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2014-08-30Rewrite filesystem code (WIP)Michael Sevakis
This patch redoes the filesystem code from the FAT driver up to the clipboard code in onplay.c. Not every aspect of this is finished therefore it is still "WIP". I don't wish to do too much at once (haha!). What is left to do is get dircache back in the sim and find an implementation for the dircache indicies in the tagcache and playlist code or do something else that has the same benefit. Leaving these out for now does not make anything unusable. All the basics are done. Phone app code should probably get vetted (and app path handling just plain rewritten as environment expansions); the SDL app and Android run well. Main things addressed: 1) Thread safety: There is none right now in the trunk code. Most of what currently works is luck when multiple threads are involved or multiple descriptors to the same file are open. 2) POSIX compliance: Many of the functions behave nothing like their counterparts on a host system. This leads to inconsistent code or very different behavior from native to hosted. One huge offender was rename(). Going point by point would fill a book. 3) Actual running RAM usage: Many targets will use less RAM and less stack space (some more RAM because I upped the number of cache buffers for large memory). There's very little memory lying fallow in rarely-used areas (see 'Key core changes' below). Also, all targets may open the same number of directory streams whereas before those with less than 8MB RAM were limited to 8, not 12 implying those targets will save slightly less. 4) Performance: The test_disk plugin shows markedly improved performance, particularly in the area of (uncached) directory scanning, due partly to more optimal directory reading and to a better sector cache algorithm. Uncached times tend to be better while there is a bit of a slowdown in dircache due to it being a bit heavier of an implementation. It's not noticeable by a human as far as I can say. Key core changes: 1) Files and directories share core code and data structures. 2) The filesystem code knows which descriptors refer to same file. This ensures that changes from one stream are appropriately reflected in every open descriptor for that file (fileobj_mgr.c). 3) File and directory cache buffers are borrowed from the main sector cache. This means that when they are not in use by a file, they are not wasted, but used for the cache. Most of the time, only a few of them are needed. It also means that adding more file and directory handles is less expensive. All one must do in ensure a large enough cache to borrow from. 4) Relative path components are supported and the namespace is unified. It does not support full relative paths to an implied current directory; what is does support is use of "." and "..". Adding the former would not be very difficult. The namespace is unified in the sense that volumes may be specified several times along with relative parts, e.g.: "/<0>/foo/../../<1>/bar" :<=> "/<1>/bar". 5) Stack usage is down due to sharing of data, static allocation and less duplication of strings on the stack. This requires more serialization than I would like but since the number of threads is limited to a low number, the tradoff in favor of the stack seems reasonable. 6) Separates and heirarchicalizes (sic) the SIM and APP filesystem code. SIM path and volume handling is just like the target. Some aspects of the APP file code get more straightforward (e.g. no path hashing is needed). Dircache: Deserves its own section. Dircache is new but pays homage to the old. The old one was not compatible and so it, since it got redone, does all the stuff it always should have done such as: 1) It may be update and used at any time during the build process. No longer has one to wait for it to finish building to do basic file management (create, remove, rename, etc.). 2) It does not need to be either fully scanned or completely disabled; it can be incomplete (i.e. overfilled, missing paths), still be of benefit and be correct. 3) Handles mounting and dismounting of individual volumes which means a full rebuild is not needed just because you pop a new SD card in the slot. Now, because it reuses its freed entry data, may rebuild only that volume. 4) Much more fundamental to the file code. When it is built, it is the keeper of the master file list whether enabled or not ("disabled" is just a state of the cache). Its must always to ready to be started and bind all streams opened prior to being enabled. 5) Maintains any short filenames in OEM format which means that it does not need to be rebuilt when changing the default codepage. Miscellaneous Compatibility: 1) Update any other code that would otherwise not work such as the hotswap mounting code in various card drivers. 2) File management: Clipboard needed updating because of the behavioral changes. Still needs a little more work on some finer points. 3) Remove now-obsolete functionality such as the mutex's "no preempt" flag (which was only for the prior FAT driver). 4) struct dirinfo uses time_t rather than raw FAT directory entry time fields. I plan to follow up on genericizing everything there (i.e. no FAT attributes). 5) unicode.c needed some redoing so that the file code does not try try to load codepages during a scan, which is actually a problem with the current code. The default codepage, if any is required, is now kept in RAM separarately (bufalloced) from codepages specified to iso_decode() (which must not be bufalloced because the conversion may be done by playback threads). Brings with it some additional reusable core code: 1) Revised file functions: Reusable code that does things such as safe path concatenation and parsing without buffer limitations or data duplication. Variants that copy or alter the input path may be based off these. To do: 1) Put dircache functionality back in the sim. Treating it internally as a different kind of file system seems the best approach at this time. 2) Restore use of dircache indexes in the playlist and database or something effectively the same. Since the cache doesn't have to be complete in order to be used, not getting a hit on the cache doesn't unambiguously say if the path exists or not. Change-Id: Ia30f3082a136253e3a0eae0784e3091d138915c8 Reviewed-on: http://gerrit.rockbox.org/566 Reviewed-by: Michael Sevakis <jethead71@rockbox.org> Tested: Michael Sevakis <jethead71@rockbox.org>
2007-07-20Makes apps and plugins interract with directories using a posix-like api ↵Kevin Ferrare
instead of calling dircache / simulator functions (no additionnal layer added, only a cosmetic change) git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13943 a1c6a512-1295-4272-9138-f99709370657
2007-06-30Accept FS#7134 - Sansa: external sd card support by Antonius Hellmann with ↵Michael Sevakis
some tweaks. All testers have given the green light. (Now for the RED ?? ;). git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13741 a1c6a512-1295-4272-9138-f99709370657
2007-02-03Removed unused 'mode' parameter from mkdir() for consistency with creat().Jens Arnold
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12183 a1c6a512-1295-4272-9138-f99709370657
2006-06-30Simplify code...Jens Arnold
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10156 a1c6a512-1295-4272-9138-f99709370657
2006-06-30volume_strip() now ignores multiple leading slashes like the rest of the ↵Jens Arnold
path handling code. Fixes the stats plugin only counting the internal flash on Ondio, and other potential problems. Posix says multiple slashes are legal. * More precise volume name check. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10155 a1c6a512-1295-4272-9138-f99709370657
2005-10-07Implemented directory caching. No more waiting for disk to spin up whileMiika Pekkarinen
browsing when cache is enabled (system -> disk -> enable directory cache). Cache building on boot is transparent except the first boot. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7588 a1c6a512-1295-4272-9138-f99709370657
2005-01-28preparations for hotswapping MMCJörg Hohensohn
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5701 a1c6a512-1295-4272-9138-f99709370657
2005-01-23int -> long where neededJean-Philippe Bernardy
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5643 a1c6a512-1295-4272-9138-f99709370657
2005-01-03using a pointer instead of array dereferencing saves ~250 bytesJörg Hohensohn
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5529 a1c6a512-1295-4272-9138-f99709370657
2005-01-01volume names look better in sharp brackets, code slightly more compactJörg Hohensohn
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5523 a1c6a512-1295-4272-9138-f99709370657
2004-12-28prepared to mount multiple partitions into one logical file system (most ↵Jörg Hohensohn
useful for Ondio, internal memory + external MMC) git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5514 a1c6a512-1295-4272-9138-f99709370657
2004-06-20infrastructure for sorting by date+time, now we "only" need to decide on the UIJörg Hohensohn
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4778 a1c6a512-1295-4272-9138-f99709370657
2004-04-20Better POSIX compatibility for mkdir(), rmdir() and opendir()Linus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4521 a1c6a512-1295-4272-9138-f99709370657
2004-04-16New function: rmdir(). Also some changes in the fat code, to track the ↵Linus Nielsen Feltzing
parent directory in opendir(), to be able to delete directories git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4509 a1c6a512-1295-4272-9138-f99709370657
2004-02-11Empty file/dir names are now rejected by open() and mkdir()Linus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4303 a1c6a512-1295-4272-9138-f99709370657
2004-01-21New feature: NOw you can store the recorded files in either /recordings (the ↵Linus Nielsen Feltzing
directory will be created automatically) or in the current directory. New feature: A "Create directory" menu option (untested in the simulator). Bug fix: The ON+Play menu could do nasty things if you pressed ON+Play in an empty dir. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4268 a1c6a512-1295-4272-9138-f99709370657
2004-01-15Second bug in mkdir() :-)Linus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4241 a1c6a512-1295-4272-9138-f99709370657
2004-01-15First mkdir() bug killed :-)Linus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4239 a1c6a512-1295-4272-9138-f99709370657
2004-01-15Implemented the mkdir() function in the FAT32 driverLinus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4238 a1c6a512-1295-4272-9138-f99709370657
2003-01-24Remove use of rockbox-mode.el in local variables list.Mats Lidell
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@3157 a1c6a512-1295-4272-9138-f99709370657
2002-10-20Snapshot of file writing code. Bugs remain. Only short names are supported yet.Björn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2726 a1c6a512-1295-4272-9138-f99709370657
2002-08-15Now doesn't truncate the lenght when comparing path componentsLinus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1757 a1c6a512-1295-4272-9138-f99709370657
2002-08-11First version of loadable fonts patch by Alex GitelmanBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1666 a1c6a512-1295-4272-9138-f99709370657
2002-07-15Some more buffer length fixingLinus Nielsen Feltzing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1361 a1c6a512-1295-4272-9138-f99709370657
2002-06-18Filenames are case insensitive in Fat32Björn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1060 a1c6a512-1295-4272-9138-f99709370657
2002-05-27Now supports multiple concurrent opendir()Björn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@727 a1c6a512-1295-4272-9138-f99709370657
2002-05-24strtok:ing a copy of the parameter insteadBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@687 a1c6a512-1295-4272-9138-f99709370657
2002-05-13Changing to C99 'bool' typeBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@561 a1c6a512-1295-4272-9138-f99709370657
2002-05-07Added open/close/read. read() only works on whole sectors right now.Björn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@498 a1c6a512-1295-4272-9138-f99709370657
2002-05-07Removed stray bad charBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@497 a1c6a512-1295-4272-9138-f99709370657
2002-05-07load rockbox-mode in emacs!Daniel Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@487 a1c6a512-1295-4272-9138-f99709370657
2002-05-06Added note about strtok() not being thread safeBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@478 a1c6a512-1295-4272-9138-f99709370657
2002-05-06Fixed dir parsingBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@476 a1c6a512-1295-4272-9138-f99709370657
2002-05-03Added opendir, closedir and readdirBjörn Stenberg
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@412 a1c6a512-1295-4272-9138-f99709370657