2 * Copyright 2017 Facebook, Inc.
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 #include <folly/portability/Config.h>
20 #include <folly/portability/IOVec.h>
21 #include <folly/portability/SysTypes.h>
23 #if !FOLLY_HAVE_PREADV
24 extern "C" ssize_t preadv(int fd, const iovec* iov, int count, off_t offset);
26 #if !FOLLY_HAVE_PWRITEV
27 extern "C" ssize_t pwritev(int fd, const iovec* iov, int count, off_t offset);
31 extern "C" ssize_t readv(int fd, const iovec* iov, int count);
32 extern "C" ssize_t writev(int fd, const iovec* iov, int count);
36 #ifdef IOV_MAX // not defined on Android
37 constexpr size_t kIovMax = IOV_MAX;
39 constexpr size_t kIovMax = UIO_MAXIOV;