diff options
Diffstat (limited to 'src/mtrie.cpp')
-rw-r--r-- | src/mtrie.cpp | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/src/mtrie.cpp b/src/mtrie.cpp new file mode 100644 index 0000000..ac1fc31 --- /dev/null +++ b/src/mtrie.cpp @@ -0,0 +1,218 @@ +/* + Copyright (c) 2007-2011 iMatix Corporation + Copyright (c) 2007-2011 Other 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 <stdlib.h> + +#include <new> +#include <algorithm> + +#include "platform.hpp" +#if defined ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#endif + +#include "err.hpp" +#include "pipe.hpp" +#include "mtrie.hpp" + +zmq::mtrie_t::mtrie_t () : + min (0), + count (0) +{ +} + +zmq::mtrie_t::~mtrie_t () +{ + if (count == 1) + delete next.node; + else if (count > 1) { + for (unsigned short i = 0; i != count; ++i) + if (next.table [i]) + delete next.table [i]; + free (next.table); + } +} + +bool zmq::mtrie_t::add (unsigned char *prefix_, size_t size_, pipe_t *pipe_) +{ + // We are at the node corresponding to the prefix. We are done. + if (!size_) { + bool result = pipes.empty (); + pipes.insert (pipe_); + return result; + } + + unsigned char c = *prefix_; + if (c < min || c >= min + count) { + + // The character is out of range of currently handled + // charcters. 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); + zmq_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 ((void*) next.table, + sizeof (mtrie_t*) * count); + zmq_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 ((void*) next.table, + sizeof (mtrie_t*) * count); + zmq_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; + zmq_assert (next.node); + } + return next.node->add (prefix_ + 1, size_ - 1, pipe_); + } + else { + if (!next.table [c - min]) { + next.table [c - min] = new (std::nothrow) mtrie_t; + zmq_assert (next.table [c - min]); + } + return next.table [c - min]->add (prefix_ + 1, size_ - 1, pipe_); + } +} + + +void zmq::mtrie_t::rm (pipe_t *pipe_, + void (*func_) (unsigned char *data_, size_t size_, void *arg_), + void *arg_) +{ + unsigned char *buff = NULL; + rm_helper (pipe_, &buff, 0, 0, func_, arg_); + free (buff); +} + +void zmq::mtrie_t::rm_helper (pipe_t *pipe_, unsigned char **buff_, + size_t buffsize_, size_t maxbuffsize_, + void (*func_) (unsigned char *data_, size_t size_, void *arg_), + void *arg_) +{ + // Remove the subscription from this node. + if (pipes.erase (pipe_) && pipes.empty ()) + func_ (*buff_, buffsize_, arg_); + + // 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_); + return; + } + + // If there are multiple subnodes. + for (unsigned char 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_); + } +} + +bool zmq::mtrie_t::rm (unsigned char *prefix_, size_t size_, pipe_t *pipe_) +{ + if (!size_) { + pipes_t::size_type erased = pipes.erase (pipe_); + zmq_assert (erased == 1); + return pipes.empty (); + } + + 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; + + return next_node->rm (prefix_ + 1, size_ - 1, pipe_); +} + +void zmq::mtrie_t::match (unsigned char *data_, size_t size_, pipes_t &pipes_) +{ + // Merge the subscriptions from this node to the resultset. + pipes_.insert (pipes.begin (), pipes.end ()); + + // If there are no subnodes in the trie, return. + if (count == 0) + return; + + // If there's one subnode (optimisation). + if (count == 1) { + next.node->match (data_ + 1, size_ - 1, pipes_); + return; + } + + // If there are multiple subnodes. + for (unsigned char c = 0; c != count; c++) { + if (next.table [c]) + next.table [c]->match (data_ + 1, size_ - 1, pipes_); + } +} + |