base: Extract FileEnumerator out of file_util.h

base/files/file_enumerator.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_FILES_FILE_ENUMERATOR_H_
+#define BASE_FILES_FILE_ENUMERATOR_H_
+
+#include <stack>
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/files/file_path.h"
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(OS_POSIX)
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+namespace base {
+class Time;
+}
+
+// TODO(tfarina): Move this into base namespace.
+namespace file_util {
+
+// A class for enumerating the files in a provided path. The order of the
+// results is not guaranteed.
+//
+// DO NOT USE FROM THE MAIN THREAD of your application unless it is a test
+// program where latency does not matter. This class is blocking.
+class BASE_EXPORT FileEnumerator {
+ public:
+#if defined(OS_WIN)
+  typedef WIN32_FIND_DATA FindInfo;
+#elif defined(OS_POSIX)
+  struct FindInfo {
+    struct stat stat;
+    std::string filename;
+  };
+#endif
+
+  enum FileType {
+    FILES                 = 1 << 0,
+    DIRECTORIES           = 1 << 1,
+    INCLUDE_DOT_DOT       = 1 << 2,
+#if defined(OS_POSIX)
+    SHOW_SYM_LINKS        = 1 << 4,
+#endif
+  };
+
+  // |root_path| is the starting directory to search for. It may or may not end
+  // in a slash.
+  //
+  // If |recursive| is true, this will enumerate all matches in any
+  // subdirectories matched as well. It does a breadth-first search, so all
+  // files in one directory will be returned before any files in a
+  // subdirectory.
+  //
+  // |file_type|, a bit mask of FileType, specifies whether the enumerator
+  // should match files, directories, or both.
+  //
+  // |pattern| is an optional pattern for which files to match. This
+  // works like shell globbing. For example, "*.txt" or "Foo???.doc".
+  // However, be careful in specifying patterns that aren't cross platform
+  // since the underlying code uses OS-specific matching routines.  In general,
+  // Windows matching is less featureful than others, so test there first.
+  // If unspecified, this will match all files.
+  // NOTE: the pattern only matches the contents of root_path, not files in
+  // recursive subdirectories.
+  // TODO(erikkay): Fix the pattern matching to work at all levels.
+  FileEnumerator(const base::FilePath& root_path,
+                 bool recursive,
+                 int file_type);
+  FileEnumerator(const base::FilePath& root_path,
+                 bool recursive,
+                 int file_type,
+                 const base::FilePath::StringType& pattern);
+  ~FileEnumerator();
+
+  // Returns an empty string if there are no more results.
+  base::FilePath Next();
+
+  // Write the file info into |info|.
+  void GetFindInfo(FindInfo* info);
+
+  // Looks inside a FindInfo and determines if it's a directory.
+  static bool IsDirectory(const FindInfo& info);
+
+  static base::FilePath GetFilename(const FindInfo& find_info);
+  static int64 GetFilesize(const FindInfo& find_info);
+  static base::Time GetLastModifiedTime(const FindInfo& find_info);
+
+ private:
+  // Returns true if the given path should be skipped in enumeration.
+  bool ShouldSkip(const base::FilePath& path);
+
+#if defined(OS_WIN)
+  // True when find_data_ is valid.
+  bool has_find_data_;
+  WIN32_FIND_DATA find_data_;
+  HANDLE find_handle_;
+#elif defined(OS_POSIX)
+  struct DirectoryEntryInfo {
+    base::FilePath filename;
+    struct stat stat;
+  };
+
+  // Read the filenames in source into the vector of DirectoryEntryInfo's
+  static bool ReadDirectory(std::vector<DirectoryEntryInfo>* entries,
+                            const base::FilePath& source,
+                            bool show_links);
+
+  // The files in the current directory
+  std::vector<DirectoryEntryInfo> directory_entries_;
+
+  // The next entry to use from the directory_entries_ vector
+  size_t current_directory_entry_;
+#endif
+
+  base::FilePath root_path_;
+  bool recursive_;
+  int file_type_;
+  base::FilePath::StringType pattern_;  // Empty when we want to find
+                                        // everything.
+
+  // A stack that keeps track of which subdirectories we still need to
+  // enumerate in the breadth-first search.
+  std::stack<base::FilePath> pending_paths_;
+
+  DISALLOW_COPY_AND_ASSIGN(FileEnumerator);
+};
+
+}  // namespace file_util
+
+#endif  // BASE_FILES_FILE_ENUMERATOR_H_