… | |
… | |
168 | use common::sense; |
168 | use common::sense; |
169 | |
169 | |
170 | use base 'Exporter'; |
170 | use base 'Exporter'; |
171 | |
171 | |
172 | BEGIN { |
172 | BEGIN { |
173 | our $VERSION = '4.0'; |
173 | our $VERSION = '4.11'; |
174 | |
174 | |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
177 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync |
177 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync |
178 | aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate |
178 | aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate |
… | |
… | |
221 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
221 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
222 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
222 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
223 | aio_truncate $fh_or_path, $offset, $callback->($status) |
223 | aio_truncate $fh_or_path, $offset, $callback->($status) |
224 | aio_chmod $fh_or_path, $mode, $callback->($status) |
224 | aio_chmod $fh_or_path, $mode, $callback->($status) |
225 | aio_unlink $pathname, $callback->($status) |
225 | aio_unlink $pathname, $callback->($status) |
226 | aio_mknod $path, $mode, $dev, $callback->($status) |
226 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
227 | aio_link $srcpath, $dstpath, $callback->($status) |
227 | aio_link $srcpath, $dstpath, $callback->($status) |
228 | aio_symlink $srcpath, $dstpath, $callback->($status) |
228 | aio_symlink $srcpath, $dstpath, $callback->($status) |
229 | aio_readlink $path, $callback->($link) |
229 | aio_readlink $pathname, $callback->($link) |
230 | aio_realpath $path, $callback->($link) |
230 | aio_realpath $pathname, $callback->($link) |
231 | aio_rename $srcpath, $dstpath, $callback->($status) |
231 | aio_rename $srcpath, $dstpath, $callback->($status) |
232 | aio_mkdir $pathname, $mode, $callback->($status) |
232 | aio_mkdir $pathname, $mode, $callback->($status) |
233 | aio_rmdir $pathname, $callback->($status) |
233 | aio_rmdir $pathname, $callback->($status) |
234 | aio_readdir $pathname, $callback->($entries) |
234 | aio_readdir $pathname, $callback->($entries) |
235 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
235 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
236 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
236 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
237 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
237 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
|
|
238 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
238 | aio_load $path, $data, $callback->($status) |
239 | aio_load $pathname, $data, $callback->($status) |
239 | aio_copy $srcpath, $dstpath, $callback->($status) |
240 | aio_copy $srcpath, $dstpath, $callback->($status) |
240 | aio_move $srcpath, $dstpath, $callback->($status) |
241 | aio_move $srcpath, $dstpath, $callback->($status) |
241 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
|
|
242 | aio_rmtree $path, $callback->($status) |
242 | aio_rmtree $pathname, $callback->($status) |
243 | aio_sync $callback->($status) |
243 | aio_sync $callback->($status) |
244 | aio_syncfs $fh, $callback->($status) |
244 | aio_syncfs $fh, $callback->($status) |
245 | aio_fsync $fh, $callback->($status) |
245 | aio_fsync $fh, $callback->($status) |
246 | aio_fdatasync $fh, $callback->($status) |
246 | aio_fdatasync $fh, $callback->($status) |
247 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
247 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
248 | aio_pathsync $path, $callback->($status) |
248 | aio_pathsync $pathname, $callback->($status) |
249 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
249 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
250 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
250 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
251 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
251 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
252 | aio_mlockall $flags, $callback->($status) |
252 | aio_mlockall $flags, $callback->($status) |
253 | aio_group $callback->(...) |
253 | aio_group $callback->(...) |
… | |
… | |
281 | =head2 AIO REQUEST FUNCTIONS |
281 | =head2 AIO REQUEST FUNCTIONS |
282 | |
282 | |
283 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
283 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
284 | with the same name (sans C<aio_>). The arguments are similar or identical, |
284 | with the same name (sans C<aio_>). The arguments are similar or identical, |
285 | and they all accept an additional (and optional) C<$callback> argument |
285 | and they all accept an additional (and optional) C<$callback> argument |
286 | which must be a code reference. This code reference will get called with |
286 | which must be a code reference. This code reference will be called after |
287 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
287 | the syscall has been executed in an asynchronous fashion. The results |
288 | perl, which usually delivers "false") as its sole argument after the given |
288 | of the request will be passed as arguments to the callback (and, if an |
289 | syscall has been executed asynchronously. |
289 | error occured, in C<$!>) - for most requests the syscall return code (e.g. |
|
|
290 | most syscalls return C<-1> on error, unlike perl, which usually delivers |
|
|
291 | "false"). |
|
|
292 | |
|
|
293 | Some requests (such as C<aio_readdir>) pass the actual results and |
|
|
294 | communicate failures by passing C<undef>. |
290 | |
295 | |
291 | All functions expecting a filehandle keep a copy of the filehandle |
296 | All functions expecting a filehandle keep a copy of the filehandle |
292 | internally until the request has finished. |
297 | internally until the request has finished. |
293 | |
298 | |
294 | All functions return request objects of type L<IO::AIO::REQ> that allow |
299 | All functions return request objects of type L<IO::AIO::REQ> that allow |
295 | further manipulation of those requests while they are in-flight. |
300 | further manipulation of those requests while they are in-flight. |
296 | |
301 | |
297 | The pathnames you pass to these routines I<must> be absolute and |
302 | The pathnames you pass to these routines I<should> be absolute. The |
298 | encoded as octets. The reason for the former is that at the time the |
303 | reason for this is that at the time the request is being executed, the |
299 | request is being executed, the current working directory could have |
304 | current working directory could have changed. Alternatively, you can |
300 | changed. Alternatively, you can make sure that you never change the |
305 | make sure that you never change the current working directory anywhere |
301 | current working directory anywhere in the program and then use relative |
306 | in the program and then use relative paths. You can also take advantage |
302 | paths. |
307 | of IO::AIOs working directory abstraction, that lets you specify paths |
|
|
308 | relative to some previously-opened "working directory object" - see the |
|
|
309 | description of the C<IO::AIO::WD> class later in this document. |
303 | |
310 | |
304 | To encode pathnames as octets, either make sure you either: a) always pass |
311 | To encode pathnames as octets, either make sure you either: a) always pass |
305 | in filenames you got from outside (command line, readdir etc.) without |
312 | in filenames you got from outside (command line, readdir etc.) without |
306 | tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
313 | tinkering, b) are in your native filesystem encoding, c) use the Encode |
307 | your pathnames to the locale (or other) encoding in effect in the user |
314 | module and encode your pathnames to the locale (or other) encoding in |
308 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
315 | effect in the user environment, d) use Glib::filename_from_unicode on |
309 | use something else to ensure your scalar has the correct contents. |
316 | unicode filenames or e) use something else to ensure your scalar has the |
|
|
317 | correct contents. |
310 | |
318 | |
311 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
319 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
312 | handles correctly whether it is set or not. |
320 | handles correctly whether it is set or not. |
313 | |
321 | |
314 | =over 4 |
322 | =over 4 |
… | |
… | |
616 | |
624 | |
617 | Asynchronously unlink (delete) a file and call the callback with the |
625 | Asynchronously unlink (delete) a file and call the callback with the |
618 | result code. |
626 | result code. |
619 | |
627 | |
620 | |
628 | |
621 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
629 | =item aio_mknod $pathname, $mode, $dev, $callback->($status) |
622 | |
630 | |
623 | [EXPERIMENTAL] |
631 | [EXPERIMENTAL] |
624 | |
632 | |
625 | Asynchronously create a device node (or fifo). See mknod(2). |
633 | Asynchronously create a device node (or fifo). See mknod(2). |
626 | |
634 | |
627 | The only (POSIX-) portable way of calling this function is: |
635 | The only (POSIX-) portable way of calling this function is: |
628 | |
636 | |
629 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
637 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
630 | |
638 | |
631 | See C<aio_stat> for info about some potentially helpful extra constants |
639 | See C<aio_stat> for info about some potentially helpful extra constants |
632 | and functions. |
640 | and functions. |
633 | |
641 | |
634 | =item aio_link $srcpath, $dstpath, $callback->($status) |
642 | =item aio_link $srcpath, $dstpath, $callback->($status) |
… | |
… | |
641 | |
649 | |
642 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
650 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
643 | the path C<$dstpath> and call the callback with the result code. |
651 | the path C<$dstpath> and call the callback with the result code. |
644 | |
652 | |
645 | |
653 | |
646 | =item aio_readlink $path, $callback->($link) |
654 | =item aio_readlink $pathname, $callback->($link) |
647 | |
655 | |
648 | Asynchronously read the symlink specified by C<$path> and pass it to |
656 | Asynchronously read the symlink specified by C<$path> and pass it to |
649 | the callback. If an error occurs, nothing or undef gets passed to the |
657 | the callback. If an error occurs, nothing or undef gets passed to the |
650 | callback. |
658 | callback. |
651 | |
659 | |
652 | |
660 | |
653 | =item aio_realpath $path, $callback->($path) |
661 | =item aio_realpath $pathname, $callback->($path) |
654 | |
662 | |
655 | Asynchronously make the path absolute and resolve any symlinks in |
663 | Asynchronously make the path absolute and resolve any symlinks in |
656 | C<$path>. The resulting path only consists of directories (Same as |
664 | C<$path>. The resulting path only consists of directories (Same as |
657 | L<Cwd::realpath>). |
665 | L<Cwd::realpath>). |
658 | |
666 | |
… | |
… | |
753 | C<$type>'s are known, which can be used to speed up some algorithms. |
761 | C<$type>'s are known, which can be used to speed up some algorithms. |
754 | |
762 | |
755 | =back |
763 | =back |
756 | |
764 | |
757 | |
765 | |
758 | =item aio_load $path, $data, $callback->($status) |
766 | =item aio_load $pathname, $data, $callback->($status) |
759 | |
767 | |
760 | This is a composite request that tries to fully load the given file into |
768 | This is a composite request that tries to fully load the given file into |
761 | memory. Status is the same as with aio_read. |
769 | memory. Status is the same as with aio_read. |
762 | |
770 | |
763 | =cut |
771 | =cut |
… | |
… | |
898 | }; |
906 | }; |
899 | |
907 | |
900 | $grp |
908 | $grp |
901 | } |
909 | } |
902 | |
910 | |
903 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
911 | =item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
904 | |
912 | |
905 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
913 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
906 | efficiently separate the entries of directory C<$path> into two sets of |
914 | efficiently separate the entries of directory C<$path> into two sets of |
907 | names, directories you can recurse into (directories), and ones you cannot |
915 | names, directories you can recurse into (directories), and ones you cannot |
908 | recurse into (everything else, including symlinks to directories). |
916 | recurse into (everything else, including symlinks to directories). |
… | |
… | |
965 | |
973 | |
966 | my $grp = aio_group $cb; |
974 | my $grp = aio_group $cb; |
967 | |
975 | |
968 | $maxreq = 4 if $maxreq <= 0; |
976 | $maxreq = 4 if $maxreq <= 0; |
969 | |
977 | |
970 | # stat once |
978 | # get a wd object |
971 | aioreq_pri $pri; |
979 | aioreq_pri $pri; |
972 | add $grp aio_stat $path, sub { |
980 | add $grp aio_wd $path, sub { |
|
|
981 | $_[0] |
973 | return $grp->result () if $_[0]; |
982 | or return $grp->result (); |
974 | my $now = time; |
|
|
975 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
976 | |
983 | |
977 | # read the directory entries |
984 | my $wd = [shift, "."]; |
|
|
985 | |
|
|
986 | # stat once |
978 | aioreq_pri $pri; |
987 | aioreq_pri $pri; |
979 | add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { |
988 | add $grp aio_stat $wd, sub { |
980 | my $entries = shift |
|
|
981 | or return $grp->result (); |
989 | return $grp->result () if $_[0]; |
|
|
990 | my $now = time; |
|
|
991 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
982 | |
992 | |
983 | # stat the dir another time |
993 | # read the directory entries |
984 | aioreq_pri $pri; |
994 | aioreq_pri $pri; |
|
|
995 | add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { |
|
|
996 | my $entries = shift |
|
|
997 | or return $grp->result (); |
|
|
998 | |
|
|
999 | # stat the dir another time |
|
|
1000 | aioreq_pri $pri; |
985 | add $grp aio_stat $path, sub { |
1001 | add $grp aio_stat $wd, sub { |
986 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
1002 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
987 | |
1003 | |
988 | my $ndirs; |
1004 | my $ndirs; |
989 | |
1005 | |
990 | # take the slow route if anything looks fishy |
1006 | # take the slow route if anything looks fishy |
991 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
1007 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
992 | $ndirs = -1; |
1008 | $ndirs = -1; |
993 | } else { |
1009 | } else { |
994 | # if nlink == 2, we are finished |
1010 | # if nlink == 2, we are finished |
995 | # for non-posix-fs's, we rely on nlink < 2 |
1011 | # for non-posix-fs's, we rely on nlink < 2 |
996 | $ndirs = (stat _)[3] - 2 |
1012 | $ndirs = (stat _)[3] - 2 |
997 | or return $grp->result ([], $entries); |
1013 | or return $grp->result ([], $entries); |
998 | } |
1014 | } |
999 | |
1015 | |
1000 | my (@dirs, @nondirs); |
1016 | my (@dirs, @nondirs); |
1001 | |
1017 | |
1002 | my $statgrp = add $grp aio_group sub { |
1018 | my $statgrp = add $grp aio_group sub { |
1003 | $grp->result (\@dirs, \@nondirs); |
1019 | $grp->result (\@dirs, \@nondirs); |
1004 | }; |
1020 | }; |
1005 | |
1021 | |
1006 | limit $statgrp $maxreq; |
1022 | limit $statgrp $maxreq; |
1007 | feed $statgrp sub { |
1023 | feed $statgrp sub { |
1008 | return unless @$entries; |
1024 | return unless @$entries; |
1009 | my $entry = shift @$entries; |
1025 | my $entry = shift @$entries; |
1010 | |
1026 | |
1011 | aioreq_pri $pri; |
1027 | aioreq_pri $pri; |
|
|
1028 | $wd->[1] = "$entry/."; |
1012 | add $statgrp aio_stat "$path/$entry/.", sub { |
1029 | add $statgrp aio_stat $wd, sub { |
1013 | if ($_[0] < 0) { |
1030 | if ($_[0] < 0) { |
1014 | push @nondirs, $entry; |
1031 | push @nondirs, $entry; |
1015 | } else { |
1032 | } else { |
1016 | # need to check for real directory |
1033 | # need to check for real directory |
1017 | aioreq_pri $pri; |
1034 | aioreq_pri $pri; |
|
|
1035 | $wd->[1] = $entry; |
1018 | add $statgrp aio_lstat "$path/$entry", sub { |
1036 | add $statgrp aio_lstat $wd, sub { |
1019 | if (-d _) { |
1037 | if (-d _) { |
1020 | push @dirs, $entry; |
1038 | push @dirs, $entry; |
1021 | |
1039 | |
1022 | unless (--$ndirs) { |
1040 | unless (--$ndirs) { |
1023 | push @nondirs, @$entries; |
1041 | push @nondirs, @$entries; |
1024 | feed $statgrp; |
1042 | feed $statgrp; |
|
|
1043 | } |
|
|
1044 | } else { |
|
|
1045 | push @nondirs, $entry; |
1025 | } |
1046 | } |
1026 | } else { |
|
|
1027 | push @nondirs, $entry; |
|
|
1028 | } |
1047 | } |
1029 | } |
1048 | } |
1030 | } |
1049 | }; |
1031 | }; |
1050 | }; |
1032 | }; |
1051 | }; |
1033 | }; |
1052 | }; |
1034 | }; |
1053 | }; |
1035 | }; |
1054 | }; |
1036 | |
1055 | |
1037 | $grp |
1056 | $grp |
1038 | } |
1057 | } |
1039 | |
1058 | |
1040 | =item aio_rmtree $path, $callback->($status) |
1059 | =item aio_rmtree $pathname, $callback->($status) |
1041 | |
1060 | |
1042 | Delete a directory tree starting (and including) C<$path>, return the |
1061 | Delete a directory tree starting (and including) C<$path>, return the |
1043 | status of the final C<rmdir> only. This is a composite request that |
1062 | status of the final C<rmdir> only. This is a composite request that |
1044 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1063 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1045 | everything else. |
1064 | everything else. |
… | |
… | |
1106 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1125 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1107 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1126 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1108 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1127 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1109 | manpage for details. |
1128 | manpage for details. |
1110 | |
1129 | |
1111 | =item aio_pathsync $path, $callback->($status) |
1130 | =item aio_pathsync $pathname, $callback->($status) |
1112 | |
1131 | |
1113 | This request tries to open, fsync and close the given path. This is a |
1132 | This request tries to open, fsync and close the given path. This is a |
1114 | composite request intended to sync directories after directory operations |
1133 | composite request intended to sync directories after directory operations |
1115 | (E.g. rename). This might not work on all operating systems or have any |
1134 | (E.g. rename). This might not work on all operating systems or have any |
1116 | specific effect, but usually it makes sure that directory changes get |
1135 | specific effect, but usually it makes sure that directory changes get |
… | |
… | |
1259 | immense (it blocks a thread for a long time) so do not use this function |
1278 | immense (it blocks a thread for a long time) so do not use this function |
1260 | except to put your application under artificial I/O pressure. |
1279 | except to put your application under artificial I/O pressure. |
1261 | |
1280 | |
1262 | =back |
1281 | =back |
1263 | |
1282 | |
|
|
1283 | |
|
|
1284 | =head2 IO::AIO::WD - multiple working directories |
|
|
1285 | |
|
|
1286 | Your process only has one current working directory, which is used by all |
|
|
1287 | threads. This makes it hard to use relative paths (some other component |
|
|
1288 | could call C<chdir> at any time, and it is hard to control when the path |
|
|
1289 | will be used by IO::AIO). |
|
|
1290 | |
|
|
1291 | One solution for this is to always use absolute paths. This usually works, |
|
|
1292 | but can be quite slow (the kernel has to walk the whole path on every |
|
|
1293 | access), and can also be a hassle to implement. |
|
|
1294 | |
|
|
1295 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1296 | futimensat and so on) that make it possible to specify working directories |
|
|
1297 | per operation. |
|
|
1298 | |
|
|
1299 | For portability, and because the clowns who "designed", or shall I write, |
|
|
1300 | perpetrated this new interface were obviously half-drunk, this abstraction |
|
|
1301 | cannot be perfect, though. |
|
|
1302 | |
|
|
1303 | IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD |
|
|
1304 | object. This object stores the canonicalised, absolute version of the |
|
|
1305 | path, and on systems that allow it, also a directory file descriptor. |
|
|
1306 | |
|
|
1307 | Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> |
|
|
1308 | or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD |
|
|
1309 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1310 | gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the |
|
|
1311 | IO::AIO::WD object is ignored, otherwise the pathname is resolved relative |
|
|
1312 | to that IO::AIO::WD object. |
|
|
1313 | |
|
|
1314 | For example, to get a wd object for F</etc> and then stat F<passwd> |
|
|
1315 | inside, you would write: |
|
|
1316 | |
|
|
1317 | aio_wd "/etc", sub { |
|
|
1318 | my $etcdir = shift; |
|
|
1319 | |
|
|
1320 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1321 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1322 | # when $etcdir is undef. |
|
|
1323 | |
|
|
1324 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1325 | # yay |
|
|
1326 | }; |
|
|
1327 | }; |
|
|
1328 | |
|
|
1329 | That C<aio_wd> is a request and not a normal function shows that creating |
|
|
1330 | an IO::AIO::WD object is itself a potentially blocking operation, which is |
|
|
1331 | why it is done asynchronously. |
|
|
1332 | |
|
|
1333 | To stat the directory obtained with C<aio_wd> above, one could write |
|
|
1334 | either of the following three request calls: |
|
|
1335 | |
|
|
1336 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1337 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1338 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1339 | |
|
|
1340 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1341 | object and the pathname string, so you could write the following without |
|
|
1342 | causing any issues due to C<$path> getting reused: |
|
|
1343 | |
|
|
1344 | my $path = [$wd, undef]; |
|
|
1345 | |
|
|
1346 | for my $name (qw(abc def ghi)) { |
|
|
1347 | $path->[1] = $name; |
|
|
1348 | aio_stat $path, sub { |
|
|
1349 | # ... |
|
|
1350 | }; |
|
|
1351 | } |
|
|
1352 | |
|
|
1353 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1354 | pathname string doesn't change, so will point to the new directory (or |
|
|
1355 | nowhere at all), while the directory fd, if available on the system, |
|
|
1356 | will still point to the original directory. Most functions accepting a |
|
|
1357 | pathname will use the directory fd on newer systems, and the string on |
|
|
1358 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1359 | string form of the pathname. |
|
|
1360 | |
|
|
1361 | So this fucntionality is mainly useful to get some protection against |
|
|
1362 | C<chdir>, to easily get an absolute path out of a relative path for future |
|
|
1363 | reference, and to speed up doing many operations in the same directory |
|
|
1364 | (e.g. when stat'ing all files in a directory). |
|
|
1365 | |
|
|
1366 | The following functions implement this working directory abstraction: |
|
|
1367 | |
|
|
1368 | =over 4 |
|
|
1369 | |
|
|
1370 | =item aio_wd $pathname, $callback->($wd) |
|
|
1371 | |
|
|
1372 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1373 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1374 | system, also open a directory fd to speed up pathname resolution relative |
|
|
1375 | to this working directory. |
|
|
1376 | |
|
|
1377 | If something goes wrong, then C<undef> is passwd to the callback instead |
|
|
1378 | of a working directory object and C<$!> is set appropriately. Since |
|
|
1379 | passing C<undef> as working directory component of a pathname fails the |
|
|
1380 | request with C<ENOENT>, there is often no need for error checking in the |
|
|
1381 | C<aio_wd> callback, as future requests using the value will fail in the |
|
|
1382 | expected way. |
|
|
1383 | |
|
|
1384 | If this call isn't available because your OS lacks it or it couldn't be |
|
|
1385 | detected, it will be emulated by calling C<fsync> instead. |
|
|
1386 | |
|
|
1387 | =item IO::AIO::CWD |
|
|
1388 | |
|
|
1389 | This is a compiletime constant (object) that represents the process |
|
|
1390 | current working directory. |
|
|
1391 | |
|
|
1392 | Specifying this object as working directory object for a pathname is as |
|
|
1393 | if the pathname would be specified directly, without a directory object, |
|
|
1394 | e.g., these calls are functionally identical: |
|
|
1395 | |
|
|
1396 | aio_stat "somefile", sub { ... }; |
|
|
1397 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1398 | |
|
|
1399 | =back |
|
|
1400 | |
|
|
1401 | |
1264 | =head2 IO::AIO::REQ CLASS |
1402 | =head2 IO::AIO::REQ CLASS |
1265 | |
1403 | |
1266 | All non-aggregate C<aio_*> functions return an object of this class when |
1404 | All non-aggregate C<aio_*> functions return an object of this class when |
1267 | called in non-void context. |
1405 | called in non-void context. |
1268 | |
1406 | |
… | |
… | |
1385 | |
1523 | |
1386 | Sets a feeder/generator on this group: every group can have an attached |
1524 | Sets a feeder/generator on this group: every group can have an attached |
1387 | generator that generates requests if idle. The idea behind this is that, |
1525 | generator that generates requests if idle. The idea behind this is that, |
1388 | although you could just queue as many requests as you want in a group, |
1526 | although you could just queue as many requests as you want in a group, |
1389 | this might starve other requests for a potentially long time. For example, |
1527 | this might starve other requests for a potentially long time. For example, |
1390 | C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, |
1528 | C<aio_scandir> might generate hundreds of thousands of C<aio_stat> |
1391 | delaying any later requests for a long time. |
1529 | requests, delaying any later requests for a long time. |
1392 | |
1530 | |
1393 | To avoid this, and allow incremental generation of requests, you can |
1531 | To avoid this, and allow incremental generation of requests, you can |
1394 | instead a group and set a feeder on it that generates those requests. The |
1532 | instead a group and set a feeder on it that generates those requests. The |
1395 | feed callback will be called whenever there are few enough (see C<limit>, |
1533 | feed callback will be called whenever there are few enough (see C<limit>, |
1396 | below) requests active in the group itself and is expected to queue more |
1534 | below) requests active in the group itself and is expected to queue more |