| // 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 arrow |
| |
| import ( |
| "encoding/binary" |
| "reflect" |
| "unsafe" |
| |
| "github.com/apache/arrow/go/arrow/float16" |
| ) |
| |
| // Float16 traits |
| var Float16Traits float16Traits |
| |
| const ( |
| // Float16SizeBytes specifies the number of bytes required to store a single float16 in memory |
| Float16SizeBytes = int(unsafe.Sizeof(uint16(0))) |
| ) |
| |
| type float16Traits struct{} |
| |
| // BytesRequired returns the number of bytes required to store n elements in memory. |
| func (float16Traits) BytesRequired(n int) int { return Float16SizeBytes * n } |
| |
| // PutValue |
| func (float16Traits) PutValue(b []byte, v float16.Num) { |
| binary.LittleEndian.PutUint16(b, uint16(v.Uint16())) |
| } |
| |
| // CastFromBytes reinterprets the slice b to a slice of type uint16. |
| // |
| // NOTE: len(b) must be a multiple of Uint16SizeBytes. |
| func (float16Traits) CastFromBytes(b []byte) []float16.Num { |
| h := (*reflect.SliceHeader)(unsafe.Pointer(&b)) |
| |
| var res []float16.Num |
| s := (*reflect.SliceHeader)(unsafe.Pointer(&res)) |
| s.Data = h.Data |
| s.Len = h.Len / Float16SizeBytes |
| s.Cap = h.Cap / Float16SizeBytes |
| |
| return res |
| } |
| |
| // CastToBytes reinterprets the slice b to a slice of bytes. |
| func (float16Traits) CastToBytes(b []float16.Num) []byte { |
| h := (*reflect.SliceHeader)(unsafe.Pointer(&b)) |
| |
| var res []byte |
| s := (*reflect.SliceHeader)(unsafe.Pointer(&res)) |
| s.Data = h.Data |
| s.Len = h.Len * Float16SizeBytes |
| s.Cap = h.Cap * Float16SizeBytes |
| |
| return res |
| } |
| |
| // Copy copies src to dst. |
| func (float16Traits) Copy(dst, src []float16.Num) { copy(dst, src) } |