Tie::PureDB - Perl extension for pure-db
use Tie::PureDB; my $file = 'foo.db'; { tie my %db, 'Tie::PureDB::Write', "$file.index", "$file.data", $file or die "Couldn't create database ($!)"; $db{createtime} = scalar gmtime; $db{$_} = rand($_) for 1..100; untie %db; tie %db, 'Tie::PureDB::Read', $file or die "Couldn't read database ($!)"; print "This database was created on $db{createtime}\n"; print " 1 => $db{1}\n 6 => $db{6}\n\n"; untie %db; } { my $db = Tie::PureDB::Write->new( "$file.index", "$file.data", $file ) or die "Couldn't create database ($!)"; $db->puredbw_add( createtime => scalar gmtime ); $db->add( $_ => rand($_)) for 1..100; undef $db; $db = Tie::PureDB::Read->($file) or die "Couldn't read database ($!)"; print "This database was created on ", $db->read( $db->puredb_find('createtime') ), \n"; print " 1 => ", $db->FETCH(1) || "EEEK!($!)", "\n"; print " 1 => ", $db->FETCH(9) || "EEEK!($!)", "\n"; undef $db; }
This is the perl interface to PureDB. If you wanna know what PureDB is, visit the PureDB home page at http://www.pureftpd.org/puredb/ .
Now go read the examples ;)
This is the interface to libpuredb_write.
If you use the tie interface, you can only use it to store values ($db{foo}=1; aka (tied %db)->STORE(foo => 1); ). It is highly reccomended that you use the tie interface.
$db{foo}=1;
(tied %db)->STORE(foo => 1);
If you use the function interface, you'll wanna use the following functions.
Also known as open, or new. It takes 3 arguments: file_index, file_data, file_final.
open
new
On success, returns a Tie::PureDB::Write object. On failure, returns nothing while setting $!.
Also known as open, or puredbw_add. It takes 2 arguments: key,value.
puredbw_add
On success, returns a true value. On failure, returns nothing while setting $!.
Don't try to use the following functions, they are not defined (for example: keys %db. See perltie for more info details.).
keys %db
# these would require an extension to libpuredb_write, which I ain't ready for sub FIRSTKEY(){} sub NEXTKEY(){} # these are NO-NOs (libpuredb_write don't know this) sub FETCH(){} sub EXISTS(){} sub DELETE(){} sub CLEAR(){}
This is the interface to libpuredb_read.
If you use the tie interface, you can only use it to read values (print $db{foo}; aka print (tied %db)->FETCH('foo'); ). It is highly reccomended that you use the tie interface.
print $db{foo};
print (tied %db)->FETCH('foo');
Also known as new, or open. It takes 1 arguments: file_final.
On success, returns a Tie::PureDB::Read object. On failure, returns nothing while setting $!.
Also known as puredb_getsize. Takes 0 arguments. Returns the size of the database in bytes (same number as -s $file).
puredb_getsize
-s $file
Also known as puredb_find. Takes 1 argument (the key to find), On success, returns offset,length. On failure, returns nothing while setting $!.
puredb_find
Also known as puredb_read. Takes 2 arguments (offset,length). On success, returns the value. On failure, returns nothing while setting $!.
puredb_read
**WARNING -- It is highly discouraged that you use read with invalid offsets. Always use those returned by find, or simply use FETCH or the tie interface.
read
find
FETCH
A utiliy method. use $db->FETCH('foo') instead of $db->read( $db->find('foo') ); Returns undef on failure.
$db->FETCH('foo')
$db->read( $db->find('foo') );
# these would require an extension to libpuredb_read, which I ain't ready for sub FIRSTKEY(){} sub NEXTKEY(){} # these are NO-NOs (libpuredb_read don't know this) sub STORE(){} sub DELETE(){} sub CLEAR(){}
AFAIK, this module and the underlying c library do not use globally shared data, and as such, they are "thread-safe".
untie()
If you aren't aware of the Gotcha, read about it before even attempting to use this module ;)
The untie Gotcha in perltie.
You could use Memoize with this module. All you have to do is add the following lines to your program:
use Tie::PureDB; BEGIN{ package Tie::PureDB::Read; use Memoize(); Memoize::memoize('puredb_read','puredb_find','FETCH'); no strict 'refs'; *read = *puredb_read; *find = *puredb_find; *EXISTS = *puredb_find; package main; } ## ... rest of your code follows
D. H. <PodMaster@cpan.org> who is very thankful to tye and the perlmonks, as well as Tim Jenness and Simon Cozens (authors of Extending and Embedding Perl -- http://www.manning.com/jenness/ ).
perl, perltie, perldata, AnyDBM_File, DB_File, BerkeleyDB.
To install Tie::PureDB, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Tie::PureDB
CPAN shell
perl -MCPAN -e shell install Tie::PureDB
For more information on module installation, please visit the detailed CPAN module installation guide.