zeroshade commented on code in PR #39187: URL: https://github.com/apache/arrow/pull/39187#discussion_r1425907554
########## go/arrow/bitutil/bitutil_go121.go: ########## @@ -0,0 +1,218 @@ +// 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. + +//go:build go1.21 +// +build go1.21 + +package bitutil + +import ( + "math" + "math/bits" + "unsafe" + + "github.com/apache/arrow/go/v15/arrow/memory" +) + +var ( + BitMask = [8]byte{1, 2, 4, 8, 16, 32, 64, 128} + FlippedBitMask = [8]byte{254, 253, 251, 247, 239, 223, 191, 127} +) + +// IsMultipleOf8 returns whether v is a multiple of 8. +func IsMultipleOf8(v int64) bool { return v&7 == 0 } + +// IsMultipleOf64 returns whether v is a multiple of 64 +func IsMultipleOf64(v int64) bool { return v&63 == 0 } + +func BytesForBits(bits int64) int64 { return (bits + 7) >> 3 } + +// NextPowerOf2 rounds x to the next power of two. +func NextPowerOf2(x int) int { return 1 << uint(bits.Len(uint(x))) } + +// CeilByte rounds size to the next multiple of 8. +func CeilByte(size int) int { return (size + 7) &^ 7 } + +// CeilByte64 rounds size to the next multiple of 8. +func CeilByte64(size int64) int64 { return (size + 7) &^ 7 } Review Comment: Rather than duplicating all of these, can you leave `bitutil.go` with all of the common stuff and make new files that use the build constraints which *only* consists of the stuff which is different for each? I'd prefer to minimize and reduce the duplication here ########## go/arrow/type_traits_decimal128_go121.go: ########## @@ -0,0 +1,61 @@ +// 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. + +//go:build go1.21 +// +build go1.21 + +package arrow + +import ( + "unsafe" + + "github.com/apache/arrow/go/v15/arrow/decimal128" + "github.com/apache/arrow/go/v15/arrow/endian" +) + +// Decimal128 traits +var Decimal128Traits decimal128Traits + +const ( + // Decimal128SizeBytes specifies the number of bytes required to store a single decimal128 in memory + Decimal128SizeBytes = int(unsafe.Sizeof(decimal128.Num{})) +) + +type decimal128Traits struct{} + +// BytesRequired returns the number of bytes required to store n elements in memory. +func (decimal128Traits) BytesRequired(n int) int { return Decimal128SizeBytes * n } + +// PutValue +func (decimal128Traits) PutValue(b []byte, v decimal128.Num) { + endian.Native.PutUint64(b[:8], uint64(v.LowBits())) + endian.Native.PutUint64(b[8:], uint64(v.HighBits())) +} + +// CastFromBytes reinterprets the slice b to a slice of type uint16. +// +// NOTE: len(b) must be a multiple of Uint16SizeBytes. +func (decimal128Traits) CastFromBytes(b []byte) []decimal128.Num { + return unsafe.Slice((*decimal128.Num)(unsafe.Pointer(unsafe.SliceData(b))), cap(b)/Decimal128SizeBytes)[:len(b)/Decimal128SizeBytes] +} + +// CastToBytes reinterprets the slice b to a slice of bytes. +func (decimal128Traits) CastToBytes(b []decimal128.Num) []byte { + return unsafe.Slice((*byte)(unsafe.Pointer(unsafe.SliceData(b))), cap(b)*Decimal128SizeBytes)[:len(b)*Decimal128SizeBytes] +} Review Comment: same goes for these, let's not duplicate the common bits -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
