> On 4 Apr 2015, at 17:21, Ken Thomases <k...@codeweavers.com> wrote: > > On Apr 4, 2015, at 4:23 AM, Gerriet M. Denkmann <gerr...@mdenkmann.de> wrote: > >> When I look at " /Library/Dictionaries/Apple >> Dictionary.dictionary/Contents/Info.plist" in Finder, it shows a preview and >> says 5 kB. Ok. >> >> But: Finder → FIle → Get Info says: >> 4,893 bytes (Zero bytes on disk) >> >> And lstat shows: >> st_size = 4893 (file size, in bytes) >> st_blocks = 0 (blocks allocated for file) >> st_flags = 0x20 (user defined flags for file) >> >> /usr/include/sys/stat.h has: >> #define UF_COMPRESSED 0x00000020 /* file is hfs-compressed */ >> >> So: where are these bytes (if not on disk)? >> And if they are really compressed: how much space they take in some unknown >> compressed location? >> >> I am trying to find who or what is taking space on my disk. So given some >> directory, I want to add the disk space of all its files (+ subdirectories). > > In this case, the compressed data was probably small enough to store it in > the file metadata. So, there really are no blocks allocated for the file's > data.
There are no blocks allocated as data, but the size of the Attributes B-tree will increase nevertheless. My Attributes B-tree has about 1 GB - so nothing to disregard. > > Do some web searching for "hfs compression" to learn more. > > As far as how you should write a program to compute the space used on disk, I > recommend that you trust NSURLTotalFileAllocatedSizeKey. I just created an empty file and added lots of extended attributes. Some ≤ 3202 bytes (which are stored inside the Attributes B-tree as kHFSPlusAttrInlineData) some larger than this (kHFSPlusAttrForkData). But NSURLTotalFileAllocatedSizeKey (which is documented as "This includes the size of any file metadata.") remains 0. Kind regards, Gerriet. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
