// 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: 2011-05-27 10:24:54 +0200 (Fr, 27. Mai 2011) $
// $LastChangedRevision: 7746 $
// $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.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;
import net.yacy.cora.document.ASCII;
import net.yacy.cora.document.UTF8;
import net.yacy.kelondro.index.RowSpaceExceededException;
import net.yacy.kelondro.logging.Log;
import net.yacy.kelondro.order.Base64Order;
import net.yacy.kelondro.order.ByteOrder;
import net.yacy.kelondro.order.Digest;
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 Map<byte[], Map<String, byte[]>>, 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 byte[] encodedKey(String key) {
return Base64Order.enhancedCoder.encodeSubstring(Digest.encodeMD5Raw(key), this.table.keylength);
}
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;
}
}
private static Map<String, byte[]> b2m(byte[] b) {
if (b == null) return null;
//System.out.println("b = " + UTF8.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;
}
/**
* the map is stored inside a file; this method may return the file
* @return the file where the map is stored
*/
public File getFile() {
return this.table.heapFile;
}
/**
* Retur the number of key-value mappings in this map.
* @return the number of entries mappings in this map
*/
public int size() {
return this.table.size();
}
/**
* return true if the table is empty
*/
public boolean isEmpty() {
return this.table.size() == 0;
}
/**
* check if a row with given key exists in the table
* @param name
* @return true if the row exists
*/
public boolean containsKey(byte[] pk) {
return this.table.containsKey(pk);
}
/**
* check if a row with given key exists in the table
* This method is here to implement the Map interface
* @param name
* @return true if the row exists
*/
public boolean containsKey(Object key) {
if (key instanceof byte[]) return containsKey((byte[]) key);
return false;
}
/**
* the containsValue method cannot be used in this method
* and is only here to implement the Map interface
*/
public boolean containsValue(Object value) {
// this method shall not be used because it is not appropriate for this kind of data
throw new UnsupportedOperationException();
}
/**
* get a map from the table
* @param name
* @return the map if one found or NULL if no entry exists or the entry is corrupt
* @throws RowSpaceExceededException
* @throws IOException
*/
public Map<String, byte[]> get(byte[] pk) throws IOException, RowSpaceExceededException {
byte[] b = this.table.get(pk);
if (b == null) return null;
return b2m(b);
}
/**
* get a map from the table
* this method is here to implement the Map interface
* @param name
* @return the map if one found or NULL if no entry exists or the entry is corrupt
*/
public Map<String, byte[]> get(Object key) {
if (key instanceof byte[])
try {
return get((byte[]) key);
} catch (IOException e) {
Log.logException(e);
return null;
} catch (RowSpaceExceededException e) {
Log.logException(e);
return null;
}
return null;
}
/**
* convenience method to get a value from a map
* @param pk
* @param key
* @return the value
* @throws IOException
* @throws RowSpaceExceededException
*/
public byte[] getProp(byte[] pk, String key) throws IOException, RowSpaceExceededException {
byte[] b = this.table.get(pk);
if (b == null) return null;
Map<String, byte[]> map = b2m(b);
return map.get(key);
}
/**
* select all rows from a table where a given matcher matches with elements in a given row
* this method makes a full-table scan of the whole table
* @param columnName the name of the column where the matcher shall match
* @param columnMatcher the matcher for the elements of the column
* @return a set of primary keys where the matcher matched
*/
public Set<byte[]> select(String columnName, Pattern columnMatcher) {
Iterator<Map.Entry<byte[], Map<String, byte[]>>> i = iterator();
Map.Entry<byte[], Map<String, byte[]>> row;
Map<String, byte[]> prop;
byte[] val;
Set<byte[]> pks = new TreeSet<byte[]>(this.table.ordering);
while (i.hasNext()) {
row = i.next();
prop = row.getValue();
val = prop.get(columnName);
if (val != null) {
if (columnMatcher.matcher(UTF8.String(val)).matches()) pks.add(row.getKey());
}
}
return pks;
}
/**
* select one row from a table where a given matcher matches with elements in a given row
* this method stops the full-table scan as soon as a first matcher was found
* @param columnName the name of the column where the matcher shall match
* @param columnMatcher the matcher for the elements of the column
* @return the row where the matcher matched the given column
*/
public Map.Entry<byte[], Map<String, byte[]>> selectOne(String columnName, Pattern columnMatcher) {
Iterator<Map.Entry<byte[], Map<String, byte[]>>> i = iterator();
Map.Entry<byte[], Map<String, byte[]>> row;
Map<String, byte[]> prop;
byte[] val;
while (i.hasNext()) {
row = i.next();
prop = row.getValue();
val = prop.get(columnName);
if (val != null) {
if (columnMatcher.matcher(UTF8.String(val)).matches()) return row;
}
}
return null;
}
/**
* insert a map into the table
* this method shall be used in exchange of the get method if the
* previous entry value is not needed.
* @param name
* @param map
* @throws RowSpaceExceededException
* @throws IOException
*/
public void insert(byte[] pk, Map<String, byte[]> map) throws RowSpaceExceededException, IOException {
byte[] b = BEncoder.encode(BEncoder.transcode(map));
this.table.insert(pk, b);
this.columnames.addAll(map.keySet());
}
public void insert(byte[] pk, String key, byte[] value) throws IOException {
byte[] b = BEncoder.encodeMap(key, value);
this.table.insert(pk, b);
this.columnames.add(key);
}
public void update(byte[] pk, Map<String, byte[]> map) throws RowSpaceExceededException, IOException {
Map<String, byte[]> entry = this.get(pk);
if (entry == null) {
insert(pk, map);
} else {
entry.putAll(map);
insert(pk, entry);
}
}
public void update(byte[] pk, String key, byte[] value) throws RowSpaceExceededException, IOException {
Map<String, byte[]> entry = this.get(pk);
if (entry == null) {
entry = new HashMap<String, byte[]>();
entry.put(key, value);
insert(pk, entry);
} else {
entry.put(key, value);
insert(pk, entry);
}
}
/**
* insert a map into the table
* @param name
* @param map
*/
public Map<String, byte[]> put(byte[] pk, Map<String, byte[]> map) {
try {
Map<String, byte[]> entry = this.get(pk);
byte[] b = BEncoder.encode(BEncoder.transcode(map));
this.table.insert(pk, b);
this.columnames.addAll(map.keySet());
return entry;
} catch (IOException e) {
Log.logException(e);
return null;
} catch (RowSpaceExceededException e) {
Log.logException(e);
return null;
}
}
/**
* delete a map from the table
* @param name
* @throws IOException
*/
public void delete(byte[] pk) throws IOException {
this.table.delete(pk);
}
/**
* delete a map from the table
* @param name
* @throws RowSpaceExceededException
* @throws IOException
*/
public Map<String, byte[]> remove(byte[] key) throws IOException, RowSpaceExceededException {
Map<String, byte[]> value = get(key);
this.delete(key);
return value;
}
public Map<String, byte[]> remove(Object key) {
if (key instanceof byte[])
try {
return remove((byte[]) key);
} catch (IOException e) {
Log.logException(e);
return null;
} catch (RowSpaceExceededException e) {
Log.logException(e);
return null;
}
return null;
}
/**
* Copy all the mappings from the specified map to this map.
*
* @param m mappings to be stored in this map
*/
public void putAll(Map<? extends byte[], ? extends Map<String, byte[]>> map) {
for (Map.Entry<? extends byte[], ? extends Map<String, byte[]>> me: map.entrySet()) {
try {
this.insert(me.getKey(), me.getValue());
} catch (RowSpaceExceededException e) {
Log.logException(e);
} catch (IOException e) {
Log.logException(e);
}
}
}
/**
* remove all entries from the map;
* possibly removes the backend-file
*/
public void clear() {
try {
this.table.clear();
} catch (IOException e) {
Log.logException(e);
}
}
/**
* close the backen-file.
* Should be called explicitely to ensure that all data
* waiting in IO write buffers are flushed
*/
public void close() {
this.table.close();
}
/**
* Return a Set of the keys contained in this map.
* This may not be a useful method, if possible use the keys()
* method instead to iterate all keys from the backend-file
*
* @return a set view of the keys contained in this map
*/
public Set<byte[]> keySet() {
TreeSet<byte[]> set = new TreeSet<byte[]>(this.table.ordering);
try {
Iterator<byte[]> i = this.table.keys(true, false);
while (i.hasNext()) set.add(i.next());
} catch (IOException e) {}
return set;
}
/**
* 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);
}
/**
* the values() method is not implemented in this class
* because it does not make sense to use such a method for
* file-based data structures. To get a collection view of
* all the entries, just use a entry iterator instead.
*
* @return nothing. The method throws always a UnsupportedOperationException
*/
public Collection<Map<String, byte[]>> values() {
// this method shall not be used because it is not appropriate for this kind of data
throw new UnsupportedOperationException();
}
/**
* The abstract method entrySet() from AbstractMap must be implemented,
* but never used because that is not useful for this file-based storage class.
* To prevent the usage, a UnsupportedOperationException is thrown.
* To prevent that the method is used by the methods from AbstractMap, all such
* methods must be overriden in this class. These methods are:
* size, containsValue, containsKey, get, remove, putAll, clear,
* keySet, values, equals, hashCode and toString
*
* Instead of using this method, use the iterator() method to iterate
* all elements in the back-end blob file
*/
public Set<Map.Entry<byte[], Map<String, byte[]>>> entrySet() {
throw new UnsupportedOperationException();
}
/**
* iterate all rows of the table.
* This method implements the
* Iterable<Map.Entry<byte[], Map<String, byte[]>>>
* interface
*/
public Iterator<Map.Entry<byte[], Map<String, byte[]>>> iterator() {
File location = this.table.location();
int keylen = this.table.keylength();
try {
this.table.flushBuffer();
return new EntryIter(location, keylen);
} catch (IOException e1) {
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);
}
/**
* a hashcode for the object
*/
@Override
public int hashCode() {
return this.table.name().hashCode();
}
/**
* Produce a list of column names from this table
* This method may be useful if the table shall be displayed
* as a table in GUIs. To show the first line of the table, the
* table header, a list of all column names is required. This can
* be generated with this method
* @return a list of column names
*/
public ArrayList<String> columns() {
if (this.columnames.size() == 0) {
for (Map.Entry<byte[], Map<String, byte[]>> row: this) {
this.columnames.addAll(row.getValue().keySet());
}
}
ArrayList<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.insert("123".getBytes(), m);
m.put("k", "111".getBytes()); map.insert("456".getBytes(), m);
m.put("k", "222".getBytes()); map.insert("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(ASCII.String(entry.getKey()) + ": " + 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(ASCII.String(entry.getKey()) + ": " + entry.getValue());
}
map.close();
} catch (IOException e) {
Log.logException(e);
}
}
}
}