src/tools/singlejar/port.cc

// Copyright 2018 The Bazel Authors. All rights reserved.
//
// 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.

#ifdef _WIN32

#include "src/tools/singlejar/port.h"

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>

ssize_t pread(int fd, void *buf, size_t count, off64_t offset) {
  DWORD ret = -1;
  HANDLE hFile = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
  if (hFile) {
    OVERLAPPED overlap;
    memset(&overlap, 0, sizeof(OVERLAPPED));
    overlap.Offset = offset;
    if (!::ReadFile(hFile, buf, count, &ret, &overlap)) {
      // For this simple implementation, we don't update errno.
      // Just return -1 as error.
      return -1;
    }
  }
  return ret;
}

#endif  // _WIN32