consensus/ethash: more fixes

consensus/ethash/algorithm.go

@@ -20,7 +20,6 @@ import (
 	"encoding/binary"
 	"hash"
 	"math/big"
-	"reflect"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -305,12 +304,7 @@ func generateDataset(dest []uint32, epoch uint64, epochLength uint64, cache []ui
 	swapped := !isLittleEndian()
 
 	// Convert our destination slice to a byte buffer
-	var dataset []byte
-	datasetHdr := (*reflect.SliceHeader)(unsafe.Pointer(&dataset))
-	destHdr := (*reflect.SliceHeader)(unsafe.Pointer(&dest))
-	datasetHdr.Data = destHdr.Data
-	datasetHdr.Len = destHdr.Len * 4
-	datasetHdr.Cap = destHdr.Cap * 4
+	dataset := unsafe.Slice((*byte)(unsafe.Pointer(&dest[0])), len(dest)*4)
 
 	// Generate the dataset on many goroutines since it takes a while
 	threads := runtime.NumCPU()

consensus/ethash/ethash.go

@@ -26,7 +26,6 @@ import (
 	"math/rand"
 	"os"
 	"path/filepath"
-	"reflect"
 	"runtime"
 	"strconv"
 	"sync"
@@ -144,11 +143,7 @@ func memoryMapFile(file *os.File, write bool) (mmap.MMap, []uint32, error) {
 		return nil, nil, err
 	}
 	// The file is now memory-mapped. Create a []uint32 view of the file.
-	var view []uint32
-	header := (*reflect.SliceHeader)(unsafe.Pointer(&view))
-	header.Data = (*reflect.SliceHeader)(unsafe.Pointer(&mem)).Data
-	header.Cap = len(mem) / 4
-	header.Len = header.Cap
+	view := unsafe.Slice((*uint32)(unsafe.Pointer(&mem[0])), len(mem)/4)
 	return mem, view, nil
 }