root/pyndexter/trunk/pyndexter/indexers/_pyndex.py

# -*- coding: utf-8 -*-
#
# Copyright (C) 2006 Alec Thomas <alec@swapoff.org>
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution.
#

"""
Pyndex
------

Pyndex_ is a pure-Python indexer written
by the busy Divmod folks. It is quite fast, but again, no longer supported.

**Note:** Pyndex does not support document deletion. I have hacked around this
by inserting an empty document but this is obviously not ideal.

.. _Pyndex: http://www.divmod.org/projects/pyndex

Usage
~~~~~

::

    pyndex://<path>

Installation
~~~~~~~~~~~~

::

    easy_install http://downloads.sourceforge.net/pyndex/Pyndex-0.3.2a.tar.gz
"""

import os
from pyndexter import *
import metakit
import pyndex
import pyndex.indexer


class PyndexIndexer(Indexer):
    def __init__(self, framework, path):
        Indexer.__init__(self, framework)
        self.path = path
        self.pyndex_path = os.path.join(self.path, 'pyndex.db')
        self.state_path = os.path.join(self.path, 'state.db')

        if framework.mode == READWRITE:
            if not os.path.exists(self.path):
                os.makedirs(self.path)

        rw = framework.mode == READWRITE and 1 or 0
        self.db = pyndex.indexer.Index(metakit.storage(self.pyndex_path, rw))

    def index(self, document):
        uri = unicode(document.uri).encode('utf-8')
        self.db.index(uri, document.content.encode('utf-8'))

    def discard(self, uri):
        # FIXME Is there a supported way of deleting documents? This is hackish.
        # FIXME Is there a way of storing attributes?
        self.db.index(unicode(uri).encode('utf-8'), '')

    def search(self, query):
        # FIXME Should probably do a search on each term, and perform set
        # operations.
        qs = ' '.join(query.terms()).encode('utf-8')
        return PyndexResult(self, query, self.db.find(qs))

    def optimise(self):
        self.db.optimize()

    def flush(self):
        self.db.commit()

    def close(self):
        self.db.close()


indexer_factory = PluginFactory(PyndexIndexer)

class PyndexResult(Result):
    def __iter__(self):
        for hit in self.context:
            yield self._translate(hit)

    def __getitem__(self, index):
        return self._translate(self.context[index])

    def _translate(self, hit):
        return Hit(uri=URI(hit.doc.docname), score=hit.score,
                   current=self.indexer.framework.fetch,
                   indexed=self.indexer.fetch)