arrow/compute/fieldref_hash.go

// 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 go1.20 || tinygo

package compute

import (
	"hash/maphash"
	"math/bits"
	"unsafe"

	"github.com/apache/arrow-go/v18/arrow"
)

func (f FieldPath) hash(h *maphash.Hash) {
	raw := unsafe.Pointer(unsafe.SliceData(f))
	var byteLen int
	if bits.UintSize == 32 {
		byteLen = arrow.Int32Traits.BytesRequired(len(f))
	} else {
		byteLen = arrow.Int64Traits.BytesRequired(len(f))
	}

	h.Write(unsafe.Slice((*byte)(raw), byteLen))
}