Avoid fragmenting the heap too much while reconstructing the index.

net/disk_cache/simple/simple_index_file_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 "net/disk_cache/simple/simple_index_file.h"
+
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <cstring>
+#include <string>
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace disk_cache {
+namespace {
+
+struct DirCloser {
+  void operator()(DIR* dir) { closedir(dir); }
+};
+
+typedef scoped_ptr<DIR, DirCloser> ScopedDir;
+
+}  // namespace
+
+// static
+bool SimpleIndexFile::TraverseCacheDirectory(
+    const std::string& cache_path,
+    const EntryFileCallback& entry_file_callback) {
+  const ScopedDir dir(opendir(cache_path.c_str()));
+  if (!dir) {
+    PLOG(ERROR) << "opendir " << cache_path;
+    return false;
+  }
+  dirent entry, *result;
+  while (readdir_r(dir.get(), &entry, &result) == 0) {
+    if (!result)
+      return true;  // The traversal completed successfully.
+    if (!strcmp(result->d_name, ".") || !strcmp(result->d_name, ".."))
+      continue;
+    entry_file_callback.Run(result->d_name);
+  }
+  PLOG(ERROR) << "readdir_r " << cache_path;
+  return false;
+}
+
+// static
+bool SimpleIndexFile::GetPlatformFileInfo(const char* path,
+                                          base::PlatformFileInfo* info) {
+  // Note that base::GetPlatformFileInfo() is not used here since it takes a
+  // file descriptor in which could be inefficient (due to the extra open() +
+  // close()).
+  struct stat stat_info;
+  if (stat(path, &stat_info) < 0) {
+    PLOG(ERROR) << "stat " << path;
+    return false;
+  }
+  memset(info, 0, sizeof(*info));
+  info->size = stat_info.st_size;
+  info->is_directory = stat_info.st_size;
+  info->last_modified = base::Time::FromTimeT(stat_info.st_mtime);
+  info->last_accessed = base::Time::FromTimeT(stat_info.st_atime);
+  return true;
+}
+
+}  // namespace disk_cache