Trait GpuScalar 

pub trait GpuScalar:
    Sealed
    + KernelScalar
    + Copy
    + Send
    + 'static {
    const BYTE_WIDTH: usize;

    // Required methods
    fn from_le_bytes(bytes: &[u8]) -> Self;
    fn to_le_bytes_into(self, buf: &mut [u8]);
    fn filter_compare_kernel() -> &'static str;
    fn compare_col_kernel() -> &'static str;
    fn allowed_scalar_types() -> &'static [ScalarType];

    // Provided method
    fn filter_scan_phase1_kernel() -> Option<&'static str> { ... }
}

Marker trait: a Rust scalar type that can round-trip through GPU column storage.

Requires cudarc::driver::DeviceRepr + known byte width + little-endian serialization.

This trait is sealed — it cannot be implemented outside xlog-cuda. The fixed set of implementations covers all GPU-compatible scalar types.

Required Associated Constants

const BYTE_WIDTH: usize

Size in bytes of this scalar type.

Required Methods

fn from_le_bytes(bytes: &[u8]) -> Self

Deserialize from a little-endian byte slice. The slice length must equal BYTE_WIDTH.

fn to_le_bytes_into(self, buf: &mut [u8])

Serialize into a little-endian byte buffer. The buffer length must equal BYTE_WIDTH.

fn filter_compare_kernel() -> &'static str

Kernel function name for const-compare mask generation.

fn compare_col_kernel() -> &'static str

Kernel function name for column-column comparison mask.

fn allowed_scalar_types() -> &'static [ScalarType]

ScalarType variants accepted for this type in filter/compare operations.

Provided Methods

fn filter_scan_phase1_kernel() -> Option<&'static str>

Optional fused compare+scan kernel (phase 1). Only u32 and f64 have optimized fused-scan paths. Returns None for types using the mask+compact path.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl GpuScalar for bool

Bool encoding:

• Write (H2D): 0x00 = false, 0x01 = true (canonical).
• Read (D2H): 0x00 = false, nonzero = true (lenient, matches the D2H bool decoding path in provider/transfer.rs).

const BYTE_WIDTH: usize = 1

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

impl GpuScalar for f32

const BYTE_WIDTH: usize = 4

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

impl GpuScalar for f64

const BYTE_WIDTH: usize = 8

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

fn filter_scan_phase1_kernel() -> Option<&'static str>

impl GpuScalar for i32

const BYTE_WIDTH: usize = 4

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

impl GpuScalar for i64

const BYTE_WIDTH: usize = 8

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

impl GpuScalar for u8

const BYTE_WIDTH: usize = 1

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

impl GpuScalar for u32

const BYTE_WIDTH: usize = 4

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

fn filter_scan_phase1_kernel() -> Option<&'static str>

impl GpuScalar for u64

const BYTE_WIDTH: usize = 8

fn from_le_bytes(bytes: &[u8]) -> Self

fn to_le_bytes_into(self, buf: &mut [u8])

fn filter_compare_kernel() -> &'static str

fn compare_col_kernel() -> &'static str

fn allowed_scalar_types() -> &'static [ScalarType]

Implementors