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