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yacy_search_server/source/net/yacy/kelondro/blob/BEncodedHeap.java

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// BEncodedHeap.java
// (C) 2010 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 12.01.2010 on http://yacy.net
//
// $LastChangedDate: 2008-03-14 01:16:04 +0100 (Fr, 14 Mrz 2008) $
// $LastChangedRevision: 6563 $
// $LastChangedBy: orbiter $
//
// LICENSE
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package net.yacy.kelondro.blob;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import net.yacy.kelondro.index.RowSpaceExceededException;
import net.yacy.kelondro.logging.Log;
import net.yacy.kelondro.order.ByteOrder;
import net.yacy.kelondro.order.NaturalOrder;
import net.yacy.kelondro.util.BDecoder;
import net.yacy.kelondro.util.BEncoder;
import net.yacy.kelondro.util.FileUtils;
import net.yacy.kelondro.util.BDecoder.BObject;
/**
* store a table of properties (instead of fixed-field entries)
* this is realized using blobs and BEncoded property lists
*/
public class BEncodedHeap implements Iterable<Map.Entry<byte[], Map<String, byte[]>>> {
private Heap table;
private LinkedHashSet<String> columnames;
/**
* produce or open a properties table
* @param location the file
* @param keylength length of access keys
* @param ordering ordering on the keys
* @param buffermax maximum number of lines that shall be buffered for writing
* @throws IOException
*/
public BEncodedHeap(
final File location,
final int keylength,
final ByteOrder ordering,
int buffermax) throws IOException {
this.table = new Heap(location, keylength, ordering, buffermax);
this.columnames = new LinkedHashSet<String>();
}
/**
* convenience method to open a properies table
* @param location the file
* @param keylength length of access keys
*/
public BEncodedHeap(
final File location,
final int keylength) throws IOException {
this.table = new Heap(location, keylength, NaturalOrder.naturalOrder, 100);
this.columnames = new LinkedHashSet<String>();
}
public File getFile() {
return this.table.heapFile;
}
public int size() {
return this.table.size();
}
public void close() {
this.table.close();
}
public void clear() throws IOException {
this.table.clear();
}
/**
* insert a map into the table
* @param key
* @param map
* @throws RowSpaceExceededException
* @throws IOException
*/
public void put(byte[] pk, Map<String, byte[]> map) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encode(BEncoder.transcode(map));
this.table.put(pk, b);
this.columnames.addAll(map.keySet());
}
public void put(
byte[] pk,
String key, byte[] value
) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encodeMap(key, value);
this.table.put(pk, b);
this.columnames.add(key);
}
public void put(
byte[] pk,
String key0, byte[] value0,
String key1, byte[] value1
) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encodeMap(
key0, value0,
key1, value1
);
this.table.put(pk, b);
this.columnames.add(key0);
this.columnames.add(key1);
}
public void put(
byte[] pk,
String key0, byte[] value0,
String key1, byte[] value1,
String key2, byte[] value2
) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encodeMap(
key0, value0,
key1, value1,
key2, value2
);
this.table.put(pk, b);
this.columnames.add(key0);
this.columnames.add(key1);
this.columnames.add(key2);
}
public void put(
byte[] pk,
String key0, byte[] value0,
String key1, byte[] value1,
String key2, byte[] value2,
String key3, byte[] value3
) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encodeMap(
key0, value0,
key1, value1,
key2, value2,
key3, value3
);
this.table.put(pk, b);
this.columnames.add(key0);
this.columnames.add(key1);
this.columnames.add(key2);
this.columnames.add(key3);
}
/**
* select a map from the table
* @param key
* @return the map if one found or NULL if no entry exists or the entry is corrupt
* @throws IOException
*/
public Map<String, byte[]> get(byte[] pk) throws IOException {
byte[] b = this.table.get(pk);
if (b == null) return null;
return b2m(b);
}
public byte[] getProp(byte[] pk, String key) throws IOException {
byte[] b = this.table.get(pk);
if (b == null) return null;
Map<String, byte[]> map = b2m(b);
return map.get(key);
}
static Map<String, byte[]> b2m(byte[] b) {
if (b == null) return null;
//System.out.println("b = " + new String(b));
BDecoder decoder = new BDecoder(b);
BObject bobj = decoder.parse();
if (bobj.getType() != BDecoder.BType.dictionary) return null;
Map<String, BDecoder.BObject> map = bobj.getMap();
Map<String, byte[]> m = new HashMap<String, byte[]>();
for (Map.Entry<String, BDecoder.BObject> entry: map.entrySet()) {
if (entry.getValue().getType() != BDecoder.BType.string) continue;
m.put(entry.getKey(), entry.getValue().getString());
}
return m;
}
/**
* delete a map from the table
* @param key
* @throws IOException
*/
public void delete(byte[] pk) throws IOException {
this.table.remove(pk);
}
/**
* check if a row with given key exists in the table
* @param key
* @return true if the row exists
*/
public boolean has(byte[] pk) {
return this.table.has(pk);
}
/**
* iterate all keys of the table
* @return an iterator of byte[]
* @throws IOException
*/
public Iterator<byte[]> keys() throws IOException {
return this.table.keys(true, false);
}
/**
* iterate all rows of the table.
* Be aware that this first closes the table to force flushing of all elements in
* the write buffer. After that an iterator on the closed file is generated and then
* the file is opened again.
*/
public Iterator<Map.Entry<byte[], Map<String, byte[]>>> iterator() {
File location = this.table.location();
int keylen = this.table.keylength();
ByteOrder order = this.table.ordering();
int buffermax = this.table.getBuffermax();
this.table.close();
try {
Iterator<Map.Entry<byte[], Map<String, byte[]>>> iter = new EntryIter(location, keylen);
this.table = new Heap(location, keylen, order, buffermax);
return iter;
} catch (IOException e) {
Log.logSevere("PropertiesTable", e.getMessage(), e);
return null;
}
}
/**
* iterate all rows of the table. this is a static method that expects that the given
* file is not opened by any other application
* @param location
* @param keylen
* @return
* @throws IOException
*/
public static Iterator<Map.Entry<byte[], Map<String, byte[]>>> iterator(File location, int keylen) throws IOException {
return new EntryIter(location, keylen);
}
private static class EntryIter implements Iterator<Map.Entry<byte[], Map<String, byte[]>>> {
HeapReader.entries iter;
public EntryIter(File location, int keylen) throws IOException {
iter = new HeapReader.entries(location, keylen);
}
public boolean hasNext() {
return iter.hasNext();
}
public Entry<byte[], Map<String, byte[]>> next() {
Map.Entry<byte[], byte[]> entry = iter.next();
Map<String, byte[]> map = b2m(entry.getValue());
return new b2mEntry(entry.getKey(), map);
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public static class b2mEntry implements Map.Entry<byte[], Map<String, byte[]>> {
private final byte[] s;
private Map<String,byte[]> b;
public b2mEntry(final byte[] s, final Map<String, byte[]> b) {
this.s = s;
this.b = b;
}
public byte[] getKey() {
return s;
}
public Map<String, byte[]> getValue() {
return b;
}
public Map<String, byte[]> setValue(Map<String, byte[]> value) {
Map<String, byte[]> b1 = b;
b = value;
return b1;
}
}
public List<String> columns() {
if (this.columnames.size() == 0) {
for (Map.Entry<byte[], Map<String, byte[]>> row: this) {
this.columnames.addAll(row.getValue().keySet());
}
}
List<String> l = new ArrayList<String>();
l.addAll(this.columnames);
return l;
}
public static void main(String[] args) {
if (args.length == 0) {
// test the class
File f = new File(new File("maptest").getAbsolutePath());
//System.out.println(f.getAbsolutePath());
//System.out.println(f.getParent());
if (f.exists()) FileUtils.deletedelete(f);
try {
BEncodedHeap map = new BEncodedHeap(f, 4);
// put some values into the map
Map<String, byte[]> m = new HashMap<String, byte[]>();
m.put("k", "000".getBytes()); map.put("123".getBytes(), m);
m.put("k", "111".getBytes()); map.put("456".getBytes(), m);
m.put("k", "222".getBytes()); map.put("789".getBytes(), m);
// iterate over keys
Iterator<Map.Entry<byte[], Map<String, byte[]>>> i = map.iterator();
while (i.hasNext()) {
Map.Entry<byte[], Map<String, byte[]>> entry = i.next();
System.out.println(new String(entry.getKey(), "UTF-8") + ": " + entry.getValue());
}
// clean up
map.close();
} catch (IOException e) {
Log.logException(e);
} catch (RowSpaceExceededException e) {
Log.logException(e);
}
} else {
File f = new File(args[0]);
try {
BEncodedHeap map = new BEncodedHeap(f, 12);
Iterator<Map.Entry<byte[], Map<String, byte[]>>> i = map.iterator();
while (i.hasNext()) {
Map.Entry<byte[], Map<String, byte[]>> entry = i.next();
System.out.println(new String(entry.getKey(), "UTF-8") + ": " + entry.getValue());
}
map.close();
} catch (IOException e) {
Log.logException(e);
}
}
}
}