def add_doc(self, writer, path, repo, repo_name):

        """

        Adding doc to writer this function itself fetches data from

        the instance of vcs backend

        """

        node = self.get_node(repo, path)

        indexed = indexed_w_content = 0

        # we just index the content of chosen files, and skip binary files

        if node.extension in INDEX_EXTENSIONS and not node.is_binary:

            u_content = node.content

            if not isinstance(u_content, unicode):

                log.warning('  >> %s Could not get this content as unicode '

                            'replacing with empty content' % path)

                u_content = u''

            else:

                log.debug('    >> %s [WITH CONTENT]' % path)

                indexed_w_content += 1

        else:

            log.debug('    >> %s' % path)

            # just index file name without it's content

            u_content = u''

            indexed += 1

        p = safe_unicode(path)

        writer.add_document(

            fileid=p,

            owner=unicode(repo.contact),

            repository=safe_unicode(repo_name),

            path=p,

            content=u_content,

            modtime=self.get_node_mtime(node),

            extension=node.extension

        )

        return indexed, indexed_w_content

    def build_index(self):

        if os.path.exists(self.index_location):

            log.debug('removing previous index')

            rmtree(self.index_location)

        if not os.path.exists(self.index_location):

            os.mkdir(self.index_location)

        idx = create_in(self.index_location, SCHEMA, indexname=IDX_NAME)

        writer = idx.writer()

        for repo_name, repo in self.repo_paths.items():

            log.debug('building index @ %s' % repo.path)

            i_cnt = iwc_cnt = 0

            for idx_path in self.get_paths(repo):

                i, iwc = self.add_doc(writer, idx_path, repo, repo_name)

                i_cnt += i

                iwc_cnt += iwc

            log.debug('added %s files %s with content for repo %s' % (

                         i_cnt + iwc_cnt, iwc_cnt, repo.path)

            )

        log.debug('>> COMMITING CHANGES <<')

        writer.commit(merge=True)

        log.debug('>>> FINISHED BUILDING INDEX <<<')

    def update_index(self):

        log.debug((u'STARTING INCREMENTAL INDEXING UPDATE FOR EXTENSIONS %s '

                   'AND REPOS %s') % (INDEX_EXTENSIONS, self.repo_paths.keys()))

        idx = open_dir(self.index_location, indexname=self.indexname)

        # The set of all paths in the index

        indexed_paths = set()

        # The set of all paths we need to re-index

        to_index = set()

        reader = idx.reader()

        writer = idx.writer()

        # Loop over the stored fields in the index

        for fields in reader.all_stored_fields():

            indexed_path = fields['path']

            indexed_repo_path = fields['repository']

            indexed_paths.add(indexed_path)

            if not indexed_repo_path in self.filtered_repo_update_paths:

                continue

            repo = self.repo_paths[indexed_repo_path]

            try:

                node = self.get_node(repo, indexed_path)

                # Check if this file was changed since it was indexed

                indexed_time = fields['modtime']

                mtime = self.get_node_mtime(node)

                if mtime > indexed_time:

                    # The file has changed, delete it and add it to the list of

                    # files to reindex

                    log.debug('adding to reindex list %s mtime: %s vs %s' % (

                                    indexed_path, mtime, indexed_time)

                    )

                    writer.delete_by_term('fileid', indexed_path)

                    to_index.add(indexed_path)

            except (ChangesetError, NodeDoesNotExistError):

                # This file was deleted since it was indexed

                log.debug('removing from index %s' % indexed_path)

                writer.delete_by_term('path', indexed_path)

        # Loop over the files in the filesystem

        # Assume we have a function that gathers the filenames of the

        # documents to be indexed

        for repo_name, repo in self.repo_paths.items():

            for path in self.get_paths(repo):

                path = safe_unicode(path)

                if path in to_index or path not in indexed_paths:

                    # This is either a file that's changed, or a new file

                    # that wasn't indexed before. So index it!

                    i, iwc = self.add_doc(writer, path, repo, repo_name)

                    log.debug('re indexing %s' % path)

                    ri_cnt += i

                    riwc_cnt += iwc

        )

        log.debug('>> COMMITING CHANGES <<')

        writer.commit(merge=True)

        log.debug('>>> FINISHED REBUILDING INDEX <<<')

    def run(self, full_index=False):

        """Run daemon"""

        if full_index or self.initial:

            self.build_index()

        else:

            self.update_index()