//===-- OutputRedirector.cpp -----------------------------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===/

#if defined(_WIN32)

#include <fcntl.h>

#include <io.h>

#else

#include <unistd.h>

#endif

#include "OutputRedirector.h"

#include "llvm/ADT/StringRef.h"

using namespace llvm;

namespace lldb_vscode {

Error RedirectFd(int fd, std::function<void(llvm::StringRef)> callback) {

  int new_fd[2];

#if defined(_WIN32)

  if (_pipe(new_fd, 4096, O_TEXT) == -1) {

#else

  if (pipe(new_fd) == -1) {

#endif

    int error = errno;

    return createStringError(inconvertibleErrorCode(),

                             "Couldn't create new pipe for fd %d. %s", fd,

                             strerror(error));

  }

  if (dup2(new_fd[1], fd) == -1) {

    int error = errno;

    return createStringError(inconvertibleErrorCode(),

                             "Couldn't override the fd %d. %s", fd,

                             strerror(error));

  }

  int read_fd = new_fd[0];

  std::thread t([read_fd, callback]() {

    char buffer[4096];

    while (true) {

      ssize_t bytes_count = read(read_fd, &buffer, sizeof(buffer));

      if (bytes_count == 0)

        return;

      if (bytes_count == -1) {

        if (errno == EAGAIN || errno == EINTR)

          continue;

        break;

      }

      callback(StringRef(buffer, bytes_count));

    }

  });

  t.detach();

  return Error::success();

}

} // namespace lldb_vscode