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	dpavlin	237	/*
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