src/disk_interface.cc

// Copyright 2011 Google Inc. 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.

#include "disk_interface.h"

#include <algorithm>

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

#ifdef _WIN32
#include <sstream>
#include <windows.h>
#include <direct.h>  // _mkdir
#else
#include <unistd.h>
#endif

#include "metrics.h"
#include "util.h"

using namespace std;

namespace {

string DirName(const string& path) {
#ifdef _WIN32
  static const char kPathSeparators[] = "\\/";
#else
  static const char kPathSeparators[] = "/";
#endif
  static const char* const kEnd = kPathSeparators + sizeof(kPathSeparators) - 1;

  string::size_type slash_pos = path.find_last_of(kPathSeparators);
  if (slash_pos == string::npos)
    return string();  // Nothing to do.
  while (slash_pos > 0 &&
         std::find(kPathSeparators, kEnd, path[slash_pos - 1]) != kEnd)
    --slash_pos;
  return path.substr(0, slash_pos);
}

int MakeDir(const string& path) {
#ifdef _WIN32
  return _mkdir(path.c_str());
#else
  return mkdir(path.c_str(), 0777);
#endif
}

}  // namespace

// DiskInterface ---------------------------------------------------------------

bool DiskInterface::MakeDirs(const string& path) {
  string dir = DirName(path);
  if (dir.empty())
    return true;  // Reached root; assume it's there.
  string err;
  TimeStamp mtime = Stat(dir, &err);
  if (mtime < 0) {
    Error("%s", err.c_str());
    return false;
  }
  if (mtime > 0)
    return true;  // Exists already; we're done.

  // Directory doesn't exist.  Try creating its parent first.
  bool success = MakeDirs(dir);
  if (!success)
    return false;
  return MakeDir(dir);
}

// RealDiskInterface -----------------------------------------------------------

TimeStamp RealDiskInterface::Stat(const string& path, string* err) const {
  METRIC_RECORD("node stat");
  return stat_cache_.Stat(path, err);
}

bool RealDiskInterface::WriteFile(const string& path, const string& contents) {
  FILE* fp = fopen(path.c_str(), "w");
  if (fp == NULL) {
    Error("WriteFile(%s): Unable to create file. %s",
          path.c_str(), strerror(errno));
    return false;
  }

  stat_cache_.Invalidate(path);
  if (fwrite(contents.data(), 1, contents.length(), fp) < contents.length())  {
    Error("WriteFile(%s): Unable to write to the file. %s",
          path.c_str(), strerror(errno));
    fclose(fp);
    return false;
  }

  if (fclose(fp) == EOF) {
    Error("WriteFile(%s): Unable to close the file. %s",
          path.c_str(), strerror(errno));
    return false;
  }

  return true;
}

bool RealDiskInterface::MakeDir(const string& path) {
  int ret = ::MakeDir(path);
  if (ret < 0 && errno == EEXIST)
    return true;

  int saved_errno = errno;
  // Invalidate just in case the call modified something on the disk.
  stat_cache_.Invalidate(path);
  if (ret < 0) {
    Error("mkdir(%s): %s", path.c_str(), strerror(saved_errno));
    return false;
  }
  return true;
}

FileReader::Status RealDiskInterface::ReadFile(const string& path,
                                               string* contents,
                                               string* err) {
  switch (::ReadFile(path, contents, err)) {
  case 0:       return Okay;
  case -ENOENT: return NotFound;
  default:      return OtherError;
  }
}

int RealDiskInterface::RemoveFile(const string& path) {
  stat_cache_.Invalidate(path);
#ifdef _WIN32
  DWORD attributes = GetFileAttributesA(path.c_str());
  if (attributes == INVALID_FILE_ATTRIBUTES) {
    DWORD win_err = GetLastError();
    if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
      return 1;
    }
  } else if (attributes & FILE_ATTRIBUTE_READONLY) {
    // On non-Windows systems, remove() will happily delete read-only files.
    // On Windows Ninja should behave the same:
    //   https://github.com/ninja-build/ninja/issues/1886
    // Skip error checking.  If this fails, accept whatever happens below.
    SetFileAttributesA(path.c_str(), attributes & ~FILE_ATTRIBUTE_READONLY);
  }
  if (attributes & FILE_ATTRIBUTE_DIRECTORY) {
    // remove() deletes both files and directories. On Windows we have to 
    // select the correct function (DeleteFile will yield Permission Denied when
    // used on a directory)
    // This fixes the behavior of ninja -t clean in some cases
    // https://github.com/ninja-build/ninja/issues/828
    if (!RemoveDirectoryA(path.c_str())) {
      DWORD win_err = GetLastError();
      if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
        return 1;
      }
      // Report remove(), not RemoveDirectory(), for cross-platform consistency.
      Error("remove(%s): %s", path.c_str(), GetLastErrorString().c_str());
      return -1;
    }
  } else {
    if (!DeleteFileA(path.c_str())) {
      DWORD win_err = GetLastError();
      if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
        return 1;
      }
      // Report as remove(), not DeleteFile(), for cross-platform consistency.
      Error("remove(%s): %s", path.c_str(), GetLastErrorString().c_str());
      return -1;
    }
  }
#else
  if (remove(path.c_str()) < 0) {
    switch (errno) {
      case ENOENT:
        return 1;
      default:
        Error("remove(%s): %s", path.c_str(), strerror(errno));
        return -1;
    }
  }
#endif
  return 0;
}

void RealDiskInterface::AllowStatCache(bool allow) {
  stat_cache_.Enable(allow);
}

void RealDiskInterface::Sync() {
  stat_cache_.Sync();
}

void RealDiskInterface::FlushCache() {
  stat_cache_.Flush();
}