Import chromium-64.0.3282.119

net/disk_cache/cache_util.cc

@@ -0,0 +1,160 @@
+// Copyright (c) 2012 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/cache_util.h"
+
+#include <limits>
+
+#include "base/files/file_enumerator.h"
+#include "base/files/file_util.h"
+#include "base/location.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/threading/thread_restrictions.h"
+
+namespace {
+
+const int kMaxOldFolders = 100;
+
+// Returns a fully qualified name from path and name, using a given name prefix
+// and index number. For instance, if the arguments are "/foo", "bar" and 5, it
+// will return "/foo/old_bar_005".
+base::FilePath GetPrefixedName(const base::FilePath& path,
+                               const std::string& name,
+                               int index) {
+  std::string tmp = base::StringPrintf("%s%s_%03d", "old_",
+                                       name.c_str(), index);
+  return path.AppendASCII(tmp);
+}
+
+// This is a simple callback to cleanup old caches.
+void CleanupCallback(const base::FilePath& path, const std::string& name) {
+  for (int i = 0; i < kMaxOldFolders; i++) {
+    base::FilePath to_delete = GetPrefixedName(path, name, i);
+    disk_cache::DeleteCache(to_delete, true);
+  }
+}
+
+// Returns a full path to rename the current cache, in order to delete it. path
+// is the current folder location, and name is the current folder name.
+base::FilePath GetTempCacheName(const base::FilePath& path,
+                                const std::string& name) {
+  // We'll attempt to have up to kMaxOldFolders folders for deletion.
+  for (int i = 0; i < kMaxOldFolders; i++) {
+    base::FilePath to_delete = GetPrefixedName(path, name, i);
+    if (!base::PathExists(to_delete))
+      return to_delete;
+  }
+  return base::FilePath();
+}
+
+int64_t PreferredCacheSizeInternal(int64_t available) {
+  using disk_cache::kDefaultCacheSize;
+  // Return 80% of the available space if there is not enough space to use
+  // kDefaultCacheSize.
+  if (available < kDefaultCacheSize * 10 / 8)
+    return available * 8 / 10;
+
+  // Return kDefaultCacheSize if it uses 10% to 80% of the available space.
+  if (available < kDefaultCacheSize * 10)
+    return kDefaultCacheSize;
+
+  // Return 10% of the available space if the target size
+  // (2.5 * kDefaultCacheSize) is more than 10%.
+  if (available < static_cast<int64_t>(kDefaultCacheSize) * 25)
+    return available / 10;
+
+  // Return the target size (2.5 * kDefaultCacheSize) if it uses 10% to 1%
+  // of the available space.
+  if (available < static_cast<int64_t>(kDefaultCacheSize) * 250)
+    return kDefaultCacheSize * 5 / 2;
+
+  // Return 1% of the available space.
+  return available / 100;
+}
+
+}  // namespace
+
+namespace disk_cache {
+
+const int kDefaultCacheSize = 80 * 1024 * 1024;
+
+void DeleteCache(const base::FilePath& path, bool remove_folder) {
+  if (remove_folder) {
+    if (!base::DeleteFile(path, /* recursive */ true))
+      LOG(WARNING) << "Unable to delete cache folder.";
+    return;
+  }
+
+  base::FileEnumerator iter(
+      path,
+      /* recursive */ false,
+      base::FileEnumerator::FILES | base::FileEnumerator::DIRECTORIES);
+  for (base::FilePath file = iter.Next(); !file.value().empty();
+       file = iter.Next()) {
+    if (!base::DeleteFile(file, /* recursive */ true)) {
+      LOG(WARNING) << "Unable to delete cache.";
+      return;
+    }
+  }
+}
+
+// In order to process a potentially large number of files, we'll rename the
+// cache directory to old_ + original_name + number, (located on the same parent
+// directory), and use a worker thread to delete all the files on all the stale
+// cache directories. The whole process can still fail if we are not able to
+// rename the cache directory (for instance due to a sharing violation), and in
+// that case a cache for this profile (on the desired path) cannot be created.
+bool DelayedCacheCleanup(const base::FilePath& full_path) {
+  // GetTempCacheName() and MoveCache() use synchronous file
+  // operations.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+
+  base::FilePath current_path = full_path.StripTrailingSeparators();
+
+  base::FilePath path = current_path.DirName();
+  base::FilePath name = current_path.BaseName();
+#if defined(OS_POSIX)
+  std::string name_str = name.value();
+#elif defined(OS_WIN)
+  // We created this file so it should only contain ASCII.
+  std::string name_str = base::UTF16ToASCII(name.value());
+#endif
+
+  base::FilePath to_delete = GetTempCacheName(path, name_str);
+  if (to_delete.empty()) {
+    LOG(ERROR) << "Unable to get another cache folder";
+    return false;
+  }
+
+  if (!disk_cache::MoveCache(full_path, to_delete)) {
+    LOG(ERROR) << "Unable to move cache folder " << full_path.value() << " to "
+               << to_delete.value();
+    return false;
+  }
+
+  base::PostTaskWithTraits(FROM_HERE,
+                           {base::MayBlock(), base::TaskPriority::BACKGROUND,
+                            base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
+                           base::Bind(&CleanupCallback, path, name_str));
+  return true;
+}
+
+// Returns the preferred maximum number of bytes for the cache given the
+// number of available bytes.
+int PreferredCacheSize(int64_t available) {
+  if (available < 0)
+    return kDefaultCacheSize;
+
+  // Limit cache size to somewhat less than kint32max to avoid potential
+  // integer overflows in cache backend implementations.
+  DCHECK_LT(kDefaultCacheSize * 4, std::numeric_limits<int32_t>::max());
+  return static_cast<int32_t>(
+      std::min(PreferredCacheSizeInternal(available),
+               static_cast<int64_t>(kDefaultCacheSize * 4)));
+}
+
+}  // namespace disk_cache