Unrevert r245135 "Created new Windows LevelDB environment."

third_party/leveldatabase/env_chromium_posix.cc

+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include <errno.h>
+
+#include "base/debug/trace_event.h"
+#include "base/files/file_path.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chromium_logger.h"
+#include "env_chromium_posix.h"
+
+#if defined(OS_WIN)
+#include <io.h>
+#include "base/win/win_util.h"
+#endif
+
+#if defined(OS_POSIX)
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/resource.h>
+#endif
+
+using namespace leveldb;
+
+namespace leveldb_env {
+
+namespace {
+
+#if (defined(OS_POSIX) && !defined(OS_LINUX)) || defined(OS_WIN)
+// The following are glibc-specific
+
+size_t fread_unlocked(void *ptr, size_t size, size_t n, FILE *file) {
+  return fread(ptr, size, n, file);
+}
+
+size_t fwrite_unlocked(const void *ptr, size_t size, size_t n, FILE *file) {
+  return fwrite(ptr, size, n, file);
+}
+
+int fflush_unlocked(FILE *file) {
+  return fflush(file);
+}
+
+#if !defined(OS_ANDROID)
+int fdatasync(int fildes) {
+#if defined(OS_WIN)
+  return _commit(fildes);
+#else
+  return HANDLE_EINTR(fsync(fildes));
+#endif
+}
+#endif
+
+#endif
+
+// Wide-char safe fopen wrapper.
+FILE* fopen_internal(const char* fname, const char* mode) {
+#if defined(OS_WIN)
+  return _wfopen(UTF8ToUTF16(fname).c_str(), ASCIIToUTF16(mode).c_str());
+#else
+  return fopen(fname, mode);
+#endif
+}
+
+class ChromiumSequentialFile: public SequentialFile {
+ private:
+  std::string filename_;
+  FILE* file_;
+  const UMALogger* uma_logger_;
+
+ public:
+  ChromiumSequentialFile(const std::string& fname, FILE* f,
+                         const UMALogger* uma_logger)
+      : filename_(fname), file_(f), uma_logger_(uma_logger) { }
+  virtual ~ChromiumSequentialFile() { fclose(file_); }
+
+  virtual Status Read(size_t n, Slice* result, char* scratch) {
+    Status s;
+    size_t r = fread_unlocked(scratch, 1, n, file_);
+    *result = Slice(scratch, r);
+    if (r < n) {
+      if (feof(file_)) {
+        // We leave status as ok if we hit the end of the file
+      } else {
+        // A partial read with an error: return a non-ok status
+        s = MakeIOError(filename_, strerror(errno), kSequentialFileRead, errno);
+        uma_logger_->RecordErrorAt(kSequentialFileRead);
+      }
+    }
+    return s;
+  }
+
+  virtual Status Skip(uint64_t n) {
+    if (fseek(file_, n, SEEK_CUR)) {
+      int saved_errno = errno;
+      uma_logger_->RecordErrorAt(kSequentialFileSkip);
+      return MakeIOError(
+          filename_, strerror(saved_errno), kSequentialFileSkip, saved_errno);
+    }
+    return Status::OK();
+  }
+};
+
+class ChromiumRandomAccessFile: public RandomAccessFile {
+ private:
+  std::string filename_;
+  ::base::PlatformFile file_;
+  const UMALogger* uma_logger_;
+
+ public:
+  ChromiumRandomAccessFile(const std::string& fname, ::base::PlatformFile file,
+                           const UMALogger* uma_logger)
+      : filename_(fname), file_(file), uma_logger_(uma_logger) { }
+  virtual ~ChromiumRandomAccessFile() { ::base::ClosePlatformFile(file_); }
+
+  virtual Status Read(uint64_t offset, size_t n, Slice* result,
+                      char* scratch) const {
+    Status s;
+    int r = ::base::ReadPlatformFile(file_, offset, scratch, n);
+    *result = Slice(scratch, (r < 0) ? 0 : r);
+    if (r < 0) {
+      // An error: return a non-ok status
+      s = MakeIOError(
+          filename_, "Could not perform read", kRandomAccessFileRead);
+      uma_logger_->RecordErrorAt(kRandomAccessFileRead);
+    }
+    return s;
+  }
+};
+
+}  // unnamed namespace
+
+Status MakeIOError(Slice filename,
+                   const char* message,
+                   MethodID method,
+                   int saved_errno) {
+  char buf[512];
+  snprintf(buf,
+           sizeof(buf),
+           "%s (ChromeMethodErrno: %d::%s::%d)",
+           message,
+           method,
+           MethodIDToString(method),
+           saved_errno);
+  return Status::IOError(filename, buf);
+}
+
+ChromiumWritableFile::ChromiumWritableFile(const std::string& fname,
+                                           FILE* f,
+                                           const UMALogger* uma_logger,
+                                           WriteTracker* tracker,
+                                           bool make_backup)
+    : filename_(fname),
+      file_(f),
+      uma_logger_(uma_logger),
+      tracker_(tracker),
+      file_type_(kOther),
+      make_backup_(make_backup) {
+  base::FilePath path = base::FilePath::FromUTF8Unsafe(fname);
+  if (FilePathToString(path.BaseName()).find("MANIFEST") == 0)
+    file_type_ = kManifest;
+  else if (ChromiumEnv::HasTableExtension(path))
+    file_type_ = kTable;
+  if (file_type_ != kManifest)
+    tracker_->DidCreateNewFile(filename_);
+  parent_dir_ = FilePathToString(ChromiumEnv::CreateFilePath(fname).DirName());
+}
+
+ChromiumWritableFile::~ChromiumWritableFile() {
+  if (file_ != NULL) {
+    // Ignoring any potential errors
+    fclose(file_);
+  }
+}
+
+Status ChromiumWritableFile::SyncParent() {
+  Status s;
+#if !defined(OS_WIN)
+  TRACE_EVENT0("leveldb", "SyncParent");
+
+  int parent_fd =
+      HANDLE_EINTR(open(parent_dir_.c_str(), O_RDONLY));
+  if (parent_fd < 0) {
+    int saved_errno = errno;
+    return MakeIOError(
+        parent_dir_, strerror(saved_errno), kSyncParent, saved_errno);
+  }
+  if (HANDLE_EINTR(fsync(parent_fd)) != 0) {
+    int saved_errno = errno;
+    s = MakeIOError(
+        parent_dir_, strerror(saved_errno), kSyncParent, saved_errno);
+  };
+  close(parent_fd);
+#endif
+  return s;
+}
+
+Status ChromiumWritableFile::Append(const Slice& data) {
+  if (file_type_ == kManifest && tracker_->DoesDirNeedSync(filename_)) {
+    Status s = SyncParent();
+    if (!s.ok())
+      return s;
+    tracker_->DidSyncDir(filename_);
+  }
+
+  size_t r = fwrite_unlocked(data.data(), 1, data.size(), file_);
+  if (r != data.size()) {
+    int saved_errno = errno;
+    uma_logger_->RecordOSError(kWritableFileAppend, saved_errno);
+    return MakeIOError(
+        filename_, strerror(saved_errno), kWritableFileAppend, saved_errno);
+  }
+  return Status::OK();
+}
+
+Status ChromiumWritableFile::Close() {
+  Status result;
+  if (fclose(file_) != 0) {
+    result = MakeIOError(filename_, strerror(errno), kWritableFileClose, errno);
+    uma_logger_->RecordErrorAt(kWritableFileClose);
+  }
+  file_ = NULL;
+  return result;
+}
+
+Status ChromiumWritableFile::Flush() {
+  Status result;
+  if (HANDLE_EINTR(fflush_unlocked(file_))) {
+    int saved_errno = errno;
+    result = MakeIOError(
+        filename_, strerror(saved_errno), kWritableFileFlush, saved_errno);
+    uma_logger_->RecordOSError(kWritableFileFlush, saved_errno);
+  }
+  return result;
+}
+
+Status ChromiumWritableFile::Sync() {
+  TRACE_EVENT0("leveldb", "ChromiumEnvPosix::Sync");
+  Status result;
+  int error = 0;
+
+  if (HANDLE_EINTR(fflush_unlocked(file_)))
+    error = errno;
+  // Sync even if fflush gave an error; perhaps the data actually got out,
+  // even though something went wrong.
+  if (fdatasync(fileno(file_)) && !error)
+    error = errno;
+  // Report the first error we found.
+  if (error) {
+    result = MakeIOError(filename_, strerror(error), kWritableFileSync, error);
+    uma_logger_->RecordErrorAt(kWritableFileSync);
+  } else if (make_backup_ && file_type_ == kTable) {
+    bool success = ChromiumEnv::MakeBackup(filename_);
+    uma_logger_->RecordBackupResult(success);
+  }
+  return result;
+}
+
+ChromiumEnvPosix::ChromiumEnvPosix() {

[jsbell, 2013/12/12 01:11:42]

Naming: Calling it Posix is confusing, since it's not POSIX specific - it's
using the PlatformFile abstractions. Eventually it may be POSIX-specific, but we
can rename then.

Not that I have great alternatives. ChromiumEnvPlatform ?

[cmumford, 2013/12/12 17:40:51]

So ChromiumEnv calls the file abstractions in base. ChromiumEnvWin32 is direct
Win32, and ChromiumEnvPosix does FILE stream I/O (AKA stdio) which is part of
POSIX. Also, an instance of ChromiumEnvPosix should now do *only* POSIX I/O, and
ChromiumEnvWin32 will do only Win32 (with one exception). Did I get that right?

[jsbell, 2013/12/12 18:11:41]

It's more about how the terms "win" and "posix" are used in Chromium. Generally,
"win" = windows specific, and "posix" = unix-like operating systems, i.e. linux,
mac osx, etc; practically speaking posix == !win. So it would be surprising for
a Chromium developer unfamiliar with this code to find that ChromiumEnvPosix
could be instantiated/used on Windows.

[cmumford, 2013/12/12 19:37:46]

TL;DR How about ChromiumEnvPosix -> ChromiumEnvStdio

Yes, I totally see your point, and agree that the assumption would be
ChromiumEnvPosix would not be instantiated on Windows. Unfortunately we have two
leaf classes:

1. PlatformFile(Win32/POSIX/etc.) + ChromiumEnv(POSIX)
2. PlatformFile(Win32) + ChromiumEnv(Win32)

And our class hierarchy is currently

ChromiumEnv
  ChromiumEnvPosix (#1 above)
  ChromiumEnvWin (#2 above)

We could do something like:

ChromiumEnv
  ChromiumEnvBase (#1 above)
  ChromiumEnvWin (#2 above)

But I think that most developers would expect a class with "Base" in it would be
a base class. Also, ChromiumEnv does "Base" (AKA PlatformFile) I/O, so that
would be doubly confusing.

We might also do:

ChromiumEnvBase
  ChromiumEnv (#1 above)
  ChromiumEnvWin (#2 above)

That would be a bit cleaner, but we would not have the normal symmetry
developers expect when looking at platform specific classes.

We could also do:

ChromiumEnv
  ChromiumEnvStdio (#1 above)
  ChromiumEnvWin (#2 above)

I'm warming to this last idea - Skia does this with SkOSFile_stdio.cpp

[dgrogan, 2013/12/12 19:39:57]

This SGTM.

+}
+
+ChromiumEnvPosix::~ChromiumEnvPosix() {
+}
+
+Status ChromiumEnvPosix::NewSequentialFile(const std::string& fname,
+                                      SequentialFile** result) {
+  FILE* f = fopen_internal(fname.c_str(), "rb");
+  if (f == NULL) {
+    *result = NULL;
+    int saved_errno = errno;
+    RecordOSError(kNewSequentialFile, saved_errno);
+    return MakeIOError(
+        fname, strerror(saved_errno), kNewSequentialFile, saved_errno);
+  } else {
+    *result = new ChromiumSequentialFile(fname, f, this);
+    return Status::OK();
+  }
+}
+
+void ChromiumEnvPosix::RecordOpenFilesLimit(const std::string& type) {
+#if defined(OS_POSIX)
+  struct rlimit nofile;
+  if (getrlimit(RLIMIT_NOFILE, &nofile))
+    return;
+  GetMaxFDHistogram(type)->Add(nofile.rlim_cur);
+#endif
+}
+
+Status ChromiumEnvPosix::NewRandomAccessFile(const std::string& fname,
+                                        RandomAccessFile** result) {
+  int flags = ::base::PLATFORM_FILE_READ | ::base::PLATFORM_FILE_OPEN;
+  bool created;
+  ::base::PlatformFileError error_code;
+  ::base::PlatformFile file = ::base::CreatePlatformFile(
+      ChromiumEnv::CreateFilePath(fname), flags, &created, &error_code);
+  if (error_code == ::base::PLATFORM_FILE_OK) {
+    *result = new ChromiumRandomAccessFile(fname, file, this);
+    RecordOpenFilesLimit("Success");
+    return Status::OK();
+  }
+  if (error_code == ::base::PLATFORM_FILE_ERROR_TOO_MANY_OPENED)
+    RecordOpenFilesLimit("TooManyOpened");
+  else
+    RecordOpenFilesLimit("OtherError");
+  *result = NULL;
+  RecordOSError(kNewRandomAccessFile, error_code);
+  return MakeIOError(fname,
+                     PlatformFileErrorString(error_code),
+                     kNewRandomAccessFile,
+                     error_code);
+}
+
+Status ChromiumEnvPosix::NewWritableFile(const std::string& fname,
+                                    WritableFile** result) {
+  *result = NULL;
+  FILE* f = fopen_internal(fname.c_str(), "wb");
+  if (f == NULL) {
+    int saved_errno = errno;
+    RecordErrorAt(kNewWritableFile);
+    return MakeIOError(
+        fname, strerror(saved_errno), kNewWritableFile, saved_errno);
+  } else {
+    *result = new ChromiumWritableFile(fname, f, this, this, make_backup_);
+    return Status::OK();
+  }
+}
+
+#if defined(OS_WIN)
+base::PlatformFileError ChromiumEnvPosix::GetDirectoryEntries(
+    const base::FilePath& dir_param,
+    std::vector<base::FilePath>* result) const {
+  result->clear();
+  base::FilePath dir_filepath = dir_param.Append(FILE_PATH_LITERAL("*"));
+  WIN32_FIND_DATA find_data;
+  HANDLE find_handle = FindFirstFile(dir_filepath.value().c_str(), &find_data);
+  if (find_handle == INVALID_HANDLE_VALUE) {
+    DWORD last_error = GetLastError();
+    if (last_error == ERROR_FILE_NOT_FOUND)
+      return base::PLATFORM_FILE_OK;
+    return base::LastErrorToPlatformFileError(last_error);
+  }
+  do {
+    base::FilePath filepath(find_data.cFileName);
+    base::FilePath::StringType basename = filepath.BaseName().value();
+    if (basename == FILE_PATH_LITERAL(".") ||
+        basename == FILE_PATH_LITERAL(".."))
+      continue;
+    result->push_back(filepath.BaseName());
+  } while (FindNextFile(find_handle, &find_data));
+  DWORD last_error = GetLastError();
+  base::PlatformFileError return_value = base::PLATFORM_FILE_OK;
+  if (last_error != ERROR_NO_MORE_FILES)
+    return_value = base::LastErrorToPlatformFileError(last_error);
+  FindClose(find_handle);
+  return return_value;
+}
+#else
+base::PlatformFileError ChromiumEnvPosix::GetDirectoryEntries(
+    const base::FilePath& dir_filepath,
+    std::vector<base::FilePath>* result) const {
+  const std::string dir_string = FilePathToString(dir_filepath);
+  result->clear();
+  DIR* dir = opendir(dir_string.c_str());
+  if (!dir)
+    return base::ErrnoToPlatformFileError(errno);
+  struct dirent dent_buf;
+  struct dirent* dent;
+  int readdir_result;
+  while ((readdir_result = readdir_r(dir, &dent_buf, &dent)) == 0 && dent) {
+    if (strcmp(dent->d_name, ".") == 0 || strcmp(dent->d_name, "..") == 0)
+      continue;
+    result->push_back(ChromiumEnv::CreateFilePath(dent->d_name));
+  }
+  int saved_errno = errno;
+  closedir(dir);
+  if (readdir_result != 0)
+    return base::ErrnoToPlatformFileError(saved_errno);
+  return base::PLATFORM_FILE_OK;
+}
+#endif
+
+Status ChromiumEnvPosix::NewLogger(const std::string& fname, Logger** result) {
+  FILE* f = fopen_internal(fname.c_str(), "w");
+  if (f == NULL) {
+    *result = NULL;
+    int saved_errno = errno;
+    RecordOSError(kNewLogger, saved_errno);
+    return MakeIOError(fname, strerror(saved_errno), kNewLogger, saved_errno);
+  } else {
+    *result = new ChromiumLogger(f);
+    return Status::OK();
+  }
+}
+
+}  // namespace leveldb_env