Problem: no unittests for mtrie

Solution: made mtrie generic (to remove complex dependency on pipe_t),
and added some unit tests

CMakeLists.txt

@@ -611,6 +611,8 @@ set (cxx-sources
 		fd.hpp
 		fq.hpp
 		gather.hpp
+		generic_mtrie.hpp
+		generic_mtrie_impl.hpp
 		gssapi_client.hpp
 		gssapi_mechanism_base.hpp
 		gssapi_server.hpp

Makefile.am

@@ -64,6 +64,8 @@ src_libzmq_la_SOURCES = \
 	src/fq.hpp \
 	src/gather.cpp \
 	src/gather.hpp \
+	src/generic_mtrie.hpp \
+	src/generic_mtrie_impl.hpp \
 	src/gssapi_mechanism_base.cpp \
 	src/gssapi_mechanism_base.hpp \
 	src/gssapi_client.cpp \
@@ -865,7 +867,8 @@ if ENABLE_STATIC
 # unit tests - these include individual source files and test the internal functions
 test_apps += \
 	unittests/unittest_poller \
-	unittests/unittest_ypipe
+	unittests/unittest_ypipe \
+	unittests/unittest_mtrie
 
 unittests_unittest_poller_SOURCES = unittests/unittest_poller.cpp
 unittests_unittest_poller_CPPFLAGS = -I$(top_srcdir)/src ${UNITY_CPPFLAGS}
@@ -878,6 +881,12 @@ unittests_unittest_ypipe_CPPFLAGS = -I$(top_srcdir)/src ${UNITY_CPPFLAGS}
 unittests_unittest_ypipe_LDADD = $(top_builddir)/src/.libs/libzmq.a \
 	${src_libzmq_la_LIBADD} \
 	${UNITY_LIBS}
+
+unittests_unittest_mtrie_SOURCES = unittests/unittest_mtrie.cpp
+unittests_unittest_mtrie_CPPFLAGS = -I$(top_srcdir)/src ${UNITY_CPPFLAGS}
+unittests_unittest_mtrie_LDADD = $(top_builddir)/src/.libs/libzmq.a \
+	${src_libzmq_la_LIBADD} \
+	${UNITY_LIBS}
 endif
 
 check_PROGRAMS = ${test_apps}

src/generic_mtrie.hpp

@@ -0,0 +1,104 @@
+/*
+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 "stdint.hpp"
+
+namespace zmq
+{
+//  Multi-trie. Each node in the trie is a set of pointers to pipes.
+template <typename T> class generic_mtrie_t
+{
+  public:
+    typedef T value_t;
+    typedef const unsigned char *prefix_t;
+
+    generic_mtrie_t ();
+    ~generic_mtrie_t ();
+
+    //  Add key to the trie. Returns true if it's a new subscription
+    //  rather than a duplicate.
+    bool add (prefix_t prefix_, size_t size_, value_t *pipe_);
+
+    //  Remove all subscriptions for a specific peer from the trie.
+    //  The call_on_uniq_ flag controls if the callback is invoked
+    //  when there are no subscriptions left on some topics or on
+    //  every removal.
+    void
+    rm (value_t *pipe_,
+        void (*func_) (const unsigned char *data_, size_t size_, void *arg_),
+        void *arg_,
+        bool call_on_uniq_);
+
+    //  Remove specific subscription from the trie. Return true is it was
+    //  actually removed rather than de-duplicated.
+    bool rm (prefix_t prefix_, size_t size_, value_t *pipe_);
+
+    //  Signal all the matching pipes.
+    void match (prefix_t data_,
+                size_t size_,
+                void (*func_) (value_t *pipe_, void *arg_),
+                void *arg_);
+
+  private:
+    bool add_helper (prefix_t prefix_, size_t size_, value_t *pipe_);
+    void rm_helper (value_t *pipe_,
+                    unsigned char **buff_,
+                    size_t buffsize_,
+                    size_t maxbuffsize_,
+                    void (*func_) (prefix_t data_, size_t size_, void *arg_),
+                    void *arg_,
+                    bool call_on_uniq_);
+    bool rm_helper (prefix_t prefix_, size_t size_, value_t *pipe_);
+    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
+    {
+        class generic_mtrie_t<value_t> *node;
+        class generic_mtrie_t<value_t> **table;
+    } next;
+
+    generic_mtrie_t (const generic_mtrie_t<value_t> &);
+    const generic_mtrie_t<value_t> &
+    operator= (const generic_mtrie_t<value_t> &);
+};
+}
+
+#endif

src/generic_mtrie_impl.hpp

@@ -0,0 +1,450 @@
+/*
+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_IMPL_HPP_INCLUDED__
+#define __ZMQ_GENERIC_MTRIE_IMPL_HPP_INCLUDED__
+
+
+#include <stdlib.h>
+
+#include <new>
+#include <algorithm>
+
+#include "err.hpp"
+#include "pipe.hpp"
+#include "macros.hpp"
+#include "generic_mtrie.hpp"
+
+template <typename T>
+zmq::generic_mtrie_t<T>::generic_mtrie_t () :
+    pipes (0),
+    min (0),
+    count (0),
+    live_nodes (0)
+{
+}
+
+template <typename T> zmq::generic_mtrie_t<T>::~generic_mtrie_t ()
+{
+    LIBZMQ_DELETE (pipes);
+
+    if (count == 1) {
+        zmq_assert (next.node);
+        LIBZMQ_DELETE (next.node);
+    } else if (count > 1) {
+        for (unsigned short i = 0; i != count; ++i) {
+            LIBZMQ_DELETE (next.table[i]);
+        }
+        free (next.table);
+    }
+}
+
+template <typename T>
+bool zmq::generic_mtrie_t<T>::add (prefix_t prefix_,
+                                   size_t size_,
+                                   value_t *pipe_)
+{
+    return add_helper (prefix_, size_, pipe_);
+}
+
+template <typename T>
+bool zmq::generic_mtrie_t<T>::add_helper (prefix_t prefix_,
+                                          size_t size_,
+                                          value_t *pipe_)
+{
+    //  We are at the node corresponding to the prefix. We are done.
+    if (!size_) {
+        bool result = !pipes;
+        if (!pipes) {
+            pipes = new (std::nothrow) pipes_t;
+            alloc_assert (pipes);
+        }
+        pipes->insert (pipe_);
+        return result;
+    }
+
+    unsigned char c = *prefix_;
+    if (c < min || c >= min + count) {
+        //  The character is out of range of currently handled
+        //  characters. We have to extend the table.
+        if (!count) {
+            min = c;
+            count = 1;
+            next.node = NULL;
+        } else if (count == 1) {
+            unsigned char oldc = min;
+            generic_mtrie_t *oldp = next.node;
+            count = (min < c ? c - min : min - c) + 1;
+            next.table =
+              (generic_mtrie_t **) malloc (sizeof (generic_mtrie_t *) * count);
+            alloc_assert (next.table);
+            for (unsigned short i = 0; i != count; ++i)
+                next.table[i] = 0;
+            min = std::min (min, c);
+            next.table[oldc - min] = oldp;
+        } else if (min < c) {
+            //  The new character is above the current character range.
+            unsigned short old_count = count;
+            count = c - min + 1;
+            next.table = (generic_mtrie_t **) realloc (
+              next.table, sizeof (generic_mtrie_t *) * count);
+            alloc_assert (next.table);
+            for (unsigned short i = old_count; i != count; i++)
+                next.table[i] = NULL;
+        } else {
+            //  The new character is below the current character range.
+            unsigned short old_count = count;
+            count = (min + old_count) - c;
+            next.table = (generic_mtrie_t **) realloc (
+              next.table, sizeof (generic_mtrie_t *) * count);
+            alloc_assert (next.table);
+            memmove (next.table + min - c, next.table,
+                     old_count * sizeof (generic_mtrie_t *));
+            for (unsigned short i = 0; i != min - c; i++)
+                next.table[i] = NULL;
+            min = c;
+        }
+    }
+
+    //  If next node does not exist, create one.
+    if (count == 1) {
+        if (!next.node) {
+            next.node = new (std::nothrow) generic_mtrie_t;
+            alloc_assert (next.node);
+            ++live_nodes;
+        }
+        return next.node->add_helper (prefix_ + 1, size_ - 1, pipe_);
+    } else {
+        if (!next.table[c - min]) {
+            next.table[c - min] = new (std::nothrow) generic_mtrie_t;
+            alloc_assert (next.table[c - min]);
+            ++live_nodes;
+        }
+        return next.table[c - min]->add_helper (prefix_ + 1, size_ - 1, pipe_);
+    }
+}
+
+
+template <typename T>
+void zmq::generic_mtrie_t<T>::rm (value_t *pipe_,
+                                  void (*func_) (prefix_t data_,
+                                                 size_t size_,
+                                                 void *arg_),
+                                  void *arg_,
+                                  bool call_on_uniq_)
+{
+    unsigned char *buff = NULL;
+    rm_helper (pipe_, &buff, 0, 0, func_, arg_, call_on_uniq_);
+    free (buff);
+}
+
+template <typename T>
+void zmq::generic_mtrie_t<T>::rm_helper (value_t *pipe_,
+                                         unsigned char **buff_,
+                                         size_t buffsize_,
+                                         size_t maxbuffsize_,
+                                         void (*func_) (prefix_t data_,
+                                                        size_t size_,
+                                                        void *arg_),
+                                         void *arg_,
+                                         bool call_on_uniq_)
+{
+    //  Remove the subscription from this node.
+    if (pipes && pipes->erase (pipe_)) {
+        if (!call_on_uniq_ || pipes->empty ()) {
+            func_ (*buff_, buffsize_, arg_);
+        }
+
+        if (pipes->empty ()) {
+            LIBZMQ_DELETE (pipes);
+        }
+    }
+
+    //  Adjust the buffer.
+    if (buffsize_ >= maxbuffsize_) {
+        maxbuffsize_ = buffsize_ + 256;
+        *buff_ = (unsigned char *) realloc (*buff_, maxbuffsize_);
+        alloc_assert (*buff_);
+    }
+
+    //  If there are no subnodes in the trie, return.
+    if (count == 0)
+        return;
+
+    //  If there's one subnode (optimisation).
+    if (count == 1) {
+        (*buff_)[buffsize_] = min;
+        buffsize_++;
+        next.node->rm_helper (pipe_, buff_, buffsize_, maxbuffsize_, func_,
+                              arg_, call_on_uniq_);
+
+        //  Prune the node if it was made redundant by the removal
+        if (next.node->is_redundant ()) {
+            LIBZMQ_DELETE (next.node);
+            count = 0;
+            --live_nodes;
+            zmq_assert (live_nodes == 0);
+        }
+        return;
+    }
+
+    //  If there are multiple subnodes.
+    //
+    //  New min non-null character in the node table after the removal
+    unsigned char new_min = min + count - 1;
+    //  New max non-null character in the node table after the removal
+    unsigned char new_max = min;
+    for (unsigned short c = 0; c != count; c++) {
+        (*buff_)[buffsize_] = min + c;
+        if (next.table[c]) {
+            next.table[c]->rm_helper (pipe_, buff_, buffsize_ + 1, maxbuffsize_,
+                                      func_, arg_, call_on_uniq_);
+
+            //  Prune redundant nodes from the mtrie
+            if (next.table[c]->is_redundant ()) {
+                LIBZMQ_DELETE (next.table[c]);
+
+                zmq_assert (live_nodes > 0);
+                --live_nodes;
+            } else {
+                //  The node is not redundant, so it's a candidate for being
+                //  the new min/max node.
+                //
+                //  We loop through the node array from left to right, so the
+                //  first non-null, non-redundant node encountered is the new
+                //  minimum index. Conversely, the last non-redundant, non-null
+                //  node encountered is the new maximum index.
+                if (c + min < new_min)
+                    new_min = c + min;
+                if (c + min > new_max)
+                    new_max = c + min;
+            }
+        }
+    }
+
+    zmq_assert (count > 1);
+
+    //  Free the node table if it's no longer used.
+    if (live_nodes == 0) {
+        free (next.table);
+        next.table = NULL;
+        count = 0;
+    }
+    //  Compact the node table if possible
+    else if (live_nodes == 1) {
+        //  If there's only one live node in the table we can
+        //  switch to using the more compact single-node
+        //  representation
+        zmq_assert (new_min == new_max);
+        zmq_assert (new_min >= min && new_min < min + count);
+        generic_mtrie_t *node = next.table[new_min - min];
+        zmq_assert (node);
+        free (next.table);
+        next.node = node;
+        count = 1;
+        min = new_min;
+    } else if (new_min > min || new_max < min + count - 1) {
+        zmq_assert (new_max - new_min + 1 > 1);
+
+        generic_mtrie_t **old_table = next.table;
+        zmq_assert (new_min > min || new_max < min + count - 1);
+        zmq_assert (new_min >= min);
+        zmq_assert (new_max <= min + count - 1);
+        zmq_assert (new_max - new_min + 1 < count);
+
+        count = new_max - new_min + 1;
+        next.table =
+          (generic_mtrie_t **) malloc (sizeof (generic_mtrie_t *) * count);
+        alloc_assert (next.table);
+
+        memmove (next.table, old_table + (new_min - min),
+                 sizeof (generic_mtrie_t *) * count);
+        free (old_table);
+
+        min = new_min;
+    }
+}
+
+template <typename T>
+bool zmq::generic_mtrie_t<T>::rm (prefix_t prefix_,
+                                  size_t size_,
+                                  value_t *pipe_)
+{
+    return rm_helper (prefix_, size_, pipe_);
+}
+
+template <typename T>
+bool zmq::generic_mtrie_t<T>::rm_helper (prefix_t prefix_,
+                                         size_t size_,
+                                         value_t *pipe_)
+{
+    if (!size_) {
+        if (pipes) {
+            typename pipes_t::size_type erased = pipes->erase (pipe_);
+            zmq_assert (erased == 1);
+            if (pipes->empty ()) {
+                LIBZMQ_DELETE (pipes);
+            }
+        }
+        return !pipes;
+    }
+
+    unsigned char c = *prefix_;
+    if (!count || c < min || c >= min + count)
+        return false;
+
+    generic_mtrie_t *next_node = count == 1 ? next.node : next.table[c - min];
+
+    if (!next_node)
+        return false;
+
+    bool ret = next_node->rm_helper (prefix_ + 1, size_ - 1, pipe_);
+
+    if (next_node->is_redundant ()) {
+        LIBZMQ_DELETE (next_node);
+        zmq_assert (count > 0);
+
+        if (count == 1) {
+            next.node = 0;
+            count = 0;
+            --live_nodes;
+            zmq_assert (live_nodes == 0);
+        } else {
+            next.table[c - min] = 0;
+            zmq_assert (live_nodes > 1);
+            --live_nodes;
+
+            //  Compact the table if possible
+            if (live_nodes == 1) {
+                //  If there's only one live node in the table we can
+                //  switch to using the more compact single-node
+                //  representation
+                unsigned short i;
+                for (i = 0; i < count; ++i)
+                    if (next.table[i])
+                        break;
+
+                zmq_assert (i < count);
+                min += i;
+                count = 1;
+                generic_mtrie_t *oldp = next.table[i];
+                free (next.table);
+                next.node = oldp;
+            } else if (c == min) {
+                //  We can compact the table "from the left"
+                unsigned short i;
+                for (i = 1; i < count; ++i)
+                    if (next.table[i])
+                        break;
+
+                zmq_assert (i < count);
+                min += i;
+                count -= i;
+                generic_mtrie_t **old_table = next.table;
+                next.table = (generic_mtrie_t **) malloc (
+                  sizeof (generic_mtrie_t *) * count);
+                alloc_assert (next.table);
+                memmove (next.table, old_table + i,
+                         sizeof (generic_mtrie_t *) * count);
+                free (old_table);
+            } else if (c == min + count - 1) {
+                //  We can compact the table "from the right"
+                unsigned short i;
+                for (i = 1; i < count; ++i)
+                    if (next.table[count - 1 - i])
+                        break;
+
+                zmq_assert (i < count);
+                count -= i;
+                generic_mtrie_t **old_table = next.table;
+                next.table = (generic_mtrie_t **) malloc (
+                  sizeof (generic_mtrie_t *) * count);
+                alloc_assert (next.table);
+                memmove (next.table, old_table,
+                         sizeof (generic_mtrie_t *) * count);
+                free (old_table);
+            }
+        }
+    }
+
+    return ret;
+}
+
+template <typename T>
+void zmq::generic_mtrie_t<T>::match (prefix_t data_,
+                                     size_t size_,
+                                     void (*func_) (value_t *pipe_, void *arg_),
+                                     void *arg_)
+{
+    generic_mtrie_t *current = this;
+    while (true) {
+        //  Signal the pipes attached to this node.
+        if (current->pipes) {
+            for (typename pipes_t::iterator it = current->pipes->begin ();
+                 it != current->pipes->end (); ++it)
+                func_ (*it, arg_);
+        }
+
+        //  If we are at the end of the message, there's nothing more to match.
+        if (!size_)
+            break;
+
+        //  If there are no subnodes in the trie, return.
+        if (current->count == 0)
+            break;
+
+        //  If there's one subnode (optimisation).
+        if (current->count == 1) {
+            if (data_[0] != current->min)
+                break;
+            current = current->next.node;
+            data_++;
+            size_--;
+            continue;
+        }
+
+        //  If there are multiple subnodes.
+        if (data_[0] < current->min
+            || data_[0] >= current->min + current->count)
+            break;
+        if (!current->next.table[data_[0] - current->min])
+            break;
+        current = current->next.table[data_[0] - current->min];
+        data_++;
+        size_--;
+    }
+}
+
+template <typename T> bool zmq::generic_mtrie_t<T>::is_redundant () const
+{
+    return !pipes && live_nodes == 0;
+}
+
+
+#endif

src/mtrie.cpp

@@ -28,389 +28,10 @@
 */
 
 #include "precompiled.hpp"
-#include <stdlib.h>
-
-#include <new>
-#include <algorithm>
-
-#include "err.hpp"
-#include "pipe.hpp"
-#include "macros.hpp"
 #include "mtrie.hpp"
+#include "generic_mtrie_impl.hpp"
 
-zmq::mtrie_t::mtrie_t () : pipes (0), min (0), count (0), live_nodes (0)
+namespace zmq
 {
-}
+template class generic_mtrie_t<pipe_t>;
-
-zmq::mtrie_t::~mtrie_t ()
-{
-    LIBZMQ_DELETE (pipes);
-
-    if (count == 1) {
-        zmq_assert (next.node);
-        LIBZMQ_DELETE (next.node);
-    } else if (count > 1) {
-        for (unsigned short i = 0; i != count; ++i) {
-            LIBZMQ_DELETE (next.table[i]);
-        }
-        free (next.table);
-    }
-}
-
-bool zmq::mtrie_t::add (prefix_t prefix_, size_t size_, pipe_t *pipe_)
-{
-    return add_helper (prefix_, size_, pipe_);
-}
-
-bool zmq::mtrie_t::add_helper (prefix_t prefix_, size_t size_, pipe_t *pipe_)
-{
-    //  We are at the node corresponding to the prefix. We are done.
-    if (!size_) {
-        bool result = !pipes;
-        if (!pipes) {
-            pipes = new (std::nothrow) pipes_t;
-            alloc_assert (pipes);
-        }
-        pipes->insert (pipe_);
-        return result;
-    }
-
-    unsigned char c = *prefix_;
-    if (c < min || c >= min + count) {
-        //  The character is out of range of currently handled
-        //  characters. We have to extend the table.
-        if (!count) {
-            min = c;
-            count = 1;
-            next.node = NULL;
-        } else if (count == 1) {
-            unsigned char oldc = min;
-            mtrie_t *oldp = next.node;
-            count = (min < c ? c - min : min - c) + 1;
-            next.table = (mtrie_t **) malloc (sizeof (mtrie_t *) * count);
-            alloc_assert (next.table);
-            for (unsigned short i = 0; i != count; ++i)
-                next.table[i] = 0;
-            min = std::min (min, c);
-            next.table[oldc - min] = oldp;
-        } else if (min < c) {
-            //  The new character is above the current character range.
-            unsigned short old_count = count;
-            count = c - min + 1;
-            next.table =
-              (mtrie_t **) realloc (next.table, sizeof (mtrie_t *) * count);
-            alloc_assert (next.table);
-            for (unsigned short i = old_count; i != count; i++)
-                next.table[i] = NULL;
-        } else {
-            //  The new character is below the current character range.
-            unsigned short old_count = count;
-            count = (min + old_count) - c;
-            next.table =
-              (mtrie_t **) realloc (next.table, sizeof (mtrie_t *) * count);
-            alloc_assert (next.table);
-            memmove (next.table + min - c, next.table,
-                     old_count * sizeof (mtrie_t *));
-            for (unsigned short i = 0; i != min - c; i++)
-                next.table[i] = NULL;
-            min = c;
-        }
-    }
-
-    //  If next node does not exist, create one.
-    if (count == 1) {
-        if (!next.node) {
-            next.node = new (std::nothrow) mtrie_t;
-            alloc_assert (next.node);
-            ++live_nodes;
-        }
-        return next.node->add_helper (prefix_ + 1, size_ - 1, pipe_);
-    } else {
-        if (!next.table[c - min]) {
-            next.table[c - min] = new (std::nothrow) mtrie_t;
-            alloc_assert (next.table[c - min]);
-            ++live_nodes;
-        }
-        return next.table[c - min]->add_helper (prefix_ + 1, size_ - 1, pipe_);
-    }
-}
-
-
-void zmq::mtrie_t::rm (pipe_t *pipe_,
-                       void (*func_) (prefix_t data_, size_t size_, void *arg_),
-                       void *arg_,
-                       bool call_on_uniq_)
-{
-    unsigned char *buff = NULL;
-    rm_helper (pipe_, &buff, 0, 0, func_, arg_, call_on_uniq_);
-    free (buff);
-}
-
-void zmq::mtrie_t::rm_helper (pipe_t *pipe_,
-                              unsigned char **buff_,
-                              size_t buffsize_,
-                              size_t maxbuffsize_,
-                              void (*func_) (prefix_t data_,
-                                             size_t size_,
-                                             void *arg_),
-                              void *arg_,
-                              bool call_on_uniq_)
-{
-    //  Remove the subscription from this node.
-    if (pipes && pipes->erase (pipe_)) {
-        if (!call_on_uniq_ || pipes->empty ()) {
-            func_ (*buff_, buffsize_, arg_);
-        }
-
-        if (pipes->empty ()) {
-            LIBZMQ_DELETE (pipes);
-        }
-    }
-
-    //  Adjust the buffer.
-    if (buffsize_ >= maxbuffsize_) {
-        maxbuffsize_ = buffsize_ + 256;
-        *buff_ = (unsigned char *) realloc (*buff_, maxbuffsize_);
-        alloc_assert (*buff_);
-    }
-
-    //  If there are no subnodes in the trie, return.
-    if (count == 0)
-        return;
-
-    //  If there's one subnode (optimisation).
-    if (count == 1) {
-        (*buff_)[buffsize_] = min;
-        buffsize_++;
-        next.node->rm_helper (pipe_, buff_, buffsize_, maxbuffsize_, func_,
-                              arg_, call_on_uniq_);
-
-        //  Prune the node if it was made redundant by the removal
-        if (next.node->is_redundant ()) {
-            LIBZMQ_DELETE (next.node);
-            count = 0;
-            --live_nodes;
-            zmq_assert (live_nodes == 0);
-        }
-        return;
-    }
-
-    //  If there are multiple subnodes.
-    //
-    //  New min non-null character in the node table after the removal
-    unsigned char new_min = min + count - 1;
-    //  New max non-null character in the node table after the removal
-    unsigned char new_max = min;
-    for (unsigned short c = 0; c != count; c++) {
-        (*buff_)[buffsize_] = min + c;
-        if (next.table[c]) {
-            next.table[c]->rm_helper (pipe_, buff_, buffsize_ + 1, maxbuffsize_,
-                                      func_, arg_, call_on_uniq_);
-
-            //  Prune redundant nodes from the mtrie
-            if (next.table[c]->is_redundant ()) {
-                LIBZMQ_DELETE (next.table[c]);
-
-                zmq_assert (live_nodes > 0);
-                --live_nodes;
-            } else {
-                //  The node is not redundant, so it's a candidate for being
-                //  the new min/max node.
-                //
-                //  We loop through the node array from left to right, so the
-                //  first non-null, non-redundant node encountered is the new
-                //  minimum index. Conversely, the last non-redundant, non-null
-                //  node encountered is the new maximum index.
-                if (c + min < new_min)
-                    new_min = c + min;
-                if (c + min > new_max)
-                    new_max = c + min;
-            }
-        }
-    }
-
-    zmq_assert (count > 1);
-
-    //  Free the node table if it's no longer used.
-    if (live_nodes == 0) {
-        free (next.table);
-        next.table = NULL;
-        count = 0;
-    }
-    //  Compact the node table if possible
-    else if (live_nodes == 1) {
-        //  If there's only one live node in the table we can
-        //  switch to using the more compact single-node
-        //  representation
-        zmq_assert (new_min == new_max);
-        zmq_assert (new_min >= min && new_min < min + count);
-        mtrie_t *node = next.table[new_min - min];
-        zmq_assert (node);
-        free (next.table);
-        next.node = node;
-        count = 1;
-        min = new_min;
-    } else if (new_min > min || new_max < min + count - 1) {
-        zmq_assert (new_max - new_min + 1 > 1);
-
-        mtrie_t **old_table = next.table;
-        zmq_assert (new_min > min || new_max < min + count - 1);
-        zmq_assert (new_min >= min);
-        zmq_assert (new_max <= min + count - 1);
-        zmq_assert (new_max - new_min + 1 < count);
-
-        count = new_max - new_min + 1;
-        next.table = (mtrie_t **) malloc (sizeof (mtrie_t *) * count);
-        alloc_assert (next.table);
-
-        memmove (next.table, old_table + (new_min - min),
-                 sizeof (mtrie_t *) * count);
-        free (old_table);
-
-        min = new_min;
-    }
-}
-
-bool zmq::mtrie_t::rm (prefix_t prefix_, size_t size_, pipe_t *pipe_)
-{
-    return rm_helper (prefix_, size_, pipe_);
-}
-
-bool zmq::mtrie_t::rm_helper (prefix_t prefix_, size_t size_, pipe_t *pipe_)
-{
-    if (!size_) {
-        if (pipes) {
-            pipes_t::size_type erased = pipes->erase (pipe_);
-            zmq_assert (erased == 1);
-            if (pipes->empty ()) {
-                LIBZMQ_DELETE (pipes);
-            }
-        }
-        return !pipes;
-    }
-
-    unsigned char c = *prefix_;
-    if (!count || c < min || c >= min + count)
-        return false;
-
-    mtrie_t *next_node = count == 1 ? next.node : next.table[c - min];
-
-    if (!next_node)
-        return false;
-
-    bool ret = next_node->rm_helper (prefix_ + 1, size_ - 1, pipe_);
-
-    if (next_node->is_redundant ()) {
-        LIBZMQ_DELETE (next_node);
-        zmq_assert (count > 0);
-
-        if (count == 1) {
-            next.node = 0;
-            count = 0;
-            --live_nodes;
-            zmq_assert (live_nodes == 0);
-        } else {
-            next.table[c - min] = 0;
-            zmq_assert (live_nodes > 1);
-            --live_nodes;
-
-            //  Compact the table if possible
-            if (live_nodes == 1) {
-                //  If there's only one live node in the table we can
-                //  switch to using the more compact single-node
-                //  representation
-                unsigned short i;
-                for (i = 0; i < count; ++i)
-                    if (next.table[i])
-                        break;
-
-                zmq_assert (i < count);
-                min += i;
-                count = 1;
-                mtrie_t *oldp = next.table[i];
-                free (next.table);
-                next.node = oldp;
-            } else if (c == min) {
-                //  We can compact the table "from the left"
-                unsigned short i;
-                for (i = 1; i < count; ++i)
-                    if (next.table[i])
-                        break;
-
-                zmq_assert (i < count);
-                min += i;
-                count -= i;
-                mtrie_t **old_table = next.table;
-                next.table = (mtrie_t **) malloc (sizeof (mtrie_t *) * count);
-                alloc_assert (next.table);
-                memmove (next.table, old_table + i, sizeof (mtrie_t *) * count);
-                free (old_table);
-            } else if (c == min + count - 1) {
-                //  We can compact the table "from the right"
-                unsigned short i;
-                for (i = 1; i < count; ++i)
-                    if (next.table[count - 1 - i])
-                        break;
-
-                zmq_assert (i < count);
-                count -= i;
-                mtrie_t **old_table = next.table;
-                next.table = (mtrie_t **) malloc (sizeof (mtrie_t *) * count);
-                alloc_assert (next.table);
-                memmove (next.table, old_table, sizeof (mtrie_t *) * count);
-                free (old_table);
-            }
-        }
-    }
-
-    return ret;
-}
-
-void zmq::mtrie_t::match (prefix_t data_,
-                          size_t size_,
-                          void (*func_) (pipe_t *pipe_, void *arg_),
-                          void *arg_)
-{
-    mtrie_t *current = this;
-    while (true) {
-        //  Signal the pipes attached to this node.
-        if (current->pipes) {
-            for (pipes_t::iterator it = current->pipes->begin ();
-                 it != current->pipes->end (); ++it)
-                func_ (*it, arg_);
-        }
-
-        //  If we are at the end of the message, there's nothing more to match.
-        if (!size_)
-            break;
-
-        //  If there are no subnodes in the trie, return.
-        if (current->count == 0)
-            break;
-
-        //  If there's one subnode (optimisation).
-        if (current->count == 1) {
-            if (data_[0] != current->min)
-                break;
-            current = current->next.node;
-            data_++;
-            size_--;
-            continue;
-        }
-
-        //  If there are multiple subnodes.
-        if (data_[0] < current->min
-            || data_[0] >= current->min + current->count)
-            break;
-        if (!current->next.table[data_[0] - current->min])
-            break;
-        current = current->next.table[data_[0] - current->min];
-        data_++;
-        size_--;
-    }
-}
-
-bool zmq::mtrie_t::is_redundant () const
-{
-    return !pipes && live_nodes == 0;
 }

src/mtrie.hpp

@@ -30,76 +30,23 @@
 #ifndef __ZMQ_MTRIE_HPP_INCLUDED__
 #define __ZMQ_MTRIE_HPP_INCLUDED__
 
-#include <stddef.h>
+#include "generic_mtrie.hpp"
-#include <set>
 
-#include "stdint.hpp"
+#if __cplusplus >= 201103L || defined(_MSC_VER)
+#define ZMQ_HAS_EXTERN_TEMPLATE 1
+#else
+#define ZMQ_HAS_EXTERN_TEMPLATE 0
+#endif
 
 namespace zmq
 {
 class pipe_t;
 
-//  Multi-trie. Each node in the trie is a set of pointers to pipes.
+#if ZMQ_HAS_EXTERN_TEMPLATE
+extern template class generic_mtrie_t<pipe_t>;
+#endif
 
-class mtrie_t
+typedef generic_mtrie_t<pipe_t> mtrie_t;
-{
-  public:
-    typedef const unsigned char *prefix_t;
-
-    mtrie_t ();
-    ~mtrie_t ();
-
-    //  Add key to the trie. Returns true if it's a new subscription
-    //  rather than a duplicate.
-    bool add (prefix_t prefix_, size_t size_, zmq::pipe_t *pipe_);
-
-    //  Remove all subscriptions for a specific peer from the trie.
-    //  The call_on_uniq_ flag controls if the callback is invoked
-    //  when there are no subscriptions left on some topics or on
-    //  every removal.
-    void
-    rm (zmq::pipe_t *pipe_,
-        void (*func_) (const unsigned char *data_, size_t size_, void *arg_),
-        void *arg_,
-        bool call_on_uniq_);
-
-    //  Remove specific subscription from the trie. Return true is it was
-    //  actually removed rather than de-duplicated.
-    bool rm (prefix_t prefix_, size_t size_, zmq::pipe_t *pipe_);
-
-    //  Signal all the matching pipes.
-    void match (prefix_t data_,
-                size_t size_,
-                void (*func_) (zmq::pipe_t *pipe_, void *arg_),
-                void *arg_);
-
-  private:
-    bool add_helper (prefix_t prefix_, size_t size_, zmq::pipe_t *pipe_);
-    void rm_helper (zmq::pipe_t *pipe_,
-                    unsigned char **buff_,
-                    size_t buffsize_,
-                    size_t maxbuffsize_,
-                    void (*func_) (prefix_t data_, size_t size_, void *arg_),
-                    void *arg_,
-                    bool call_on_uniq_);
-    bool rm_helper (prefix_t prefix_, size_t size_, zmq::pipe_t *pipe_);
-    bool is_redundant () const;
-
-    typedef std::set<zmq::pipe_t *> pipes_t;
-    pipes_t *pipes;
-
-    unsigned char min;
-    unsigned short count;
-    unsigned short live_nodes;
-    union
-    {
-        class mtrie_t *node;
-        class mtrie_t **table;
-    } next;
-
-    mtrie_t (const mtrie_t &);
-    const mtrie_t &operator= (const mtrie_t &);
-};
 }
 
 #endif

unittests/CMakeLists.txt

@@ -4,6 +4,7 @@ cmake_minimum_required(VERSION "2.8.1")
 set(unittests
   unittest_ypipe
   unittest_poller
+  unittest_mtrie
 )
 
 #IF (ENABLE_DRAFTS)

unittests/unittest_mtrie.cpp

@@ -0,0 +1,113 @@
+/*
+Copyright (c) 2018 Contributors as noted in the AUTHORS file
+
+This file is part of 0MQ.
+
+0MQ 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.
+
+0MQ 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/>.
+*/
+
+#include "../tests/testutil.hpp"
+
+#if defined(min)
+#undef min
+#endif
+
+#include <generic_mtrie_impl.hpp>
+
+#include <unity.h>
+
+void setUp ()
+{
+}
+void tearDown ()
+{
+}
+
+void test_create ()
+{
+    zmq::generic_mtrie_t<int> mtrie;
+}
+
+void mtrie_count (int *pipe, void *arg)
+{
+    LIBZMQ_UNUSED (pipe);
+    int *count = static_cast<int *> (arg);
+    ++*count;
+}
+
+void test_check_empty_match_nonempty_data ()
+{
+    zmq::generic_mtrie_t<int> mtrie;
+    const zmq::generic_mtrie_t<int>::prefix_t test_name =
+      reinterpret_cast<zmq::generic_mtrie_t<int>::prefix_t> ("foo");
+
+    int count = 0;
+    mtrie.match (test_name, 3, mtrie_count, &count);
+    TEST_ASSERT_EQUAL_INT (0, count);
+}
+
+void test_check_empty_match_empty_data ()
+{
+    zmq::generic_mtrie_t<int> mtrie;
+
+    int count = 0;
+    mtrie.match (NULL, 0, mtrie_count, &count);
+    TEST_ASSERT_EQUAL_INT (0, count);
+}
+
+void test_add_single_entry_match_exact ()
+{
+    int pipe;
+
+    zmq::generic_mtrie_t<int> mtrie;
+    const zmq::generic_mtrie_t<int>::prefix_t test_name =
+      reinterpret_cast<zmq::generic_mtrie_t<int>::prefix_t> ("foo");
+
+    bool res = mtrie.add (test_name, 3, &pipe);
+    TEST_ASSERT_TRUE (res);
+
+    int count = 0;
+    mtrie.match (test_name, 3, mtrie_count, &count);
+    TEST_ASSERT_EQUAL_INT (1, count);
+}
+
+void test_add_rm_single_entry_match_exact ()
+{
+    int pipe;
+    zmq::generic_mtrie_t<int> mtrie;
+    const zmq::generic_mtrie_t<int>::prefix_t test_name =
+      reinterpret_cast<zmq::generic_mtrie_t<int>::prefix_t> ("foo");
+
+    mtrie.add (test_name, 3, &pipe);
+    bool res = mtrie.rm (test_name, 3, &pipe);
+    TEST_ASSERT_TRUE (res);
+
+    int count = 0;
+    mtrie.match (test_name, 3, mtrie_count, &count);
+    TEST_ASSERT_EQUAL_INT (0, count);
+}
+
+int main (void)
+{
+    setup_test_environment ();
+
+    UNITY_BEGIN ();
+    RUN_TEST (test_create);
+    RUN_TEST (test_check_empty_match_nonempty_data);
+    RUN_TEST (test_check_empty_match_empty_data);
+    RUN_TEST (test_add_single_entry_match_exact);
+    RUN_TEST (test_add_rm_single_entry_match_exact);
+
+    return UNITY_END ();
+}