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UKKQueue.m
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UKKQueue.m
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//
// UKKQueue.m
// Filie
//
// Created by Uli Kusterer on 21.12.2003
// Copyright 2003 Uli Kusterer.
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
//
// -----------------------------------------------------------------------------
// Headers:
// -----------------------------------------------------------------------------
#import "UKKQueue.h"
#import "UKMainThreadProxy.h"
#import <unistd.h>
#import <fcntl.h>
#include <sys/stat.h>
// -----------------------------------------------------------------------------
// Macros:
// -----------------------------------------------------------------------------
#define DEBUG_LOG_THREAD_LIFETIME 1
#define DEBUG_DETAILED_MESSAGES 1
#ifndef MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4
#define NSUInteger unsigned
#endif
// -----------------------------------------------------------------------------
// Helper class:
// -----------------------------------------------------------------------------
@interface UKKQueuePathEntry : NSObject
{
NSString* path;
int watchedFD;
u_int subscriptionFlags;
int pathRefCount;
}
-(id) initWithPath: (NSString*)inPath flags: (u_int)fflags;
-(void) retainPath;
-(BOOL) releasePath;
-(NSString*) path;
-(int) watchedFD;
-(u_int) subscriptionFlags;
-(void) setSubscriptionFlags: (u_int)fflags;
@end
@implementation UKKQueuePathEntry
-(id) initWithPath: (NSString*)inPath flags: (u_int)fflags;
{
if(( self = [super init] ))
{
path = [inPath copy];
watchedFD = open( [path fileSystemRepresentation], O_EVTONLY, 0 );
if( watchedFD < 0 )
{
[self autorelease];
return nil;
}
subscriptionFlags = fflags;
pathRefCount = 1;
}
return self;
}
-(void) dealloc
{
[path release];
path = nil;
if( watchedFD >= 0 )
close(watchedFD);
watchedFD = -1;
pathRefCount = 0;
[super dealloc];
}
-(void) retainPath
{
@synchronized( self )
{
pathRefCount++;
}
}
-(BOOL) releasePath
{
@synchronized( self )
{
pathRefCount--;
return (pathRefCount == 0);
}
return NO;
}
-(NSString*) path
{
return path;
}
-(int) watchedFD
{
return watchedFD;
}
-(u_int) subscriptionFlags
{
return subscriptionFlags;
}
-(void) setSubscriptionFlags: (u_int)fflags
{
subscriptionFlags = fflags;
}
@end
// -----------------------------------------------------------------------------
// Private stuff:
// -----------------------------------------------------------------------------
@interface UKKQueueCentral : NSObject
{
int queueFD; // The actual queue ID (Unix file descriptor).
NSMutableDictionary* watchedFiles; // List of UKKQueuePathEntries.
BOOL keepThreadRunning;
}
-(int) queueFD; // I know you unix geeks want this...
// UKFileWatcher protocol methods:
-(void) addPath: (NSString*)path;
-(void) addPath: (NSString*)path notifyingAbout: (u_int)fflags;
-(void) removePath: (NSString*)path;
-(void) removeAllPaths;
// Main bottleneck for subscribing:
-(UKKQueuePathEntry*) addPathToQueue: (NSString*)path notifyingAbout: (u_int)fflags;
// Actual work is done here:
-(void) watcherThread: (id)sender;
-(void) postNotification: (NSString*)nm forFile: (NSString*)fp; // Message-posting bottleneck.
@end
// -----------------------------------------------------------------------------
// Globals:
// -----------------------------------------------------------------------------
static UKKQueueCentral * gUKKQueueSharedQueueSingleton = nil;
static id gUKKQueueSharedNotificationCenterProxy = nil; // Object to which we send notifications so they get put in the main thread.
@implementation UKKQueueCentral
// -----------------------------------------------------------------------------
// * CONSTRUCTOR:
// Creates a new KQueue and starts that thread we use for our
// notifications.
//
// REVISIONS:
// 2008-11-07 UK Adapted to new threading model.
// 2004-11-12 UK Doesn't pass self as parameter to watcherThread anymore,
// because detachNewThreadSelector retains target and args,
// which would cause us to never be released.
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(id) init
{
self = [super init];
if( self )
{
if( !gUKKQueueSharedNotificationCenterProxy )
{
gUKKQueueSharedNotificationCenterProxy = [[[NSWorkspace sharedWorkspace] notificationCenter] copyMainThreadProxy]; // Singleton, 'intentional leak'.
[gUKKQueueSharedNotificationCenterProxy setWaitForCompletion: NO]; // Better performance and avoid deadlocks.
}
queueFD = kqueue();
if( queueFD == -1 )
{
[self release];
return nil;
}
watchedFiles = [[NSMutableDictionary alloc] init];
}
return self;
}
// -----------------------------------------------------------------------------
// * DESTRUCTOR:
// Releases the kqueue again.
//
// REVISIONS:
// 2008-11-07 UK Adapted to new threading model.
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(void) dealloc
{
keepThreadRunning = NO;
// Close all our file descriptors so the files can be deleted:
[self removeAllPaths];
[watchedFiles release];
watchedFiles = nil;
[super dealloc];
}
// -----------------------------------------------------------------------------
// removeAllPaths:
// Stop listening for changes to all paths. This removes all
// notifications.
//
// REVISIONS:
// 2008-11-07 UK Renamed from unsubscribeAll, for consistency.
// 2004-12-28 UK Added as suggested by bbum.
// -----------------------------------------------------------------------------
-(void) removeAllPaths
{
@synchronized( self )
{
[watchedFiles removeAllObjects];
}
}
// -----------------------------------------------------------------------------
// queueFD:
// Returns a Unix file descriptor for the KQueue this uses. The descriptor
// is owned by this object. Do not close it!
//
// REVISIONS:
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(int) queueFD
{
return queueFD;
}
-(void) addPath: (NSString*)path
{
[self addPath: path notifyingAbout: UKKQueueNotifyDefault];
}
-(void) addPath: (NSString*)path notifyingAbout: (u_int)fflags
{
[self addPathToQueue: path notifyingAbout: fflags];
}
-(UKKQueuePathEntry*) addPathToQueue: (NSString*)path notifyingAbout: (u_int)fflags
{
@synchronized( self )
{
UKKQueuePathEntry* pe = [watchedFiles objectForKey: path]; // Already watching this path?
if( pe )
{
[pe retainPath]; // Just add another subscription to this entry.
if( ([pe subscriptionFlags] & fflags) == fflags ) // All flags already set?
return [[pe retain] autorelease];
fflags |= [pe subscriptionFlags];
}
struct timespec nullts = { 0, 0 };
struct kevent ev;
if( !pe )
pe = [[[UKKQueuePathEntry alloc] initWithPath: path flags: fflags] autorelease];
if( pe )
{
EV_SET( &ev, [pe watchedFD], EVFILT_VNODE,
EV_ADD | EV_ENABLE | EV_CLEAR,
fflags, 0, pe );
[pe setSubscriptionFlags: fflags];
[watchedFiles setObject: pe forKey: path];
kevent( queueFD, &ev, 1, NULL, 0, &nullts );
// Start new thread that fetches and processes our events:
if( !keepThreadRunning )
{
keepThreadRunning = YES;
[NSThread detachNewThreadSelector:@selector(watcherThread:) toTarget:self withObject:nil];
}
}
return [[pe retain] autorelease];
}
return nil;
}
// -----------------------------------------------------------------------------
// removePath:
// Stop listening for changes to the specified path. Use this to balance
// both addPath:notfyingAbout: as well as addPath:.
//
// REVISIONS:
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(void) removePath: (NSString*)path
{
@synchronized( self )
{
UKKQueuePathEntry* pe = [watchedFiles objectForKey: path]; // Already watching this path?
if( pe && [pe releasePath] ) // Give up one subscription. Is this the last subscription?
[watchedFiles removeObjectForKey: path]; // Unsubscribe from this file.
}
}
// -----------------------------------------------------------------------------
// description:
// This method can be used to help in debugging. It provides the value
// used by NSLog & co. when you request to print this object using the
// %@ format specifier.
//
// REVISIONS:
// 2008-11-05 UK Made this indentation-aware.
// 2004-11-12 UK Created.
// -----------------------------------------------------------------------------
-(NSString*) descriptionWithLocale: (id)locale indent: (NSUInteger)level
{
NSMutableString* mutStr = [NSMutableString string];
int x = 0;
for( x = 0; x < level; x++ )
[mutStr appendString: @" "];
[mutStr appendString: NSStringFromClass([self class])];
for( x = 0; x < level; x++ )
[mutStr appendString: @" "];
[mutStr appendString: @"{"];
for( x = 0; x < level; x++ )
[mutStr appendString: @" "];
[mutStr appendFormat: @"watchedFiles = %@", [watchedFiles descriptionWithLocale: locale indent: level +1]];
for( x = 0; x < level; x++ )
[mutStr appendString: @" "];
[mutStr appendString: @"}"];
return mutStr;
}
// -----------------------------------------------------------------------------
// watcherThread:
// This method is called by our NSThread to loop and poll for any file
// changes that our kqueue wants to tell us about. This sends separate
// notifications for the different kinds of changes that can happen.
// All messages are sent via the postNotification:forFile: main bottleneck.
//
// This also calls sharedWorkspace's noteFileSystemChanged.
//
// To terminate this method (and its thread), set keepThreadRunning to NO.
//
// REVISIONS:
// 2008-11-07 UK Adapted to new threading model.
// 2005-08-27 UK Changed to use keepThreadRunning instead of kqueueFD
// being -1 as termination criterion, and to close the
// queue in this thread so the main thread isn't blocked.
// 2004-11-12 UK Fixed docs to include termination criterion, added
// timeout to make sure the bugger gets disposed.
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(void) watcherThread: (id)sender
{
int n;
struct kevent ev;
struct timespec timeout = { 1, 0 }; // 1 second timeout. Should be longer, but we need this thread to exit when a kqueue is dealloced, so 1 second timeout is quite a while to wait.
int theFD = queueFD; // So we don't have to risk accessing iVars when the thread is terminated.
#if DEBUG_LOG_THREAD_LIFETIME
NSLog(@"watcherThread started.");
#endif
while( keepThreadRunning )
{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
NS_DURING
n = kevent( queueFD, NULL, 0, &ev, 1, &timeout );
if( n > 0 )
{
NSLog( @"KEVENT returned %d", n );
if( ev.filter == EVFILT_VNODE )
{
NSLog( @"KEVENT filter is EVFILT_VNODE" );
if( ev.fflags )
{
NSLog( @"KEVENT flags are set" );
UKKQueuePathEntry* pe = [[(UKKQueuePathEntry*)ev.udata retain] autorelease]; // In case one of the notified folks removes the path.
NSString* fpath = [pe path];
[[NSWorkspace sharedWorkspace] noteFileSystemChanged: fpath];
if( (ev.fflags & NOTE_RENAME) == NOTE_RENAME )
[self postNotification: UKFileWatcherRenameNotification forFile: fpath];
if( (ev.fflags & NOTE_WRITE) == NOTE_WRITE )
[self postNotification: UKFileWatcherWriteNotification forFile: fpath];
if( (ev.fflags & NOTE_DELETE) == NOTE_DELETE )
[self postNotification: UKFileWatcherDeleteNotification forFile: fpath];
if( (ev.fflags & NOTE_ATTRIB) == NOTE_ATTRIB )
[self postNotification: UKFileWatcherAttributeChangeNotification forFile: fpath];
if( (ev.fflags & NOTE_EXTEND) == NOTE_EXTEND )
[self postNotification: UKFileWatcherSizeIncreaseNotification forFile: fpath];
if( (ev.fflags & NOTE_LINK) == NOTE_LINK )
[self postNotification: UKFileWatcherLinkCountChangeNotification forFile: fpath];
if( (ev.fflags & NOTE_REVOKE) == NOTE_REVOKE )
[self postNotification: UKFileWatcherAccessRevocationNotification forFile: fpath];
}
}
}
NS_HANDLER
NSLog(@"Error in UKKQueue watcherThread: %@",localException);
NS_ENDHANDLER
[pool release];
}
// Close our kqueue's file descriptor:
if( close( theFD ) == -1 )
NSLog(@"watcherThread: Couldn't close main kqueue (%d)", errno);
#if DEBUG_LOG_THREAD_LIFETIME
NSLog(@"watcherThread finished.");
#endif
}
// -----------------------------------------------------------------------------
// postNotification:forFile:
// This is the main bottleneck for posting notifications. If you don't want
// the notifications to go through NSWorkspace, override this method and
// send them elsewhere.
//
// REVISIONS:
// 2008-11-07 UK Got rid of old notifications.
// 2004-02-27 UK Changed this to send new notification, and the old one
// only to objects that respond to it. The old category on
// NSObject could cause problems with the proxy itself.
// 2004-10-31 UK Helloween fun: Make this use a mainThreadProxy and
// allow sending the notification even if we have a
// delegate.
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(void) postNotification: (NSString*)nm forFile: (NSString*)fp
{
#if DEBUG_DETAILED_MESSAGES
NSLog( @"%@: %@", nm, fp );
#endif
[gUKKQueueSharedNotificationCenterProxy postNotificationName: nm object: self
userInfo: [NSDictionary dictionaryWithObjectsAndKeys: fp, @"path", nil]]; // The proxy sends the notification on the main thread.
}
@end
@implementation UKKQueue
// -----------------------------------------------------------------------------
// sharedFileWatcher:
// Returns a singleton queue object. In many apps (especially those that
// subscribe to the notifications) there will only be one kqueue instance,
// and in that case you can use this.
//
// For all other cases, feel free to create additional instances to use
// independently.
//
// REVISIONS:
// 2006-03-13 UK Renamed from sharedQueue.
// 2005-07-02 UK Created.
// -----------------------------------------------------------------------------
+(id) sharedFileWatcher
{
@synchronized( [UKKQueueCentral class] )
{
if( !gUKKQueueSharedQueueSingleton )
gUKKQueueSharedQueueSingleton = [[UKKQueueCentral alloc] init]; // This is a singleton, and thus an intentional "leak".
}
return gUKKQueueSharedQueueSingleton;
}
-(id) init
{
if(( self = [super init] ))
{
watchedFiles = [[NSMutableDictionary alloc] init];
NSNotificationCenter* nc = [[NSWorkspace sharedWorkspace] notificationCenter];
UKKQueueCentral* kqc = [[self class] sharedFileWatcher];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherRenameNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherWriteNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherDeleteNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherAttributeChangeNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherSizeIncreaseNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherLinkCountChangeNotification object: kqc];
[nc addObserver: self selector: @selector(fileChangeNotification:)
name: UKFileWatcherAccessRevocationNotification object: kqc];
}
return self;
}
-(void) finalize
{
[self removeAllPaths];
[super finalize];
}
-(void) dealloc
{
delegate = nil;
// Close all our file descriptors so the files can be deleted:
[self removeAllPaths];
[watchedFiles release];
watchedFiles = nil;
NSNotificationCenter* nc = [[NSWorkspace sharedWorkspace] notificationCenter];
UKKQueueCentral* kqc = [[self class] sharedFileWatcher];
[nc removeObserver: self
name: UKFileWatcherRenameNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherWriteNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherDeleteNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherAttributeChangeNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherSizeIncreaseNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherLinkCountChangeNotification object: kqc];
[nc removeObserver: self
name: UKFileWatcherAccessRevocationNotification object: kqc];
[super dealloc];
}
-(int) queueFD
{
return [[UKKQueue sharedFileWatcher] queueFD]; // We're all one big, happy family now.
}
// -----------------------------------------------------------------------------
// addPath:
// Tell this queue to listen for all interesting notifications sent for
// the object at the specified path. If you want more control, use the
// addPath:notifyingAbout: variant instead.
//
// REVISIONS:
// 2004-03-13 UK Documented.
// -----------------------------------------------------------------------------
-(void) addPath: (NSString*)path
{
[self addPath: path notifyingAbout: UKKQueueNotifyDefault];
}
// -----------------------------------------------------------------------------
// addPath:notfyingAbout:
// Tell this queue to listen for the specified notifications sent for
// the object at the specified path.
// -----------------------------------------------------------------------------
-(void) addPath: (NSString*)path notifyingAbout: (u_int)fflags
{
UKKQueuePathEntry* entry = [watchedFiles objectForKey: path];
if( entry )
return; // Already have this one.
entry = [[UKKQueue sharedFileWatcher] addPathToQueue: path notifyingAbout: fflags];
[watchedFiles setObject: entry forKey: path];
}
-(void) removePath: (NSString*)fpath
{
UKKQueuePathEntry* entry = [watchedFiles objectForKey: fpath];
if( entry ) // Don't have this one, do nothing.
{
[watchedFiles removeObjectForKey: fpath];
[[UKKQueue sharedFileWatcher] removePath: fpath];
}
}
-(id) delegate
{
return delegate;
}
-(void) setDelegate: (id)newDelegate
{
delegate = newDelegate;
}
-(BOOL) alwaysNotify
{
return alwaysNotify;
}
-(void) setAlwaysNotify: (BOOL)state
{
alwaysNotify = state;
}
-(void) removeAllPaths
{
NSEnumerator* enny = [watchedFiles objectEnumerator];
UKKQueuePathEntry* entry = nil;
UKKQueueCentral* sfw = [UKKQueue sharedFileWatcher];
// Unsubscribe all:
while(( entry = [enny nextObject] ))
[sfw removePath: [entry path]];
[watchedFiles removeAllObjects]; // Empty the list now we don't have any subscriptions anymore.
}
-(void) fileChangeNotification: (NSNotification*)notif
{
NSString* fp = [[notif userInfo] objectForKey: @"path"];
NSString* nm = [notif name];
if( [watchedFiles objectForKey: fp] == nil ) // Don't notify about files we don't care about.
return;
[delegate watcher: self receivedNotification: nm forPath: fp];
if( !delegate || alwaysNotify )
{
[[[NSWorkspace sharedWorkspace] notificationCenter] postNotificationName: nm object: self
userInfo: [notif userInfo]]; // Send the notification on to *our* clients only.
}
}
@end