--- IO-AIO/AIO.pm 2011/09/27 01:43:03 1.210 +++ IO-AIO/AIO.pm 2012/08/13 01:02:30 1.234 @@ -170,13 +170,13 @@ use base 'Exporter'; BEGIN { - our $VERSION = '4.0'; + our $VERSION = '4.15'; - our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close + our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx aio_scandir aio_symlink aio_readlink aio_realpath aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate - aio_pathsync aio_readahead + aio_pathsync aio_readahead aio_fiemap aio_rename aio_link aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown aio_chmod aio_utime aio_truncate @@ -204,13 +204,14 @@ =head2 QUICK OVERVIEW -This section simply lists the prototypes of the most important functions -for quick reference. See the following sections for function-by-function +This section simply lists the prototypes most of the functions for +quick reference. See the following sections for function-by-function documentation. aio_wd $pathname, $callback->($wd) aio_open $pathname, $flags, $mode, $callback->($fh) aio_close $fh, $callback->($status) + aio_seek $fh,$offset,$whence, $callback->($offs) aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) @@ -220,8 +221,10 @@ aio_statvfs $fh_or_path, $callback->($statvfs) aio_utime $fh_or_path, $atime, $mtime, $callback->($status) aio_chown $fh_or_path, $uid, $gid, $callback->($status) - aio_truncate $fh_or_path, $offset, $callback->($status) aio_chmod $fh_or_path, $mode, $callback->($status) + aio_truncate $fh_or_path, $offset, $callback->($status) + aio_allocate $fh, $mode, $offset, $len, $callback->($status) + aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) aio_unlink $pathname, $callback->($status) aio_mknod $pathname, $mode, $dev, $callback->($status) aio_link $srcpath, $dstpath, $callback->($status) @@ -235,10 +238,10 @@ aio_readdirx $pathname, $flags, $callback->($entries, $flags) IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN + aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) aio_load $pathname, $data, $callback->($status) aio_copy $srcpath, $dstpath, $callback->($status) aio_move $srcpath, $dstpath, $callback->($status) - aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) aio_rmtree $pathname, $callback->($status) aio_sync $callback->($status) aio_syncfs $fh, $callback->($status) @@ -273,20 +276,27 @@ IO::AIO::sendfile $ofh, $ifh, $offset, $count IO::AIO::fadvise $fh, $offset, $len, $advice + IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] + IO::AIO::munmap $scalar IO::AIO::madvise $scalar, $offset, $length, $advice IO::AIO::mprotect $scalar, $offset, $length, $protect IO::AIO::munlock $scalar, $offset = 0, $length = undef IO::AIO::munlockall -=head2 AIO REQUEST FUNCTIONS +=head2 API NOTES All the C calls are more or less thin wrappers around the syscall with the same name (sans C). The arguments are similar or identical, and they all accept an additional (and optional) C<$callback> argument -which must be a code reference. This code reference will get called with -the syscall return code (e.g. most syscalls return C<-1> on error, unlike -perl, which usually delivers "false") as its sole argument after the given -syscall has been executed asynchronously. +which must be a code reference. This code reference will be called after +the syscall has been executed in an asynchronous fashion. The results +of the request will be passed as arguments to the callback (and, if an +error occured, in C<$!>) - for most requests the syscall return code (e.g. +most syscalls return C<-1> on error, unlike perl, which usually delivers +"false"). + +Some requests (such as C) pass the actual results and +communicate failures by passing C. All functions expecting a filehandle keep a copy of the filehandle internally until the request has finished. @@ -296,22 +306,26 @@ The pathnames you pass to these routines I be absolute. The reason for this is that at the time the request is being executed, the -current working directory could have changed. Alternatively, you can make -sure that you never change the current working directory anywhere in -the program and then use relative paths. Lastly, you can take advantage -of IO::AIOs working directory abstraction - see the description of the -C class later in this document. +current working directory could have changed. Alternatively, you can +make sure that you never change the current working directory anywhere +in the program and then use relative paths. You can also take advantage +of IO::AIOs working directory abstraction, that lets you specify paths +relative to some previously-opened "working directory object" - see the +description of the C class later in this document. To encode pathnames as octets, either make sure you either: a) always pass in filenames you got from outside (command line, readdir etc.) without -tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode -your pathnames to the locale (or other) encoding in effect in the user -environment, d) use Glib::filename_from_unicode on unicode filenames or e) -use something else to ensure your scalar has the correct contents. +tinkering, b) are in your native filesystem encoding, c) use the Encode +module and encode your pathnames to the locale (or other) encoding in +effect in the user environment, d) use Glib::filename_from_unicode on +unicode filenames or e) use something else to ensure your scalar has the +correct contents. This works, btw. independent of the internal UTF-8 bit, which IO::AIO handles correctly whether it is set or not. +=head2 AIO REQUEST FUNCTIONS + =over 4 =item $prev_pri = aioreq_pri [$pri] @@ -350,7 +364,7 @@ =item aio_open $pathname, $flags, $mode, $callback->($fh) Asynchronously open or create a file and call the callback with a newly -created filehandle for the file. +created filehandle for the file (or C in case of an error). The pathname passed to C must be absolute. See API NOTES, above, for an explanation. @@ -403,6 +417,26 @@ =cut +=item aio_seek $fh, $offset, $whence, $callback->($offs) + +Seeks the filehandle to the new C<$offset>, similarly to perl's +C. The C<$whence> can use the traditional values (C<0> for +C, C<1> for C or C<2> for +C). + +The resulting absolute offset will be passed to the callback, or C<-1> in +case of an error. + +In theory, the C<$whence> constants could be different than the +corresponding values from L, but perl guarantees they are the same, +so don't panic. + +As a GNU/Linux (and maybe Solaris) extension, also the constants +C and C are available, if they +could be found. No guarantees about suitability for use in C or +Perl's C can be made though, although I would naively assume they +"just work". + =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) @@ -608,6 +642,22 @@ Works like truncate(2) or ftruncate(2). +=item aio_allocate $fh, $mode, $offset, $len, $callback->($status) + +Allocates or freed disk space according to the C<$mode> argument. See the +linux C docuemntation for details. + +C<$mode> can currently be C<0> or C +to allocate space, or C, to deallocate a file range. + +The file system block size used by C is presumably the +C returned by C. + +If C isn't available or cannot be emulated (currently no +emulation will be attempted), passes C<-1> and sets C<$!> to C. + + =item aio_chmod $fh_or_path, $mode, $callback->($status) Works like perl's C function. @@ -969,9 +1019,11 @@ $maxreq = 4 if $maxreq <= 0; # get a wd object - aioreq_pri $pri; add $grp aio_wd $path, sub { + $_[0] + or return $grp->result (); + my $wd = [shift, "."]; # stat once @@ -1225,6 +1277,51 @@ aio_mlockall IO::AIO::MCL_FUTURE; +=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) + +Queries the extents of the given file (by calling the Linux C +ioctl, see L for details). If +the ioctl is not available on your OS, then this request will fail with +C. + +C<$start> is the starting offset to query extents for, C<$length> is the +size of the range to query - if it is C, then the whole file will +be queried. + +C<$flags> is a combination of flags (C or +C - C is also +exported), and is normally C<0> or C to query +the data portion. + +C<$count> is the maximum number of extent records to return. If it is +C, then IO::AIO queries all extents of the range. As a very special +case, if it is C<0>, then the callback receives the number of extents +instead of the extents themselves (which is unreliable, see below). + +If an error occurs, the callback receives no arguments. The special +C value C is available to test for flag errors. + +Otherwise, the callback receives an array reference with extent +structures. Each extent structure is an array reference itself, with the +following members: + + [$logical, $physical, $length, $flags] + +Flags is any combination of the following flag values (typically either C<0> +or C (1)): + +C, C, +C, C, +C, C, +C, C, +C, C or +C. + +At the time of this writing (Linux 3.2), this requets is unreliable unless +C<$count> is C, as the kernel has all sorts of bugs preventing +it to return all extents of a range for files with large number of +extents. The code works around all these issues if C<$count> is undef. + =item aio_group $callback->(...) This is a very special aio request: Instead of doing something, it is a @@ -1297,8 +1394,9 @@ Everywhere where a pathname is accepted by IO::AIO (e.g. in C or C), one can specify an array reference with an IO::AIO::WD -object and a pathname instead. If the pathname is absolute, the -IO::AIO::WD objetc is ignored, otherwise the pathname is resolved relative +object and a pathname instead (or the IO::AIO::WD object alone, which +gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the +IO::AIO::WD object is ignored, otherwise the pathname is resolved relative to that IO::AIO::WD object. For example, to get a wd object for F and then stat F @@ -1316,8 +1414,16 @@ }; }; -This shows that creating an IO::AIO::WD object is itself a potentially -blocking operation, which is why it is done asynchronously. +That C is a request and not a normal function shows that creating +an IO::AIO::WD object is itself a potentially blocking operation, which is +why it is done asynchronously. + +To stat the directory obtained with C above, one could write +either of the following three request calls: + + aio_lstat "/etc" , sub { ... # pathname as normal string + aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) + aio_lstat $wd , sub { ... # shorthand for the previous As with normal pathnames, IO::AIO keeps a copy of the working directory object and the pathname string, so you could write the following without @@ -1507,8 +1613,8 @@ generator that generates requests if idle. The idea behind this is that, although you could just queue as many requests as you want in a group, this might starve other requests for a potentially long time. For example, -C might generate hundreds of thousands C requests, -delaying any later requests for a long time. +C might generate hundreds of thousands of C +requests, delaying any later requests for a long time. To avoid this, and allow incremental generation of requests, you can instead a group and set a feeder on it that generates those requests. The @@ -1827,7 +1933,8 @@ =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] Memory-maps a file (or anonymous memory range) and attaches it to the -given C<$scalar>, which will act like a string scalar. +given C<$scalar>, which will act like a string scalar. Returns true on +success, and false otherwise. The only operations allowed on the scalar are C/C that don't change the string length, and most read-only operations such as copying it @@ -1890,6 +1997,26 @@ On systems that do not implement C, this function returns ENOSYS, otherwise the return value of C. +=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags + +Calls the GNU/Linux C syscall, if available. If C<$r_off> or +C<$w_off> are C, then C is passed for these, otherwise they +should be the file offset. + +C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might +silently corrupt the data in this case. + +The following symbol flag values are available: C, +C, C and +C. + +See the C manpage for details. + +=item IO::AIO::tee $r_fh, $w_fh, $length, $flags + +Calls the GNU/Linux C syscall, see it's manpage and the +description for C above for details. + =back =cut