php/Isis/File.php

<?php
/*
        OpenIsis - an open implementation of the CDS/ISIS database
        Version 0.8.x (patchlevel see file Version)
        Copyright (C) 2001-2003 by Erik Grziwotz, erik@openisis.org

        This library is free software; you can redistribute it and/or
        modify it under the terms of the GNU Lesser General Public
        License as published by the Free Software Foundation; either
        version 2.1 of the License, or (at your option) any later version.

        This library is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        Lesser General Public License for more details.

        You should have received a copy of the GNU Lesser General Public
        License along with this library; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

        see README for more information
EOH */

// $Id: File.php,v 1.4 2003/06/13 19:35:24 kripke Exp $


/**
        the magic for a 4/4/0 little endian isis xref file.
        http://OpenIsis.org/openisis/doc/Serialized
*/
define( 'ISIS_FILE_MAGIC', "ISIXD\0:)" );
/**
        The flat file database.
        It does not know anything about isis records,
        it's just dealing with the string representation.

        58971 records (unesb), 29442129 bytes flat (34565120 as .mst)
        mkxrf: 8.1 sec (7280 recs / sec)
        read all (just the string): 3.48 sec (~17.000 recs / sec)
        read 10.000, creating recs: 3.95 sec
        read 1.000, creating recs, printing: ~2 sec

        @version $Revision: 1.4 $
        @license LGPL
        @package Isis
*/
class Isis_File {
        var $name;
        var $mst;
        var $xrf = 0;
        var $w;
        /** number of records == number of last record
        */
        var $len = 0;

        function Isis_File ( $name, $write = 0 )
        {
                $this->name = $name;
                $this->w = $write;
                $this->mst = fopen($name.'.txt', $write ? 'a+' : 'r');
                if ( ! $this->mst )
                        return;
                flock($this->mst, $write ? LOCK_EX : LOCK_SH);
                $s = fstat($this->mst);
                $mtime = $s['mtime'];
                if ( file_exists($name.'.ptr') ) // avoid annoying warning
                        $this->xrf = fopen($name.'.ptr', $write ? 'r+' : 'r');
                if (!$this->xrf)
                        $remake = 1;
                else {
                        $s = fstat($this->xrf);
                        $magic = fread($this->xrf, 8);
                        $remake = $s['mtime'] < $mtime || ISIS_FILE_MAGIC != $magic;
                        if ( !$remake )
                                $this->len = $s['size'] / 8 - 1;
                        if ( $remake && !$write ) {
                                fclose($this->xrf);
                                $this->xrf = 0;
                        }
                }
                if ( !$this->xrf && !($this->xrf = fopen($name.'.ptr','w+')) ) {
                        fclose($this->mst);
                        return;
                }
                if ( $remake )
                        $this->mkxref();
        }


        function mkxref ()
        {
                fseek($this->mst, 0);
                ftruncate($this->xrf, 0);
                fseek($this->xrf, 0);
                fwrite( $this->xrf, ISIS_FILE_MAGIC, 8 );
                $mfn = 0;
                $lines = 0;
                for (;;) {
                        $line = fgets($this->mst);
                        $end = !is_string($line) || '' == $line;
                        if ( $end || "\n" == $line{0} ) {
                                $now = ftell($this->mst);
                                $len = $now - $pos - 1;
                                if ( $len && !$end )
                                        $len--;
                                if ($mfn) {
                                        $xrf = pack('VV', $pos, $len);
                                        // echo "mfn $mfn pos $pos len $len\n";
                                        if ( 8 != ($foo = fwrite($this->xrf, $xrf)) )
                                                echo "FOO! $foo\n";
                                        if ($this->len < $mfn)
                                                $this->len = $mfn;
                                }
                                if ($end)
                                        break;
                                $mfn++;
                                $pos = $now;
                                $lines = 0;
                                continue;
                        }
                        if ( ! $lines
                                && ! (int)$line
                                && 2 == sscanf($line, "%c %d", &$ctrl, &$num)
                                && 'W' == $ctrl
                        ) {
                                echo "W $num\n";
                                $pos = ftell($this->mst);
                                $mfn = $num;
                                fseek($this->xrf, 8*$mfn);
                                continue;
                        }
                        $lines++;
                }
                fflush( $this->xrf );
        }       // mkxref


        /**
                @return string number $mfn or null
        */
        function read ( $mfn )
        {
                fseek($this->xrf, 8*$mfn);
                $xrf = fread( $this->xrf, 8 );
                if ( 8 != strlen($xrf) ) {
                        // echo "no xrf for $mfn\n";
                        return null;
                }
                $xrf = unpack('Vpos/Vlen', $xrf);
                // echo "mfn $mfn pos ${xrf['pos']} len ${xrf['len']}\n";
                if ( !$xrf['pos'] || !$xrf['len'] )
                        return null;
                fseek($this->mst, $xrf['pos']);
                $rec = fread($this->mst, $xrf['len']);
                return $xrf['len'] == strlen($rec) ? $rec : null;
        }


        /**
                write $data as $mfn or ++$this->len
                @return mfn
        */
        function write ( $data, $mfn = 0 )
        {
                if ( !$this->w )
                        trigger_error( $this->name.' not writable', E_USER_ERROR );
                if ( !$mfn )
                        $mfn = ++$this->len;
                elseif ($this->len < $mfn)
                        $this->len = $mfn;
                if ( !is_string($data) )
                        $len = 0;
                elseif ( $len = strlen($data) ) {
                        if ("\n" == $data{$len-1})
                                $len--;
                        else
                                $data .= "\n";
                }
                fseek($this->mst, 0, SEEK_END); // prbly not needed by mode a+
                fwrite($this->mst, "\nW\t$mfn\n");
                fflush($this->mst);
                $pos = ftell($this->mst);
                if ( $len )
                        fwrite($this->mst, $data);
                fseek($this->xrf, 8*$mfn);
                // echo "write $mfn len $len\n";
                fwrite($this->xrf, pack('VV', $pos, $len));
                fflush($this->xrf);
                return $mfn;
        }


        function compact ()
        {
                if ( !$this->w )
                        trigger_error( $this->name.' not writable', E_USER_ERROR );
                $c = fopen($this->name.'.new', 'w+');
                flock($c, LOCK_EX); // so we have exclusive locks on both
                for ( $n=1; $n<=$this->len; $n++ )
                        fwrite($c, is_null($data = $this->read($n))
                                ? "\n" : "\n".$data."\n"
                        );
                fflush($c);
                if ( file_exists($this->name.'.old') )
                        unlink($this->name.'.old');
                rename($this->name.'.txt', $this->name.'.old');
                rename($this->name.'.new', $this->name.'.txt');
                fclose($this->mst);
                $this->mst = $c;
                $this->mkxref(); // frob the xref in place
        }

}       // class Isis_File
?>
1	dpavlin	237	<?php
2			/*
3			OpenIsis - an open implementation of the CDS/ISIS database
4			Version 0.8.x (patchlevel see file Version)
5			Copyright (C) 2001-2003 by Erik Grziwotz, erik@openisis.org
6
7			This library is free software; you can redistribute it and/or
8			modify it under the terms of the GNU Lesser General Public
9			License as published by the Free Software Foundation; either
10			version 2.1 of the License, or (at your option) any later version.
11
12			This library is distributed in the hope that it will be useful,
13			but WITHOUT ANY WARRANTY; without even the implied warranty of
14			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15			Lesser General Public License for more details.
16
17			You should have received a copy of the GNU Lesser General Public
18			License along with this library; if not, write to the Free Software
19			Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20
21			see README for more information
22			EOH */
23
24			// $Id: File.php,v 1.4 2003/06/13 19:35:24 kripke Exp $
25
26
27			/**
28			the magic for a 4/4/0 little endian isis xref file.
29			http://OpenIsis.org/openisis/doc/Serialized
30			*/
31			define( 'ISIS_FILE_MAGIC', "ISIXD\0:)" );
32			/**
33			The flat file database.
34			It does not know anything about isis records,
35			it's just dealing with the string representation.
36
37			58971 records (unesb), 29442129 bytes flat (34565120 as .mst)
38			mkxrf: 8.1 sec (7280 recs / sec)
39			read all (just the string): 3.48 sec (~17.000 recs / sec)
40			read 10.000, creating recs: 3.95 sec
41			read 1.000, creating recs, printing: ~2 sec
42
43			@version $Revision: 1.4 $
44			@license LGPL
45			@package Isis
46			*/
47			class Isis_File {
48			var $name;
49			var $mst;
50			var $xrf = 0;
51			var $w;
52			/** number of records == number of last record
53			*/
54			var $len = 0;
55
56			function Isis_File ( $name, $write = 0 )
57			{
58			$this->name = $name;
59			$this->w = $write;
60			$this->mst = fopen($name.'.txt', $write ? 'a+' : 'r');
61			if ( ! $this->mst )
62			return;
63			flock($this->mst, $write ? LOCK_EX : LOCK_SH);
64			$s = fstat($this->mst);
65			$mtime = $s['mtime'];
66			if ( file_exists($name.'.ptr') ) // avoid annoying warning
67			$this->xrf = fopen($name.'.ptr', $write ? 'r+' : 'r');
68			if (!$this->xrf)
69			$remake = 1;
70			else {
71			$s = fstat($this->xrf);
72			$magic = fread($this->xrf, 8);
73			$remake = $s['mtime'] < $mtime \|\| ISIS_FILE_MAGIC != $magic;
74			if ( !$remake )
75			$this->len = $s['size'] / 8 - 1;
76			if ( $remake && !$write ) {
77			fclose($this->xrf);
78			$this->xrf = 0;
79			}
80			}
81			if ( !$this->xrf && !($this->xrf = fopen($name.'.ptr','w+')) ) {
82			fclose($this->mst);
83			return;
84			}
85			if ( $remake )
86			$this->mkxref();
87			}
88
89
90			function mkxref ()
91			{
92			fseek($this->mst, 0);
93			ftruncate($this->xrf, 0);
94			fseek($this->xrf, 0);
95			fwrite( $this->xrf, ISIS_FILE_MAGIC, 8 );
96			$mfn = 0;
97			$lines = 0;
98			for (;;) {
99			$line = fgets($this->mst);
100			$end = !is_string($line) \|\| '' == $line;
101			if ( $end \|\| "\n" == $line{0} ) {
102			$now = ftell($this->mst);
103			$len = $now - $pos - 1;
104			if ( $len && !$end )
105			$len--;
106			if ($mfn) {
107			$xrf = pack('VV', $pos, $len);
108			// echo "mfn $mfn pos $pos len $len\n";
109			if ( 8 != ($foo = fwrite($this->xrf, $xrf)) )
110			echo "FOO! $foo\n";
111			if ($this->len < $mfn)
112			$this->len = $mfn;
113			}
114			if ($end)
115			break;
116			$mfn++;
117			$pos = $now;
118			$lines = 0;
119			continue;
120			}
121			if ( ! $lines
122			&& ! (int)$line
123			&& 2 == sscanf($line, "%c %d", &$ctrl, &$num)
124			&& 'W' == $ctrl
125			) {
126			echo "W $num\n";
127			$pos = ftell($this->mst);
128			$mfn = $num;
129			fseek($this->xrf, 8*$mfn);
130			continue;
131			}
132			$lines++;
133			}
134			fflush( $this->xrf );
135			} // mkxref
136
137
138			/**
139			@return string number $mfn or null
140			*/
141			function read ( $mfn )
142			{
143			fseek($this->xrf, 8*$mfn);
144			$xrf = fread( $this->xrf, 8 );
145			if ( 8 != strlen($xrf) ) {
146			// echo "no xrf for $mfn\n";
147			return null;
148			}
149			$xrf = unpack('Vpos/Vlen', $xrf);
150			// echo "mfn $mfn pos ${xrf['pos']} len ${xrf['len']}\n";
151			if ( !$xrf['pos'] \|\| !$xrf['len'] )
152			return null;
153			fseek($this->mst, $xrf['pos']);
154			$rec = fread($this->mst, $xrf['len']);
155			return $xrf['len'] == strlen($rec) ? $rec : null;
156			}
157
158
159			/**
160			write $data as $mfn or ++$this->len
161			@return mfn
162			*/
163			function write ( $data, $mfn = 0 )
164			{
165			if ( !$this->w )
166			trigger_error( $this->name.' not writable', E_USER_ERROR );
167			if ( !$mfn )
168			$mfn = ++$this->len;
169			elseif ($this->len < $mfn)
170			$this->len = $mfn;
171			if ( !is_string($data) )
172			$len = 0;
173			elseif ( $len = strlen($data) ) {
174			if ("\n" == $data{$len-1})
175			$len--;
176			else
177			$data .= "\n";
178			}
179			fseek($this->mst, 0, SEEK_END); // prbly not needed by mode a+
180			fwrite($this->mst, "\nW\t$mfn\n");
181			fflush($this->mst);
182			$pos = ftell($this->mst);
183			if ( $len )
184			fwrite($this->mst, $data);
185			fseek($this->xrf, 8*$mfn);
186			// echo "write $mfn len $len\n";
187			fwrite($this->xrf, pack('VV', $pos, $len));
188			fflush($this->xrf);
189			return $mfn;
190			}
191
192
193			function compact ()
194			{
195			if ( !$this->w )
196			trigger_error( $this->name.' not writable', E_USER_ERROR );
197			$c = fopen($this->name.'.new', 'w+');
198			flock($c, LOCK_EX); // so we have exclusive locks on both
199			for ( $n=1; $n<=$this->len; $n++ )
200			fwrite($c, is_null($data = $this->read($n))
201			? "\n" : "\n".$data."\n"
202			);
203			fflush($c);
204			if ( file_exists($this->name.'.old') )
205			unlink($this->name.'.old');
206			rename($this->name.'.txt', $this->name.'.old');
207			rename($this->name.'.new', $this->name.'.txt');
208			fclose($this->mst);
209			$this->mst = $c;
210			$this->mkxref(); // frob the xref in place
211			}
212
213			} // class Isis_File
214			?>