base/files/file_enumerator_win.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/files/file_enumerator.h"
   6
   7 #include <string.h>
   8
   9 #include "base/logging.h"
  10 #include "base/threading/thread_restrictions.h"
  11 #include "base/win/windows_version.h"
  12
  13 namespace base {
  14
  15 // FileEnumerator::FileInfo ----------------------------------------------------
  16
  17 FileEnumerator::FileInfo::FileInfo() {
  18   memset(&find_data_, 0, sizeof(find_data_));
  19 }
  20
  21 bool FileEnumerator::FileInfo::IsDirectory() const {
  22   return (find_data_.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
  23 }
  24
  25 FilePath FileEnumerator::FileInfo::GetName() const {
  26   return FilePath(find_data_.cFileName);
  27 }
  28
  29 int64 FileEnumerator::FileInfo::GetSize() const {
  30   ULARGE_INTEGER size;
  31   size.HighPart = find_data_.nFileSizeHigh;
  32   size.LowPart = find_data_.nFileSizeLow;
  33   DCHECK_LE(size.QuadPart, std::numeric_limits<int64>::max());
  34   return static_cast<int64>(size.QuadPart);
  35 }
  36
  37 base::Time FileEnumerator::FileInfo::GetLastModifiedTime() const {
  38   return base::Time::FromFileTime(find_data_.ftLastWriteTime);
  39 }
  40
  41 // FileEnumerator --------------------------------------------------------------
  42
  43 FileEnumerator::FileEnumerator(const FilePath& root_path,
  44                                bool recursive,
  45                                int file_type)
  46     : recursive_(recursive),
  47       file_type_(file_type),
  48       has_find_data_(false),
  49       find_handle_(INVALID_HANDLE_VALUE) {
  50   // INCLUDE_DOT_DOT must not be specified if recursive.
  51   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
  52   memset(&find_data_, 0, sizeof(find_data_));
  53   pending_paths_.push(root_path);
  54 }
  55
  56 FileEnumerator::FileEnumerator(const FilePath& root_path,
  57                                bool recursive,
  58                                int file_type,
  59                                const FilePath::StringType& pattern)
  60     : recursive_(recursive),
  61       file_type_(file_type),
  62       has_find_data_(false),
  63       pattern_(pattern),
  64       find_handle_(INVALID_HANDLE_VALUE) {
  65   // INCLUDE_DOT_DOT must not be specified if recursive.
  66   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
  67   memset(&find_data_, 0, sizeof(find_data_));
  68   pending_paths_.push(root_path);
  69 }
  70
  71 FileEnumerator::~FileEnumerator() {
  72   if (find_handle_ != INVALID_HANDLE_VALUE)
  73     FindClose(find_handle_);
  74 }
  75
  76 FileEnumerator::FileInfo FileEnumerator::GetInfo() const {
  77   if (!has_find_data_) {
  78     NOTREACHED();
  79     return FileInfo();
  80   }
  81   FileInfo ret;
  82   memcpy(&ret.find_data_, &find_data_, sizeof(find_data_));
  83   return ret;
  84 }
  85
  86 FilePath FileEnumerator::Next() {
  87   base::ThreadRestrictions::AssertIOAllowed();
  88
  89   while (has_find_data_ || !pending_paths_.empty()) {
  90     if (!has_find_data_) {
  91       // The last find FindFirstFile operation is done, prepare a new one.
  92       root_path_ = pending_paths_.top();
  93       pending_paths_.pop();
  94
  95       // Start a new find operation.
  96       FilePath src = root_path_;
  97
  98       if (pattern_.empty())
  99         src = src.Append(L"*");  // No pattern = match everything.
 100       else
 101         src = src.Append(pattern_);
 102
 103       if (base::win::GetVersion() >= base::win::VERSION_WIN7) {
 104         // Use a "large fetch" on newer Windows which should speed up large
 105         // enumerations (we seldom abort in the middle).
 106         find_handle_ = FindFirstFileEx(src.value().c_str(),
 107                                        FindExInfoBasic,  // Omit short name.
 108                                        &find_data_,
 109                                        FindExSearchNameMatch,
 110                                        NULL,
 111                                        FIND_FIRST_EX_LARGE_FETCH);
 112       } else {
 113         find_handle_ = FindFirstFile(src.value().c_str(), &find_data_);
 114       }
 115       has_find_data_ = true;
 116     } else {
 117       // Search for the next file/directory.
 118       if (!FindNextFile(find_handle_, &find_data_)) {
 119         FindClose(find_handle_);
 120         find_handle_ = INVALID_HANDLE_VALUE;
 121       }
 122     }
 123
 124     if (INVALID_HANDLE_VALUE == find_handle_) {
 125       has_find_data_ = false;
 126
 127       // This is reached when we have finished a directory and are advancing to
 128       // the next one in the queue. We applied the pattern (if any) to the files
 129       // in the root search directory, but for those directories which were
 130       // matched, we want to enumerate all files inside them. This will happen
 131       // when the handle is empty.
 132       pattern_ = FilePath::StringType();
 133
 134       continue;
 135     }
 136
 137     FilePath cur_file(find_data_.cFileName);
 138     if (ShouldSkip(cur_file))
 139       continue;
 140
 141     // Construct the absolute filename.
 142     cur_file = root_path_.Append(find_data_.cFileName);
 143
 144     if (find_data_.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
 145       if (recursive_) {
 146         // If |cur_file| is a directory, and we are doing recursive searching,
 147         // add it to pending_paths_ so we scan it after we finish scanning this
 148         // directory. However, don't do recursion through reparse points or we
 149         // may end up with an infinite cycle.
 150         if (!(find_data_.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT))
 151           pending_paths_.push(cur_file);
 152       }
 153       if (file_type_ & FileEnumerator::DIRECTORIES)
 154         return cur_file;
 155     } else if (file_type_ & FileEnumerator::FILES) {
 156       return cur_file;
 157     }
 158   }
 159
 160   return FilePath();
 161 }
 162
 163 }  // namespace base