Added PDUCacher class template.

include/pdu_cacher.h

@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2012, Nasel
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef TINS_PDU_CACHER_H
+#define TINS_PDU_CACHER_H
+
+#include <algorithm>
+#include "pdu.h"
+
+namespace Tins {
+/**
+ * \brief PDU wrapper that caches the result of the wrapped PDU's 
+ * serialization.
+ * 
+ * This wrapper class holds a PDU of the template parameter type, and
+ * forwards every PDU virtual call to the stored object. Whenever a
+ * call to write_serialization is performed on this wrapper, the result
+ * is cached in a PDU::serialization_type. On subsequent calls to
+ * PDUCacher::write_serialization, the contents of that cache will be
+ * written to the output buffer.
+ * 
+ * This class should provide a nice performance boost if you're sending
+ * over and over a packet that requires some computation while being
+ * serialized, such as performing checksums, iterate and copy options,
+ * etc.
+ */
+template<typename T>
+class PDUCacher : public PDU {
+public:
+    /**
+     * The cached PDU type.
+     */
+    typedef T cached_type;
+    
+    /**
+     * 
+     */
+    static const PDU::PDUType pdu_flag = cached_type::pdu_flag;
+    
+    /**
+     * Default constructs the cached PDU.
+     */
+    PDUCacher() {}
+    
+    /**
+     * Constructor from a cached_type.
+     * \param pdu The PDU to be copy constructed.
+     */
+    PDUCacher(const cached_type &pdu) : cached(pdu) {}
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::header_size.
+     */
+    uint32_t header_size() const {
+        return cached.header_size();
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::trailer_size.
+     */
+    uint32_t trailer_size() const {
+        return cached.trailer_size();
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::clone.
+     */
+    PDUCacher *clone() const {
+        return new PDUCacher<T>(*this);
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::send.
+     */
+    bool send(PacketSender &sender) {
+        return cached.send(sender);
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::recv_responde.
+     */
+    PDU *recv_response(PacketSender &sender) {
+        return cached.recv_response(sender);
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::matches_response.
+     */
+    bool matches_response(uint8_t *ptr, uint32_t total_sz) {
+        return cached.matches_response(ptr, total_sz);
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::matches_flag.
+     */
+    bool matches_flag(PDUType flag) {
+        return cached.matches_flag(flag);
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::pdu_type.
+     */
+    PDUType pdu_type() const {
+        return cached.pdu_type();
+    }
+    
+    /**
+     * Forwards the call to the cached PDU. \sa PDU::clone_packet.
+     */
+    PDU *clone_packet(const uint8_t *ptr, uint32_t total_sz) {
+        return cached.clone_packet(ptr, total_sz);
+    }
+private:
+    void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
+        if(cached_serialization.size() != total_sz)
+            cached_serialization = cached.serialize();
+        std::copy(cached_serialization.begin(), cached_serialization.end(), buffer);
+    }
+
+    cached_type cached;
+    PDU::serialization_type cached_serialization;
+};
+}
+
+#endif // TINS_PDU_CACHER_H

include/tins.h

@@ -53,5 +53,6 @@
 #include "dns.h"
 #include "tcp_stream.h"
 #include "crypto.h"
+#include "pdu_cacher.h"
 
 #endif // TINS_TINS_H