path: root/src/corelib/io/qfilesystemwatcher_inotify.cpp

// Copyright (C) 2016 The Qt Company Ltd.// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only#include"qfilesystemwatcher.h"#include"qfilesystemwatcher_inotify_p.h"#include"private/qcore_unix_p.h"#include"private/qsystemerror_p.h"#include <qdebug.h>#include <qfile.h>#include <qfileinfo.h>#include <qscopeguard.h>#include <qsocketnotifier.h>#include <qvarlengtharray.h>#if defined(Q_OS_LINUX)#include <sys/syscall.h>#include <sys/ioctl.h>#include <unistd.h>#include <fcntl.h>#endif#if defined(QT_NO_INOTIFY)#if defined(Q_OS_QNX)// These files should only be compiled on QNX if the inotify headers are found#error"Should not get here."#endif#include <linux/types.h>#if defined(__i386__)# define __NR_inotify_init 291# define __NR_inotify_add_watch 292# define __NR_inotify_rm_watch 293# define __NR_inotify_init1 332#elif defined(__x86_64__)# define __NR_inotify_init 253# define __NR_inotify_add_watch 254# define __NR_inotify_rm_watch 255# define __NR_inotify_init1 294#elif defined(__powerpc__) || defined(__powerpc64__)# define __NR_inotify_init 275# define __NR_inotify_add_watch 276# define __NR_inotify_rm_watch 277# define __NR_inotify_init1 318#elif defined (__ia64__)# define __NR_inotify_init 1277# define __NR_inotify_add_watch 1278# define __NR_inotify_rm_watch 1279# define __NR_inotify_init1 1318#elif defined (__s390__) || defined (__s390x__)# define __NR_inotify_init 284# define __NR_inotify_add_watch 285# define __NR_inotify_rm_watch 286# define __NR_inotify_init1 324#elif defined (__alpha__)# define __NR_inotify_init 444# define __NR_inotify_add_watch 445# define __NR_inotify_rm_watch 446// no inotify_init1 for the Alpha#elif defined (__sparc__) || defined (__sparc64__)# define __NR_inotify_init 151# define __NR_inotify_add_watch 152# define __NR_inotify_rm_watch 156# define __NR_inotify_init1 322#elif defined (__arm__)# define __NR_inotify_init 316# define __NR_inotify_add_watch 317# define __NR_inotify_rm_watch 318# define __NR_inotify_init1 360#elif defined (__sh__)# define __NR_inotify_init 290# define __NR_inotify_add_watch 291# define __NR_inotify_rm_watch 292# define __NR_inotify_init1 332#elif defined (__sh64__)# define __NR_inotify_init 318# define __NR_inotify_add_watch 319# define __NR_inotify_rm_watch 320# define __NR_inotify_init1 360#elif defined (__mips__)# define __NR_inotify_init 284# define __NR_inotify_add_watch 285# define __NR_inotify_rm_watch 286# define __NR_inotify_init1 329#elif defined (__hppa__)# define __NR_inotify_init 269# define __NR_inotify_add_watch 270# define __NR_inotify_rm_watch 271# define __NR_inotify_init1 314#elif defined (__avr32__)# define __NR_inotify_init 240# define __NR_inotify_add_watch 241# define __NR_inotify_rm_watch 242// no inotify_init1 for AVR32#elif defined (__mc68000__)# define __NR_inotify_init 284# define __NR_inotify_add_watch 285# define __NR_inotify_rm_watch 286# define __NR_inotify_init1 328#elif defined (__aarch64__)# define __NR_inotify_init1 26# define __NR_inotify_add_watch 27# define __NR_inotify_rm_watch 28// no inotify_init for aarch64#else# error"This architecture is not supported. Please see http://www.qt-project.org/"#endif#if !defined(IN_CLOEXEC) && defined(O_CLOEXEC) && defined(__NR_inotify_init1)# define IN_CLOEXEC O_CLOEXEC#endif QT_BEGIN_NAMESPACE #ifdef QT_LINUXBASE// ### the LSB doesn't standardize syscall, need to wait until glib2.4 is standardizedstaticinlineintsyscall(...) {return-1; }#endifstaticinlineintinotify_init(){#ifdef __NR_inotify_initreturnsyscall(__NR_inotify_init);#elsereturnsyscall(__NR_inotify_init1,0);#endif}staticinlineintinotify_add_watch(int fd,const char*name, __u32 mask){returnsyscall(__NR_inotify_add_watch, fd, name, mask);}staticinlineintinotify_rm_watch(int fd, __u32 wd){returnsyscall(__NR_inotify_rm_watch, fd, wd);}#ifdef IN_CLOEXECstaticinlineintinotify_init1(int flags){returnsyscall(__NR_inotify_init1, flags);}#endif// the following struct and values are documented in linux/inotify.hextern"C"{struct inotify_event { __s32 wd; __u32 mask; __u32 cookie; __u32 len;char name[0];};#define IN_ACCESS 0x00000001#define IN_MODIFY 0x00000002#define IN_ATTRIB 0x00000004#define IN_CLOSE_WRITE 0x00000008#define IN_CLOSE_NOWRITE 0x00000010#define IN_OPEN 0x00000020#define IN_MOVED_FROM 0x00000040#define IN_MOVED_TO 0x00000080#define IN_CREATE 0x00000100#define IN_DELETE 0x00000200#define IN_DELETE_SELF 0x00000400#define IN_MOVE_SELF 0x00000800#define IN_UNMOUNT 0x00002000#define IN_Q_OVERFLOW 0x00004000#define IN_IGNORED 0x00008000#define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)#define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO)} QT_END_NAMESPACE // --------- inotify.h end ----------#else/* QT_NO_INOTIFY */#include <sys/inotify.h>// see https://github.com/android-ndk/ndk/issues/394# if defined(Q_OS_ANDROID) && (__ANDROID_API__ < 21)staticinlineintinotify_init1(int flags){returnsyscall(__NR_inotify_init1, flags);}# endif#endif QT_BEGIN_NAMESPACE QInotifyFileSystemWatcherEngine *QInotifyFileSystemWatcherEngine::create(QObject *parent){int fd = -1;#if defined(IN_CLOEXEC) fd =inotify_init1(IN_CLOEXEC);#endifif(fd == -1) { fd =inotify_init();if(fd == -1)returnnullptr;}return newQInotifyFileSystemWatcherEngine(fd, parent);}QInotifyFileSystemWatcherEngine::QInotifyFileSystemWatcherEngine(int fd, QObject *parent):QFileSystemWatcherEngine(parent),inotifyFd(fd),notifier(fd,QSocketNotifier::Read,this){fcntl(inotifyFd, F_SETFD, FD_CLOEXEC);QObject::connect(&notifier, &QSocketNotifier::activated,this, &QInotifyFileSystemWatcherEngine::readFromInotify);}QInotifyFileSystemWatcherEngine::~QInotifyFileSystemWatcherEngine(){ notifier.setEnabled(false);for(int id :std::as_const(pathToID))inotify_rm_watch(inotifyFd, id <0? -id : id);::close(inotifyFd);} QStringList QInotifyFileSystemWatcherEngine::addPaths(const QStringList &paths, QStringList *files, QStringList *directories){ QStringList unhandled;for(const QString &path : paths) { QFileInfo fi(path);bool isDir = fi.isDir();auto sg =qScopeGuard([&]{ unhandled.push_back(path); });if(isDir) {if(directories->contains(path))continue;}else{if(files->contains(path))continue;}int wd =inotify_add_watch(inotifyFd,QFile::encodeName(path),(isDir ? (0| IN_ATTRIB | IN_MOVE | IN_CREATE | IN_DELETE | IN_DELETE_SELF ): (0| IN_ATTRIB | IN_MODIFY | IN_MOVE | IN_MOVE_SELF | IN_DELETE_SELF )));if(wd <0) {if(errno != ENOENT)qErrnoWarning("inotify_add_watch(%ls) failed:", path.constData());continue;} sg.dismiss();int id = isDir ? -wd : wd;if(id <0) { directories->append(path);}else{ files->append(path);} pathToID.insert(path, id); idToPath.insert(id, path);}return unhandled;} QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &paths, QStringList *files, QStringList *directories){ QStringList unhandled;for(const QString &path : paths) {int id = pathToID.take(path);auto sg =qScopeGuard([&]{ unhandled.push_back(path); });// Multiple paths could be associated to the same watch descriptor// when a file is moved and added with the new name.// So we should find and delete the correct one by using// both id and pathauto path_range = idToPath.equal_range(id);auto path_it =std::find(path_range.first, path_range.second, path);if(path_it == idToPath.end())continue;const ssize_t num_elements =std::distance(path_range.first, path_range.second); idToPath.erase(path_it);// If there was only one path associated to the given id we should remove the watchif(num_elements ==1) {int wd = id <0? -id : id;inotify_rm_watch(inotifyFd, wd);} sg.dismiss();if(id <0) { directories->removeAll(path);}else{ files->removeAll(path);}}return unhandled;}voidQInotifyFileSystemWatcherEngine::readFromInotify(){// qDebug("QInotifyFileSystemWatcherEngine::readFromInotify");int buffSize =0;if(ioctl(inotifyFd, FIONREAD, (char*) &buffSize) == -1|| buffSize ==0)return; QVarLengthArray<char,4096>buffer(buffSize); buffSize =int(read(inotifyFd, buffer.data(), buffSize));char*at = buffer.data();char*const end = at + buffSize; QHash<int, inotify_event *> eventForId;while(at < end) { inotify_event *event =reinterpret_cast<inotify_event *>(at);if(eventForId.contains(event->wd)) eventForId[event->wd]->mask |= event->mask;else eventForId.insert(event->wd, event); at +=sizeof(inotify_event) + event->len;} QHash<int, inotify_event *>::const_iterator it = eventForId.constBegin();while(it != eventForId.constEnd()) {const inotify_event &event = **it;++it;// qDebug() << "inotify event, wd" << event.wd << "mask" << Qt::hex << event.mask;int id = event.wd; QString path =getPathFromID(id);if(path.isEmpty()) {// perhaps a directory? id = -id; path =getPathFromID(id);if(path.isEmpty())continue;}// qDebug() << "event for path" << path;if((event.mask & (IN_DELETE_SELF | IN_MOVE_SELF | IN_UNMOUNT)) !=0) { pathToID.remove(path); idToPath.remove(id,getPathFromID(id));if(!idToPath.contains(id))inotify_rm_watch(inotifyFd, event.wd);if(id <0) emit directoryChanged(path,true);else emit fileChanged(path,true);}else{if(id <0) emit directoryChanged(path,false);else emit fileChanged(path,false);}}}template<typename Hash, typename Key> typename Hash::const_iterator find_last_in_equal_range(const Hash &c,const Key &key){// find c.equal_range(key).second - 1 without backwards iteration:auto i = c.find(key);constauto end = c.cend();if(i == end)return end;decltype(i) prev;do{ prev = i;++i;}while(i != end && i.key() == key);return prev;} QString QInotifyFileSystemWatcherEngine::getPathFromID(int id)const{auto i =find_last_in_equal_range(idToPath, id);return i == idToPath.cend() ?QString() : i.value() ;} QT_END_NAMESPACE #include"moc_qfilesystemwatcher_inotify_p.cpp"