Initial commit

vendor/github.com/cockroachdb/pebble/sstable/unsafe.go

@@ -0,0 +1,35 @@
+// Copyright 2018 The LevelDB-Go and Pebble Authors. All rights reserved. Use
+// of this source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package sstable
+
+import (
+	"unsafe"
+
+	"github.com/cockroachdb/pebble/internal/manual"
+)
+
+func getBytes(ptr unsafe.Pointer, length int) []byte {
+	return (*[manual.MaxArrayLen]byte)(ptr)[:length:length]
+}
+
+func decodeVarint(ptr unsafe.Pointer) (uint32, unsafe.Pointer) {
+	if a := *((*uint8)(ptr)); a < 128 {
+		return uint32(a),
+			unsafe.Pointer(uintptr(ptr) + 1)
+	} else if a, b := a&0x7f, *((*uint8)(unsafe.Pointer(uintptr(ptr) + 1))); b < 128 {
+		return uint32(b)<<7 | uint32(a),
+			unsafe.Pointer(uintptr(ptr) + 2)
+	} else if b, c := b&0x7f, *((*uint8)(unsafe.Pointer(uintptr(ptr) + 2))); c < 128 {
+		return uint32(c)<<14 | uint32(b)<<7 | uint32(a),
+			unsafe.Pointer(uintptr(ptr) + 3)
+	} else if c, d := c&0x7f, *((*uint8)(unsafe.Pointer(uintptr(ptr) + 3))); d < 128 {
+		return uint32(d)<<21 | uint32(c)<<14 | uint32(b)<<7 | uint32(a),
+			unsafe.Pointer(uintptr(ptr) + 4)
+	} else {
+		d, e := d&0x7f, *((*uint8)(unsafe.Pointer(uintptr(ptr) + 4)))
+		return uint32(e)<<28 | uint32(d)<<21 | uint32(c)<<14 | uint32(b)<<7 | uint32(a),
+			unsafe.Pointer(uintptr(ptr) + 5)
+	}
+}