GH-35344: [Go][Format] Implementation of the LIST_VIEW and LARGE_LIST_VIEW array formats

go/arrow/array/array.go

@@ -176,6 +176,8 @@ func init() {
 		arrow.LARGE_LIST:              func(data arrow.ArrayData) arrow.Array { return NewLargeListData(data) },
 		arrow.INTERVAL_MONTH_DAY_NANO: func(data arrow.ArrayData) arrow.Array { return NewMonthDayNanoIntervalData(data) },
 		arrow.RUN_END_ENCODED:         func(data arrow.ArrayData) arrow.Array { return NewRunEndEncodedData(data) },
+		arrow.LIST_VIEW:               func(data arrow.ArrayData) arrow.Array { return NewListViewData(data) },
+		arrow.LARGE_LIST_VIEW:         func(data arrow.ArrayData) arrow.Array { return NewLargeListViewData(data) },
 
 		// invalid data types to fill out array to size 2^6 - 1
 		63: invalidDataType,

go/arrow/array/builder.go

@@ -342,6 +342,12 @@ func NewBuilder(mem memory.Allocator, dtype arrow.DataType) Builder {
 	case arrow.MAP:
 		typ := dtype.(*arrow.MapType)
 		return NewMapBuilderWithType(mem, typ)
+	case arrow.LIST_VIEW:
+		typ := dtype.(*arrow.ListViewType)
+		return NewListViewBuilderWithField(mem, typ.ElemField())
+	case arrow.LARGE_LIST_VIEW:
+		typ := dtype.(*arrow.LargeListViewType)
+		return NewLargeListViewBuilderWithField(mem, typ.ElemField())
 	case arrow.EXTENSION:
 		typ := dtype.(arrow.ExtensionType)
 		bldr := NewExtensionBuilder(mem, typ)

go/arrow/array/compare.go

@@ -292,6 +292,12 @@ func Equal(left, right arrow.Array) bool {
 	case *LargeList:
 		r := right.(*LargeList)
 		return arrayEqualLargeList(l, r)
+	case *ListView:
+		r := right.(*ListView)
+		return arrayEqualListView(l, r)
+	case *LargeListView:
+		r := right.(*LargeListView)
+		return arrayEqualLargeListView(l, r)
 	case *FixedSizeList:
 		r := right.(*FixedSizeList)
 		return arrayEqualFixedSizeList(l, r)
@@ -536,6 +542,12 @@ func arrayApproxEqual(left, right arrow.Array, opt equalOption) bool {
 	case *LargeList:
 		r := right.(*LargeList)
 		return arrayApproxEqualLargeList(l, r, opt)
+	case *ListView:
+		r := right.(*ListView)
+		return arrayApproxEqualListView(l, r, opt)
+	case *LargeListView:
+		r := right.(*LargeListView)
+		return arrayApproxEqualLargeListView(l, r, opt)
 	case *FixedSizeList:
 		r := right.(*FixedSizeList)
 		return arrayApproxEqualFixedSizeList(l, r, opt)
@@ -682,6 +694,44 @@ func arrayApproxEqualLargeList(left, right *LargeList, opt equalOption) bool {
 	return true
 }
 
+func arrayApproxEqualListView(left, right *ListView, opt equalOption) bool {
+	for i := 0; i < left.Len(); i++ {
+		if left.IsNull(i) {
+			continue
+		}
+		o := func() bool {
+			l := left.newListValue(i)
+			defer l.Release()
+			r := right.newListValue(i)
+			defer r.Release()
+			return arrayApproxEqual(l, r, opt)
+		}()
+		if !o {
+			return false
+		}
+	}
+	return true
+}
+
+func arrayApproxEqualLargeListView(left, right *LargeListView, opt equalOption) bool {
+	for i := 0; i < left.Len(); i++ {
+		if left.IsNull(i) {
+			continue
+		}
+		o := func() bool {
+			l := left.newListValue(i)
+			defer l.Release()
+			r := right.newListValue(i)
+			defer r.Release()
+			return arrayApproxEqual(l, r, opt)
+		}()
+		if !o {
+			return false
+		}
+	}
+	return true
+}
+
 func arrayApproxEqualFixedSizeList(left, right *FixedSizeList, opt equalOption) bool {
 	for i := 0; i < left.Len(); i++ {
 		if left.IsNull(i) {

go/arrow/array/concat.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"math"
 	"math/bits"
+	"unsafe"
 
 	"github.com/apache/arrow/go/v14/arrow"
 	"github.com/apache/arrow/go/v14/arrow/bitutil"
@@ -355,6 +356,164 @@ func concatOffsets(buffers []*memory.Buffer, byteWidth int, mem memory.Allocator
 	}
 }
 
+func sumArraySizes(data []arrow.ArrayData) int {
+	outSize := 0
+	for _, arr := range data {
+		outSize += arr.Len()
+	}
+	return outSize
+}
+
+func getListViewBufferValues[T int32 | int64](data arrow.ArrayData, i int) []T {
+	bytes := data.Buffers()[i].Bytes()
+	base := (*T)(unsafe.Pointer(&bytes[0]))
+	ret := unsafe.Slice(base, data.Offset()+data.Len())
+	return ret[data.Offset():]
+}
+
+func putListViewOffsets32(in arrow.ArrayData, displacement int32, out *memory.Buffer, outOff int) {
+	debug.Assert(in.DataType().ID() == arrow.LIST_VIEW, "putListViewOffsets32: expected LIST_VIEW data")
+	inOff, inLen := in.Offset(), in.Len()
+	if inLen == 0 {
+		return
+	}
+	bitmap := in.Buffers()[0]
+	srcOffsets := getListViewBufferValues[int32](in, 1)
+	srcSizes := getListViewBufferValues[int32](in, 2)
+	isValidAndNonEmpty := func(i int) bool {
+		return (bitmap == nil || bitutil.BitIsSet(bitmap.Bytes(), inOff+i)) && srcSizes[i] > 0
+	}
+
+	dstOffsets := arrow.Int32Traits.CastFromBytes(out.Bytes())
+	for i, offset := range srcOffsets {
+		if isValidAndNonEmpty(i) {
+			// This is guaranteed by RangeOfValuesUsed returning the smallest offset
+			// of valid and non-empty list-views.
+			debug.Assert(offset+displacement >= 0, "putListViewOffsets32: offset underflow while concatenating arrays")
+			dstOffsets[outOff+i] = offset + displacement
+		} else {
+			dstOffsets[outOff+i] = 0
+		}
+	}
+}
+
+func putListViewOffsets64(in arrow.ArrayData, displacement int64, out *memory.Buffer, outOff int) {
+	debug.Assert(in.DataType().ID() == arrow.LARGE_LIST_VIEW, "putListViewOffsets64: expected LARGE_LIST_VIEW data")
+	inOff, inLen := in.Offset(), in.Len()
+	if inLen == 0 {
+		return
+	}
+	bitmap := in.Buffers()[0]
+	srcOffsets := getListViewBufferValues[int64](in, 1)
+	srcSizes := getListViewBufferValues[int64](in, 2)
+	isValidAndNonEmpty := func(i int) bool {
+		return (bitmap == nil || bitutil.BitIsSet(bitmap.Bytes(), inOff+i)) && srcSizes[i] > 0
+	}
+
+	dstOffsets := arrow.Int64Traits.CastFromBytes(out.Bytes())
+	for i, offset := range srcOffsets {
+		if isValidAndNonEmpty(i) {
+			// This is guaranteed by RangeOfValuesUsed returning the smallest offset
+			// of valid and non-empty list-views.
+			debug.Assert(offset+displacement >= 0, "putListViewOffsets64: offset underflow while concatenating arrays")
+			dstOffsets[outOff+i] = offset + displacement
+		} else {
+			dstOffsets[outOff+i] = 0
+		}
+	}
+}
+
+// Concatenate buffers holding list-view offsets into a single buffer of offsets
+//
+// valueRanges contains the relevant ranges of values in the child array actually
+// referenced to by the views. Most commonly, these ranges will start from 0,
+// but when that is not the case, we need to adjust the displacement of offsets.
+// The concatenated child array does not contain values from the beginning
+// if they are not referenced to by any view.
+func concatListViewOffsets(data []arrow.ArrayData, byteWidth int, valueRanges []rng, mem memory.Allocator) (*memory.Buffer, error) {
+	outSize := sumArraySizes(data)
+	if byteWidth == 4 && outSize > math.MaxInt32 {
+		return nil, fmt.Errorf("%w: offset overflow while concatenating arrays", arrow.ErrInvalid)
+	}
+	out := memory.NewResizableBuffer(mem)
+	out.Resize(byteWidth * outSize)
+
+	numChildValues, elementsLength := 0, 0
+	for i, arr := range data {
+		displacement := numChildValues - valueRanges[i].offset
+		if byteWidth == 4 {
+			putListViewOffsets32(arr, int32(displacement), out, elementsLength)
+		} else {
+			putListViewOffsets64(arr, int64(displacement), out, elementsLength)
+		}
+		elementsLength += arr.Len()
+		numChildValues += valueRanges[i].len
+	}
+	debug.Assert(elementsLength == outSize, "implementation error")
+
+	return out, nil
+}
+
+func zeroNullListViewSizes[T int32 | int64](data arrow.ArrayData) {
+	if data.Len() == 0 || data.Buffers()[0] == nil {
+		return
+	}
+	validity := data.Buffers()[0].Bytes()
+	sizes := getListViewBufferValues[T](data, 2)
+
+	for i := 0; i < data.Len(); i++ {
+		if !bitutil.BitIsSet(validity, data.Offset()+i) {
+			sizes[i] = 0
+		}
+	}
+}
+
+func concatListView(data []arrow.ArrayData, offsetType arrow.FixedWidthDataType, out *Data, mem memory.Allocator) (err error) {
+	// Calculate the ranges of values that each list-view array uses
+	valueRanges := make([]rng, len(data))
+	for i, input := range data {
+		offset, len := rangeOfValuesUsed(input)
+		valueRanges[i].offset = offset
+		valueRanges[i].len = len
+	}
+
+	// Gather the children ranges of each input array
+	childData := gatherChildrenRanges(data, 0, valueRanges)
+	for _, c := range childData {
+		defer c.Release()
+	}
+
+	// Concatenate the values
+	values, err := concat(childData, mem)
+	if err != nil {
+		return err
+	}
+
+	// Concatenate the offsets
+	offsetBuffer, err := concatListViewOffsets(data, offsetType.Bytes(), valueRanges, mem)
+	if err != nil {
+		return err
+	}
+
+	// Concatenate the sizes
+	sizeBuffers := gatherBuffersFixedWidthType(data, 2, offsetType)
+	sizeBuffer := concatBuffers(sizeBuffers, mem)
+
+	out.childData = []arrow.ArrayData{values}
+	out.buffers[1] = offsetBuffer
+	out.buffers[2] = sizeBuffer
+
+	// To make sure the sizes don't reference values that are not in the new
+	// concatenated values array, we zero the sizes of null list-view values.
+	if offsetType.ID() == arrow.INT32 {
+		zeroNullListViewSizes[int32](out)
+	} else {
+		zeroNullListViewSizes[int64](out)
+	}
+
+	return nil
+}
+
 // concat is the implementation for actually performing the concatenation of the arrow.ArrayData
 // objects that we can call internally for nested types.
 func concat(data []arrow.ArrayData, mem memory.Allocator) (arr arrow.ArrayData, err error) {
@@ -483,6 +642,18 @@ func concat(data []arrow.ArrayData, mem memory.Allocator) (arr arrow.ArrayData,
 		if err != nil {
 			return nil, err
 		}
+	case *arrow.ListViewType:
+		offsetType := arrow.PrimitiveTypes.Int32.(arrow.FixedWidthDataType)
+		err := concatListView(data, offsetType, out, mem)
+		if err != nil {
+			return nil, err
+		}
+	case *arrow.LargeListViewType:
+		offsetType := arrow.PrimitiveTypes.Int64.(arrow.FixedWidthDataType)
+		err := concatListView(data, offsetType, out, mem)
+		if err != nil {
+			return nil, err
+		}
 	case *arrow.FixedSizeListType:
 		childData := gatherChildrenMultiplier(data, 0, int(dt.Len()))
 		for _, c := range childData {

go/arrow/array/concat_test.go

@@ -78,6 +78,8 @@ func TestConcatenate(t *testing.T) {
 		{arrow.BinaryTypes.LargeString},
 		{arrow.ListOf(arrow.PrimitiveTypes.Int8)},
 		{arrow.LargeListOf(arrow.PrimitiveTypes.Int8)},
+		{arrow.ListViewOf(arrow.PrimitiveTypes.Int8)},
+		{arrow.LargeListViewOf(arrow.PrimitiveTypes.Int8)},
 		{arrow.FixedSizeListOf(3, arrow.PrimitiveTypes.Int8)},
 		{arrow.StructOf()},
 		{arrow.MapOf(arrow.PrimitiveTypes.Uint16, arrow.PrimitiveTypes.Int8)},
@@ -200,6 +202,16 @@ func (cts *ConcatTestSuite) generateArr(size int64, nullprob float64) arrow.Arra
 			}
 		}
 		return bldr.NewArray()
+	case arrow.LIST_VIEW:
+		arr := cts.rng.ListView(cts.dt.(arrow.VarLenListLikeType), size, 0, 20, nullprob)
+		err := arr.ValidateFull()
+		cts.NoError(err)
+		return arr
+	case arrow.LARGE_LIST_VIEW:
+		arr := cts.rng.LargeListView(cts.dt.(arrow.VarLenListLikeType), size, 0, 20, nullprob)
+		err := arr.ValidateFull()
+		cts.NoError(err)
+		return arr
 	case arrow.FIXED_SIZE_LIST:
 		const listsize = 3
 		valuesSize := size * listsize
@@ -317,11 +329,20 @@ func (cts *ConcatTestSuite) TestCheckConcat() {
 
 					slices := cts.slices(arr, offsets)
 					for _, s := range slices {
+						if s.DataType().ID() == arrow.LIST_VIEW {
+							err := s.(*array.ListView).ValidateFull()
+							cts.NoError(err)
+						}
 						defer s.Release()
 					}
 
 					actual, err := array.Concatenate(slices, cts.mem)
 					cts.NoError(err)
+					if arr.DataType().ID() == arrow.LIST_VIEW {
+						lv := actual.(*array.ListView)
+						err := lv.ValidateFull()
+						cts.NoError(err)
+					}
 					defer actual.Release()
 
 					cts.Truef(array.Equal(expected, actual), "expected: %s\ngot: %s\n", expected, actual)