--- IO-AIO/AIO.pm 2011/09/26 20:19:08 1.208 +++ IO-AIO/AIO.pm 2012/05/28 17:00:19 1.226 @@ -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 @@ -211,6 +211,7 @@ 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) @@ -220,14 +221,14 @@ 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_unlink $pathname, $callback->($status) - aio_mknod $path, $mode, $dev, $callback->($status) + aio_mknod $pathname, $mode, $dev, $callback->($status) aio_link $srcpath, $dstpath, $callback->($status) aio_symlink $srcpath, $dstpath, $callback->($status) - aio_readlink $path, $callback->($link) - aio_realpath $path, $callback->($link) + aio_readlink $pathname, $callback->($link) + aio_realpath $pathname, $callback->($link) aio_rename $srcpath, $dstpath, $callback->($status) aio_mkdir $pathname, $mode, $callback->($status) aio_rmdir $pathname, $callback->($status) @@ -235,17 +236,17 @@ 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_load $path, $data, $callback->($status) + 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 $path, $maxreq, $callback->($dirs, $nondirs) - aio_rmtree $path, $callback->($status) + aio_rmtree $pathname, $callback->($status) aio_sync $callback->($status) aio_syncfs $fh, $callback->($status) aio_fsync $fh, $callback->($status) aio_fdatasync $fh, $callback->($status) aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) - aio_pathsync $path, $callback->($status) + aio_pathsync $pathname, $callback->($status) aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) @@ -273,20 +274,27 @@ 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. @@ -294,23 +302,28 @@ All functions return request objects of type L that allow further manipulation of those requests while they are in-flight. -The pathnames you pass to these routines I be absolute and -encoded as octets. The reason for the former 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. +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. 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] @@ -402,6 +415,26 @@ =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) @@ -618,7 +651,7 @@ result code. -=item aio_mknod $path, $mode, $dev, $callback->($status) +=item aio_mknod $pathname, $mode, $dev, $callback->($status) [EXPERIMENTAL] @@ -626,7 +659,7 @@ The only (POSIX-) portable way of calling this function is: - aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... + aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... See C for info about some potentially helpful extra constants and functions. @@ -643,14 +676,14 @@ the path C<$dstpath> and call the callback with the result code. -=item aio_readlink $path, $callback->($link) +=item aio_readlink $pathname, $callback->($link) Asynchronously read the symlink specified by C<$path> and pass it to the callback. If an error occurs, nothing or undef gets passed to the callback. -=item aio_realpath $path, $callback->($path) +=item aio_realpath $pathname, $callback->($path) Asynchronously make the path absolute and resolve any symlinks in C<$path>. The resulting path only consists of directories (Same as @@ -755,7 +788,7 @@ =back -=item aio_load $path, $data, $callback->($status) +=item aio_load $pathname, $data, $callback->($status) This is a composite request that tries to fully load the given file into memory. Status is the same as with aio_read. @@ -900,7 +933,7 @@ $grp } -=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) +=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) Scans a directory (similar to C) but additionally tries to efficiently separate the entries of directory C<$path> into two sets of @@ -967,67 +1000,78 @@ $maxreq = 4 if $maxreq <= 0; - # stat once + # get a wd object aioreq_pri $pri; - add $grp aio_stat $path, sub { - return $grp->result () if $_[0]; - my $now = time; - my $hash1 = join ":", (stat _)[0,1,3,7,9]; + add $grp aio_wd $path, sub { + $_[0] + or return $grp->result (); + + my $wd = [shift, "."]; - # read the directory entries + # stat once aioreq_pri $pri; - add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { - my $entries = shift - or return $grp->result (); + add $grp aio_stat $wd, sub { + return $grp->result () if $_[0]; + my $now = time; + my $hash1 = join ":", (stat _)[0,1,3,7,9]; - # stat the dir another time + # read the directory entries aioreq_pri $pri; - add $grp aio_stat $path, sub { - my $hash2 = join ":", (stat _)[0,1,3,7,9]; + add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { + my $entries = shift + or return $grp->result (); - my $ndirs; + # stat the dir another time + aioreq_pri $pri; + add $grp aio_stat $wd, sub { + my $hash2 = join ":", (stat _)[0,1,3,7,9]; - # take the slow route if anything looks fishy - if ($hash1 ne $hash2 or (stat _)[9] == $now) { - $ndirs = -1; - } else { - # if nlink == 2, we are finished - # for non-posix-fs's, we rely on nlink < 2 - $ndirs = (stat _)[3] - 2 - or return $grp->result ([], $entries); - } + my $ndirs; - my (@dirs, @nondirs); + # take the slow route if anything looks fishy + if ($hash1 ne $hash2 or (stat _)[9] == $now) { + $ndirs = -1; + } else { + # if nlink == 2, we are finished + # for non-posix-fs's, we rely on nlink < 2 + $ndirs = (stat _)[3] - 2 + or return $grp->result ([], $entries); + } - my $statgrp = add $grp aio_group sub { - $grp->result (\@dirs, \@nondirs); - }; + my (@dirs, @nondirs); - limit $statgrp $maxreq; - feed $statgrp sub { - return unless @$entries; - my $entry = shift @$entries; + my $statgrp = add $grp aio_group sub { + $grp->result (\@dirs, \@nondirs); + }; - aioreq_pri $pri; - add $statgrp aio_stat "$path/$entry/.", sub { - if ($_[0] < 0) { - push @nondirs, $entry; - } else { - # need to check for real directory - aioreq_pri $pri; - add $statgrp aio_lstat "$path/$entry", sub { - if (-d _) { - push @dirs, $entry; - - unless (--$ndirs) { - push @nondirs, @$entries; - feed $statgrp; + limit $statgrp $maxreq; + feed $statgrp sub { + return unless @$entries; + my $entry = shift @$entries; + + aioreq_pri $pri; + $wd->[1] = "$entry/."; + add $statgrp aio_stat $wd, sub { + if ($_[0] < 0) { + push @nondirs, $entry; + } else { + # need to check for real directory + aioreq_pri $pri; + $wd->[1] = $entry; + add $statgrp aio_lstat $wd, sub { + if (-d _) { + push @dirs, $entry; + + unless (--$ndirs) { + push @nondirs, @$entries; + feed $statgrp; + } + } else { + push @nondirs, $entry; } - } else { - push @nondirs, $entry; } } - } + }; }; }; }; @@ -1037,7 +1081,7 @@ $grp } -=item aio_rmtree $path, $callback->($status) +=item aio_rmtree $pathname, $callback->($status) Delete a directory tree starting (and including) C<$path>, return the status of the final C only. This is a composite request that @@ -1108,7 +1152,7 @@ C: refer to the sync_file_range manpage for details. -=item aio_pathsync $path, $callback->($status) +=item aio_pathsync $pathname, $callback->($status) This request tries to open, fsync and close the given path. This is a composite request intended to sync directories after directory operations @@ -1215,6 +1259,46 @@ aio_mlockall IO::AIO::MCL_FUTURE; +=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) + +Queries the extents of the given file (by calling the Linux FIEMAP ioctl, +see L for details). If the +C is not available on your OS, then this rquiest will fail with +C. + +C<$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<$count> is the maximum number of extent records to return. If it is +C, then IO::AIO queries all extents of the file. As a very special +case, if it is C<0>, then the callback receives the number of extents +instead of the extents themselves. + +If an error occurs, the callback receives no arguments. The special +C value C is available to test for flag errors. + +Otherwise, the callback receives an array reference with extent +structures. Each extent structure is an array reference itself, with the +following members: + + [$logical, $physical, $length, $flags] + +Flags is any combination of the following flag values (typically either C<0> +or C): + +C, C, +C, C, +C, C, +C, C, +C, C or +C. + =item aio_group $callback->(...) This is a very special aio request: Instead of doing something, it is a @@ -1261,6 +1345,125 @@ =back + +=head2 IO::AIO::WD - multiple working directories + +Your process only has one current working directory, which is used by all +threads. This makes it hard to use relative paths (some other component +could call C at any time, and it is hard to control when the path +will be used by IO::AIO). + +One solution for this is to always use absolute paths. This usually works, +but can be quite slow (the kernel has to walk the whole path on every +access), and can also be a hassle to implement. + +Newer POSIX systems have a number of functions (openat, fdopendir, +futimensat and so on) that make it possible to specify working directories +per operation. + +For portability, and because the clowns who "designed", or shall I write, +perpetrated this new interface were obviously half-drunk, this abstraction +cannot be perfect, though. + +IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD +object. This object stores the canonicalised, absolute version of the +path, and on systems that allow it, also a directory file descriptor. + +Everywhere where a pathname is accepted by IO::AIO (e.g. in C +or C), one can specify an array reference with an IO::AIO::WD +object and a pathname instead (or the IO::AIO::WD object alone, which +gets interpreted as C<[$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 +inside, you would write: + + aio_wd "/etc", sub { + my $etcdir = shift; + + # although $etcdir can be undef on error, there is generally no reason + # to check for errors here, as aio_stat will fail with ENOENT + # when $etcdir is undef. + + aio_stat [$etcdir, "passwd"], sub { + # yay + }; + }; + +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 $wd , sub { ... # shorthand for the previous + +As with normal pathnames, IO::AIO keeps a copy of the working directory +object and the pathname string, so you could write the following without +causing any issues due to C<$path> getting reused: + + my $path = [$wd, undef]; + + for my $name (qw(abc def ghi)) { + $path->[1] = $name; + aio_stat $path, sub { + # ... + }; + } + +There are some caveats: when directories get renamed (or deleted), the +pathname string doesn't change, so will point to the new directory (or +nowhere at all), while the directory fd, if available on the system, +will still point to the original directory. Most functions accepting a +pathname will use the directory fd on newer systems, and the string on +older systems. Some functions (such as realpath) will always rely on the +string form of the pathname. + +So this fucntionality is mainly useful to get some protection against +C, to easily get an absolute path out of a relative path for future +reference, and to speed up doing many operations in the same directory +(e.g. when stat'ing all files in a directory). + +The following functions implement this working directory abstraction: + +=over 4 + +=item aio_wd $pathname, $callback->($wd) + +Asynchonously canonicalise the given pathname and convert it to an +IO::AIO::WD object representing it. If possible and supported on the +system, also open a directory fd to speed up pathname resolution relative +to this working directory. + +If something goes wrong, then C is passwd to the callback instead +of a working directory object and C<$!> is set appropriately. Since +passing C as working directory component of a pathname fails the +request with C, there is often no need for error checking in the +C callback, as future requests using the value will fail in the +expected way. + +If this call isn't available because your OS lacks it or it couldn't be +detected, it will be emulated by calling C instead. + +=item IO::AIO::CWD + +This is a compiletime constant (object) that represents the process +current working directory. + +Specifying this object as working directory object for a pathname is as +if the pathname would be specified directly, without a directory object, +e.g., these calls are functionally identical: + + aio_stat "somefile", sub { ... }; + aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; + +=back + + =head2 IO::AIO::REQ CLASS All non-aggregate C functions return an object of this class when @@ -1387,8 +1590,8 @@ 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 @@ -1770,6 +1973,23 @@ 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. + +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