1/*
2 * Copyright 2016-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#pragma once
18
19#include <folly/portability/Config.h>
20#include <folly/portability/IOVec.h>
21#include <folly/portability/SysTypes.h>
22
23#if !FOLLY_HAVE_PREADV
24extern "C" ssize_t preadv(int fd, const iovec* iov, int count, off_t offset);
25#endif
26#if !FOLLY_HAVE_PWRITEV
27extern "C" ssize_t pwritev(int fd, const iovec* iov, int count, off_t offset);
28#endif
29
30#ifdef _WIN32
31extern "C" ssize_t readv(int fd, const iovec* iov, int count);
32extern "C" ssize_t writev(int fd, const iovec* iov, int count);
33#endif
34
35namespace folly {
36#ifdef IOV_MAX // not defined on Android
37constexpr size_t kIovMax = IOV_MAX;
38#else
39constexpr size_t kIovMax = UIO_MAXIOV;
40#endif
41} // namespace folly
42