dom/filesystem/FileSystemUtils.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/FileSystemUtils.h"
   8 #include "nsCharSeparatedTokenizer.h"
   9 #include "nsIEventTarget.h"
  10 #include "nsThreadUtils.h"
  11
  12 namespace mozilla::dom {
  13
  14 /* static */
  15 bool FileSystemUtils::IsDescendantPath(const nsAString& aPath,
  16                                        const nsAString& aDescendantPath) {
  17   // Check the sub-directory path to see if it has the parent path as prefix.
  18   if (!aDescendantPath.Equals(aPath) &&
  19       !StringBeginsWith(aDescendantPath, aPath)) {
  20     return false;
  21   }
  22
  23   return true;
  24 }
  25
  26 /* static */
  27 bool FileSystemUtils::IsValidRelativeDOMPath(const nsAString& aPath,
  28                                              nsTArray<nsString>& aParts) {
  29   // We don't allow empty relative path to access the root.
  30   if (aPath.IsEmpty()) {
  31     return false;
  32   }
  33
  34   // Leading and trailing "/" are not allowed.
  35   if (aPath.First() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR ||
  36       aPath.Last() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR) {
  37     return false;
  38   }
  39
  40   constexpr auto kCurrentDir = u"."_ns;
  41   constexpr auto kParentDir = u".."_ns;
  42
  43   // Split path and check each path component.
  44   for (const nsAString& pathComponent :
  45        nsCharSeparatedTokenizerTemplate<NS_TokenizerIgnoreNothing>{
  46            aPath, FILESYSTEM_DOM_PATH_SEPARATOR_CHAR}
  47            .ToRange()) {
  48     // The path containing empty components, such as "foo//bar", is invalid.
  49     // We don't allow paths, such as "../foo", "foo/./bar" and "foo/../bar",
  50     // to walk up the directory.
  51     if (pathComponent.IsEmpty() || pathComponent.Equals(kCurrentDir) ||
  52         pathComponent.Equals(kParentDir)) {
  53       return false;
  54     }
  55
  56     aParts.AppendElement(pathComponent);
  57   }
  58
  59   return true;
  60 }
  61
  62 /* static */
  63 nsresult FileSystemUtils::DispatchRunnable(
  64     nsIGlobalObject* aGlobal, already_AddRefed<nsIRunnable>&& aRunnable) {
  65   nsCOMPtr<nsIRunnable> runnable = aRunnable;
  66
  67   nsCOMPtr<nsIEventTarget> target;
  68   if (!aGlobal) {
  69     target = GetMainThreadSerialEventTarget();
  70   } else {
  71     target = aGlobal->SerialEventTarget();
  72   }
  73
  74   MOZ_ASSERT(target);
  75
  76   nsresult rv = target->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL);
  77   if (NS_WARN_IF(NS_FAILED(rv))) {
  78     return rv;
  79   }
  80
  81   return NS_OK;
  82 }
  83
  84 }  // namespace mozilla::dom