base: Extract FileEnumerator out of file_util.h

base/files/file_enumerator_win.cc

+// 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.
+
+#include "base/files/file_enumerator.h"
+
+#include <string.h>
+
+#include "base/logging.h"
+#include "base/threading/thread_restrictions.h"
+#include "base/time.h"
+
+using base::FilePath;
+using base::Time;
+using base::ThreadRestrictions;
+
+namespace file_util {
+
+FileEnumerator::FileEnumerator(const FilePath& root_path,
+                               bool recursive,
+                               int file_type)
+    : recursive_(recursive),
+      file_type_(file_type),
+      has_find_data_(false),
+      find_handle_(INVALID_HANDLE_VALUE) {
+  // INCLUDE_DOT_DOT must not be specified if recursive.
+  DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
+  memset(&find_data_, 0, sizeof(find_data_));
+  pending_paths_.push(root_path);
+}
+
+FileEnumerator::FileEnumerator(const FilePath& root_path,
+                               bool recursive,
+                               int file_type,
+                               const FilePath::StringType& pattern)
+    : recursive_(recursive),
+      file_type_(file_type),
+      has_find_data_(false),
+      pattern_(pattern),
+      find_handle_(INVALID_HANDLE_VALUE) {
+  // INCLUDE_DOT_DOT must not be specified if recursive.
+  DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
+  memset(&find_data_, 0, sizeof(find_data_));
+  pending_paths_.push(root_path);
+}
+
+FileEnumerator::~FileEnumerator() {
+  if (find_handle_ != INVALID_HANDLE_VALUE)
+    FindClose(find_handle_);
+}
+
+void FileEnumerator::GetFindInfo(FindInfo* info) {
+  DCHECK(info);
+
+  if (!has_find_data_)
+    return;
+
+  memcpy(info, &find_data_, sizeof(*info));
+}
+
+// static
+bool FileEnumerator::IsDirectory(const FindInfo& info) {
+  return (info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
+}
+
+// static
+FilePath FileEnumerator::GetFilename(const FindInfo& find_info) {
+  return FilePath(find_info.cFileName);
+}
+
+// static
+int64 FileEnumerator::GetFilesize(const FindInfo& find_info) {
+  ULARGE_INTEGER size;
+  size.HighPart = find_info.nFileSizeHigh;
+  size.LowPart = find_info.nFileSizeLow;
+  DCHECK_LE(size.QuadPart, std::numeric_limits<int64>::max());
+  return static_cast<int64>(size.QuadPart);
+}
+
+// static
+Time FileEnumerator::GetLastModifiedTime(const FindInfo& find_info) {
+  return Time::FromFileTime(find_info.ftLastWriteTime);
+}
+
+FilePath FileEnumerator::Next() {
+  ThreadRestrictions::AssertIOAllowed();
+
+  while (has_find_data_ || !pending_paths_.empty()) {
+    if (!has_find_data_) {
+      // The last find FindFirstFile operation is done, prepare a new one.
+      root_path_ = pending_paths_.top();
+      pending_paths_.pop();
+
+      // Start a new find operation.
+      FilePath src = root_path_;
+
+      if (pattern_.empty())
+        src = src.Append(L"*");  // No pattern = match everything.
+      else
+        src = src.Append(pattern_);
+
+      find_handle_ = FindFirstFile(src.value().c_str(), &find_data_);
+      has_find_data_ = true;
+    } else {
+      // Search for the next file/directory.
+      if (!FindNextFile(find_handle_, &find_data_)) {
+        FindClose(find_handle_);
+        find_handle_ = INVALID_HANDLE_VALUE;
+      }
+    }
+
+    if (INVALID_HANDLE_VALUE == find_handle_) {
+      has_find_data_ = false;
+
+      // This is reached when we have finished a directory and are advancing to
+      // the next one in the queue. We applied the pattern (if any) to the files
+      // in the root search directory, but for those directories which were
+      // matched, we want to enumerate all files inside them. This will happen
+      // when the handle is empty.
+      pattern_ = FilePath::StringType();
+
+      continue;
+    }
+
+    FilePath cur_file(find_data_.cFileName);
+    if (ShouldSkip(cur_file))
+      continue;
+
+    // Construct the absolute filename.
+    cur_file = root_path_.Append(find_data_.cFileName);
+
+    if (find_data_.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+      if (recursive_) {
+        // If |cur_file| is a directory, and we are doing recursive searching,
+        // add it to pending_paths_ so we scan it after we finish scanning this
+        // directory.
+        pending_paths_.push(cur_file);
+      }
+      if (file_type_ & FileEnumerator::DIRECTORIES)
+        return cur_file;
+    } else if (file_type_ & FileEnumerator::FILES) {
+      return cur_file;
+    }
+  }
+
+  return FilePath();
+}
+
+}  // namespace file_util