internal: create package for unsafe bytes convertion (#8733)

Co-authored-by: Alessio Treglia <alessio@tendermint.com>

types/address/hash.go

@@ -4,10 +4,9 @@ import (
 	"bytes"
 	"crypto/sha256"
 	"fmt"
-	"reflect"
 	"sort"
-	"unsafe"
 
+	"github.com/cosmos/cosmos-sdk/internal/conv"
 	"github.com/cosmos/cosmos-sdk/types/errors"
 )
 
@@ -21,7 +20,7 @@ type Addressable interface {
 // Hash creates a new address from address type and key
 func Hash(typ string, key []byte) []byte {
 	hasher := sha256.New()
-	hasher.Write(unsafeStrToByteArray(typ))
+	hasher.Write(conv.UnsafeStrToBytes(typ))
 	th := hasher.Sum(nil)
 
 	hasher.Reset()
@@ -63,11 +62,3 @@ func Module(moduleName string, key []byte) []byte {
 	mKey := append([]byte(moduleName), 0)
 	return Hash("module", append(mKey, key...))
 }
-
-// unsafeStrToByteArray uses unsafe to convert string into byte array. Returned bytes
-// must not be altered after this function is called as it will cause a segmentation fault.
-func unsafeStrToByteArray(s string) []byte {
-	var buf = *(*[]byte)(unsafe.Pointer(&s))
-	(*reflect.SliceHeader)(unsafe.Pointer(&buf)).Cap = len(s)
-	return buf
-}

types/address/hash_test.go

@@ -2,9 +2,7 @@ package address
 
 import (
 	"crypto/sha256"
-	"runtime"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/suite"
@@ -77,23 +75,6 @@ func (suite *AddressSuite) TestModule() {
 	assert.NotEqual(addr2, addr3, "changing key must change address")
 }
 
-func unsafeConvertABC() []byte {
-	return unsafeStrToByteArray("abc")
-}
-
-func (suite *AddressSuite) TestUnsafeStrToBytes() {
-	// we convert in other function to trigger GC. We want to check that
-	// the underlying array in []bytes is accessible after GC will finish swapping.
-	for i := 0; i < 5; i++ {
-		b := unsafeConvertABC()
-		runtime.GC()
-		<-time.NewTimer(2 * time.Millisecond).C
-		b2 := append(b, 'd')
-		suite.Equal("abc", string(b))
-		suite.Equal("abcd", string(b2))
-	}
-}
-
 type addrMock struct {
 	Addr []byte
 }