Merge commit 'e988fee1679536137b87d10e939eff5c1f27c8ab' as 'libs/libzmq'

libs/libzmq/src/generic_mtrie.hpp

@@ -0,0 +1,117 @@
+/*
+Copyright (c) 2018 Contributors as noted in the AUTHORS file
+
+This file is part of libzmq, the ZeroMQ core engine in C++.
+
+libzmq is free software; you can redistribute it and/or modify it under
+the terms of the GNU Lesser General Public License (LGPL) as published
+by the Free Software Foundation; either version 3 of the License, or
+(at your option) any later version.
+
+As a special exception, the Contributors give you permission to link
+this library with independent modules to produce an executable,
+regardless of the license terms of these independent modules, and to
+copy and distribute the resulting executable under terms of your choice,
+provided that you also meet, for each linked independent module, the
+terms and conditions of the license of that module. An independent
+module is a module which is not derived from or based on this library.
+If you modify this library, you must extend this exception to your
+version of the library.
+
+libzmq 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 __ZMQ_GENERIC_MTRIE_HPP_INCLUDED__
+#define __ZMQ_GENERIC_MTRIE_HPP_INCLUDED__
+
+#include <stddef.h>
+#include <set>
+
+#include "macros.hpp"
+#include "stdint.hpp"
+
+namespace zmq
+{
+//  Multi-trie (prefix tree). Each node in the trie is a set of pointers.
+template <typename T> class generic_mtrie_t
+{
+  public:
+    typedef T value_t;
+    typedef const unsigned char *prefix_t;
+
+    enum rm_result
+    {
+        not_found,
+        last_value_removed,
+        values_remain
+    };
+
+    generic_mtrie_t ();
+    ~generic_mtrie_t ();
+
+    //  Add key to the trie. Returns true iff no entry with the same prefix_
+    //  and size_ existed before.
+    bool add (prefix_t prefix_, size_t size_, value_t *value_);
+
+    //  Remove all entries with a specific value from the trie.
+    //  The call_on_uniq_ flag controls if the callback is invoked
+    //  when there are no entries left on a prefix only (true)
+    //  or on every removal (false). The arg_ argument is passed
+    //  through to the callback function.
+    template <typename Arg>
+    void rm (value_t *value_,
+             void (*func_) (const unsigned char *data_, size_t size_, Arg arg_),
+             Arg arg_,
+             bool call_on_uniq_);
+
+    //  Removes a specific entry from the trie.
+    //  Returns the result of the operation.
+    rm_result rm (prefix_t prefix_, size_t size_, value_t *value_);
+
+    //  Calls a callback function for all matching entries, i.e. any node
+    //  corresponding to data_ or a prefix of it. The arg_ argument
+    //  is passed through to the callback function.
+    template <typename Arg>
+    void match (prefix_t data_,
+                size_t size_,
+                void (*func_) (value_t *value_, Arg arg_),
+                Arg arg_);
+
+  private:
+    bool is_redundant () const;
+
+    typedef std::set<value_t *> pipes_t;
+    pipes_t *_pipes;
+
+    unsigned char _min;
+    unsigned short _count;
+    unsigned short _live_nodes;
+    union _next_t
+    {
+        class generic_mtrie_t<value_t> *node;
+        class generic_mtrie_t<value_t> **table;
+    } _next;
+
+    struct iter
+    {
+        generic_mtrie_t<value_t> *node;
+        generic_mtrie_t<value_t> *next_node;
+        prefix_t prefix;
+        size_t size;
+        unsigned short current_child;
+        unsigned char new_min;
+        unsigned char new_max;
+        bool processed_for_removal;
+    };
+
+    ZMQ_NON_COPYABLE_NOR_MOVABLE (generic_mtrie_t)
+};
+}
+
+#endif