path: root/src/uscxml/plugins/invoker/filesystem/dirmon/FileWatcher/FileWatcherOSX.cpp

/**
	Copyright (c) 2009 James Wynn (james@jameswynn.com)

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	THE SOFTWARE.

	James Wynn james@jameswynn.com
*/

#include <FileWatcher/FileWatcherOSX.h>

#if FILEWATCHER_PLATFORM == FILEWATCHER_PLATFORM_KQUEUE

#include <sys/event.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <string.h>
#include <iostream>

// this is more suited:
// https://developer.apple.com/library/mac/#documentation/Darwin/Conceptual/FSEvents_ProgGuide/UsingtheFSEventsFramework/UsingtheFSEventsFramework.html

namespace FW {

#define MAX_CHANGE_EVENT_SIZE 2000

typedef struct kevent KEvent;

struct EntryStruct {
	EntryStruct(const char* filename, time_t mtime = 0)
		: mFilename(filename), mModifiedTime(mtime) {
	}
	~EntryStruct() {
		delete[] mFilename;
	}
	const char* mFilename;
	time_t mModifiedTime;
};

int comparator(const void* ke1, const void* ke2) {
	/*KEvent* kevent1 = (KEvent*) ke1;
	KEvent* kevent2 = (KEvent*) ke2;

	EntryStruct* event1 = (EntryStruct*)kevent1->udata;
	EntryStruct* event2 = (EntryStruct*)kevent2->udata;
	return strcmp(event1->mFilename, event2->mFilename);
	*/
	return strcmp(((EntryStruct*)(((KEvent*)(ke1))->udata))->mFilename, ((EntryStruct*)(((KEvent*)(ke2))->udata))->mFilename);
}

struct WatchStruct {
	WatchID mWatchID;
	String mDirName;
	FileWatchListener* mListener;
	FileWatcherOSX* mWatcher;
	bool mRecursive;

	// index 0 is always the directory
	KEvent mChangeList[MAX_CHANGE_EVENT_SIZE];
	size_t mChangeListCount;

	WatchStruct(WatchID watchid, const String& dirname, FileWatchListener* listener, FileWatcherOSX* watcher, bool recursive = false)
		: mWatchID(watchid), mDirName(dirname), mListener(listener), mWatcher(watcher), mRecursive(recursive) {
		mChangeListCount = 0;
		addAll();
	}

	void addFile(const String& name, bool emitEvents = true) {
		//fprintf(stderr, "ADDED: %s\n", name.c_str());

		// create entry
		struct stat attrib;
		stat(name.c_str(), &attrib);

		int fd = open(name.c_str(), O_RDONLY);

		if(fd == -1)
			throw FileNotFoundException(name);

		++mChangeListCount;

		char* namecopy = new char[name.length() + 1];
		strncpy(namecopy, name.c_str(), name.length());
		namecopy[name.length()] = 0;
		EntryStruct* entry = new EntryStruct(namecopy, attrib.st_mtime);

		// set the event data at the end of the list
		EV_SET(&mChangeList[mChangeListCount], fd, EVFILT_VNODE,
		       EV_ADD | EV_ENABLE | EV_ONESHOT,
		       NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_ATTRIB | NOTE_RENAME,
		       0, (void*)entry);

		// qsort
		qsort(mChangeList + 1, mChangeListCount, sizeof(KEvent), comparator);

		// handle action
		if(emitEvents)
			handleAction(name, Actions::Add);
	}

	void removeFile(const String& name, bool emitEvents = true) {
		// bsearch
		KEvent target;
		EntryStruct tempEntry(name.c_str(), 0);
		target.udata = &tempEntry;
		KEvent* ke = (KEvent*)bsearch(&target, &mChangeList, mChangeListCount + 1, sizeof(KEvent), comparator);
		if(!ke)
			throw FileNotFoundException(name);

		tempEntry.mFilename = 0;

		// delete
		close(ke->ident);
		delete((EntryStruct*)ke->udata);
		memset(ke, 0, sizeof(KEvent));

		// move end to current
		memcpy(ke, &mChangeList[mChangeListCount], sizeof(KEvent));
		memset(&mChangeList[mChangeListCount], 0, sizeof(KEvent));
		--mChangeListCount;

		// qsort
		qsort(mChangeList + 1, mChangeListCount, sizeof(KEvent), comparator);

		// handle action
		if(emitEvents)
			handleAction(name, Actions::Delete);
	}

	// called when the directory is actually changed
	// means a file has been added or removed
	// rescans the watched directory adding/removing files and sending notices
	void rescan() {
		// if new file, call addFile
		// if missing file, call removeFile
		// if timestamp modified, call handleAction(filename, ACTION_MODIFIED);
		DIR* dir = opendir(mDirName.c_str());
		if(!dir)
			return;

		struct dirent* dentry;
		KEvent* ke = &mChangeList[1];
		EntryStruct* entry = 0;
		struct stat attrib;

		while((dentry = readdir(dir)) != NULL) {
			String fname = mDirName + "/" + dentry->d_name;
			stat(fname.c_str(), &attrib);
			if(!S_ISREG(attrib.st_mode))
				continue;

			if(ke <= &mChangeList[mChangeListCount]) {
				entry = (EntryStruct*)ke->udata;
				int result = strcmp(entry->mFilename, fname.c_str());
				//fprintf(stderr, "[%s cmp %s]\n", entry->mFilename, fname.c_str());
				if(result == 0) {
					stat(entry->mFilename, &attrib);
					time_t timestamp = attrib.st_mtime;

					if(entry->mModifiedTime != timestamp) {
						entry->mModifiedTime = timestamp;
						handleAction(entry->mFilename, Actions::Modified);
					}
					ke++;
				} else if(result < 0) {
					// f1 was deleted
					removeFile(entry->mFilename);
					ke++;
				} else {
					// f2 was created
					addFile(fname);
					ke++;
				}
			} else {
				// just add
				addFile(fname);
				ke++;
			}
		}//end while

		closedir(dir);
	};

	void handleAction(const String& filename, FW::Action action) {
		mListener->handleFileAction(mWatchID, mDirName, filename, action);
	}

	void addAll() {
		// add base dir
		int fd = open(mDirName.c_str(), O_RDONLY);
		EV_SET(&mChangeList[0], fd, EVFILT_VNODE,
		       EV_ADD | EV_ENABLE | EV_ONESHOT,
		       NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_ATTRIB | NOTE_RENAME,
		       0, 0);

		//fprintf(stderr, "ADDED: %s\n", mDirName.c_str());

		// scan directory and call addFile(name, false) on each file
		DIR* dir = opendir(mDirName.c_str());
		if(!dir)
			throw FileNotFoundException(mDirName);

		struct dirent* entry;
		struct stat attrib;
		while((entry = readdir(dir)) != NULL) {
			String fname = (mDirName + "/" + String(entry->d_name));
			stat(fname.c_str(), &attrib);
			if(S_ISREG(attrib.st_mode)) {
				addFile(fname, false);
			} else if(S_IFDIR && mRecursive && entry->d_name[0] != '.') {
				mWatcher->addWatch(fname, mListener, mRecursive);
			} else {
				fprintf(stderr, "NOT ADDED: %s (%d)\n", fname.c_str(), attrib.st_mode);
			}
		}//end while

		closedir(dir);
	}

	void removeAll() {
		KEvent* ke = NULL;

		// go through list removing each file and sending an event
		for(int i = 0; i < mChangeListCount; ++i) {
			ke = &mChangeList[i];
			//handleAction(name, Action::Delete);
			EntryStruct* entry = (EntryStruct*)ke->udata;

			handleAction(entry->mFilename, Actions::Delete);

			// delete
			close(ke->ident);
			delete((EntryStruct*)ke->udata);
		}
	}
};

void FileWatcherOSX::update() {
	int nev = 0;
	struct kevent event;

	WatchMap::iterator iter = mWatches.begin();
	WatchMap::iterator end = mWatches.end();
	for(; iter != end; ++iter) {
		WatchStruct* watch = iter->second;

		while((nev = kevent(mDescriptor, (KEvent*)&(watch->mChangeList), watch->mChangeListCount + 1, &event, 1, &mTimeOut)) != 0) {
			if(nev == -1)
				perror("kevent");
			else {
				if (event.fflags & NOTE_DELETE) {
					fprintf(stderr, "NOTE_DELETE ");
				}
				if (event.fflags & NOTE_EXTEND) {
					fprintf(stderr, "NOTE_EXTEND ");
				}
				if (event.fflags & NOTE_WRITE) {
					fprintf(stderr, "NOTE_WRITE ");
				}
				if (event.fflags & NOTE_ATTRIB) {
					fprintf(stderr, "NOTE_ATTRIB ");
				}
				if (event.fflags & NOTE_RENAME) {
					fprintf(stderr, "NOTE_RENAME ");
				}

				EntryStruct* entry = 0;
				if((entry = (EntryStruct*)event.udata) != 0) {
					fprintf(stderr, " to %s -- \n", (char*)entry->mFilename);

					if(event.fflags & NOTE_DELETE) {
						//watch->handleAction(entry->mFilename, Action::Delete);
						watch->removeFile(entry->mFilename);
					}
					if(event.fflags & NOTE_EXTEND ||
					        event.fflags & NOTE_WRITE ||
					        event.fflags & NOTE_ATTRIB) {
						//watch->rescan();
						struct stat attrib;
						stat(entry->mFilename, &attrib);
						entry->mModifiedTime = attrib.st_mtime;
						watch->handleAction(entry->mFilename, FW::Actions::Modified);
					}
				} else {
					fprintf(stderr, " in %s -- rescanning\n", watch->mDirName.c_str());
					watch->rescan();
				}
			}
		}
	}
}

//--------
FileWatcherOSX::FileWatcherOSX() {
	mDescriptor = kqueue();
	mTimeOut.tv_sec = 0;
	mTimeOut.tv_nsec = 20000000;
}

//--------
FileWatcherOSX::~FileWatcherOSX() {
	WatchMap::iterator iter = mWatches.begin();
	WatchMap::iterator end = mWatches.end();
	for(; iter != end; ++iter) {
		delete iter->second;
	}
	mWatches.clear();

	close(mDescriptor);
}

//--------
WatchID FileWatcherOSX::addWatch(const String& directory, FileWatchListener* watcher, bool recursive) {
	/*		int fd = open(directory.c_str(), O_RDONLY);
			if(fd == -1)
				perror("open");

			EV_SET(&change, fd, EVFILT_VNODE,
				   EV_ADD | EV_ENABLE | EV_ONESHOT,
				   NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_ATTRIB,
				   0, (void*)"testing");
	*/

	std::cout << "Adding watch for " << directory << std::endl;

	WatchID currWatch = ++mLastWatchID;
	WatchStruct* watch = new WatchStruct(currWatch, directory, watcher, this, recursive);
	mWatches.insert(std::make_pair(currWatch, watch));
	return currWatch;
}

//--------
void FileWatcherOSX::removeWatch(const String& directory) {
	WatchMap::iterator iter = mWatches.begin();
	WatchMap::iterator end = mWatches.end();
	for(; iter != end; ++iter) {
		if(directory == iter->second->mDirName) {
			removeWatch(iter->first);
			return;
		}
	}
}

//--------
void FileWatcherOSX::removeWatch(WatchID watchid) {
	WatchMap::iterator iter = mWatches.find(watchid);

	if(iter == mWatches.end())
		return;

	WatchStruct* watch = iter->second;
	mWatches.erase(iter);

	//inotify_rm_watch(mFD, watchid);

	delete watch;
	watch = 0;
}

//--------
void FileWatcherOSX::handleAction(WatchStruct* watch, const String& filename, unsigned long action) {
}

};//namespace FW

#endif//FILEWATCHER_PLATFORM_KQUEUE