Initial commit

vendor/github.com/cockroachdb/pebble/vfs/prefetch_linux.go

@@ -0,0 +1,18 @@
+// Copyright 2020 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.
+
+//go:build linux
+// +build linux
+
+package vfs
+
+import "syscall"
+
+// Prefetch signals the OS (on supported platforms) to fetch the next size
+// bytes in file (as returned by os.File.Fd()) after offset into cache. Any
+// subsequent reads in that range will not issue disk IO.
+func Prefetch(file uintptr, offset uint64, size uint64) error {
+	_, _, err := syscall.Syscall(syscall.SYS_READAHEAD, uintptr(file), uintptr(offset), uintptr(size))
+	return err
+}