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/*
* Copyright 2018 The Native Object Protocols Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef LIBNOP_INCLUDE_NOP_UTILITY_FD_READER_H_
#define LIBNOP_INCLUDE_NOP_UTILITY_FD_READER_H_
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <utility>
#include <nop/status.h>
namespace nop {
// FdReader is a reader type that wraps around a UNIX file descriptor. The
// reader takes ownerhip of the fd and automatically closes it when destroyed,
// unless it is released.
class FdReader {
public:
FdReader() = default;
FdReader(int fd) : fd_{fd} {}
FdReader(const FdReader&) = delete;
FdReader(FdReader&& other) { *this = std::move(other); }
~FdReader() { Clear(); }
FdReader& operator=(const FdReader&) = delete;
FdReader& operator=(FdReader&& other) {
if (this != &other) {
Clear();
std::swap(fd_, other.fd_);
}
return *this;
}
void Clear() {
::close(fd_);
fd_ = -1;
}
int Release() {
const int released_fd = fd_;
fd_ = -1;
return released_fd;
}
Status<void> Ensure(std::size_t) { return {}; }
Status<void> Read(std::uint8_t* byte) {
while (true) {
const int ret = ::read(fd_, byte, sizeof(*byte));
if (ret == 1)
return {};
else if (ret == 0)
return ErrorStatus::ReadLimitReached;
else if (errno != EINTR)
return ErrorStatus::IOError;
else
continue; // Interrupted by signal.
}
}
Status<void> Read(void* begin, void* end) {
std::uint8_t* begin_byte = static_cast<std::uint8_t*>(begin);
std::uint8_t* end_byte = static_cast<std::uint8_t*>(end);
for (std::uint8_t* byte = begin_byte; byte < end_byte; byte++) {
auto status = Read(byte);
if (!status)
return status;
}
return {};
}
private:
int fd_{-1};
};
} // namespace nop
#endif // LIBNOP_INCLUDE_NOP_UTILITY_FD_READER_H_
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