sparse

package
v0.0.0-...-cf24451 Latest Latest
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 Go to latest Published: Mar 27, 2023 License: Apache-2.0 Imports: 3 Imported by: 0

Documentation

Overview

Package sparse contains abstractions to help work on arrays of values in sparse memory locations.

Conversion between array types is supported when converting integers to a lower size (e.g. int32 to int16, or uint64 to uint8), or converting from signed integers to unsigned. Float types can also be converted to unsigned integers of the same size, in which case the conversion is similar to using the standard library's math.Float32bits and math.Float64bits functions.

All array types can be converted to a generic Array type that can be used to erase type information and bypass type conversion rules. This conversion is similar to using Go's unsafe package to bypass Go's type system and should usually be avoided and a sign that the application is attempting to break type safety boundaries.

The package provides Gather* functions which retrieve values from sparse arrays into contiguous memory buffers. On platforms that support it, these operations are implemented using SIMD gather instructions (e.g. VPGATHER on Intel CPUs).

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

func GatherBits 

func GatherBits(dst []byte, src Uint8Array) int

func GatherFloat32 

func GatherFloat32(dst []float32, src Float32Array) int

func GatherFloat64 

func GatherFloat64(dst []float64, src Float64Array) int

func GatherInt32 

func GatherInt32(dst []int32, src Int32Array) int

func GatherInt64 

func GatherInt64(dst []int64, src Int64Array) int

func GatherString 

func GatherString(dst []string, src StringArray) int
Example 
package main

import (
	"fmt"
	"strconv"
	"unsafe"

	"github.com/alxarno/parquet-go-athena-list-hack/sparse"
)

func main() {
	buf := make([][2]string, 10)
	dst := make([]string, 10)
	src := sparse.UnsafeStringArray(unsafe.Pointer(&buf[0][1]), len(buf), unsafe.Sizeof(buf[0]))

	for i := range buf {
		buf[i][0] = "-"
		buf[i][1] = strconv.Itoa(i)
	}

	n := sparse.GatherString(dst, src)

	for i, v := range dst[:n] {
		fmt.Printf("points[%d].Y = %v\n", i, v)
	}

}

Output:

points[0].Y = 0
points[1].Y = 1
points[2].Y = 2
points[3].Y = 3
points[4].Y = 4
points[5].Y = 5
points[6].Y = 6
points[7].Y = 7
points[8].Y = 8
points[9].Y = 9

func GatherUint128 

func GatherUint128(dst [][16]byte, src Uint128Array) int
Example 
package main

import (
	"encoding/binary"
	"fmt"
	"math"
	"unsafe"

	"github.com/alxarno/parquet-go-athena-list-hack/sparse"
)

func main() {
	type point2D struct{ X, Y [16]byte }

	buf := make([]point2D, 10)
	dst := make([][16]byte, 10)
	src := sparse.UnsafeUint128Array(unsafe.Pointer(&buf[0].Y), len(buf), unsafe.Sizeof(buf[0]))

	for i := range buf {
		x := uint64(math.MaxUint64)
		y := uint64(2 * i)
		binary.LittleEndian.PutUint64(buf[i].X[:], x)
		binary.LittleEndian.PutUint64(buf[i].Y[:], y)
	}

	n := sparse.GatherUint128(dst, src)

	for i, v := range dst[:n] {
		fmt.Printf("points[%d].Y = %v\n", i, binary.LittleEndian.Uint64(v[:]))
	}

}

Output:

points[0].Y = 0
points[1].Y = 2
points[2].Y = 4
points[3].Y = 6
points[4].Y = 8
points[5].Y = 10
points[6].Y = 12
points[7].Y = 14
points[8].Y = 16
points[9].Y = 18

func GatherUint32 

func GatherUint32(dst []uint32, src Uint32Array) int
Example 
package main

import (
	"fmt"
	"math"
	"unsafe"

	"github.com/alxarno/parquet-go-athena-list-hack/sparse"
)

func main() {
	type point2D struct{ X, Y uint32 }

	buf := make([]point2D, 10)
	dst := make([]uint32, 10)
	src := sparse.UnsafeUint32Array(unsafe.Pointer(&buf[0].Y), len(buf), unsafe.Sizeof(buf[0]))

	for i := range buf {
		buf[i].X = math.MaxUint32
		buf[i].Y = uint32(2 * i)
	}

	n := sparse.GatherUint32(dst, src)

	for i, v := range dst[:n] {
		fmt.Printf("points[%d].Y = %d\n", i, v)
	}

}

Output:

points[0].Y = 0
points[1].Y = 2
points[2].Y = 4
points[3].Y = 6
points[4].Y = 8
points[5].Y = 10
points[6].Y = 12
points[7].Y = 14
points[8].Y = 16
points[9].Y = 18

func GatherUint64 

func GatherUint64(dst []uint64, src Uint64Array) int
Example 
package main

import (
	"fmt"
	"math"
	"unsafe"

	"github.com/alxarno/parquet-go-athena-list-hack/sparse"
)

func main() {
	type point2D struct{ X, Y uint64 }

	buf := make([]point2D, 10)
	dst := make([]uint64, 10)
	src := sparse.UnsafeUint64Array(unsafe.Pointer(&buf[0].Y), len(buf), unsafe.Sizeof(buf[0]))

	for i := range buf {
		buf[i].X = math.MaxUint64
		buf[i].Y = uint64(2 * i)
	}

	n := sparse.GatherUint64(dst, src)

	for i, v := range dst[:n] {
		fmt.Printf("points[%d].Y = %v\n", i, v)
	}

}

Output:

points[0].Y = 0
points[1].Y = 2
points[2].Y = 4
points[3].Y = 6
points[4].Y = 8
points[5].Y = 10
points[6].Y = 12
points[7].Y = 14
points[8].Y = 16
points[9].Y = 18

Types

type Array 

type Array struct {
	// contains filtered or unexported fields
}

func UnsafeArray 

func UnsafeArray(base unsafe.Pointer, length int, offset uintptr) Array

func (Array) BoolArray 

func (a Array) BoolArray() BoolArray

func (Array) Float32Array 

func (a Array) Float32Array() Float32Array

func (Array) Float64Array 

func (a Array) Float64Array() Float64Array

func (Array) Index 

func (a Array) Index(i int) unsafe.Pointer

func (Array) Int16Array 

func (a Array) Int16Array() Int16Array

func (Array) Int32Array 

func (a Array) Int32Array() Int32Array

func (Array) Int64Array 

func (a Array) Int64Array() Int64Array

func (Array) Int8Array 

func (a Array) Int8Array() Int8Array

func (Array) Len 

func (a Array) Len() int

func (Array) Offset 

func (a Array) Offset(off uintptr) Array

func (Array) Slice 

func (a Array) Slice(i, j int) Array

func (Array) StringArray 

func (a Array) StringArray() StringArray

func (Array) TimeArray 

func (a Array) TimeArray() TimeArray

func (Array) Uint128Array 

func (a Array) Uint128Array() Uint128Array

func (Array) Uint16Array 

func (a Array) Uint16Array() Uint16Array

func (Array) Uint32Array 

func (a Array) Uint32Array() Uint32Array

func (Array) Uint64Array 

func (a Array) Uint64Array() Uint64Array

func (Array) Uint8Array 

func (a Array) Uint8Array() Uint8Array

type BoolArray 

type BoolArray struct {
	// contains filtered or unexported fields
}

func MakeBoolArray 

func MakeBoolArray(values []bool) BoolArray

func UnsafeBoolArray 

func UnsafeBoolArray(base unsafe.Pointer, length int, offset uintptr) BoolArray

func (BoolArray) Index 

func (a BoolArray) Index(i int) bool

func (BoolArray) Len 

func (a BoolArray) Len() int

func (BoolArray) Slice 

func (a BoolArray) Slice(i, j int) BoolArray

func (BoolArray) Uint8Array 

func (a BoolArray) Uint8Array() Uint8Array

func (BoolArray) UnsafeArray 

func (a BoolArray) UnsafeArray() Array

type Float32Array 

type Float32Array struct {
	// contains filtered or unexported fields
}

func MakeFloat32Array 

func MakeFloat32Array(values []float32) Float32Array

func UnsafeFloat32Array 

func UnsafeFloat32Array(base unsafe.Pointer, length int, offset uintptr) Float32Array

func (Float32Array) Array 

func (a Float32Array) Array() Array

func (Float32Array) Index 

func (a Float32Array) Index(i int) float32

func (Float32Array) Len 

func (a Float32Array) Len() int

func (Float32Array) Slice 

func (a Float32Array) Slice(i, j int) Float32Array

func (Float32Array) Uint32Array 

func (a Float32Array) Uint32Array() Uint32Array

func (Float32Array) UnsafeArray 

func (a Float32Array) UnsafeArray() Array

type Float64Array 

type Float64Array struct {
	// contains filtered or unexported fields
}

func MakeFloat64Array 

func MakeFloat64Array(values []float64) Float64Array

func UnsafeFloat64Array 

func UnsafeFloat64Array(base unsafe.Pointer, length int, offset uintptr) Float64Array

func (Float64Array) Index 

func (a Float64Array) Index(i int) float64

func (Float64Array) Len 

func (a Float64Array) Len() int

func (Float64Array) Slice 

func (a Float64Array) Slice(i, j int) Float64Array

func (Float64Array) Uint64Array 

func (a Float64Array) Uint64Array() Uint64Array

func (Float64Array) UnsafeArray 

func (a Float64Array) UnsafeArray() Array

type Int16Array 

type Int16Array struct {
	// contains filtered or unexported fields
}

func MakeInt16Array 

func MakeInt16Array(values []int16) Int16Array

func UnsafeInt16Array 

func UnsafeInt16Array(base unsafe.Pointer, length int, offset uintptr) Int16Array

func (Int16Array) Index 

func (a Int16Array) Index(i int) int16

func (Int16Array) Int8Array 

func (a Int16Array) Int8Array() Int8Array

func (Int16Array) Len 

func (a Int16Array) Len() int

func (Int16Array) Slice 

func (a Int16Array) Slice(i, j int) Int16Array

func (Int16Array) Uint16Array 

func (a Int16Array) Uint16Array() Uint16Array

func (Int16Array) Uint8Array 

func (a Int16Array) Uint8Array() Uint8Array

func (Int16Array) UnsafeArray 

func (a Int16Array) UnsafeArray() Array

type Int32Array 

type Int32Array struct {
	// contains filtered or unexported fields
}

func MakeInt32Array 

func MakeInt32Array(values []int32) Int32Array

func UnsafeInt32Array 

func UnsafeInt32Array(base unsafe.Pointer, length int, offset uintptr) Int32Array

func (Int32Array) Index 

func (a Int32Array) Index(i int) int32

func (Int32Array) Int16Array 

func (a Int32Array) Int16Array() Int16Array

func (Int32Array) Int8Array 

func (a Int32Array) Int8Array() Int8Array

func (Int32Array) Len 

func (a Int32Array) Len() int

func (Int32Array) Slice 

func (a Int32Array) Slice(i, j int) Int32Array

func (Int32Array) Uint16Array 

func (a Int32Array) Uint16Array() Uint16Array

func (Int32Array) Uint32Array 

func (a Int32Array) Uint32Array() Uint32Array

func (Int32Array) Uint8Array 

func (a Int32Array) Uint8Array() Uint8Array

func (Int32Array) UnsafeArray 

func (a Int32Array) UnsafeArray() Array

type Int64Array 

type Int64Array struct {
	// contains filtered or unexported fields
}

func MakeInt64Array 

func MakeInt64Array(values []int64) Int64Array

func UnsafeInt64Array 

func UnsafeInt64Array(base unsafe.Pointer, length int, offset uintptr) Int64Array

func (Int64Array) Index 

func (a Int64Array) Index(i int) int64

func (Int64Array) Int16Array 

func (a Int64Array) Int16Array() Int16Array

func (Int64Array) Int32Array 

func (a Int64Array) Int32Array() Int32Array

func (Int64Array) Int8Array 

func (a Int64Array) Int8Array() Int8Array

func (Int64Array) Len 

func (a Int64Array) Len() int

func (Int64Array) Slice 

func (a Int64Array) Slice(i, j int) Int64Array

func (Int64Array) Uint16Array 

func (a Int64Array) Uint16Array() Uint16Array

func (Int64Array) Uint32Array 

func (a Int64Array) Uint32Array() Uint32Array

func (Int64Array) Uint64Array 

func (a Int64Array) Uint64Array() Uint64Array

func (Int64Array) Uint8Array 

func (a Int64Array) Uint8Array() Uint8Array

func (Int64Array) UnsafeArray 

func (a Int64Array) UnsafeArray() Array

type Int8Array 

type Int8Array struct {
	// contains filtered or unexported fields
}

func MakeInt8Array 

func MakeInt8Array(values []int8) Int8Array

func UnsafeInt8Array 

func UnsafeInt8Array(base unsafe.Pointer, length int, offset uintptr) Int8Array

func (Int8Array) Index 

func (a Int8Array) Index(i int) int8

func (Int8Array) Len 

func (a Int8Array) Len() int

func (Int8Array) Slice 

func (a Int8Array) Slice(i, j int) Int8Array

func (Int8Array) Uint8Array 

func (a Int8Array) Uint8Array() Uint8Array

func (Int8Array) UnsafeArray 

func (a Int8Array) UnsafeArray() Array

type StringArray 

type StringArray struct {
	// contains filtered or unexported fields
}

func MakeStringArray 

func MakeStringArray(values []string) StringArray

func UnsafeStringArray 

func UnsafeStringArray(base unsafe.Pointer, length int, offset uintptr) StringArray

func (StringArray) Index 

func (a StringArray) Index(i int) string

func (StringArray) Len 

func (a StringArray) Len() int

func (StringArray) Slice 

func (a StringArray) Slice(i, j int) StringArray

func (StringArray) UnsafeArray 

func (a StringArray) UnsafeArray() Array

type TimeArray 

type TimeArray struct {
	// contains filtered or unexported fields
}

func MakeTimeArray 

func MakeTimeArray(values []time.Time) TimeArray

func UnsafeTimeArray 

func UnsafeTimeArray(base unsafe.Pointer, length int, offset uintptr) TimeArray

func (TimeArray) Index 

func (a TimeArray) Index(i int) time.Time

func (TimeArray) Len 

func (a TimeArray) Len() int

func (TimeArray) Slice 

func (a TimeArray) Slice(i, j int) TimeArray

func (TimeArray) UnsafeArray 

func (a TimeArray) UnsafeArray() Array

type Uint128Array 

type Uint128Array struct {
	// contains filtered or unexported fields
}

func MakeUint128Array 

func MakeUint128Array(values [][16]byte) Uint128Array

func UnsafeUint128Array 

func UnsafeUint128Array(base unsafe.Pointer, length int, offset uintptr) Uint128Array

func (Uint128Array) Index 

func (a Uint128Array) Index(i int) [16]byte

func (Uint128Array) Len 

func (a Uint128Array) Len() int

func (Uint128Array) Slice 

func (a Uint128Array) Slice(i, j int) Uint128Array

func (Uint128Array) Uint16Array 

func (a Uint128Array) Uint16Array() Uint16Array

func (Uint128Array) Uint32Array 

func (a Uint128Array) Uint32Array() Uint32Array

func (Uint128Array) Uint64Array 

func (a Uint128Array) Uint64Array() Uint64Array

func (Uint128Array) Uint8Array 

func (a Uint128Array) Uint8Array() Uint8Array

func (Uint128Array) UnsafeArray 

func (a Uint128Array) UnsafeArray() Array

type Uint16Array 

type Uint16Array struct {
	// contains filtered or unexported fields
}

func MakeUint16Array 

func MakeUint16Array(values []uint16) Uint16Array

func UnsafeUint16Array 

func UnsafeUint16Array(base unsafe.Pointer, length int, offset uintptr) Uint16Array

func (Uint16Array) Index 

func (a Uint16Array) Index(i int) uint16

func (Uint16Array) Len 

func (a Uint16Array) Len() int

func (Uint16Array) Slice 

func (a Uint16Array) Slice(i, j int) Uint16Array

func (Uint16Array) Uint8Array 

func (a Uint16Array) Uint8Array() Uint8Array

func (Uint16Array) UnsafeArray 

func (a Uint16Array) UnsafeArray() Array

type Uint32Array 

type Uint32Array struct {
	// contains filtered or unexported fields
}

func MakeUint32Array 

func MakeUint32Array(values []uint32) Uint32Array

func UnsafeUint32Array 

func UnsafeUint32Array(base unsafe.Pointer, length int, offset uintptr) Uint32Array

func (Uint32Array) Index 

func (a Uint32Array) Index(i int) uint32

func (Uint32Array) Len 

func (a Uint32Array) Len() int

func (Uint32Array) Slice 

func (a Uint32Array) Slice(i, j int) Uint32Array

func (Uint32Array) Uint16Array 

func (a Uint32Array) Uint16Array() Uint16Array

func (Uint32Array) Uint8Array 

func (a Uint32Array) Uint8Array() Uint8Array

func (Uint32Array) UnsafeArray 

func (a Uint32Array) UnsafeArray() Array

type Uint64Array 

type Uint64Array struct {
	// contains filtered or unexported fields
}

func MakeUint64Array 

func MakeUint64Array(values []uint64) Uint64Array

func UnsafeUint64Array 

func UnsafeUint64Array(base unsafe.Pointer, length int, offset uintptr) Uint64Array

func (Uint64Array) Index 

func (a Uint64Array) Index(i int) uint64

func (Uint64Array) Len 

func (a Uint64Array) Len() int

func (Uint64Array) Slice 

func (a Uint64Array) Slice(i, j int) Uint64Array

func (Uint64Array) Uint16Array 

func (a Uint64Array) Uint16Array() Uint16Array

func (Uint64Array) Uint32Array 

func (a Uint64Array) Uint32Array() Uint32Array

func (Uint64Array) Uint8Array 

func (a Uint64Array) Uint8Array() Uint8Array

func (Uint64Array) UnsafeArray 

func (a Uint64Array) UnsafeArray() Array

type Uint8Array 

type Uint8Array struct {
	// contains filtered or unexported fields
}

func MakeUint8Array 

func MakeUint8Array(values []uint8) Uint8Array

func UnsafeUint8Array 

func UnsafeUint8Array(base unsafe.Pointer, length int, offset uintptr) Uint8Array

func (Uint8Array) Index 

func (a Uint8Array) Index(i int) uint8

func (Uint8Array) Len 

func (a Uint8Array) Len() int

func (Uint8Array) Slice 

func (a Uint8Array) Slice(i, j int) Uint8Array

func (Uint8Array) UnsafeArray 

func (a Uint8Array) UnsafeArray() Array

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