You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
137 lines
4.8 KiB
137 lines
4.8 KiB
// BufferedIndex.java
|
|
// -----------------------------
|
|
// (C) 2009 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
|
|
// first published 15.3.2009 on http://yacy.net
|
|
//
|
|
// This is a part of YaCy, a peer-to-peer based web search engine
|
|
//
|
|
// $LastChangedDate$
|
|
// $LastChangedRevision$
|
|
// $LastChangedBy$
|
|
//
|
|
// 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.rwi;
|
|
|
|
import java.io.IOException;
|
|
import java.util.TreeSet;
|
|
|
|
import net.yacy.cora.order.CloneableIterator;
|
|
|
|
|
|
/*
|
|
* a BufferedIndex is an integration of different index types, i.e.
|
|
* - ReferenceContainerArray
|
|
* - ReferenceContainerCache
|
|
* - IndexCache (which is a wrapper of a ReferenceContainerCache)
|
|
* - IndexCollection
|
|
* This interface was created from the methods that are used in CachedIndexCollection
|
|
* (which integrates IndexCache and IndexCollection)
|
|
* and is applied to the new index integration class IndexCell
|
|
* (which integrates ReferenceContainerArray and ReferenceContainerCache)
|
|
* to make it possible to switch between the old and new index data structure
|
|
*/
|
|
public interface BufferedIndex<ReferenceType extends Reference> extends Index<ReferenceType> {
|
|
|
|
/*
|
|
* methods for monitoring of the buffer
|
|
*/
|
|
|
|
/**
|
|
* set the size of the buffer, which can be defined with a given maximum number
|
|
* of words that shall be stored. Because an arbitrary number of references can
|
|
* be stored at each word entry, this does not limit the memory that the buffer
|
|
* takes. It is possible to monitor the memory occupation of the buffer with the
|
|
* getBufferSizeBytes() method, and then adopt the buffer size with a new word number
|
|
* limit.
|
|
*/
|
|
public void setBufferMaxWordCount(final int maxWords);
|
|
|
|
/**
|
|
* return the maximum number of references, that one buffer entry has stored
|
|
* @return
|
|
*/
|
|
public int getBufferMaxReferences();
|
|
|
|
/**
|
|
* return the date of the oldest buffer entry
|
|
* @return a time as milliseconds from epoch
|
|
*/
|
|
public long getBufferMinAge();
|
|
|
|
/**
|
|
* return the date of the most recent buffer entry
|
|
* @return a time as milliseconds from epoch
|
|
*/
|
|
public long getBufferMaxAge();
|
|
|
|
/**
|
|
* calculate the memory that is taken by the buffer.
|
|
* This does not simply return a variable content. it is necessary
|
|
* to iterate over all entries to get the whole size.
|
|
* please use this method with great care
|
|
* @return number of bytes that the buffer has allocated
|
|
*/
|
|
public long getBufferSizeBytes();
|
|
|
|
/**
|
|
* get the size of the buffer content
|
|
* @return number of word references
|
|
*/
|
|
public int getBufferSize();
|
|
|
|
/**
|
|
* iterate over entries in index. this method differs from the iterator in an Index
|
|
* object in such a way that it has the additional 'buffer' flag. When using this method,
|
|
* the iteration goes only over the buffer content, or over the backend-content, but
|
|
* not over a merged content.
|
|
* @param startHash
|
|
* @param rot
|
|
* @param buffer
|
|
* @return
|
|
* @throws IOException
|
|
*/
|
|
public CloneableIterator<ReferenceContainer<ReferenceType>> referenceContainerIterator(
|
|
byte[] startHash,
|
|
boolean rot,
|
|
boolean excludePrivate,
|
|
boolean buffer
|
|
) throws IOException;
|
|
|
|
|
|
/**
|
|
* collect reference container in index. this method differs from the collector in an Index
|
|
* object in such a way that it has the additional 'buffer' flag. When using this method,
|
|
* the collection goes only over the buffer content, or over the backend-content, but
|
|
* not over a merged content.
|
|
* @param startHash
|
|
* @param rot
|
|
* @param count
|
|
* @param buffer
|
|
* @return
|
|
* @throws IOException
|
|
*/
|
|
public TreeSet<ReferenceContainer<ReferenceType>> referenceContainer(
|
|
byte[] startHash,
|
|
boolean rot,
|
|
boolean excludePrivate,
|
|
int count,
|
|
boolean buffer
|
|
) throws IOException;
|
|
|
|
}
|