Add m-esr52 at 52.6.0

1 files changed, 314 insertions, 0 deletions

diff --git a/xpcom/io/nsAnonymousTemporaryFile.cpp b/xpcom/io/nsAnonymousTemporaryFile.cpp
new file mode 100644
index 000000000..586e552c4
--- /dev/null
+++ b/xpcom/io/nsAnonymousTemporaryFile.cpp
@@ -0,0 +1,314 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/SyncRunnable.h"
+#include "nsAnonymousTemporaryFile.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsXULAppAPI.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "prio.h"
+#include "private/pprio.h"
+
+#ifdef XP_WIN
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "mozilla/Services.h"
+#include "nsIIdleService.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIFile.h"
+#include "nsAutoPtr.h"
+#include "nsITimer.h"
+#include "nsCRT.h"
+
+#endif
+
+using namespace mozilla;
+
+// We store the temp files in the system temp dir.
+//
+// On Windows systems in particular we use a sub-directory of the temp
+// directory, because:
+//   1. DELETE_ON_CLOSE is unreliable on Windows, in particular if we power
+//      cycle (and perhaps if we crash) the files are not deleted. We store
+//      the temporary files in a known sub-dir so that we can find and delete
+//      them easily and quickly.
+//   2. On Windows NT the system temp dir is in the user's $HomeDir/AppData,
+//      so we can be sure the user always has write privileges to that directory;
+//      if the sub-dir for our temp files was in some shared location and
+//      was created by a privileged user, it's possible that other users
+//      wouldn't have write access to that sub-dir. (Non-Windows systems
+//      don't store their temp files in a sub-dir, so this isn't an issue on
+//      those platforms).
+//   3. Content processes can access the system temp dir
+//      (NS_GetSpecialDirectory fails on NS_APP_USER_PROFILE_LOCAL_50_DIR
+//      for content process for example, which is where we previously stored
+//      temp files on Windows). This argument applies to all platforms, not
+//      just Windows.
+static nsresult
+GetTempDir(nsIFile** aTempDir)
+{
+  if (NS_WARN_IF(!aTempDir)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  nsCOMPtr<nsIFile> tmpFile;
+  nsresult rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(tmpFile));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+#ifdef XP_WIN
+  // On windows DELETE_ON_CLOSE is unreliable, so we store temporary files
+  // in a subdir of the temp dir and delete that in an idle service observer
+  // to ensure it's been cleared.
+  rv = tmpFile->AppendNative(nsDependentCString("mozilla-temp-files"));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  rv = tmpFile->Create(nsIFile::DIRECTORY_TYPE, 0700);
+  if (rv != NS_ERROR_FILE_ALREADY_EXISTS && NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+#endif
+
+  tmpFile.forget(aTempDir);
+
+  return NS_OK;
+}
+
+namespace {
+
+class nsRemoteAnonymousTemporaryFileRunnable : public Runnable
+{
+public:
+  dom::FileDescOrError *mResultPtr;
+  explicit nsRemoteAnonymousTemporaryFileRunnable(dom::FileDescOrError *aResultPtr)
+  : mResultPtr(aResultPtr)
+  { }
+
+protected:
+  NS_IMETHOD Run() override {
+    dom::ContentChild* child = dom::ContentChild::GetSingleton();
+    MOZ_ASSERT(child);
+    child->SendOpenAnonymousTemporaryFile(mResultPtr);
+    return NS_OK;
+  }
+};
+
+} // namespace
+
+nsresult
+NS_OpenAnonymousTemporaryFile(PRFileDesc** aOutFileDesc)
+{
+  if (NS_WARN_IF(!aOutFileDesc)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (dom::ContentChild* child = dom::ContentChild::GetSingleton()) {
+    dom::FileDescOrError fd = NS_OK;
+    if (NS_IsMainThread()) {
+      child->SendOpenAnonymousTemporaryFile(&fd);
+    } else {
+      nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
+      MOZ_ASSERT(mainThread);
+      SyncRunnable::DispatchToThread(mainThread,
+        new nsRemoteAnonymousTemporaryFileRunnable(&fd));
+    }
+    if (fd.type() == dom::FileDescOrError::Tnsresult) {
+      nsresult rv = fd.get_nsresult();
+      MOZ_ASSERT(NS_FAILED(rv));
+      return rv;
+    }
+    auto rawFD = fd.get_FileDescriptor().ClonePlatformHandle();
+    *aOutFileDesc = PR_ImportFile(PROsfd(rawFD.release()));
+    return NS_OK;
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIFile> tmpFile;
+  rv = GetTempDir(getter_AddRefs(tmpFile));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Give the temp file a name with a random element. CreateUnique will also
+  // append a counter to the name if it encounters a name collision. Adding
+  // a random element to the name reduces the likelihood of a name collision,
+  // so that CreateUnique() doesn't end up trying a lot of name variants in
+  // its "try appending an incrementing counter" loop, as file IO can be
+  // expensive on some mobile flash drives.
+  nsAutoCString name("mozilla-temp-");
+  name.AppendInt(rand());
+
+  rv = tmpFile->AppendNative(name);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = tmpFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0700);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = tmpFile->OpenNSPRFileDesc(PR_RDWR | nsIFile::DELETE_ON_CLOSE,
+                                 PR_IRWXU, aOutFileDesc);
+
+  return rv;
+}
+
+#ifdef XP_WIN
+
+// On Windows we have an idle service observer that runs some time after
+// startup and deletes any stray anonymous temporary files...
+
+// Duration of idle time before we'll get a callback whereupon we attempt to
+// remove any stray and unused anonymous temp files.
+#define TEMP_FILE_IDLE_TIME_S 30
+
+// The nsAnonTempFileRemover is created in a timer, which sets an idle observer.
+// This is expiration time (in ms) which initial timer is set for (3 minutes).
+#define SCHEDULE_TIMEOUT_MS 3 * 60 * 1000
+
+#define XPCOM_SHUTDOWN_TOPIC "xpcom-shutdown"
+
+// This class adds itself as an idle observer. When the application has
+// been idle for about 30 seconds we'll get a notification, whereupon we'll
+// attempt to delete ${TempDir}/mozilla-temp-files/. This is to ensure all
+// temp files that were supposed to be deleted on application exit were actually
+// deleted, as they may not be if we previously crashed. See bugs 572579 and
+// 785662. This is only needed on some versions of Windows,
+// nsIFile::DELETE_ON_CLOSE works on other platforms.
+// This class adds itself as a shutdown observer so that it can cancel the
+// idle observer and its timer on shutdown. Note: the observer and idle
+// services hold references to instances of this object, and those references
+// are what keep this object alive.
+class nsAnonTempFileRemover final : public nsIObserver
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  nsAnonTempFileRemover() {}
+
+  nsresult Init()
+  {
+    // We add the idle observer in a timer, so that the app has enough
+    // time to start up before we add the idle observer. If we register the
+    // idle observer too early, it will be registered before the fake idle
+    // service is installed when running in xpcshell, and this interferes with
+    // the fake idle service, causing xpcshell-test failures.
+    mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+    if (NS_WARN_IF(!mTimer)) {
+      return NS_ERROR_FAILURE;
+    }
+    nsresult rv = mTimer->Init(this,
+                               SCHEDULE_TIMEOUT_MS,
+                               nsITimer::TYPE_ONE_SHOT);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    // Register shutdown observer so we can cancel the timer if we shutdown before
+    // the timer runs.
+    nsCOMPtr<nsIObserverService> obsSrv = services::GetObserverService();
+    if (NS_WARN_IF(!obsSrv)) {
+      return NS_ERROR_FAILURE;
+    }
+    return obsSrv->AddObserver(this, XPCOM_SHUTDOWN_TOPIC, false);
+  }
+
+  void Cleanup()
+  {
+    // Cancel timer.
+    if (mTimer) {
+      mTimer->Cancel();
+      mTimer = nullptr;
+    }
+    // Remove idle service observer.
+    nsCOMPtr<nsIIdleService> idleSvc =
+      do_GetService("@mozilla.org/widget/idleservice;1");
+    if (idleSvc) {
+      idleSvc->RemoveIdleObserver(this, TEMP_FILE_IDLE_TIME_S);
+    }
+    // Remove shutdown observer.
+    nsCOMPtr<nsIObserverService> obsSrv = services::GetObserverService();
+    if (obsSrv) {
+      obsSrv->RemoveObserver(this, XPCOM_SHUTDOWN_TOPIC);
+    }
+  }
+
+  NS_IMETHODIMP Observe(nsISupports* aSubject,
+                        const char* aTopic,
+                        const char16_t* aData)
+  {
+    if (nsCRT::strcmp(aTopic, NS_TIMER_CALLBACK_TOPIC) == 0 &&
+        NS_FAILED(RegisterIdleObserver())) {
+      Cleanup();
+    } else if (nsCRT::strcmp(aTopic, OBSERVER_TOPIC_IDLE) == 0) {
+      // The user has been idle for a while, clean up the temp files.
+      // The idle service will drop its reference to this object after
+      // we exit, destroying this object.
+      RemoveAnonTempFileFiles();
+      Cleanup();
+    } else if (nsCRT::strcmp(aTopic, XPCOM_SHUTDOWN_TOPIC) == 0) {
+      Cleanup();
+    }
+    return NS_OK;
+  }
+
+  nsresult RegisterIdleObserver()
+  {
+    // Add this as an idle observer. When we've been idle for
+    // TEMP_FILE_IDLE_TIME_S seconds, we'll get a notification, and we'll then
+    // try to delete any stray temp files.
+    nsCOMPtr<nsIIdleService> idleSvc =
+      do_GetService("@mozilla.org/widget/idleservice;1");
+    if (!idleSvc) {
+      return NS_ERROR_FAILURE;
+    }
+    return idleSvc->AddIdleObserver(this, TEMP_FILE_IDLE_TIME_S);
+  }
+
+  void RemoveAnonTempFileFiles()
+  {
+    nsCOMPtr<nsIFile> tmpDir;
+    nsresult rv = GetTempDir(getter_AddRefs(tmpDir));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return;
+    }
+
+    // Remove the directory recursively.
+    tmpDir->Remove(true);
+  }
+
+private:
+  ~nsAnonTempFileRemover() {}
+
+  nsCOMPtr<nsITimer> mTimer;
+};
+
+NS_IMPL_ISUPPORTS(nsAnonTempFileRemover, nsIObserver)
+
+nsresult
+CreateAnonTempFileRemover()
+{
+  // Create a temp file remover. If Init() succeeds, the temp file remover is kept
+  // alive by a reference held by the observer service, since the temp file remover
+  // is a shutdown observer. We only create the temp file remover if we're running
+  // in the main process; there's no point in doing the temp file removal multiple
+  // times per startup.
+  if (!XRE_IsParentProcess()) {
+    return NS_OK;
+  }
+  RefPtr<nsAnonTempFileRemover> tempRemover = new nsAnonTempFileRemover();
+  return tempRemover->Init();
+}
+
+#endif
+