For my app I need to use the Carbon file manager API to get the size of a folder (NSEnumerator is slow, and using NSTask with a shell command is even worse). I've imported the Carbon framework, and I'm using this method to get the size of a folder:
http://www.cocoabuilder.com/archive/message/cocoa/2005/5/20/136503
It uses an FSRef as an argument, and my path string is currently an NSString. I tried using this to convert the NSString to an FSRef:
FSRef f;
OSStatus os_status = FSPathMakeRef((const UInt8 *)[filePath fileSystemRepresentation], &f, NULL);
if (os_status != noErr) {
NSLog(#"fsref creation failed");
}
And then I called the folder size method:
[self fastFolderSizeAtFSRef:f];
However when I try to build, I get this error regarding the above line:
error: incompatible type for argument one of 'fastFolderSizeAtFSRef:'
Any help would be appreciated. Thanks
The "fastFolderSizeAtFSRef" method takes an FSRef* (FSRef pointer). You're giving it an FSRef. It's a one character fix, luckily enough. You have:
[self fastFolderSizeAtFSRef:f];
Simply change that to:
[self fastFolderSizeAtFSRef:&f];
And you should be good to go. However, I was implementing this same method yesterday but was having trouble creating the FSRef itself. I eventually went with the following code:
FSRef convertNSStringToFSRef(NSString * theString) {
FSRef output;
const char *filePathAsCString = [theString UTF8String];
CFURLRef url = CFURLCreateWithBytes(kCFAllocatorDefault,
(const UInt8 *)filePathAsCString,
strlen(filePathAsCString),
kCFStringEncodingUTF8,
NULL);
CFURLGetFSRef(url, &output);
CFRelease(url);
return output;
}
This has been working flawlessly for me.
EDIT: I just open sourced the code that I'm using this in. It's these files:
This file adds a method to NSFileManager that uses an FSRef to find the complete size of a directory.
This file adds a method to NSString that will convert it to an FSRef.
Everything happens on line 46 of this file.
Related
I have a document path as an NSString. How do I get its UTI as an NSString? I currently use LSCopyItemAttribute but that requires an FSRef and all the functions for making an FSRef seems to be deprecated.
(Note: This is for Mac OS 10.8+.)
You will be able to get it using mobile core services framework. Refer the code below
NSString *path; // contains the file path
// Get the UTI from the file's extension:
CFStringRef pathExtension = (__bridge_retained CFStringRef)[path pathExtension];
CFStringRef type = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, pathExtension, NULL);
CFRelease(pathExtension);
The code snippet is taken from here.
Use can use url.resourceValues(forKeys: (as mentioned in the comments):
if let resourceValues = try? url.resourceValues(forKeys: [.typeIdentifierKey]),
let uti = resourceValues.typeIdentifier {
return uti
}
Is there a faster file system API that I can use if I only need to know if a file is a folder/symlink and its size. I'm currently using [NSFileManager attributesOfItemAtPath...] and only NSFileSize and NSFileType.
Are there any bulk filesystem enumeration APIs I should be using? I suspect this could be faster without having to jump in and out of user code.
My goal is to quickly recurse through directories to get a folders true file size and currently calling attributesOfItemAtPath is my 95% bottleneck.
Some of the code I'm currently using:
NSDictionary* properties = [fileManager attributesOfItemAtPath:filePath error:&error];
long long fileSize = [[properties objectForKey:NSFileSize] longLongValue];
NSObject* fileType = [[properties objectForKey:NSFileType isEqual:NSFileTypeDirectory];
If you want to get really hairy, the Mac OS kernel implements a unique getdirentriesattr() system call which will return a list of files and attributes from a specified directory. It's messy to set up and call, and it's not supported on all filesystems (!), but if you can get it to work for you, it can speed things up significantly.
There's also a closely related searchfs() system call which can be used to rapidly search for files. It's subject to most of the same gotchas.
You can use stat and lstat. Take a look at this answer for calculating directory size.
CPU raises with attributesOfItemAtPath:error:
Whether it's faster or not I'm not certain, but NSURL will give you this information via getResourceValue:forKey:error:
NSError * e;
NSNumber * isDirectory;
BOOL success = [URLToFile getResourceValue:&isDirectory
forKey:NSURLIsDirectoryKey
error:&e];
if( !success ){
// error
}
NSNumber * fileSize;
BOOL success = [URLToFile getResourceValue:&fileSize
forKey:NSURLFileSizeKey
error:&e];
You might also find it convenient to wrap this up if you don't really care about the error:
#implementation NSURL (WSSSimpleResourceValueRetrieval)
- (id)WSSResourceValueForKey: (NSString *)key
{
id value = nil;
BOOL success = [self getResourceValue:&value
forKey:key
error:nil];
if( !success ){
value = nil;
}
return value;
}
#end
This is given as the substitute for the deprecated File Manager function FSGetCatalogInfo(), which is used in a solution in an old Cocoa-dev thread that Dave DeLong gives the thumbs up to.
For the enumeration part, the File System Programming Guide has a section "Getting the Contents of a Directory in a Single Batch Operation", which discusses using contentsOfDirectoryAtURL:includingPropertiesForKeys:options:error:
When I changed the current directory path of main.m to newDir why does it still say that there are no files in newDir? Also I ran this program multiple times with no errors. Does that mean I ended up creating multiple newDir?
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[])
{
#autoreleasepool {
NSString *newDir = #"newDir";
NSFileManager *manager = [NSFileManager defaultManager];
if ([manager createDirectoryAtPath:newDir withIntermediateDirectories:YES attributes:nil error:NULL] == NO) {
NSLog(#"couldnt create new directory");
return 1;
}
if ([manager changeCurrentDirectoryPath: newDir] == NO) {
NSLog(#"couldnt change directory path");
return 2;
}
NSLog(#"%#", [manager currentDirectoryPath]);
NSLog(#"%#", [manager contentsOfDirectoryAtPath:newDir error:NULL]);
}
return 0;
}
Output:
2012-08-07 10:27:20.428 Test[853:707] /Users/ss/Library/Developer/Xcode/DerivedData/Test-bfrqtnrhaafmdzghoyirjnfqjbfc/Build/Products/Debug/newDir
2012-08-07 10:36:47.832 Test[885:707] (null)
The path to main.m does not play into what happens when you run your program: the only question is whether the directory has any files or not, and from the log it appears that it doesn't.
To create some files in the directory, run these commands in the terminal window:
touch /Users/ss/Library/Developer/Xcode/DerivedData/Test-bfrqtnrhaafmdzghoyirjnfqjbfc/Build/Products/Debug/newDir/quick.txt
touch /Users/ss/Library/Developer/Xcode/DerivedData/Test-bfrqtnrhaafmdzghoyirjnfqjbfc/Build/Products/Debug/newDir/brown.txt
touch /Users/ss/Library/Developer/Xcode/DerivedData/Test-bfrqtnrhaafmdzghoyirjnfqjbfc/Build/Products/Debug/newDir/fox.txt
This will create three empty files. Now run your program, and see if it discovers the newly created txt files; it should.
On your second question, the operating system would not let you create multiple file system objects with identical names, so the answer is no, you created only one newDir.
Since you're ignoring errors on your contentsOfDirectoryAtPath call, it's entirely possible that the call is failing -- hence the null.
Without looking at references, it appears that you're looking for directory .../newDir/newDir, a directory that likely does not exist.
In any event, since newDir is new it wouldn't contain any entries (other than . and ..).
It appears after much searching that there seems to be a common problem when trying to do a file copy and show a progress indicator relative to the amount of the file that has been copied. After spending some considerable time trying to resolve this issue, I find myself at the mercy of the StackOverflow Gods once again :-) - Hopefully one day I'll be among those that can help out the rookies too!
I am trying to get a progress bar to show the status of a copy process and once the copy process has finished, call a Cocoa method. The challenge - I need to make use of File Manager Carbon calls because NSFileManager does not give me the full ability I need.
I started out by trying to utilize the code on Matt Long's site Cocoa Is My Girlfriend. The code got me some good distance. I managed to get the file copy progress working. The bar updates and (with some additional searching within Apple docs) I found out how to tell if the file copy process has finished...
if (stage == kFSOperationStageComplete)
However, I have one last hurdle that is a little larger than my leap right now. I don't know how to pass an object reference into the callback and I don't know how to call a Cocoa method from the callback once finished. This is a limit of my Carbon -> Cocoa -> Carbon understanding. One of the comments on the blog said
"Instead of accessing the progress indicator via a static pointer, you can just use the void *info field of the FSFileOperationClientContext struct, and passing either the AppDelegate or the progress indicator itself."
Sounds like a great idea. Not sure how to do this. For the sake of everyone else that appears to bump into this issue and is coming from a non-Carbon background, based mostly upon the code from Matt's example, here is some simplified code as an example of the problem...
In a normal cocoa method:
CFRunLoopRef runLoop = CFRunLoopGetCurrent();
FSFileOperationRef fileOp = FSFileOperationCreate(kCFAllocatorDefault);
OSStatus status = FSFileOperationScheduleWithRunLoop(fileOp,
runLoop, kCFRunLoopDefaultMode);
if (status) {
NSLog(#"Failed to schedule operation with run loop: %#", status);
return NO;
}
// Create a filesystem ref structure for the source and destination and
// populate them with their respective paths from our NSTextFields.
FSRef source;
FSRef destination;
// Used FSPathMakeRefWithOptions instead of FSPathMakeRef which is in the
// original example because I needed to use the kFSPathMakeRefDefaultOptions
// to deal with file paths to remote folders via a /Volume reference
FSPathMakeRefWithOptions((const UInt8 *)[aSource fileSystemRepresentation],
kFSPathMakeRefDefaultOptions,
&source,
NULL);
Boolean isDir = true;
FSPathMakeRefWithOptions((const UInt8 *)[aDestDir fileSystemRepresentation],
kFSPathMakeRefDefaultOptions,
&destination,
&isDir);
// Needed to change from the original to use CFStringRef so I could convert
// from an NSString (aDestFile) to a CFStringRef (targetFilename)
CFStringRef targetFilename = (CFStringRef)aDestFile;
// Start the async copy.
status = FSCopyObjectAsync (fileOp,
&source,
&destination, // Full path to destination dir
targetFilename,
kFSFileOperationDefaultOptions,
statusCallback,
1.0,
NULL);
CFRelease(fileOp);
if (status) {
NSString * errMsg = [NSString stringWithFormat:#"%# - %#",
[self class], status];
NSLog(#"Failed to begin asynchronous object copy: %#", status);
}
Then the callback (in the same file)
static void statusCallback (FSFileOperationRef fileOp,
const FSRef *currentItem,
FSFileOperationStage stage,
OSStatus error,
CFDictionaryRef statusDictionary,
void *info )
{
NSLog(#"Callback got called.");
// If the status dictionary is valid, we can grab the current values to
// display status changes, or in our case to update the progress indicator.
if (statusDictionary)
{
CFNumberRef bytesCompleted;
bytesCompleted = (CFNumberRef) CFDictionaryGetValue(statusDictionary,
kFSOperationBytesCompleteKey);
CGFloat floatBytesCompleted;
CFNumberGetValue (bytesCompleted, kCFNumberMaxType,
&floatBytesCompleted);
NSLog(#"Copied %d bytes so far.",
(unsigned long long)floatBytesCompleted);
// fileProgressIndicator is currently declared as a pointer to a
// static progress bar - but this needs to change so that it is a
// pointer passed in via the controller. Would like to have a
// pointer to an instance of a progress bar
[fileProgressIndicator setDoubleValue:(double)floatBytesCompleted];
[fileProgressIndicator displayIfNeeded];
}
if (stage == kFSOperationStageComplete) {
NSLog(#"Finished copying the file");
// Would like to call a Cocoa Method here...
}
}
So the bottom line is how can I:
Pass a pointer to an instance of a progress bar from the calling method to the callback
Upon completion, call back out to a normal Cocoa method
And as always, help is much appreciated (and hopefully the answer will solve many of the issues and complaints I have seen in many threads!!)
You can do this by using the last parameter to FSCopyObjectAsync(), which is a struct of type FSFileOperationClientContext. One of the fields of that struct is info, which is a void* parameter that you can basically use as you see fit. Whatever you assign to that field of the struct you pass into FSCopyObjectAsync() will be passed in turn to your callback function as the last info function parameter there. A void* can be anything, including a pointer to an object, so you can use that to pass the instance of your object that you want to handle the callback.
The setup code would look like this:
FSFileOperationClientContext clientContext = {0}; //zero out the struct to begin with
clientContext.info = myProgressIndicator;
//All the other setup code
status = FSCopyObjectAsync (fileOp,
&source,
&destination, // Full path to destination dir
targetFilename,
kFSFileOperationDefaultOptions,
statusCallback,
1.0,
&clientContext);
Then, in your callback function:
static void statusCallback (FSFileOperationRef fileOp,
const FSRef *currentItem,
FSFileOperationStage stage,
OSStatus error,
CFDictionaryRef statusDictionary,
void *info )
{
NSProgressIndicator* fileProgressIndicator = (NSProgressIndicator*)info;
[fileProgressIndicator setDoubleValue:(double)floatBytesCompleted];
[fileProgressIndicator displayIfNeeded];
}
I would like to find the mount point of a volume for a given NSString path.
Though I'm a beginner in Cocoa and objective-C, I'm trying to do this "elegantly", ie. using one of the provided class, rather than making an external shell call or listing mounted filesystems and finding which one the path belongs to.
I did find NSWorkspace and getFileSystemInfoForPath, but it does not mention the mount point.
Can anybody help ?
thanks
This should go something along those lines:
+ (NSString*)volumeNameForPath:(NSString *)inPath
{
HFSUniStr255 volumeName;
FSRef volumeFSRef;
unsigned int volumeIndex = 1;
while (FSGetVolumeInfo(kFSInvalidVolumeRefNum, volumeIndex++, NULL, kFSVolInfoNone, NULL, &volumeName, &volumeFSRef) == noErr) {
NSURL *url = [(NSURL *)CFURLCreateFromFSRef(NULL, &volumeFSRef) autorelease];
NSString *path = [url path];
if ([inPath hasPrefix:path]) {
return [NSString stringWithCharacters:volumeName.unicode length:volumeName.length]
}
}
return nil;
}
I've run by this a month after it has been asked, but anyway: in Python standard library there's os.path.ismount() function, which detects if a path is a mount point. From its description it does it so:
The function checks whether path‘s parent, path/.., is on a different device than path, or whether path/.. and path point to the same i-node on the same device — this should detect mount points for all Unix and POSIX variants.