3 # Copyright (C) 2007 Jason Woofenden
5 # This file is part of wfpl.
7 # wfpl is free software; you can redistribute it and/or modify it under the
8 # terms of the GNU Lesser General Public License as published by the Free
9 # Software Foundation; either version 2.1 of the License, or (at your option)
12 # wfpl is distributed in the hope that it will be useful, but WITHOUT ANY
13 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 # FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
17 # You should have received a copy of the GNU Lesser General Public License
18 # along with wfpl; if not, write to the Free Software Foundation, Inc., 51
19 # Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 # This file contains code to use a web-writeable directory full of files as a
23 # very simple database.
25 # Keys are truncated to 32 bytes, made lowercase, and all characters that are
26 # not alpha/numeric are replaced with underscores. Periods and hyphens are only
27 # replaced if they are at the begining.
29 # Data can be either a string or an array.
31 # To set up the database, make a directory that's writeable by PHP and call
32 # fdb_set_dir() passing the path to that directory.
35 require_once('code/wfpl/file.php');
37 # call this to set what directory is used to store the files
38 function fdb_set_dir($dir) {
39 $GLOBALS['fdb_dir'] = $dir;
42 function fdb_get_dir() {
43 if(!isset($GLOBALS['fdb_dir'])) {
44 die('you must call fdb_set_dir() before calling other functions in code/wfpl/fdb.php');
46 return $GLOBALS['fdb_dir'];
49 # return a 4 bytes that represent the passed integer as a big-endian binary number
50 function to_raw_int($int) {
51 return chr($int >> 24) . chr(($int >> 16) & 0xff) . chr(($int >> 8) & 0xff) . chr($int & 0xff);
54 # return a php number from the string you pass in. The first 4 bytes of the
55 # string are read in as a binary value in big-endian format.
56 function from_raw_int($quad) {
57 return (ord(substr($quad, 0, 1)) << 24) + (ord(substr($quad, 1, 1)) << 16) + (ord(substr($quad, 2, 1)) << 8) + ord(substr($quad, 3, 1));
60 function int_at($string, $index) {
61 return from_raw_int(substr($string, $index * 4, 4));
64 # remove the first 4 bytes of the string, and return them as an int
65 function pop_int(&$string) {
66 $int = from_raw_int(substr($string, 0, 4));
67 $string = substr($string, 4);
72 function fdb_fix_key($key) {
73 $key = ereg_replace('[^a-z0-9.-]', '_', strtolower($key));
74 $key = ereg_replace('^[-.]', '_', strtolower($key));
75 return substr($key, 0, 32);
79 function fdb_get_raw($key) {
80 $key = fdb_fix_key($key);
81 return read_whole_file_or_false(fdb_get_dir() . "/$key");
84 function fdb_set_raw($key, $data) {
85 $key = fdb_fix_key($key);
86 write_whole_file(fdb_get_dir() . "/$key", $data);
89 # like fdb_get() except it returns an array even when there's just one element
90 function fdb_geta($key) {
91 $key = fdb_fix_key($key);
92 $data = fdb_get_raw($key);
96 $header_count = pop_int($data);
98 while($header_count--) {
99 $size = pop_int($data);
100 $out[] = substr($data, 0, $size);
101 $data = substr($data, $size);
108 # false if the key is not found in the database
110 # an array from the file otherwise
112 # a string if there's one field in that file (use fdb_geta() if you want an
113 # array in this case too)
114 function fdb_get($key) {
115 $ret = fdb_geta($key);
119 if(count($ret) == 1) {
126 # data can be a string or array
127 function fdb_set($key, $data) {
128 $key = fdb_fix_key($key);
129 if(!is_array($data)) {
130 $data = array($data);
132 $out = to_raw_int(count($data));
133 foreach($data as $dat) {
134 $out .= to_raw_int(strlen($dat));
137 fdb_set_raw($key, $out);
140 function fdb_delete($key) {
141 $key = fdb_fix_key($key);
142 $path = fdb_get_dir() . "/$key";
143 if(file_exists($path)) {
144 return unlink($path);