watchedDirType Class Reference

represents a watched directory inside a directory tree. More...

Collaboration diagram for watchedDirType:

Public Member Functions
void	buildPath (std::string &path)
	fill path with the fill path to this directory More...
void	buildPath (std::string &path, const std::string &aName)
	fill path with the full path to a file in this directory More...
std::string	getPath ()
	return full path to this dir, for use in error messages only More...
	watchedDirType (const std::string &aName, int aFd, watchedDirType *aParent=nullptr)
	construct a new watchedDir. More...
	~watchedDirType ()
	destruct watchedDir. More...
void	invalidateId ()
int	getId () const
watchedDirType *	getChild (const std::string &aName)
void	getAdoptedBy (const std::string &newName, watchedDirType *newParent)
	move to a new place in the directory tree. More...

Static Public Member Functions
static void	dump (std::ostream &out)
static watchedDirType *	get (int aId)
	get a watcheDir by the inotify id More...
static bool	empty ()
	test if any directories are watched More...
static size_t	size ()
	return number of watched directories More...
static void	setExtraEventMask (int extraMask)

Private Member Functions
void	becomeChildOfMyParent (watchedDirType *aParent)
	set object a child of the parent. More...

Static Private Member Functions
static std::map< int, watchedDirType * > &	getWatchedDirs ()

Private Attributes
std::string	name
	basename of the directory, i.e. not the full path More...
watchedDirType *	parent
int	fd
	fd for the inotify instance, needed for destructor More...
int	id
	the watch id More...
std::map< std::string, watchedDirType * >	children
decltype(getWatchedDirs().begin())	watchIterator
	iterator in the map that holds this object More...
decltype(children.begin())	childIterator
	iterator in parent's child map that holds this object More...

Static Private Attributes
static int	extraEventMask = 0

Detailed Description

represents a watched directory inside a directory tree.

Holds pointers to paren and children in the tree as well as info on the inotify watch.

Definition at line 285 of file inotify_watch.cpp.

Constructor & Destructor Documentation

watchedDirType()

watchedDirType::watchedDirType ( const std::string &  aName, int  aFd, watchedDirType *  aParent = nullptr  )

inline

construct a new watchedDir.

If it has a parent then name is the basename of the directory, i.e. without path If parent is nullptr then name is the full path to the directory. [in] aFd is the fd to the inotify object. If something goes wrong the id will be -1. Also inserts this directory into the watched directory tree and the id map.

Definition at line 379 of file inotify_watch.cpp.

                                                     :
        name(aName),
        parent(aParent),
        fd(aFd) {
        std::string path;
        buildPath(path);
        watchIterator = getWatchedDirs().end();
        id = inotify_add_watch(fd, path.c_str(),
                               IN_CLOSE_WRITE
                               | IN_DELETE
                               | IN_MOVED_TO | IN_MOVED_FROM
                               | IN_CREATE
                               | IN_DELETE_SELF
                               | IN_EXCL_UNLINK
                               | IN_DONT_FOLLOW
                               | IN_ONLYDIR
                               | extraEventMask);
 
        if (id == -1 && (errno == ENOENT || errno == ENOTDIR)) { // we fell prey to a race
            parent = nullptr;
            return;
        }
 
        throwcall::badval(id, -1, "inotify_add_watch failed on ", path);
 
        auto result = getWatchedDirs().emplace(id, this);
 
        if (result.second == false) { // watch for this object already exists, declare this as invalid
            parent = nullptr;
            id = -1;
            return;
        } else {
            watchIterator = result.first;
        }
 
        becomeChildOfMyParent(aParent);
    }

References throwcall::badval(), becomeChildOfMyParent(), buildPath(), extraEventMask, fd, getWatchedDirs(), parent, and watchIterator.

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~watchedDirType()

watchedDirType::~watchedDirType ( )

inline

destruct watchedDir.

Unwatchews it in the inotify_object, removes it from the directory tree (destroig all leftover children, which should be gone now anyway), and unregisters it in the map.

Definition at line 424 of file inotify_watch.cpp.

                      {
        if (id != -1) {
            auto retval = inotify_rm_watch(fd, id);
 
            if (retval && errno == EINVAL) {
                *errStream << errPrefix << "oops " << getPath() << " id " << id << "could not be unwatched" << std::endl;
            } else {
                throwcall::good0(retval, "can't unwatch ", getPath());
            }
        }
 
        if (watchIterator != getWatchedDirs().end()) {
            getWatchedDirs().erase(watchIterator);
        }
 
        for (auto& child : children) {
            *errStream << errPrefix << "oops " << getPath() << " still has child " << child.second->getPath() << ", deleting it" << std::endl;
            delete child.second;
        }
 
        if (parent) {
            parent->children.erase(childIterator);
        }
    }

References childIterator, children, errPrefix, errStream(), fd, getPath(), getWatchedDirs(), throwcall::good0(), parent, and watchIterator.

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Member Function Documentation

becomeChildOfMyParent()

void watchedDirType::becomeChildOfMyParent ( watchedDirType *  aParent )

inlineprivate

set object a child of the parent.

The parent should not have a child of this name, but in extreme stress cases it can have one. In order to continue working we "orphan" that child.

Definition at line 305 of file inotify_watch.cpp.

                                                        {
        parent = aParent;
 
        if (parent) {
            auto result = parent->children.emplace(name, this);
 
            if (result.second == false) {
                result.first->second->parent = nullptr; // orphanize old child
                result.first->second = this; // overwrite old child
            }
 
            childIterator = result.first;
        }
    }

References childIterator, children, name, and parent.

Referenced by getAdoptedBy(), and watchedDirType().

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buildPath() [1/2]

void watchedDirType::buildPath ( std::string &  path )

inline

fill path with the fill path to this directory

Definition at line 333 of file inotify_watch.cpp.

                                    {
        if (parent) {
            parent->buildPath(path);
            path += "/";
        }
 
        path += name;
    }

References buildPath(), name, and parent.

Referenced by buildPath(), getPath(), main(), watchDirectory(), and watchedDirType().

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buildPath() [2/2]

void watchedDirType::buildPath ( std::string &  path, const std::string &  aName  )

inline

fill path with the full path to a file in this directory

Definition at line 342 of file inotify_watch.cpp.

                                           {
        buildPath(path);
        path += "/";
        path += aName;
    }

References buildPath().

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dump()

static void watchedDirType::dump ( std::ostream &  out )

inlinestatic

Definition at line 321 of file inotify_watch.cpp.

                                      {
        out << errPrefix << "begin list of watched directories (" << getWatchedDirs().size() << "):\n";
        for (const auto& item: getWatchedDirs()) {
            std::string path;
            item.second->buildPath(path);
            out << errPrefix << item.first << ": " << path << "\n";
        }
        out << errPrefix << "end list of watched directories.\n";
    }

References errPrefix, and getWatchedDirs().

Referenced by main().

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empty()

static bool watchedDirType::empty ( )

inlinestatic

test if any directories are watched

Definition at line 360 of file inotify_watch.cpp.

                        {
        return getWatchedDirs().empty();
    }

References getWatchedDirs().

Referenced by main().

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get()

static watchedDirType* watchedDirType::get ( int  aId )

inlinestatic

get a watcheDir by the inotify id

Definition at line 356 of file inotify_watch.cpp.

                                        {
        return getWatchedDirs()[aId];
    }

References getWatchedDirs().

Referenced by main().

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getAdoptedBy()

void watchedDirType::getAdoptedBy ( const std::string &  newName, watchedDirType *  newParent  )

inline

move to a new place in the directory tree.

This is needed when a directory is moved (renamed) and changes the tree as well as the name of this directory.

Definition at line 467 of file inotify_watch.cpp.

                                                 {
        if (parent) {
            parent->children.erase(childIterator);
        }
 
        name = newName;
        becomeChildOfMyParent(newParent);
    }

References becomeChildOfMyParent(), childIterator, children, name, and parent.

Referenced by main().

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getChild()

watchedDirType* watchedDirType::getChild ( const std::string &  aName )

inline

Definition at line 454 of file inotify_watch.cpp.

                                                     {
        auto it = children.find(aName);
 
        if (it == children.end()) {
            return nullptr;
        } else {
            return it->second;
        }
    }

References children.

Referenced by main().

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getId()

int watchedDirType::getId ( ) const

inline

Definition at line 451 of file inotify_watch.cpp.

                      {
        return id;
    }

References id.

getPath()

std::string watchedDirType::getPath ( )

inline

return full path to this dir, for use in error messages only

Definition at line 349 of file inotify_watch.cpp.

                        {
        std::string path;
        buildPath(path);
        return path;
    }

References buildPath().

Referenced by ~watchedDirType().

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getWatchedDirs()

static std::map<int, watchedDirType*>& watchedDirType::getWatchedDirs ( )

inlinestaticprivate

Definition at line 286 of file inotify_watch.cpp.

                                                          {
        static std::remove_reference<decltype(getWatchedDirs())>::type watchedDirs;
        return watchedDirs;
    }

Referenced by dump(), empty(), get(), size(), watchedDirType(), and ~watchedDirType().

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invalidateId()

void watchedDirType::invalidateId ( )

inline

Definition at line 448 of file inotify_watch.cpp.

                        {
        id = -1;
    }

setExtraEventMask()

static void watchedDirType::setExtraEventMask ( int  extraMask )

inlinestatic

Definition at line 368 of file inotify_watch.cpp.

                                                 {
        extraEventMask = extraMask;
    }

References extraEventMask.

Referenced by main().

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size()

static size_t watchedDirType::size ( )

inlinestatic

return number of watched directories

Definition at line 364 of file inotify_watch.cpp.

                         {
        return getWatchedDirs().size();
    }

References getWatchedDirs().

Referenced by main().

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Member Data Documentation

childIterator

decltype(children.begin()) watchedDirType::childIterator

private

iterator in parent's child map that holds this object

Definition at line 298 of file inotify_watch.cpp.

Referenced by becomeChildOfMyParent(), getAdoptedBy(), and ~watchedDirType().

children

std::map<std::string, watchedDirType*> watchedDirType::children

private

Definition at line 296 of file inotify_watch.cpp.

Referenced by becomeChildOfMyParent(), getAdoptedBy(), getChild(), and ~watchedDirType().

extraEventMask

int watchedDirType::extraEventMask = 0

staticprivate

Definition at line 290 of file inotify_watch.cpp.

Referenced by setExtraEventMask(), and watchedDirType().

fd

int watchedDirType::fd

private

fd for the inotify instance, needed for destructor

Definition at line 294 of file inotify_watch.cpp.

Referenced by watchedDirType(), and ~watchedDirType().

id

int watchedDirType::id

private

the watch id

Definition at line 295 of file inotify_watch.cpp.

Referenced by getId().

name

std::string watchedDirType::name

private

basename of the directory, i.e. not the full path

Definition at line 292 of file inotify_watch.cpp.

Referenced by becomeChildOfMyParent(), buildPath(), and getAdoptedBy().

parent

watchedDirType* watchedDirType::parent

private

Definition at line 293 of file inotify_watch.cpp.

Referenced by becomeChildOfMyParent(), buildPath(), getAdoptedBy(), watchedDirType(), and ~watchedDirType().

watchIterator

decltype(getWatchedDirs().begin()) watchedDirType::watchIterator

private

iterator in the map that holds this object

Definition at line 297 of file inotify_watch.cpp.

Referenced by watchedDirType(), and ~watchedDirType().

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The documentation for this class was generated from the following file:

• src/inotify_watch.cpp (v0.19-24-g0617ca1 with changes)