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/*
Copyright (c) 2012 250bpm s.r.o.
Copyright (c) 2011-2012 Spotify AB
Copyright (c) 2012 Other contributors as noted in the AUTHORS file
This file is part of Crossroads I/O project.
Crossroads I/O is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
Crossroads 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __XS_PREFIX_FILTER_HPP_INCLUDED__
#define __XS_PREFIX_FILTER_HPP_INCLUDED__
#include <stddef.h>
#include <map>
#include "stdint.hpp"
namespace xs
{
// Canonical extension object.
extern void *prefix_filter;
class prefix_filter_t
{
public:
prefix_filter_t ();
~prefix_filter_t ();
int subscribe (void *core_, void *subscriber_,
const unsigned char *data_, size_t size_);
int unsubscribe (void *core_, void *subscriber_,
const unsigned char *data_, size_t size_);
void unsubscribe_all (void *core_, void *subscriber_);
void enumerate (void *core_);
int match (void *core_, const unsigned char *data_, size_t size_);
void match_all (void *core_, const unsigned char *data_, size_t size_);
private:
struct node_t
{
// Pointer to particular subscriber associated with
// the reference count.
typedef std::map <void*, int> subscribers_t;
subscribers_t *subscribers;
unsigned char min;
unsigned short count;
unsigned short live_nodes;
union {
struct node_t *node;
struct node_t **table;
} next;
};
static void init (node_t *node_);
static void close (node_t *node_);
// Add key to the trie. Returns true if it's a new subscription
// rather than a duplicate.
static bool add (node_t *node_, const unsigned char *prefix_,
size_t size_, void *subscriber_);
// Remove specific subscription from the trie. Return true is it
// was actually removed rather than de-duplicated.
static bool rm (node_t *node_, const unsigned char *prefix_,
size_t size_, void *subscriber_);
// Remove all subscriptions for a specific peer from the trie.
// If there are no subscriptions left on some topics, invoke the
// supplied callback function.
static void rm (node_t *node_, void *subscriber_, void *arg_);
static void rm_helper (node_t *node_, void *subscriber_,
unsigned char **buff_, size_t buffsize_, size_t maxbuffsize_,
void *arg_);
// Lists all the subscriptions in the trie.
static void list (node_t *node_, unsigned char **buff_,
size_t buffsize_, size_t maxbuffsize_, void *arg_);
// Checks whether node can be safely removed.
static bool is_redundant (node_t *node_);
node_t root;
prefix_filter_t (const prefix_filter_t&);
const prefix_filter_t &operator = (const prefix_filter_t&);
};
}
#endif
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