relation by name, or insert an empty buffer with the given schema

This is useful for semi-naive evaluation where delta relations may not exist yet on the first iteration. If the relation doesn’t exist, an empty buffer with the given schema is inserted into the store.

Arguments

• name - The name of the relation
• schema - The schema to use if creating an empty buffer

Returns

A reference to the existing buffer, or the newly inserted empty buffer

pub fn get_or_insert_empty_mut( &mut self, name: &str, schema: &Schema, ) -> Result<&mut CudaBuffer>

Get a mutable reference to a relation, or insert an empty buffer with the given schema

This is useful for semi-naive evaluation where delta relations may not exist yet on the first iteration. If the relation doesn’t exist, an empty buffer with the given schema is inserted into the store.

Arguments

• name - The name of the relation
• schema - The schema to use if creating an empty buffer

Returns

A mutable reference to the existing buffer, or the newly inserted empty buffer

pub fn contains(&self, name: &str) -> bool

Check if a relation exists in the store

Arguments

• name - The name of the relation

Returns

true if the relation exists, false otherwise

pub fn remove(&mut self, name: &str) -> Option<CudaBuffer>

Remove a relation from the store

Arguments

• name - The name of the relation

Returns

Some(CudaBuffer) if the relation existed, None otherwise

pub fn clear(&mut self)

Clear all relations from the store

This removes all stored relations. The GPU memory will be freed when the CudaBuffer instances are dropped.

pub fn len(&self) -> usize

Get the number of relations in the store

pub fn is_empty(&self) -> bool

Check if the store is empty

pub fn names(&self) -> impl Iterator<Item = &str>

Get an iterator over relation names