Add recursive pattern matching for subfolders in file_enumerator.

base/files/file_enumerator_posix.cc

 // Copyright (c) 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 <dirent.h>
 #include <errno.h>
 #include <fnmatch.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "base/logging.h"
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 
 namespace base {
+namespace {
+
+void GetStat(const FilePath& path, bool show_links, struct stat* st) {
+  DCHECK(st);
+  const int res = show_links ? lstat(path.value().c_str(), st)
+                             : stat(path.value().c_str(), st);
+  if (res < 0) {
+    // Print the stat() error message unless it was ENOENT and we're following
+    // symlinks.
+    if (!(errno == ENOENT && !show_links))
+      DPLOG(ERROR) << "Couldn't stat" << path.value();
+    memset(st, 0, sizeof(*st));
+  }
+}
+
+}  // namespace
 
 // FileEnumerator::FileInfo ----------------------------------------------------
 
 FileEnumerator::FileInfo::FileInfo() {
   memset(&stat_, 0, sizeof(stat_));
 }
 
 bool FileEnumerator::FileInfo::IsDirectory() const {
   return S_ISDIR(stat_.st_mode);
 }
 
 FilePath FileEnumerator::FileInfo::GetName() const {
   return filename_;
 }
 
 int64_t FileEnumerator::FileInfo::GetSize() const {
   return stat_.st_size;
 }
 
 base::Time FileEnumerator::FileInfo::GetLastModifiedTime() const {
   return base::Time::FromTimeT(stat_.st_mtime);
 }
 
 // FileEnumerator --------------------------------------------------------------
 
 FileEnumerator::FileEnumerator(const FilePath& root_path,
                                bool recursive,
                                int file_type)
-    : current_directory_entry_(0),
-      root_path_(root_path),
-      recursive_(recursive),
-      file_type_(file_type) {
-  // INCLUDE_DOT_DOT must not be specified if recursive.
-  DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
-  pending_paths_.push(root_path);
-}
+    : FileEnumerator(root_path,
+                     recursive,
+                     file_type,
+                     FilePath::StringType(),
+                     FolderSearchPolicy::MATCH_ONLY) {}
 
 FileEnumerator::FileEnumerator(const FilePath& root_path,
                                bool recursive,
                                int file_type,
                                const FilePath::StringType& pattern)
+    : FileEnumerator(root_path,
+                     recursive,
+                     file_type,
+                     pattern,
+                     FolderSearchPolicy::MATCH_ONLY) {}
+
+FileEnumerator::FileEnumerator(const FilePath& root_path,
+                               bool recursive,
+                               int file_type,
+                               const FilePath::StringType& pattern,
+                               FolderSearchPolicy folder_search_policy)
     : current_directory_entry_(0),
       root_path_(root_path),
       recursive_(recursive),
       file_type_(file_type),
-      pattern_(root_path.Append(pattern).value()) {
+      pattern_(pattern),
+      folder_search_policy_(folder_search_policy) {
   // INCLUDE_DOT_DOT must not be specified if recursive.
   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
-  // The Windows version of this code appends the pattern to the root_path,
-  // potentially only matching against items in the top-most directory.
-  // Do the same here.
-  if (pattern.empty())
-    pattern_ = FilePath::StringType();
+
   pending_paths_.push(root_path);
 }
 
 FileEnumerator::~FileEnumerator() {
 }
 
 FilePath FileEnumerator::Next() {
+  base::ThreadRestrictions::AssertIOAllowed();
+
   ++current_directory_entry_;
 
   // While we've exhausted the entries in the current directory, do the next
   while (current_directory_entry_ >= directory_entries_.size()) {
     if (pending_paths_.empty())
       return FilePath();
 
     root_path_ = pending_paths_.top();
     root_path_ = root_path_.StripTrailingSeparators();
     pending_paths_.pop();
 
-    std::vector<FileInfo> entries;
-    if (!ReadDirectory(&entries, root_path_, file_type_ & SHOW_SYM_LINKS))
+    DIR* dir = opendir(root_path_.value().c_str());
+    if (!dir)
       continue;
 
     directory_entries_.clear();
+
+#if defined(OS_FUCHSIA)
+    // Fuchsia does not support .. on the file system server side, see
+    // https://fuchsia.googlesource.com/docs/+/master/dotdot.md and
+    // https://crbug.com/735540. However, for UI purposes, having the parent
+    // directory show up in directory listings makes sense, so we add it here to
+    // match the expectation on other operating systems. In cases where this
+    // is useful it should be resolvable locally.
+    FileInfo dotdot;
+    dotdot.stat_.st_mode = S_IFDIR;
+    dotdot.filename_ = FilePath("..");
+    directory_entries_->push_back(dotdot);
+#endif  // OS_FUCHSIA
+
     current_directory_entry_ = 0;
-    for (std::vector<FileInfo>::const_iterator i = entries.begin();
-         i != entries.end(); ++i) {
-      FilePath full_path = root_path_.Append(i->filename_);
-      if (ShouldSkip(full_path))
+    struct dirent* dent;
+    while ((dent = readdir(dir))) {
+      FileInfo info;
+      info.filename_ = FilePath(dent->d_name);
+
+      if (ShouldSkip(info.filename_))
         continue;
 
-      if (pattern_.size() &&
-          fnmatch(pattern_.c_str(), full_path.value().c_str(), FNM_NOESCAPE))
+      const bool is_pattern_matched = IsPatternMatched(info.filename_);
+
+      // MATCH_ONLY policy enumerates files and directories which matching
+      // pattern only. So we can early skip further checks.
+      if (folder_search_policy_ == FolderSearchPolicy::MATCH_ONLY &&
+          !is_pattern_matched)
         continue;
 
-      if (recursive_ && S_ISDIR(i->stat_.st_mode))
+      // Do not call OS stat/lstat if there is no sense to do it. If pattern is
+      // not matched (file will not appear in results) and search is not
+      // recursive (possible directory will not be added to pending paths) -
+      // there is no sense to obtain item below.
+      if (!recursive_ && !is_pattern_matched)
+        continue;
+
+      const FilePath full_path = root_path_.Append(info.filename_);
+      GetStat(full_path, file_type_ & SHOW_SYM_LINKS, &info.stat_);
+
+      const bool is_dir = S_ISDIR(info.stat_.st_mode);
+
+      if (recursive_ && is_dir)
         pending_paths_.push(full_path);
 
-      if ((S_ISDIR(i->stat_.st_mode) && (file_type_ & DIRECTORIES)) ||
-          (!S_ISDIR(i->stat_.st_mode) && (file_type_ & FILES)))
-        directory_entries_.push_back(*i);
+      if (is_pattern_matched && IsTypeMatched(is_dir))
+        directory_entries_.push_back(std::move(info));
     }
+    closedir(dir);
+
+    // MATCH_ONLY policy enumerates files in matched subfolders by "*" pattern.
+    // ALL policy enumerates files in all subfolders by origin pattern.
+    if (folder_search_policy_ == FolderSearchPolicy::MATCH_ONLY)
+      pattern_.clear();
   }
 
   return root_path_.Append(
       directory_entries_[current_directory_entry_].filename_);
 }
 
 FileEnumerator::FileInfo FileEnumerator::GetInfo() const {
   return directory_entries_[current_directory_entry_];
 }
 
-bool FileEnumerator::ReadDirectory(std::vector<FileInfo>* entries,
-                                   const FilePath& source, bool show_links) {
-  base::ThreadRestrictions::AssertIOAllowed();
-  DIR* dir = opendir(source.value().c_str());
-  if (!dir)
-    return false;
-
-#if defined(OS_FUCHSIA)
-  // Fuchsia does not support .. on the file system server side, see
-  // https://fuchsia.googlesource.com/docs/+/master/dotdot.md and
-  // https://crbug.com/735540. However, for UI purposes, having the parent
-  // directory show up in directory listings makes sense, so we add it here to
-  // match the expectation on other operating systems. In cases where this
-  // is useful it should be resolvable locally.
-  FileInfo dotdot;
-  dotdot.stat_.st_mode = S_IFDIR;
-  dotdot.filename_ = FilePath("..");
-  entries->push_back(dotdot);
-#endif  // OS_FUCHSIA
-
-  struct dirent* dent;
-  while ((dent = readdir(dir))) {
-    FileInfo info;
-    info.filename_ = FilePath(dent->d_name);
-
-    FilePath full_name = source.Append(dent->d_name);
-    int ret;
-    if (show_links)
-      ret = lstat(full_name.value().c_str(), &info.stat_);
-    else
-      ret = stat(full_name.value().c_str(), &info.stat_);
-    if (ret < 0) {
-      // Print the stat() error message unless it was ENOENT and we're
-      // following symlinks.
-      if (!(errno == ENOENT && !show_links)) {
-        DPLOG(ERROR) << "Couldn't stat "
-                     << source.Append(dent->d_name).value();
-      }
-      memset(&info.stat_, 0, sizeof(info.stat_));
-    }
-    entries->push_back(info);
-  }
-
-  closedir(dir);
-  return true;
+bool FileEnumerator::IsPatternMatched(const FilePath& path) const {
+  return pattern_.empty() ||
+         !fnmatch(pattern_.c_str(), path.value().c_str(), FNM_NOESCAPE);
 }
 
 }  // namespace base