emkornfield commented on a change in pull request #12158: URL: https://github.com/apache/arrow/pull/12158#discussion_r800129147
########## File path: go/arrow/array/dictionary.go ########## @@ -0,0 +1,1305 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package array + +import ( + "errors" + "fmt" + "math" + "sync/atomic" + "unsafe" + + "github.com/apache/arrow/go/v7/arrow" + "github.com/apache/arrow/go/v7/arrow/bitutil" + "github.com/apache/arrow/go/v7/arrow/decimal128" + "github.com/apache/arrow/go/v7/arrow/float16" + "github.com/apache/arrow/go/v7/arrow/internal/debug" + "github.com/apache/arrow/go/v7/arrow/memory" + "github.com/apache/arrow/go/v7/internal/hashing" + "github.com/goccy/go-json" +) + +// Dictionary represents the type for dictionary-encoded data with a data +// dependent dictionary. +// +// A dictionary array contains an array of non-negative integers (the "dictionary" +// indices") along with a data type containing a "dictionary" corresponding to +// the distinct values represented in the data. +// +// For example, the array: +// +// ["foo", "bar", "foo", "bar", "foo", "bar"] +// +// with dictionary ["bar", "foo"], would have the representation of: +// +// indices: [1, 0, 1, 0, 1, 0] +// dictionary: ["bar", "foo"] +// +// The indices in principle may be any integer type. +type Dictionary struct { + array + + indices Interface + dict Interface +} + +// NewDictionaryArray constructs a dictionary array with the provided indices +// and dictionary using the given type. +func NewDictionaryArray(typ arrow.DataType, indices, dict Interface) *Dictionary { + a := &Dictionary{} + a.array.refCount = 1 + dictdata := NewData(typ, indices.Len(), indices.Data().Buffers(), indices.Data().Children(), indices.NullN(), indices.Data().Offset()) + dictdata.dictionary = dict.Data().(*Data) + dict.Data().Retain() + + defer dictdata.Release() + a.setData(dictdata) + return a +} + +// checkIndexBounds returns an error if any value in the provided integer +// arraydata is >= the passed upperlimit or < 0. otherwise nil +func checkIndexBounds(indices *Data, upperlimit uint64) error { + if indices.length == 0 { + return nil + } + + var maxval uint64 + switch indices.dtype.ID() { + case arrow.UINT8: + maxval = math.MaxUint8 + case arrow.UINT16: + maxval = math.MaxUint16 + case arrow.UINT32: + maxval = math.MaxUint32 + case arrow.UINT64: + maxval = math.MaxUint64 + } + isSigned := maxval == 0 + if !isSigned && upperlimit > maxval { + return nil + } + + // TODO(mtopol): lift BitSetRunReader from parquet to utils + // and use it here for performance improvement. + var nullbitmap []byte + if indices.buffers[0] != nil { + nullbitmap = indices.buffers[0].Bytes() + } + + var outOfBounds func(i int) error + switch indices.dtype.ID() { + case arrow.INT8: + data := arrow.Int8Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] < 0 || data[i] >= int8(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.UINT8: + data := arrow.Uint8Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] >= uint8(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.INT16: + data := arrow.Int16Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] < 0 || data[i] >= int16(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.UINT16: + data := arrow.Uint16Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] >= uint16(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.INT32: + data := arrow.Int32Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] < 0 || data[i] >= int32(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.UINT32: + data := arrow.Uint32Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] >= uint32(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.INT64: + data := arrow.Int64Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] < 0 || data[i] >= int64(upperlimit) { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + case arrow.UINT64: + data := arrow.Uint64Traits.CastFromBytes(indices.buffers[1].Bytes()) + outOfBounds = func(i int) error { + if data[i] >= upperlimit { + return fmt.Errorf("index %d out of bounds", data[i]) + } + return nil + } + default: + return fmt.Errorf("invalid type for bounds checking: %T", indices.dtype) + } + + for i := 0; i < indices.length; i++ { + if len(nullbitmap) > 0 && bitutil.BitIsNotSet(nullbitmap, i+indices.offset) { + continue + } + + if err := outOfBounds(i + indices.offset); err != nil { + return err + } + } + return nil +} + +// NewValidatedDictionaryArray constructs a dictionary array from the provided indices +// and dictionary arrays, while also performing validation checks to ensure correctness +// such as bounds checking at are usually skipped for performance. +func NewValidatedDictionaryArray(typ *arrow.DictionaryType, indices, dict Interface) (*Dictionary, error) { + if indices.DataType().ID() != typ.IndexType.ID() { + return nil, fmt.Errorf("dictionary type index (%T) does not match indices array type (%T)", typ.IndexType, indices.DataType()) + } + + if !arrow.TypeEqual(typ.ValueType, dict.DataType()) { + return nil, fmt.Errorf("dictionary value type (%T) does not match dict array type (%T)", typ.ValueType, dict.DataType()) + } + + if err := checkIndexBounds(indices.Data().(*Data), uint64(dict.Len())); err != nil { + return nil, err + } + + return NewDictionaryArray(typ, indices, dict), nil +} + +// NewDictionaryData creates a strongly typed Dictionary array from +// an ArrayData object with a datatype of arrow.Dictionary and a dictionary +func NewDictionaryData(data arrow.ArrayData) *Dictionary { + a := &Dictionary{} + a.refCount = 1 + a.setData(data.(*Data)) + return a +} + +func (d *Dictionary) Retain() { + atomic.AddInt64(&d.refCount, 1) +} + +func (d *Dictionary) Release() { + debug.Assert(atomic.LoadInt64(&d.refCount) > 0, "too many releases") + + if atomic.AddInt64(&d.refCount, -1) == 0 { + d.data.Release() + d.data, d.nullBitmapBytes = nil, nil + d.indices.Release() + d.indices = nil + if d.dict != nil { + d.dict.Release() + d.dict = nil + } + } +} + +func (d *Dictionary) setData(data *Data) { + d.array.setData(data) + + if data.dictionary == nil { + panic("arrow/array: no dictionary set in Data for Dictionary array") + } + + dictType := data.dtype.(*arrow.DictionaryType) + debug.Assert(arrow.TypeEqual(dictType.ValueType, data.dictionary.DataType()), "mismatched dictionary value types") + + indexData := NewData(dictType.IndexType, data.length, data.buffers, data.childData, data.nulls, data.offset) + defer indexData.Release() + d.indices = MakeFromData(indexData) +} + +// Dictionary returns the values array that makes up the dictionary for this +// array. +func (d *Dictionary) Dictionary() Interface { + if d.dict == nil { + d.dict = MakeFromData(d.data.dictionary) + } + return d.dict +} + +// Indices returns the underlying array of indices as it's own array +func (d *Dictionary) Indices() Interface { + return d.indices +} + +// CanCompareIndices returns true if the dictionary arrays can be compared +// without having to unify the dictionaries themselves first. +func (d *Dictionary) CanCompareIndices(other *Dictionary) bool { + if !arrow.TypeEqual(d.indices.DataType(), other.indices.DataType()) { + return false + } + + minlen := int64(min(d.data.dictionary.length, other.data.dictionary.length)) + return ArraySliceEqual(d.Dictionary(), 0, minlen, other.Dictionary(), 0, minlen) +} + +func (d *Dictionary) String() string { + return fmt.Sprintf("{ dictionary: %v\n indices: %v }", d.Dictionary(), d.Indices()) +} + +// GetValueIndex returns the dictionary index for the value at index i of the array. +// The actual value can be retrieved by using d.Dictionary().(valuetype).Value(d.GetValueIndex(i)) +func (d *Dictionary) GetValueIndex(i int) int { + indiceData := d.data.buffers[1].Bytes() + // we know the value is non-negative per the spec, so + // we can use the unsigned value regardless. + switch d.indices.DataType().ID() { + case arrow.UINT8, arrow.INT8: + return int(uint8(indiceData[d.data.offset+i])) + case arrow.UINT16, arrow.INT16: + return int(arrow.Uint16Traits.CastFromBytes(indiceData)[d.data.offset+i]) + case arrow.UINT32, arrow.INT32: + return int(arrow.Uint32Traits.CastFromBytes(indiceData)[d.data.offset+i]) + case arrow.UINT64, arrow.INT64: + return int(arrow.Uint64Traits.CastFromBytes(indiceData)[d.data.offset+i]) + } + debug.Assert(false, "unreachable dictionary index") + return -1 +} + +func (d *Dictionary) getOneForMarshal(i int) interface{} { + if d.IsNull(i) { + return nil + } + vidx := d.GetValueIndex(i) + return d.Dictionary().(arraymarshal).getOneForMarshal(vidx) +} + +func (d *Dictionary) MarshalJSON() ([]byte, error) { + vals := make([]interface{}, d.Len()) + for i := 0; i < d.Len(); i++ { + vals[i] = d.getOneForMarshal(i) + } + return json.Marshal(vals) +} + +func arrayEqualDict(l, r *Dictionary) bool { + return ArrayEqual(l.Dictionary(), r.Dictionary()) && ArrayEqual(l.indices, r.indices) +} + +func arrayApproxEqualDict(l, r *Dictionary, opt equalOption) bool { + return arrayApproxEqual(l.Dictionary(), r.Dictionary(), opt) && arrayApproxEqual(l.indices, r.indices, opt) +} + +// helper for building the properly typed indices of the dictionary builder +type indexBuilder struct { + Builder + Append func(int) +} + +func createIndexBuilder(mem memory.Allocator, dt arrow.FixedWidthDataType) (ret indexBuilder, err error) { + ret = indexBuilder{Builder: NewBuilder(mem, dt)} + switch dt.ID() { + case arrow.INT8: + ret.Append = func(idx int) { + ret.Builder.(*Int8Builder).Append(int8(idx)) + } + case arrow.UINT8: + ret.Append = func(idx int) { + ret.Builder.(*Uint8Builder).Append(uint8(idx)) + } + case arrow.INT16: + ret.Append = func(idx int) { + ret.Builder.(*Int16Builder).Append(int16(idx)) + } + case arrow.UINT16: + ret.Append = func(idx int) { + ret.Builder.(*Uint16Builder).Append(uint16(idx)) + } + case arrow.INT32: + ret.Append = func(idx int) { + ret.Builder.(*Int32Builder).Append(int32(idx)) + } + case arrow.UINT32: + ret.Append = func(idx int) { + ret.Builder.(*Uint32Builder).Append(uint32(idx)) + } + case arrow.INT64: + ret.Append = func(idx int) { + ret.Builder.(*Int64Builder).Append(int64(idx)) + } + case arrow.UINT64: + ret.Append = func(idx int) { + ret.Builder.(*Uint64Builder).Append(uint64(idx)) + } + default: + debug.Assert(false, "dictionary index type must be integral") + err = fmt.Errorf("dictionary index type must be integral, not %s", dt) + } + + return +} + +// helper function to construct an appropriately typed memo table based on +// the value type for the dictionary +func createMemoTable(mem memory.Allocator, dt arrow.DataType) (ret hashing.MemoTable, err error) { + switch dt.ID() { + case arrow.INT8: + ret = hashing.NewInt8MemoTable(0) + case arrow.UINT8: + ret = hashing.NewUint8MemoTable(0) + case arrow.INT16: + ret = hashing.NewInt16MemoTable(0) + case arrow.UINT16: + ret = hashing.NewUint16MemoTable(0) + case arrow.INT32: + ret = hashing.NewInt32MemoTable(0) + case arrow.UINT32: + ret = hashing.NewUint32MemoTable(0) + case arrow.INT64: + ret = hashing.NewInt64MemoTable(0) + case arrow.UINT64: + ret = hashing.NewUint64MemoTable(0) + case arrow.DURATION, arrow.TIMESTAMP, arrow.DATE64, arrow.TIME64: + ret = hashing.NewInt64MemoTable(0) + case arrow.TIME32, arrow.DATE32, arrow.INTERVAL_MONTHS: + ret = hashing.NewInt32MemoTable(0) + case arrow.FLOAT16: + ret = hashing.NewUint16MemoTable(0) + case arrow.FLOAT32: + ret = hashing.NewFloat32MemoTable(0) + case arrow.FLOAT64: + ret = hashing.NewFloat64MemoTable(0) + case arrow.BINARY, arrow.FIXED_SIZE_BINARY, arrow.DECIMAL128, arrow.INTERVAL_DAY_TIME, arrow.INTERVAL_MONTH_DAY_NANO: + ret = hashing.NewBinaryMemoTable(0, 0, NewBinaryBuilder(mem, arrow.BinaryTypes.Binary)) + case arrow.STRING: + ret = hashing.NewBinaryMemoTable(0, 0, NewBinaryBuilder(mem, arrow.BinaryTypes.String)) + case arrow.NULL: + default: + debug.Assert(false, "unimplemented dictionary value type") + err = fmt.Errorf("unimplemented dictionary value type, %s", dt) + } + + return +} + +type DictionaryBuilder interface { + Builder + + NewDictionaryArray() *Dictionary + NewDelta() (indices, delta Interface, err error) + AppendArray(Interface) error + ResetFull() +} + +type dictionaryBuilder struct { + builder + + dt *arrow.DictionaryType + deltaOffset int + memoTable hashing.MemoTable + idxBuilder indexBuilder +} + +func NewDictionaryBuilderWithDict(mem memory.Allocator, dt *arrow.DictionaryType, init Interface) DictionaryBuilder { + if init != nil && !arrow.TypeEqual(dt.ValueType, init.DataType()) { + panic(fmt.Errorf("arrow/array: cannot initialize dictionary type %T with array of type %T", dt.ValueType, init.DataType())) + } + + idxbldr, err := createIndexBuilder(mem, dt.IndexType.(arrow.FixedWidthDataType)) + if err != nil { + panic(fmt.Errorf("arrow/array: unsupported builder for index type of %T", dt)) + } + + memo, err := createMemoTable(mem, dt.ValueType) + if err != nil { + panic(fmt.Errorf("arrow/array: unsupported builder for value type of %T", dt)) + } + + bldr := dictionaryBuilder{ + builder: builder{refCount: 1, mem: mem}, + idxBuilder: idxbldr, + memoTable: memo, + dt: dt, + } + + switch dt.ValueType.ID() { + case arrow.NULL: + ret := &NullDictionaryBuilder{bldr} + debug.Assert(init == nil, "arrow/array: doesn't make sense to init a null dictionary") + return ret + case arrow.UINT8: + ret := &Uint8DictionaryBuilder{bldr} + if init != nil { + if err = ret.InsertDictValues(init.(*Uint8)); err != nil { + panic(err) + } + } + return ret + case arrow.INT8: + ret := &Int8DictionaryBuilder{bldr} + if init != nil { + if err = ret.InsertDictValues(init.(*Int8)); err != nil { + panic(err) Review comment: why is panic the right thing here? -- This is an automated message from the Apache Git Service. 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