Files
loki/pkg/columnar/datum_number.go
2026-02-09 11:43:39 -05:00

257 lines
6.8 KiB
Go

package columnar
import (
"fmt"
"reflect"
"unsafe"
"github.com/grafana/loki/v3/pkg/memory"
)
// Numeric is a constraint for recognized numeric types.
type Numeric interface{ int64 | uint64 }
// NumberScalar is a [Scalar] representing a [Numeric] value.
type NumberScalar[T Numeric] struct {
Value T // Value of the scalar.
Null bool // True if the scalar is null.
kind Kind // Cached kind.
}
var _ Scalar = (*NumberScalar[int64])(nil)
// Kind implements [Datum] and returns the kind matching T.
func (s *NumberScalar[T]) Kind() Kind {
if s.kind == KindNull {
s.init()
}
return s.kind
}
//go:noinline
func (s *NumberScalar[T]) init() {
var zero T
switch reflect.TypeOf(zero).Kind() {
case reflect.Int64:
s.kind = KindInt64
case reflect.Uint64:
s.kind = KindUint64
default:
panic(fmt.Sprintf("unsupported type %T", zero))
}
}
// IsNull implements [Scalar] and returns s.Null.
func (s *NumberScalar[T]) IsNull() bool { return s.Null }
func (s *NumberScalar[T]) isDatum() {}
func (s *NumberScalar[T]) isScalar() {}
// Number is an [Array] of 64-bit unsigned [Numeric] values.
type Number[T Numeric] struct {
validity memory.Bitmap // Empty when there's no nulls.
values []T
nullCount int
kind Kind // Determined in [Number.init] based on T.
}
var _ Array = (*Number[int64])(nil)
// NewNumber creates a new Number array from the given values and optional
// validity bitmap.
//
// Number arrays made from memory owned by a [memory.Allocator] are invalidated
// when the allocator reclaims memory.
//
// If validity is of length zero, all elements are considered valid. Otherwise,
// NewNumber panics if the number of elements does not match the length of
// validity.
func NewNumber[T Numeric](values []T, validity memory.Bitmap) *Number[T] {
arr := &Number[T]{
validity: validity,
values: values,
}
arr.init()
return arr
}
//go:noinline
func (arr *Number[T]) init() {
if arr.validity.Len() > 0 && arr.validity.Len() != len(arr.values) {
panic("length mismatch between values and validity")
}
arr.nullCount = arr.validity.ClearCount()
var zero T
switch reflect.TypeOf(zero).Kind() {
case reflect.Int64:
arr.kind = KindInt64
case reflect.Uint64:
arr.kind = KindUint64
default:
panic(fmt.Sprintf("unsupported type %T", zero))
}
}
// Len returns the total number of elements in the array.
func (arr *Number[T]) Len() int { return len(arr.values) }
// Nulls returns the number of null elements in the array. The number of
// non-null elements can be calculated from Len() - Nulls().
func (arr *Number[T]) Nulls() int { return arr.nullCount }
// Get returns the value at index i. If the element at index i is null, Get
// returns an undefined value.
//
// Get panics if i is out of range.
func (arr *Number[T]) Get(i int) T {
return arr.values[i]
}
// IsNull returns true if the element at index i is null.
func (arr *Number[T]) IsNull(i int) bool {
if arr.nullCount == 0 {
return false
}
return !arr.validity.Get(i)
}
// Values returns the underlying array of values.
func (arr *Number[T]) Values() []T { return arr.values }
// Validity returns the validity bitmap of the array. The returned bitmap
// may be of length 0 if there are no nulls.
//
// A value of 1 in the Validity bitmap indicates that the corresponding
// element at that position is valid (not null).
func (arr *Number[T]) Validity() memory.Bitmap { return arr.validity }
// Size returns the size in bytes of the array's buffers.
func (arr *Number[T]) Size() int {
var zero T
var (
validitySize = arr.validity.Len() / 8
valuesSize = len(arr.values) * int(unsafe.Sizeof(zero))
)
return validitySize + valuesSize
}
// Kind returns the kind of Array being represented.
func (arr *Number[T]) Kind() Kind { return arr.kind }
// Slice returns a slice of arr from i to j.
func (arr *Number[T]) Slice(i, j int) Array {
if i < 0 || j < i || j > arr.Len() {
panic(errorSliceBounds{i, j, arr.Len()})
}
var (
validity = sliceValidity(arr.validity, i, j)
values = arr.values[i:j:j]
)
return NewNumber[T](values, validity)
}
func (arr *Number[T]) isDatum() {}
func (arr *Number[T]) isArray() {}
// A NumberBuilder assists with constructing a [Number] array. A NumberBuilder
// must be constructed by calling [NewNumberBuilder].
type NumberBuilder[T Numeric] struct {
alloc *memory.Allocator
validity memory.Bitmap
values memory.Buffer[T]
}
var _ Builder = (*NumberBuilder[int64])(nil)
// NewNumberBuilder creates a new NumberBuilder for constructing a [Number]
// array.
func NewNumberBuilder[T Numeric](alloc *memory.Allocator) *NumberBuilder[T] {
return &NumberBuilder[T]{
alloc: alloc,
validity: memory.NewBitmap(alloc, 0),
values: memory.NewBuffer[T](alloc, 0),
}
}
// Grow increases b's capacity, if necessary, to guarantee space for another n
// elements. After Grow(n), at least n elements can be appended to b without
// another allocation. If n is negative or too large to allocate the memory,
// Grow panics.
func (b *NumberBuilder[T]) Grow(n int) {
if !b.needGrow(n) {
return
}
b.validity.Grow(n)
b.values.Grow(n)
}
func (b *NumberBuilder[T]) needGrow(n int) bool {
return b.values.Len()+n > b.values.Cap()
}
// AppendNull adds a new null element to b.
func (b *NumberBuilder[T]) AppendNull() {
if b.needGrow(1) {
b.Grow(1)
}
var zero T
b.validity.AppendUnsafe(false)
b.values.Push(zero)
}
// AppendNulls appends the given number of null elements to b.
func (b *NumberBuilder[T]) AppendNulls(count int) {
if b.needGrow(count) {
b.Grow(count)
}
var zero T
b.validity.AppendCount(false, count)
b.values.AppendCount(zero, count)
}
// AppendValue adds a new element to b.
func (b *NumberBuilder[T]) AppendValue(v T) {
if b.needGrow(1) {
b.Grow(1)
}
// We can use unsafe appends here because we guarantee in the check above
// that there's enough capacity. This saves 40% of CPU time.
b.validity.AppendUnsafe(true)
b.values.Push(v)
}
// AppendValue adds a new element to b.
func (b *NumberBuilder[T]) AppendValueCount(v T, count int) {
if b.needGrow(count) {
b.Grow(count)
}
// We can use unsafe appends here because we guarantee in the check above
// that there's enough capacity. This saves 40% of CPU time.
b.validity.AppendCountUnsafe(true, count)
b.values.AppendCount(v, count)
}
// BuildArray returns the constructed array. After calling Build, the builder
// is reset to an initial state.
func (b *NumberBuilder[T]) BuildArray() Array { return b.Build() }
// Build returns the constructed [Number] array. After calling Build, the builder
// is reset to an initial state.
func (b *NumberBuilder[T]) Build() *Number[T] {
// Move the original bitmaps to the constructed array, then reset the
// builder's bitmaps since they've been moved.
arr := NewNumber[T](b.values.Data(), b.validity)
b.validity = memory.NewBitmap(b.alloc, 0)
b.values = memory.NewBuffer[T](b.alloc, 0)
return arr
}