1 /*

     2  *    Copyright 2004-2006 Intel Corporation

     3  *

     4  *    Licensed under the Apache License, Version 2.0 (the "License");

     5  *    you may not use this file except in compliance with the License.

     6  *    You may obtain a copy of the License at

     7  *

     8  *        http://www.apache.org/licenses/LICENSE-2.0

     9  *

    10  *    Unless required by applicable law or agreed to in writing, software

    11  *    distributed under the License is distributed on an "AS IS" BASIS,

    12  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    13  *    See the License for the specific language governing permissions and

    14  *    limitations under the License.

    15  */

    16 

    17 #ifndef __BPQ_CACHE__

    18 #define __BPQ_CACHE__

    19 

    20 #ifdef HAVE_CONFIG_H

    21 #  include <dtn-config.h>

    22 #endif

    23 

    24 #include "Bundle.h"

    25 #include <oasys/debug/Log.h>

    26 #include <oasys/util/StringUtils.h>

    27 

    28 namespace dtn {

    29 

    30 class BPQBlock;

    31 class FragmentState;

    32 class EndpointID;

    33 class BPQResponse;

    34 

    35 class BPQCache : public oasys::Logger {

    36 public:

    37 	BPQCache() :

    38         Logger("BPQCache", "/dtn/bundle/bpq") {}

    39 

    40 	/**

    41 	 * Add a new BPQ response to the to the cache

    42 	 */

    43     bool add_response_bundle(Bundle* bundle, BPQBlock* block);

    44 

    45     /**

    46      * Try to answer a BPQ query with a response in the cache

    47      */

    48     bool answer_query(Bundle* bundle, BPQBlock* block);

    49 

    50     /**

    51      * Number of bundles in the cache

    52      */

    53     size_t size() {return bpq_table_.size();}

    54 

    55     static const size_t MAX_KEY_SIZE = 4096;

    56 

    57 protected:

    58 

    59     void create_cache_entry(Bundle* bundle, std::string key);

    60     void replace_cache_entry(Bundle* bundle, std::string key);

    61     void append_cache_entry(Bundle* bundle, std::string key);

    62     int  update_bpq_block(Bundle* bundle, BPQBlock* block);

    63 

    64     /**

    65      * Calculate a hash table key from a bundle

    66      * This is a concatenation of the Matching Rule and the Query

    67      *

    68      * If the query is too long, use a hash of the query

    69      */

    70     void get_hash_key(Bundle* bundle, std::string* key);

    71     void get_hash_key(BPQBlock* block, std::string* key);

    72 

    73 

    74     /**

    75      * Table of partial BPQ bundles

    76      */

    77     typedef oasys::StringHashMap<FragmentState*> Cache;

    78     Cache bpq_table_;

    79 

    80 };

    81 

    82 } // namespace dtn

    83 

    84 #endif