10 |
use Fuse; |
use Fuse; |
11 |
use DBI; |
use DBI; |
12 |
use Carp; |
use Carp; |
|
use Proc::Simple; |
|
13 |
use Data::Dumper; |
use Data::Dumper; |
14 |
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|
15 |
|
|
16 |
our $VERSION = '0.01'; |
our $VERSION = '0.06'; |
17 |
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|
18 |
=head1 NAME |
=head1 NAME |
19 |
|
|
24 |
use Fuse::DBI; |
use Fuse::DBI; |
25 |
Fuse::DBI->mount( ... ); |
Fuse::DBI->mount( ... ); |
26 |
|
|
27 |
See L<run> below for examples how to set parametars. |
See C<run> below for examples how to set parameters. |
28 |
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|
29 |
=head1 DESCRIPTION |
=head1 DESCRIPTION |
30 |
|
|
31 |
This module will use L<Fuse> module, part of C<FUSE (Filesystem in USErspace)> |
This module will use C<Fuse> module, part of C<FUSE (Filesystem in USErspace)> |
32 |
available at L<http://sourceforge.net/projects/avf> to mount |
available at L<http://fuse.sourceforge.net/> to mount |
33 |
your database as file system. |
your database as file system. |
34 |
|
|
35 |
That will give you posibility to use normal file-system tools (cat, grep, vi) |
That will give you possibility to use normal file-system tools (cat, grep, vi) |
36 |
to manipulate data in database. |
to manipulate data in database. |
37 |
|
|
38 |
It's actually opposite of Oracle's intention to put everything into database. |
It's actually opposite of Oracle's intention to put everything into database. |
46 |
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|
47 |
Mount your database as filesystem. |
Mount your database as filesystem. |
48 |
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|
49 |
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Let's suppose that your database have table C<files> with following structure: |
50 |
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|
51 |
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id: int |
52 |
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filename: text |
53 |
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size: int |
54 |
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content: text |
55 |
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writable: boolean |
56 |
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|
57 |
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Following is example how to mount table like that to C</mnt>: |
58 |
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|
59 |
my $mnt = Fuse::DBI->mount({ |
my $mnt = Fuse::DBI->mount({ |
60 |
filenames => 'select name from filenamefilenames, |
'filenames' => 'select id,filename,size,writable from files', |
61 |
read => 'sql read', |
'read' => 'select content from files where id = ?', |
62 |
update => 'sql update', |
'update' => 'update files set content = ? where id = ?', |
63 |
dsn => 'DBI:Pg:dbname=webgui', |
'dsn' => 'DBI:Pg:dbname=test_db', |
64 |
user => 'database_user', |
'user' => 'database_user', |
65 |
password => 'database_password' |
'password' => 'database_password', |
66 |
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'invalidate' => sub { ... }, |
67 |
}); |
}); |
68 |
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|
69 |
|
Options: |
70 |
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|
71 |
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=over 5 |
72 |
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|
73 |
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=item filenames |
74 |
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|
75 |
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SQL query which returns C<id> (unique id for that row), C<filename>, |
76 |
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C<size> and C<writable> boolean flag. |
77 |
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|
78 |
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=item read |
79 |
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|
80 |
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SQL query which returns only one column with content of file and has |
81 |
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placeholder C<?> for C<id>. |
82 |
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|
83 |
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=item update |
84 |
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|
85 |
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SQL query with two pace-holders, one for new content and one for C<id>. |
86 |
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|
87 |
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=item dsn |
88 |
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|
89 |
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C<DBI> dsn to connect to (contains database driver and name of database). |
90 |
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|
91 |
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=item user |
92 |
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93 |
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User with which to connect to database |
94 |
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|
95 |
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=item password |
96 |
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|
97 |
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Password for connecting to database |
98 |
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|
99 |
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=item invalidate |
100 |
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|
101 |
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Optional anonymous code reference which will be executed when data is updated in |
102 |
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database. It can be used as hook to delete cache (for example on-disk-cache) |
103 |
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which is created from data edited through C<Fuse::DBI>. |
104 |
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|
105 |
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=item fork |
106 |
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|
107 |
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Optional flag which forks after mount so that executing script will continue |
108 |
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running. Implementation is experimental. |
109 |
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110 |
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=back |
111 |
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|
112 |
=cut |
=cut |
113 |
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|
114 |
my $dbh; |
my $dbh; |
116 |
my $ctime_start; |
my $ctime_start; |
117 |
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|
118 |
sub read_filenames; |
sub read_filenames; |
119 |
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sub fuse_module_loaded; |
120 |
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121 |
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# evil, evil way to solve this. It makes this module non-reentrant. But, since |
122 |
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# fuse calls another copy of this script for each mount anyway, this shouldn't |
123 |
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# be a problem. |
124 |
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my $fuse_self; |
125 |
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|
126 |
sub mount { |
sub mount { |
127 |
my $class = shift; |
my $class = shift; |
135 |
carp "mount needs 'dsn' to connect to (e.g. dsn => 'DBI:Pg:dbname=test')" unless ($arg->{'dsn'}); |
carp "mount needs 'dsn' to connect to (e.g. dsn => 'DBI:Pg:dbname=test')" unless ($arg->{'dsn'}); |
136 |
carp "mount needs 'mount' as mountpoint" unless ($arg->{'mount'}); |
carp "mount needs 'mount' as mountpoint" unless ($arg->{'mount'}); |
137 |
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|
138 |
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# save (some) arguments in self |
139 |
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foreach (qw(mount invalidate)) { |
140 |
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$self->{$_} = $arg->{$_}; |
141 |
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} |
142 |
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|
143 |
foreach (qw(filenames read update)) { |
foreach (qw(filenames read update)) { |
144 |
carp "mount needs '$_' SQL" unless ($arg->{$_}); |
carp "mount needs '$_' SQL" unless ($arg->{$_}); |
145 |
} |
} |
146 |
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|
147 |
$dbh = DBI->connect($arg->{'dsn'},$arg->{'user'},$arg->{'password'}, { AutoCommit => 0 }) || die $DBI::errstr; |
$ctime_start = time(); |
148 |
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|
149 |
print "start transaction\n"; |
my $pid; |
150 |
#$dbh->begin_work || die $dbh->errstr; |
if ($arg->{'fork'}) { |
151 |
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$pid = fork(); |
152 |
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die "fork() failed: $!" unless defined $pid; |
153 |
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# child will return to caller |
154 |
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if ($pid) { |
155 |
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return $self; |
156 |
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} |
157 |
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} |
158 |
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159 |
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$dbh = DBI->connect($arg->{'dsn'},$arg->{'user'},$arg->{'password'}, {AutoCommit => 0, RaiseError => 1}) || die $DBI::errstr; |
160 |
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161 |
$sth->{filenames} = $dbh->prepare($arg->{'filenames'}) || die $dbh->errstr(); |
$sth->{'filenames'} = $dbh->prepare($arg->{'filenames'}) || die $dbh->errstr(); |
162 |
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163 |
$sth->{'read'} = $dbh->prepare($arg->{'read'}) || die $dbh->errstr(); |
$sth->{'read'} = $dbh->prepare($arg->{'read'}) || die $dbh->errstr(); |
164 |
$sth->{'update'} = $dbh->prepare($arg->{'update'}) || die $dbh->errstr(); |
$sth->{'update'} = $dbh->prepare($arg->{'update'}) || die $dbh->errstr(); |
165 |
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$ctime_start = time(); |
|
166 |
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167 |
read_filenames; |
$self->{'sth'} = $sth; |
168 |
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169 |
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$self->{'read_filenames'} = sub { $self->read_filenames }; |
170 |
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$self->read_filenames; |
171 |
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172 |
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$fuse_self = \$self; |
173 |
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|
174 |
$self->{'proc'} = Proc::Simple->new(); |
Fuse::main( |
175 |
$self->{'proc'}->kill_on_destroy(1); |
mountpoint=>$arg->{'mount'}, |
176 |
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getattr=>\&e_getattr, |
177 |
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getdir=>\&e_getdir, |
178 |
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open=>\&e_open, |
179 |
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statfs=>\&e_statfs, |
180 |
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read=>\&e_read, |
181 |
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write=>\&e_write, |
182 |
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utime=>\&e_utime, |
183 |
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truncate=>\&e_truncate, |
184 |
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unlink=>\&e_unlink, |
185 |
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rmdir=>\&e_unlink, |
186 |
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debug=>0, |
187 |
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); |
188 |
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189 |
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exit(0) if ($arg->{'fork'}); |
190 |
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|
191 |
$self->{'proc'}->start( sub { |
return 1; |
|
Fuse::main( |
|
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mountpoint=>$arg->{'mount'}, |
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getattr=>\&e_getattr, |
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getdir=>\&e_getdir, |
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open=>\&e_open, |
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statfs=>\&e_statfs, |
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read=>\&e_read, |
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write=>\&e_write, |
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utime=>\&e_utime, |
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truncate=>\&e_truncate, |
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debug=>0, |
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); |
|
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} ); |
|
192 |
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$self ? return $self : return undef; |
|
193 |
}; |
}; |
194 |
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|
195 |
=head2 umount |
=head2 umount |
206 |
sub umount { |
sub umount { |
207 |
my $self = shift; |
my $self = shift; |
208 |
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|
209 |
confess "no process running?" unless ($self->{'proc'}); |
if ($self->{'mount'}) { |
210 |
$self->{'proc'}->kill; |
if (open(MTAB, "/etc/mtab")) { |
211 |
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my $mounted = 0; |
212 |
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my $mount = $self->{'mount'}; |
213 |
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while(<MTAB>) { |
214 |
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$mounted = 1 if (/ $mount fuse /i); |
215 |
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} |
216 |
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close(MTAB); |
217 |
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218 |
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if ($mounted) { |
219 |
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system "fusermount -u ".$self->{'mount'}." 2>&1 >/dev/null" || return 0; |
220 |
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return 1; |
221 |
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} |
222 |
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223 |
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} else { |
224 |
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warn "can't open /etc/mtab: $!"; |
225 |
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return 0; |
226 |
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} |
227 |
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} |
228 |
} |
} |
229 |
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230 |
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$SIG{'INT'} = sub { |
231 |
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if ($fuse_self && $$fuse_self->umount) { |
232 |
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print STDERR "umount called by SIG INT\n"; |
233 |
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} |
234 |
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}; |
235 |
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|
236 |
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$SIG{'QUIT'} = sub { |
237 |
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if ($fuse_self && $$fuse_self->umount) { |
238 |
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print STDERR "umount called by SIG QUIT\n"; |
239 |
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} |
240 |
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}; |
241 |
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|
242 |
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sub DESTROY { |
243 |
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my $self = shift; |
244 |
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if ($self->umount) { |
245 |
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print STDERR "umount called by DESTROY\n"; |
246 |
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} |
247 |
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} |
248 |
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|
249 |
|
=head2 fuse_module_loaded |
250 |
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|
251 |
|
Checks if C<fuse> module is loaded in kernel. |
252 |
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|
253 |
|
die "no fuse module loaded in kernel" |
254 |
|
unless (Fuse::DBI::fuse_module_loaded); |
255 |
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|
256 |
|
This function in called by C<mount>, but might be useful alone also. |
257 |
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|
258 |
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=cut |
259 |
|
|
260 |
|
sub fuse_module_loaded { |
261 |
|
my $lsmod = `lsmod`; |
262 |
|
die "can't start lsmod: $!" unless ($lsmod); |
263 |
|
if ($lsmod =~ m/fuse/s) { |
264 |
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return 1; |
265 |
|
} else { |
266 |
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return 0; |
267 |
|
} |
268 |
|
} |
269 |
|
|
270 |
my %files; |
my %files; |
271 |
my %dirs; |
my %dirs; |
273 |
sub read_filenames { |
sub read_filenames { |
274 |
my $self = shift; |
my $self = shift; |
275 |
|
|
276 |
|
my $sth = $self->{'sth'} || die "no sth argument"; |
277 |
|
|
278 |
# create empty filesystem |
# create empty filesystem |
279 |
(%files) = ( |
(%files) = ( |
280 |
'.' => { |
'.' => { |
281 |
type => 0040, |
type => 0040, |
282 |
mode => 0755, |
mode => 0755, |
283 |
}, |
}, |
284 |
|
'..' => { |
285 |
|
type => 0040, |
286 |
|
mode => 0755, |
287 |
|
}, |
288 |
# a => { |
# a => { |
289 |
# cont => "File 'a'.\n", |
# cont => "File 'a'.\n", |
290 |
# type => 0100, |
# type => 0100, |
361 |
# return as many text filenames as you like, followed by the retval. |
# return as many text filenames as you like, followed by the retval. |
362 |
print((scalar keys %files)." files total\n"); |
print((scalar keys %files)." files total\n"); |
363 |
my %out; |
my %out; |
364 |
foreach (keys %files) { |
foreach my $f (sort keys %files) { |
|
my $f = $_; |
|
|
$f =~ s/^\E$dirname\Q//; |
|
|
$f =~ s/^\///; |
|
365 |
if ($dirname) { |
if ($dirname) { |
366 |
$out{$f}++ if (/^\E$dirname\Q/ && $f =~ /^[^\/]+$/); |
if ($f =~ s/^\Q$dirname\E\///) { |
367 |
|
$out{$f}++ if ($f =~ /^[^\/]+$/); |
368 |
|
} |
369 |
} else { |
} else { |
370 |
$out{$f}++ if ($f =~ /^[^\/]+$/); |
$out{$f}++ if ($f =~ /^[^\/]+$/); |
371 |
} |
} |
374 |
$out{'no files? bug?'}++; |
$out{'no files? bug?'}++; |
375 |
} |
} |
376 |
print scalar keys %out," files in dir '$dirname'\n"; |
print scalar keys %out," files in dir '$dirname'\n"; |
377 |
|
print "## ",join(" ",keys %out),"\n"; |
378 |
return (keys %out),0; |
return (keys %out),0; |
379 |
} |
} |
380 |
|
|
381 |
|
sub read_content { |
382 |
|
my ($file,$id) = @_; |
383 |
|
|
384 |
|
die "read_content needs file and id" unless ($file && $id); |
385 |
|
|
386 |
|
$sth->{'read'}->execute($id) || die $sth->{'read'}->errstr; |
387 |
|
$files{$file}{cont} = $sth->{'read'}->fetchrow_array; |
388 |
|
# I should modify ctime only if content in database changed |
389 |
|
#$files{$file}{ctime} = time() unless ($files{$file}{ctime}); |
390 |
|
print "file '$file' content [",length($files{$file}{cont})," bytes] read in cache\n"; |
391 |
|
} |
392 |
|
|
393 |
|
|
394 |
sub e_open { |
sub e_open { |
395 |
# VFS sanity check; it keeps all the necessary state, not much to do here. |
# VFS sanity check; it keeps all the necessary state, not much to do here. |
396 |
my $file = filename_fixup(shift); |
my $file = filename_fixup(shift); |
399 |
return -ENOENT() unless exists($files{$file}); |
return -ENOENT() unless exists($files{$file}); |
400 |
return -EISDIR() unless exists($files{$file}{id}); |
return -EISDIR() unless exists($files{$file}{id}); |
401 |
|
|
402 |
if (!exists($files{$file}{cont})) { |
read_content($file,$files{$file}{id}) unless exists($files{$file}{cont}); |
403 |
$sth->{'read'}->execute($files{$file}{id}) || die $sth->{'read'}->errstr; |
|
|
$files{$file}{cont} = $sth->{'read'}->fetchrow_array; |
|
|
print "file '$file' content read in cache\n"; |
|
|
} |
|
404 |
print "open '$file' ",length($files{$file}{cont})," bytes\n"; |
print "open '$file' ",length($files{$file}{cont})," bytes\n"; |
405 |
return 0; |
return 0; |
406 |
} |
} |
421 |
return -EINVAL() if ($off > $len); |
return -EINVAL() if ($off > $len); |
422 |
return 0 if ($off == $len); |
return 0 if ($off == $len); |
423 |
|
|
424 |
$buf_len = $buf_len-$off if ($off+$buf_len > $len); |
$buf_len = $len-$off if ($len - $off < $buf_len); |
425 |
|
|
426 |
return substr($files{$file}{cont},$off,$buf_len); |
return substr($files{$file}{cont},$off,$buf_len); |
427 |
} |
} |
432 |
print "invalidate all cached content\n"; |
print "invalidate all cached content\n"; |
433 |
foreach my $f (keys %files) { |
foreach my $f (keys %files) { |
434 |
delete $files{$f}{cont}; |
delete $files{$f}{cont}; |
435 |
|
delete $files{$f}{ctime}; |
436 |
} |
} |
437 |
print "begin new transaction\n"; |
print "begin new transaction\n"; |
438 |
$dbh->begin_work || die $dbh->errstr; |
#$dbh->begin_work || die $dbh->errstr; |
439 |
} |
} |
440 |
|
|
441 |
|
|
444 |
|
|
445 |
$files{$file}{ctime} = time(); |
$files{$file}{ctime} = time(); |
446 |
|
|
447 |
if (!$sth->{'update'}->execute($files{$file}{cont},$files{$file}{id})) { |
my ($cont,$id) = ( |
448 |
|
$files{$file}{cont}, |
449 |
|
$files{$file}{id} |
450 |
|
); |
451 |
|
|
452 |
|
if (!$sth->{'update'}->execute($cont,$id)) { |
453 |
print "update problem: ",$sth->{'update'}->errstr; |
print "update problem: ",$sth->{'update'}->errstr; |
454 |
clear_cont; |
clear_cont; |
455 |
return 0; |
return 0; |
460 |
return 0; |
return 0; |
461 |
} |
} |
462 |
print "updated '$file' [",$files{$file}{id},"]\n"; |
print "updated '$file' [",$files{$file}{id},"]\n"; |
463 |
|
|
464 |
|
$$fuse_self->{'invalidate'}->() if (ref $$fuse_self->{'invalidate'}); |
465 |
} |
} |
466 |
return 1; |
return 1; |
467 |
} |
} |
468 |
|
|
469 |
sub e_write { |
sub e_write { |
470 |
my $file = filename_fixup(shift); |
my $file = filename_fixup(shift); |
471 |
my ($buf_len,$off) = @_; |
my ($buffer,$off) = @_; |
472 |
|
|
473 |
return -ENOENT() unless exists($files{$file}); |
return -ENOENT() unless exists($files{$file}); |
474 |
|
|
475 |
my $len = length($files{$file}{cont}); |
my $cont = $files{$file}{cont}; |
476 |
|
my $len = length($cont); |
477 |
|
|
478 |
|
print "write '$file' [$len bytes] offset $off length ",length($buffer),"\n"; |
479 |
|
|
480 |
|
$files{$file}{cont} = ""; |
481 |
|
|
482 |
print "write '$file' [$len bytes] offset $off length\n"; |
$files{$file}{cont} .= substr($cont,0,$off) if ($off > 0); |
483 |
|
$files{$file}{cont} .= $buffer; |
484 |
|
$files{$file}{cont} .= substr($cont,$off+length($buffer),$len-$off-length($buffer)) if ($off+length($buffer) < $len); |
485 |
|
|
486 |
$files{$file}{cont} = |
$files{$file}{size} = length($files{$file}{cont}); |
|
substr($files{$file}{cont},0,$off) . |
|
|
$buf_len . |
|
|
substr($files{$file}{cont},$off+length($buf_len)); |
|
487 |
|
|
488 |
if (! update_db($file)) { |
if (! update_db($file)) { |
489 |
return -ENOSYS(); |
return -ENOSYS(); |
490 |
} else { |
} else { |
491 |
return length($buf_len); |
return length($buffer); |
492 |
} |
} |
493 |
} |
} |
494 |
|
|
496 |
my $file = filename_fixup(shift); |
my $file = filename_fixup(shift); |
497 |
my $size = shift; |
my $size = shift; |
498 |
|
|
499 |
|
print "truncate to $size\n"; |
500 |
|
|
501 |
$files{$file}{cont} = substr($files{$file}{cont},0,$size); |
$files{$file}{cont} = substr($files{$file}{cont},0,$size); |
502 |
|
$files{$file}{size} = $size; |
503 |
return 0 |
return 0 |
504 |
}; |
}; |
505 |
|
|
518 |
|
|
519 |
sub e_statfs { return 255, 1, 1, 1, 1, 2 } |
sub e_statfs { return 255, 1, 1, 1, 1, 2 } |
520 |
|
|
521 |
|
sub e_unlink { |
522 |
|
my $file = filename_fixup(shift); |
523 |
|
|
524 |
|
if (exists( $dirs{$file} )) { |
525 |
|
print "unlink '$file' will re-read template names\n"; |
526 |
|
print Dumper($fuse_self); |
527 |
|
$$fuse_self->{'read_filenames'}->(); |
528 |
|
return 0; |
529 |
|
} elsif (exists( $files{$file} )) { |
530 |
|
print "unlink '$file' will invalidate cache\n"; |
531 |
|
read_content($file,$files{$file}{id}); |
532 |
|
return 0; |
533 |
|
} |
534 |
|
|
535 |
|
return -ENOENT(); |
536 |
|
} |
537 |
1; |
1; |
538 |
__END__ |
__END__ |
539 |
|
|
541 |
|
|
542 |
Nothing. |
Nothing. |
543 |
|
|
544 |
|
=head1 BUGS |
545 |
|
|
546 |
|
Size information (C<ls -s>) is wrong. It's a problem in upstream Fuse module |
547 |
|
(for which I'm to blame lately), so when it gets fixes, C<Fuse::DBI> will |
548 |
|
automagically pick it up. |
549 |
|
|
550 |
=head1 SEE ALSO |
=head1 SEE ALSO |
551 |
|
|
552 |
C<FUSE (Filesystem in USErspace)> website |
C<FUSE (Filesystem in USErspace)> website |
553 |
L<http://sourceforge.net/projects/avf> |
L<http://fuse.sourceforge.net/> |
554 |
|
|
555 |
|
Example for WebGUI which comes with this distribution in |
556 |
|
directory C<examples/webgui.pl>. It also contains a lot of documentation |
557 |
|
about design of this module, usage and limitations. |
558 |
|
|
559 |
=head1 AUTHOR |
=head1 AUTHOR |
560 |
|
|