// Copyright 2010 Google Inc. All Rights Reserved.

#include "file_linux.h"

#include <errno.h>
#include <unistd.h>

#include "logging.h"

namespace art {

LinuxFile::~LinuxFile() {
  // Close the file if necessary (unless it's a standard stream).
  if (auto_close_ && fd_ > STDERR_FILENO) {
    Close();
  }
}

void LinuxFile::Close() {
  DCHECK_GT(fd_, 0);
  int err = close(fd_);
  if (err != 0) {
    PLOG(WARNING) << "Problem closing " << name();
  }
  fd_ = kClosedFd;
}


bool LinuxFile::IsClosed() {
  return fd_ == kClosedFd;
}


int64_t LinuxFile::Read(void* buffer, int64_t num_bytes) {
  DCHECK_GE(fd_, 0);
  return read(fd_, buffer, num_bytes);
}


int64_t LinuxFile::Write(const void* buffer, int64_t num_bytes) {
  DCHECK_GE(fd_, 0);
  return write(fd_, buffer, num_bytes);
}


off_t LinuxFile::Position() {
  DCHECK_GE(fd_, 0);
  return lseek(fd_, 0, SEEK_CUR);
}


off_t LinuxFile::Length() {
  DCHECK_GE(fd_, 0);
  off_t position = lseek(fd_, 0, SEEK_CUR);
  if (position < 0) {
    // The file is not capable of seeking. Return an error.
    return -1;
  }
  off_t result = lseek(fd_, 0, SEEK_END);
  lseek(fd_, position, SEEK_SET);
  return result;
}

}  // namespace art