github.com/vanus-labs/vanus/lib@v0.0.0-20231221070800-1334a7b9605e/bytes/unsafe_test.go (about)

     1  // Copyright 2023 Linkall Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package bytes
    16  
    17  import (
    18  	// standard libraries.
    19  	"reflect"
    20  	"testing"
    21  	"unsafe"
    22  
    23  	// third-party libraries.
    24  	. "github.com/smartystreets/goconvey/convey"
    25  )
    26  
    27  func TestUnsafe(t *testing.T) {
    28  	Convey("unsafe", t, func() {
    29  		Convey("from string", func() {
    30  			s := "hello"
    31  			b := UnsafeFromString(s)
    32  			strHdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
    33  			byteHdr := (*reflect.SliceHeader)(unsafe.Pointer(&b))
    34  			So(byteHdr.Data, ShouldEqual, strHdr.Data)
    35  			So(byteHdr.Len, ShouldEqual, strHdr.Len)
    36  			So(byteHdr.Cap, ShouldEqual, strHdr.Len)
    37  		})
    38  
    39  		Convey("to string", func() {
    40  			b := []byte("hello")
    41  			s := UnsafeToString(b)
    42  			byteHdr := (*reflect.SliceHeader)(unsafe.Pointer(&b))
    43  			strHdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
    44  			So(strHdr.Data, ShouldEqual, byteHdr.Data)
    45  			So(strHdr.Len, ShouldEqual, byteHdr.Len)
    46  		})
    47  
    48  		Convey("slice", func() {
    49  			s := "hello"
    50  			b := UnsafeSlice(s, 1, 4)
    51  			strHdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
    52  			byteHdr := (*reflect.SliceHeader)(unsafe.Pointer(&b))
    53  			So(unsafe.Pointer(byteHdr.Data), ShouldEqual,
    54  				unsafe.Add(unsafe.Pointer(strHdr.Data), 1))
    55  			So(byteHdr.Len, ShouldEqual, 3)
    56  			So(byteHdr.Cap, ShouldEqual, 3)
    57  		})
    58  
    59  		Convey("at", func() {
    60  			s := "hello"
    61  			for i := range s {
    62  				c := UnsafeAt(s, i)
    63  				So(c, ShouldEqual, s[i])
    64  			}
    65  		})
    66  	})
    67  }