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Diffstat (limited to 'cpp/lib/broker/TopicExchange.cpp')
-rw-r--r-- | cpp/lib/broker/TopicExchange.cpp | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/cpp/lib/broker/TopicExchange.cpp b/cpp/lib/broker/TopicExchange.cpp new file mode 100644 index 0000000000..3ebb3c8c56 --- /dev/null +++ b/cpp/lib/broker/TopicExchange.cpp @@ -0,0 +1,156 @@ +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * + */ +#include <TopicExchange.h> +#include <ExchangeBinding.h> +#include <algorithm> + +using namespace qpid::broker; +using namespace qpid::framing; +using namespace qpid::sys; + +// TODO aconway 2006-09-20: More efficient matching algorithm. +// Areas for improvement: +// - excessive string copying: should be 0 copy, match from original buffer. +// - match/lookup: use descision tree or other more efficient structure. + +Tokens& Tokens::operator=(const std::string& s) { + clear(); + if (s.empty()) return *this; + std::string::const_iterator i = s.begin(); + while (true) { + // Invariant: i is at the beginning of the next untokenized word. + std::string::const_iterator j = find(i, s.end(), '.'); + push_back(std::string(i, j)); + if (j == s.end()) return *this; + i = j + 1; + } + return *this; +} + +TopicPattern& TopicPattern::operator=(const Tokens& tokens) { + Tokens::operator=(tokens); + normalize(); + return *this; +} + +namespace { +const std::string hashmark("#"); +const std::string star("*"); +} + +void TopicPattern::normalize() { + std::string word; + Tokens::iterator i = begin(); + while (i != end()) { + if (*i == hashmark) { + ++i; + while (i != end()) { + // Invariant: *(i-1)==#, [begin()..i-1] is normalized. + if (*i == star) { // Move * before #. + std::swap(*i, *(i-1)); + ++i; + } else if (*i == hashmark) { + erase(i); // Remove extra # + } else { + break; + } + } + } else { + i ++; + } + } +} + + +namespace { +// TODO aconway 2006-09-20: Ineficient to convert every routingKey to a string. +// Need StringRef class that operates on a string in place witout copy. +// Should be applied everywhere strings are extracted from frames. +// +bool do_match(Tokens::const_iterator pattern_begin, Tokens::const_iterator pattern_end, Tokens::const_iterator target_begin, Tokens::const_iterator target_end) +{ + // Invariant: [pattern_begin..p) matches [target_begin..t) + Tokens::const_iterator p = pattern_begin; + Tokens::const_iterator t = target_begin; + while (p != pattern_end && t != target_end) + { + if (*p == star || *p == *t) { + ++p, ++t; + } else if (*p == hashmark) { + ++p; + if (do_match(p, pattern_end, t, target_end)) return true; + while (t != target_end) { + ++t; + if (do_match(p, pattern_end, t, target_end)) return true; + } + return false; + } else { + return false; + } + } + while (p != pattern_end && *p == hashmark) ++p; // Ignore trailing # + return t == target_end && p == pattern_end; +} +} + +bool TopicPattern::match(const Tokens& target) const +{ + return do_match(begin(), end(), target.begin(), target.end()); +} + +TopicExchange::TopicExchange(const string& _name) : Exchange(_name) { } + +void TopicExchange::bind(Queue::shared_ptr queue, const string& routingKey, const FieldTable* args){ + Monitor::ScopedLock l(lock); + TopicPattern routingPattern(routingKey); + bindings[routingPattern].push_back(queue); + queue->bound(new ExchangeBinding(this, queue, routingKey, args)); +} + +void TopicExchange::unbind(Queue::shared_ptr queue, const string& routingKey, const FieldTable* /*args*/){ + Monitor::ScopedLock l(lock); + BindingMap::iterator bi = bindings.find(TopicPattern(routingKey)); + Queue::vector& qv(bi->second); + if (bi == bindings.end()) return; + Queue::vector::iterator q = find(qv.begin(), qv.end(), queue); + if(q == qv.end()) return; + qv.erase(q); + if(qv.empty()) bindings.erase(bi); +} + + +void TopicExchange::route(Deliverable& msg, const string& routingKey, const FieldTable* /*args*/){ + Monitor::ScopedLock l(lock); + for (BindingMap::iterator i = bindings.begin(); i != bindings.end(); ++i) { + if (i->first.match(routingKey)) { + Queue::vector& qv(i->second); + for(Queue::vector::iterator j = qv.begin(); j != qv.end(); j++){ + msg.deliverTo(*j); + } + } + } +} + +TopicExchange::~TopicExchange() {} + +const std::string TopicExchange::typeName("topic"); + + |