org/openisis/NativeDb.java

/*
        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 */

package org.openisis;

import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.NoSuchElementException;


/**
        This class is the native implementation of class Db.
<h3>Installation</h3>
        The shared library "openjsis" must be loadable.
        On a UNIX System, make sure that the file libopenjsis.so
        resides in a directory listed by the environment variable
        LD_LIBRARY_PATH or in /etc/ld.so.conf. 
        If you just drop it in /usr/lib or similar dir,
        you may have to run a command like ldconfig.
<p>
        On Windows, put openjsis.dll somewhere in the PATH.
<p>
        $Id: NativeDb.java,v 1.5 2003/04/08 00:20:53 kripke Exp $
        @version $Revision: 1.5 $
        @author  $Author: kripke $
*/
public class NativeDb extends Db {

        private static synchronized native
        short nopen ( String dbname, String[] args );

        /** read a record by rowid.
         *      The native implementation gives character data as byte[],
         *      since we need to employ java encoding mechanisms anyway.
         *      The tag is packed as four bytes little endian.
         *      @param db a db number as returned by open
         *      @param rowid the number (aka mfn) of the row
         *      @param tag in which to look for txt, negative for any
         *      @param txt to grep from record, null for no grep
         *      @return an array of Objects:
         *              the first is an array of ints filled with rowid an tags
         *              the others are byte[] with field character data in encoding
         *      @see #encoding
        */
        private static synchronized native
        Object[] nreadRow ( short db, int rowid, int tag, byte[] txt );

        /** search for terms */
        private static synchronized native
        Object[] nTerms ( short db, byte[] term, byte[] start );

        /** get matching rowids */
        private static synchronized native
        int[] nsearch ( short db, byte[] key, int mode );

        /** plain write */
        private static synchronized native
        short nwriteRow ( short db, Object[] data );

        /** 
         * Indexed write
         * @param db database handle returned by open
         * @param data an Object array with an int[] on idx 0 containing
         * rowid and tags and with byte[] containing appropriate data for
         * the tags; thus a simple sanity check for a properly structured 
         * data is: data.length == data[ 0 ].length
         * @param idx same as data but contains a record that holds index
         * information
         */
        private static synchronized native
        short nwriteXRow ( short db, Object[] data, Object[] idx );

        static {
                // TODO: try some explicit paths like our jar's location with System.load
                // in order to not have to export LD_LIBRARY_PATH or so
                System.loadLibrary( "openjsis" );
        }

        public byte[] cvt ( String txt ) {
                try {
                        return txt.getBytes(encoding);
                } catch ( UnsupportedEncodingException e ) {
                        // shouldn't happen -- our fault
                        throw new Error( "failed to check for support of encoding "+encoding );
                }
        }

        public String cvt ( byte[] b ) {
                try {
                        // System.err.println( "got "+b.length+" bytes "+b );
                        for ( int l=b.length; 0<l; l-- ) {
                                String s = new String( b, 0, l, encoding );
                                if ( null != s && 0 != s.length() )
                                        return s;
                                for ( int i=0; i<l; i++ )
                                        System.err.print(
                                                (
                                                b[i] > 0 ? "0" : // 0... self-contained
                                                b[i] < -64 ? "f" : // 10... six follower bits
                                                b[i] < -32 ? "1" : // 110... five bits, one follower
                                                b[i] < -16 ? "2" : // 1110... four bits, two followers
                                                "b" // bad
                                                ) + "("+b[i]+")"
                                        );
                                return "";
                        }
                        return "";
                } catch ( UnsupportedEncodingException e ) {
                        // shouldn't happen -- our fault
                        throw new Error( "failed to check for support of encoding "+encoding );
                }
        }


        /** Number of this db.
        */
        public final short db;
        

        public NativeDb ( String enc, String dbname, String[] args )
                throws IOException
        {
                super( enc );
                db = nopen( dbname, args );
                if ( 0 > db )
                        throw new FileNotFoundException();
        }

        Rec mkRow ( Object[] buf ) {
                if ( null == buf )
                        return null;
                int[] ids = (int[])buf[0];
                int rowid = ids[0];
                Field[] f = new Field[ buf.length-1 ];
                for ( int i=1; i<buf.length; i++ )
                        f[i-1] = new Field( ids[i], cvt( (byte[])buf[i] ) );
                return new Rec( rowid, f );
        }       // readrow

        Object[] mkBuf ( Rec rec ) {
                if ( null == rec )
                        return null;
                int len = rec.getLen() + 1;
                Object[] buf = new Object[ len ];
                int[] tags = new int[ len ];
                for ( int i = 1; i < len; i++ ) {
                        Field f = rec.getField( i - 1 );
                        tags[ i ] = f.tag;
                        buf[ i ] = cvt( f.val );
                        String tttt = new String( cvt( f.val ) );
                        System.out.println( "field [ " + i + "] = " + tttt + " len is " + tttt.length() );
                }
                tags[ 0 ] = rec.getRowId();
                buf[ 0 ] = tags;
                return buf;
        }

        public Rec readRow ( int rowid ) {
                return mkRow( nreadRow( db, rowid, -1, null ) );
        }

        public short writeRow ( Rec rec ) {
                return nwriteRow( db, mkBuf( rec ) ); 
        }

        public short writeXRow ( Rec rec, Rec idx ) {
                return nwriteXRow( db, mkBuf( rec ), mkBuf( idx ) ); 
        }

        public Rec scanRow ( int rowid, int tag, String txt ) {
                return mkRow( nreadRow( db, rowid, tag, cvt(txt) ) );
        }

        public int[] search ( String key, int mode ) {
                return nsearch( db, cvt(key), mode );
        }

        public class TermIterator implements Iterator {
                byte[] _prefix;
                Object[] buf;
                int nxt;

                public TermIterator ( String prefix ) {
                        _prefix = cvt(prefix+"$");
                }

                public boolean hasNext () {
                        if ( null != buf && nxt < buf.length ) return true;
                        if ( nxt < 0 ) return false;
                        nxt = -1; // mark, just in case we bomb
                        buf = nTerms( db, _prefix,
                                null == buf ? null : (byte[])buf[buf.length-1] );
                        if ( null == buf || 1 >= buf.length ) {
                                buf = null;
                                return false;
                        }
                        nxt = 1;
                        return true;
                }

                public Object next () {
                        if ( ! hasNext() ) throw new NoSuchElementException();
                        return cvt( (byte[])buf[nxt++] );
                }

                public void remove () { throw new UnsupportedOperationException(); }

        }

        public Iterator terms ( String prefix ) {
                return new TermIterator( prefix );
        }

}       // NativeDb
1	/*
2	openisis - an open implementation of the CDS/ISIS database
3	Version 0.8.x (patchlevel see file Version)
4	Copyright (C) 2001-2003 by Erik Grziwotz, erik@openisis.org
5
6	This library is free software; you can redistribute it and/or
7	modify it under the terms of the GNU Lesser General Public
8	License as published by the Free Software Foundation; either
9	version 2.1 of the License, or (at your option) any later version.
10
11	This library is distributed in the hope that it will be useful,
12	but WITHOUT ANY WARRANTY; without even the implied warranty of
13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14	Lesser General Public License for more details.
15
16	You should have received a copy of the GNU Lesser General Public
17	License along with this library; if not, write to the Free Software
18	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19
20	see README for more information
21	EOH */
22
23	package org.openisis;
24
25	import java.io.IOException;
26	import java.io.FileNotFoundException;
27	import java.io.UnsupportedEncodingException;
28	import java.util.Iterator;
29	import java.util.NoSuchElementException;
30
31
32	/**
33	This class is the native implementation of class Db.
34	<h3>Installation</h3>
35	The shared library "openjsis" must be loadable.
36	On a UNIX System, make sure that the file libopenjsis.so
37	resides in a directory listed by the environment variable
38	LD_LIBRARY_PATH or in /etc/ld.so.conf.
39	If you just drop it in /usr/lib or similar dir,
40	you may have to run a command like ldconfig.
41	<p>
42	On Windows, put openjsis.dll somewhere in the PATH.
43	<p>
44	$Id: NativeDb.java,v 1.5 2003/04/08 00:20:53 kripke Exp $
45	@version $Revision: 1.5 $
46	@author $Author: kripke $
47	*/
48	public class NativeDb extends Db {
49
50	private static synchronized native
51	short nopen ( String dbname, String[] args );
52
53	/** read a record by rowid.
54	* The native implementation gives character data as byte[],
55	* since we need to employ java encoding mechanisms anyway.
56	* The tag is packed as four bytes little endian.
57	* @param db a db number as returned by open
58	* @param rowid the number (aka mfn) of the row
59	* @param tag in which to look for txt, negative for any
60	* @param txt to grep from record, null for no grep
61	* @return an array of Objects:
62	* the first is an array of ints filled with rowid an tags
63	* the others are byte[] with field character data in encoding
64	* @see #encoding
65	*/
66	private static synchronized native
67	Object[] nreadRow ( short db, int rowid, int tag, byte[] txt );
68
69	/** search for terms */
70	private static synchronized native
71	Object[] nTerms ( short db, byte[] term, byte[] start );
72
73	/** get matching rowids */
74	private static synchronized native
75	int[] nsearch ( short db, byte[] key, int mode );
76
77	/** plain write */
78	private static synchronized native
79	short nwriteRow ( short db, Object[] data );
80
81	/**
82	* Indexed write
83	* @param db database handle returned by open
84	* @param data an Object array with an int[] on idx 0 containing
85	* rowid and tags and with byte[] containing appropriate data for
86	* the tags; thus a simple sanity check for a properly structured
87	* data is: data.length == data[ 0 ].length
88	* @param idx same as data but contains a record that holds index
89	* information
90	*/
91	private static synchronized native
92	short nwriteXRow ( short db, Object[] data, Object[] idx );
93
94	static {
95	// TODO: try some explicit paths like our jar's location with System.load
96	// in order to not have to export LD_LIBRARY_PATH or so
97	System.loadLibrary( "openjsis" );
98	}
99
100	public byte[] cvt ( String txt ) {
101	try {
102	return txt.getBytes(encoding);
103	} catch ( UnsupportedEncodingException e ) {
104	// shouldn't happen -- our fault
105	throw new Error( "failed to check for support of encoding "+encoding );
106	}
107	}
108
109	public String cvt ( byte[] b ) {
110	try {
111	// System.err.println( "got "+b.length+" bytes "+b );
112	for ( int l=b.length; 0<l; l-- ) {
113	String s = new String( b, 0, l, encoding );
114	if ( null != s && 0 != s.length() )
115	return s;
116	for ( int i=0; i<l; i++ )
117	System.err.print(
118	(
119	b[i] > 0 ? "0" : // 0... self-contained
120	b[i] < -64 ? "f" : // 10... six follower bits
121	b[i] < -32 ? "1" : // 110... five bits, one follower
122	b[i] < -16 ? "2" : // 1110... four bits, two followers
123	"b" // bad
124	) + "("+b[i]+")"
125	);
126	return "";
127	}
128	return "";
129	} catch ( UnsupportedEncodingException e ) {
130	// shouldn't happen -- our fault
131	throw new Error( "failed to check for support of encoding "+encoding );
132	}
133	}
134
135
136	/** Number of this db.
137	*/
138	public final short db;
139
140
141	public NativeDb ( String enc, String dbname, String[] args )
142	throws IOException
143	{
144	super( enc );
145	db = nopen( dbname, args );
146	if ( 0 > db )
147	throw new FileNotFoundException();
148	}
149
150	Rec mkRow ( Object[] buf ) {
151	if ( null == buf )
152	return null;
153	int[] ids = (int[])buf[0];
154	int rowid = ids[0];
155	Field[] f = new Field[ buf.length-1 ];
156	for ( int i=1; i<buf.length; i++ )
157	f[i-1] = new Field( ids[i], cvt( (byte[])buf[i] ) );
158	return new Rec( rowid, f );
159	} // readrow
160
161	Object[] mkBuf ( Rec rec ) {
162	if ( null == rec )
163	return null;
164	int len = rec.getLen() + 1;
165	Object[] buf = new Object[ len ];
166	int[] tags = new int[ len ];
167	for ( int i = 1; i < len; i++ ) {
168	Field f = rec.getField( i - 1 );
169	tags[ i ] = f.tag;
170	buf[ i ] = cvt( f.val );
171	String tttt = new String( cvt( f.val ) );
172	System.out.println( "field [ " + i + "] = " + tttt + " len is " + tttt.length() );
173	}
174	tags[ 0 ] = rec.getRowId();
175	buf[ 0 ] = tags;
176	return buf;
177	}
178
179	public Rec readRow ( int rowid ) {
180	return mkRow( nreadRow( db, rowid, -1, null ) );
181	}
182
183	public short writeRow ( Rec rec ) {
184	return nwriteRow( db, mkBuf( rec ) );
185	}
186
187	public short writeXRow ( Rec rec, Rec idx ) {
188	return nwriteXRow( db, mkBuf( rec ), mkBuf( idx ) );
189	}
190
191	public Rec scanRow ( int rowid, int tag, String txt ) {
192	return mkRow( nreadRow( db, rowid, tag, cvt(txt) ) );
193	}
194
195	public int[] search ( String key, int mode ) {
196	return nsearch( db, cvt(key), mode );
197	}
198
199	public class TermIterator implements Iterator {
200	byte[] _prefix;
201	Object[] buf;
202	int nxt;
203
204	public TermIterator ( String prefix ) {
205	_prefix = cvt(prefix+"$");
206	}
207
208	public boolean hasNext () {
209	if ( null != buf && nxt < buf.length ) return true;
210	if ( nxt < 0 ) return false;
211	nxt = -1; // mark, just in case we bomb
212	buf = nTerms( db, _prefix,
213	null == buf ? null : (byte[])buf[buf.length-1] );
214	if ( null == buf \|\| 1 >= buf.length ) {
215	buf = null;
216	return false;
217	}
218	nxt = 1;
219	return true;
220	}
221
222	public Object next () {
223	if ( ! hasNext() ) throw new NoSuchElementException();
224	return cvt( (byte[])buf[nxt++] );
225	}
226
227	public void remove () { throw new UnsupportedOperationException(); }
228
229	}
230
231	public Iterator terms ( String prefix ) {
232	return new TermIterator( prefix );
233	}
234
235	} // NativeDb