| 1 | // [License]
|
---|
| 2 | // The Ariba-Underlay Copyright
|
---|
| 3 | //
|
---|
| 4 | // Copyright (c) 2008-2009, Institute of Telematics, UniversitÀt Karlsruhe (TH)
|
---|
| 5 | //
|
---|
| 6 | // Institute of Telematics
|
---|
| 7 | // UniversitÀt Karlsruhe (TH)
|
---|
| 8 | // Zirkel 2, 76128 Karlsruhe
|
---|
| 9 | // Germany
|
---|
| 10 | //
|
---|
| 11 | // Redistribution and use in source and binary forms, with or without
|
---|
| 12 | // modification, are permitted provided that the following conditions are
|
---|
| 13 | // met:
|
---|
| 14 | //
|
---|
| 15 | // 1. Redistributions of source code must retain the above copyright
|
---|
| 16 | // notice, this list of conditions and the following disclaimer.
|
---|
| 17 | // 2. Redistributions in binary form must reproduce the above copyright
|
---|
| 18 | // notice, this list of conditions and the following disclaimer in the
|
---|
| 19 | // documentation and/or other materials provided with the distribution.
|
---|
| 20 | //
|
---|
| 21 | // THIS SOFTWARE IS PROVIDED BY THE INSTITUTE OF TELEMATICS ``AS IS'' AND
|
---|
| 22 | // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
---|
| 23 | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
---|
| 24 | // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OF TELEMATICS OR
|
---|
| 25 | // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
| 26 | // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
---|
| 27 | // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
---|
| 28 | // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
---|
| 29 | // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
---|
| 30 | // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
---|
| 31 | // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
---|
| 32 | //
|
---|
| 33 | // The views and conclusions contained in the software and documentation
|
---|
| 34 | // are those of the authors and should not be interpreted as representing
|
---|
| 35 | // official policies, either expressed or implied, of the Institute of
|
---|
| 36 | // Telematics.
|
---|
| 37 | // [License]
|
---|
| 38 | #ifndef CHORD_ROUTING_TABLE_HPP_
|
---|
| 39 | #define CHORD_ROUTING_TABLE_HPP_
|
---|
| 40 |
|
---|
| 41 | #include <vector>
|
---|
| 42 | #include <iostream>
|
---|
| 43 |
|
---|
| 44 | #include <boost/foreach.hpp>
|
---|
| 45 |
|
---|
| 46 | #include "distances.hpp"
|
---|
| 47 | #include "comparators.hpp"
|
---|
| 48 | #include "minimizer_table.hpp"
|
---|
| 49 |
|
---|
| 50 | #include "ariba/Identifiers.h"
|
---|
| 51 |
|
---|
| 52 | using namespace ariba;
|
---|
| 53 |
|
---|
| 54 | using namespace distances;
|
---|
| 55 | using namespace comparators;
|
---|
| 56 | using namespace std;
|
---|
| 57 |
|
---|
| 58 | // placeholders for route info and nodeid type
|
---|
| 59 | typedef ariba::NodeID nodeid_t;
|
---|
| 60 | typedef ariba::LinkID routeinfo_t;
|
---|
| 61 |
|
---|
| 62 | /**
|
---|
| 63 | * Implementation of a chord routing table.
|
---|
| 64 | *
|
---|
| 65 | * @author Sebastian Mies <mies@tm.uka.de>
|
---|
| 66 | */
|
---|
| 67 | class chord_routing_table {
|
---|
| 68 | private:
|
---|
| 69 | typedef chord_routing_table self;
|
---|
| 70 | typedef distance_compare<nodeid_t&, nodeid_t, ring_succ_distance>
|
---|
| 71 | succ_compare_type;
|
---|
| 72 | typedef distance_compare<nodeid_t&, nodeid_t, ring_pred_distance>
|
---|
| 73 | pred_compare_type;
|
---|
| 74 | typedef distance_compare<nodeid_t, nodeid_t, ring_distance>
|
---|
| 75 | finger_compare_type;
|
---|
| 76 |
|
---|
| 77 | public:
|
---|
| 78 | typedef minimizer_table<nodeid_t, succ_compare_type, self> succ_table;
|
---|
| 79 | typedef minimizer_table<nodeid_t, pred_compare_type, self> pred_table;
|
---|
| 80 | typedef minimizer_table<nodeid_t, finger_compare_type, self> finger_table;
|
---|
| 81 |
|
---|
| 82 | // a routing table entry
|
---|
| 83 | class item {
|
---|
| 84 | public:
|
---|
| 85 | uint8_t ref_count;
|
---|
| 86 | nodeid_t id;
|
---|
| 87 | routeinfo_t info;
|
---|
| 88 | };
|
---|
| 89 | typedef vector<item> route_table;
|
---|
| 90 |
|
---|
| 91 |
|
---|
| 92 | private:
|
---|
| 93 | // maximum number of fingers
|
---|
| 94 | static const int max_fingers = 32;
|
---|
| 95 |
|
---|
| 96 | // the own node id
|
---|
| 97 | nodeid_t id;
|
---|
| 98 |
|
---|
| 99 | // successor and predecessor tables
|
---|
| 100 | succ_table succ;
|
---|
| 101 | pred_table pred;
|
---|
| 102 | finger_table* finger[max_fingers*2];
|
---|
| 103 |
|
---|
| 104 | // main routing table
|
---|
| 105 | route_table table;
|
---|
| 106 |
|
---|
| 107 | // some internal flags
|
---|
| 108 | item* item_added;
|
---|
| 109 | item item_removed;
|
---|
| 110 | bool item_removed_flag;
|
---|
| 111 | bool simulate;
|
---|
| 112 |
|
---|
| 113 | // finds an item inside the routing table
|
---|
| 114 | item* find_item(const nodeid_t& id) {
|
---|
| 115 | BOOST_FOREACH( item& i, table )
|
---|
| 116 | if ( i.id == id ) return &i;
|
---|
| 117 | return NULL;
|
---|
| 118 | }
|
---|
| 119 |
|
---|
| 120 | /// Adds a item to the routing table
|
---|
| 121 | item* add_item( const nodeid_t& id ) {
|
---|
| 122 | item i;
|
---|
| 123 | i.id = id;
|
---|
| 124 | i.ref_count = 1;
|
---|
| 125 | table.push_back(i);
|
---|
| 126 | item_added = &table.back();
|
---|
| 127 | return item_added;
|
---|
| 128 | }
|
---|
| 129 |
|
---|
| 130 | /// Removes an item from the routing table
|
---|
| 131 | bool remove_item( const nodeid_t& id ) {
|
---|
| 132 | for (route_table::iterator i = table.begin(); i!=table.end(); i++) {
|
---|
| 133 | if ( (*i).id == id ) {
|
---|
| 134 | (*i).ref_count--;
|
---|
| 135 | if ((*i).ref_count == 0) {
|
---|
| 136 | item_removed = *i;
|
---|
| 137 | item_removed_flag = true;
|
---|
| 138 | return true;
|
---|
| 139 | }
|
---|
| 140 | break;
|
---|
| 141 | }
|
---|
| 142 | }
|
---|
| 143 | return false;
|
---|
| 144 | }
|
---|
| 145 |
|
---|
| 146 | public:
|
---|
| 147 |
|
---|
| 148 | // handles events from minimizers
|
---|
| 149 | template<class Table>
|
---|
| 150 | void on_table( table_listener::type_ type, const Table& tab, typename Table::iterator pos ) {
|
---|
| 151 | switch (type) {
|
---|
| 152 | case table_listener::insert: {
|
---|
| 153 | item* i = find_item( *pos );
|
---|
| 154 | if (i == NULL) i = add_item( *pos ); else i->ref_count++;
|
---|
| 155 | break;
|
---|
| 156 | }
|
---|
| 157 | case table_listener::remove: {
|
---|
| 158 | remove_item(*pos);
|
---|
| 159 | break;
|
---|
| 160 | }
|
---|
| 161 | case table_listener::update:
|
---|
| 162 | break;
|
---|
| 163 | }
|
---|
| 164 | }
|
---|
| 165 |
|
---|
| 166 |
|
---|
| 167 | public:
|
---|
| 168 | /// constructs the reactive chord routing table
|
---|
| 169 | explicit chord_routing_table( const nodeid_t& id, int redundancy = 2 ) :
|
---|
| 170 | id(id), succ( redundancy, succ_compare_type(this->id), *this ),
|
---|
| 171 | pred( redundancy, pred_compare_type(this->id), *this ) {
|
---|
| 172 |
|
---|
| 173 | // create finger tables
|
---|
| 174 | nodeid_t nid = Identifier(2);
|
---|
| 175 | for (size_t i=0; i<max_fingers; i++) {
|
---|
| 176 | finger[i*2+0] =
|
---|
| 177 | new finger_table( redundancy,
|
---|
| 178 | finger_compare_type(this->id - nid), *this);
|
---|
| 179 | finger[i*2+1] =
|
---|
| 180 | new finger_table( redundancy,
|
---|
| 181 | finger_compare_type(this->id + nid), *this);
|
---|
| 182 | nid = nid << 1;
|
---|
| 183 | }
|
---|
| 184 | }
|
---|
| 185 |
|
---|
| 186 | /// check whether a node could fit the routing table
|
---|
| 187 | bool is_insertable( const nodeid_t& value ) {
|
---|
| 188 | if (find_item(value)!=NULL) return false;
|
---|
| 189 | bool is_insertable_ = false;
|
---|
| 190 | is_insertable_ |= succ.insertable(value);
|
---|
| 191 | is_insertable_ |= pred.insertable(value);
|
---|
| 192 | for (size_t i=0; i<max_fingers*2; i++)
|
---|
| 193 | is_insertable_ |= finger[i]->insertable(value);
|
---|
| 194 | return is_insertable_;
|
---|
| 195 | }
|
---|
| 196 |
|
---|
| 197 | /// searches an item
|
---|
| 198 | item* get( const nodeid_t& value ) {
|
---|
| 199 | return find_item(value);
|
---|
| 200 | }
|
---|
| 201 |
|
---|
| 202 | inline item* operator[] ( size_t index ) {
|
---|
| 203 | return &table[index];
|
---|
| 204 | }
|
---|
| 205 |
|
---|
| 206 | inline size_t size() const {
|
---|
| 207 | return table.size();
|
---|
| 208 | }
|
---|
| 209 |
|
---|
| 210 | /// adds a node
|
---|
| 211 | item* insert( const nodeid_t& value ) {
|
---|
| 212 | if (value==id) return NULL;
|
---|
| 213 | item_added = NULL;
|
---|
| 214 | item_removed_flag = false;
|
---|
| 215 | succ.insert(value);
|
---|
| 216 | pred.insert(value);
|
---|
| 217 | for (size_t i=0; i<max_fingers*2; i++) finger[i]->insert(value);
|
---|
| 218 | return item_added;
|
---|
| 219 | }
|
---|
| 220 |
|
---|
| 221 | /// adds an orphan
|
---|
| 222 | item* insert_orphan( const nodeid_t& value ) {
|
---|
| 223 | item* it = find_item(value);
|
---|
| 224 | if (it!=NULL) return it;
|
---|
| 225 | item i;
|
---|
| 226 | i.id = id;
|
---|
| 227 | i.ref_count = 0;
|
---|
| 228 | table.push_back(i);
|
---|
| 229 | return &table.back();
|
---|
| 230 | }
|
---|
| 231 |
|
---|
| 232 | /// removes an node
|
---|
| 233 | const item* remove( const nodeid_t& value ) {
|
---|
| 234 | item_removed_flag = false;
|
---|
| 235 | succ.remove(value);
|
---|
| 236 | pred.remove(value);
|
---|
| 237 | for (size_t i=0; i<max_fingers*2; i++) finger[i]->remove(value);
|
---|
| 238 | if (!item_removed_flag) remove_orphan(value);
|
---|
| 239 | return item_removed_flag ? &item_removed : NULL;
|
---|
| 240 | }
|
---|
| 241 |
|
---|
| 242 | /// removes an orphan
|
---|
| 243 | item* remove_orphan( const nodeid_t& value ) {
|
---|
| 244 | item_removed_flag = false;
|
---|
| 245 | remove_item(value);
|
---|
| 246 | return item_removed_flag ? &item_removed : NULL;
|
---|
| 247 | }
|
---|
| 248 |
|
---|
| 249 | /// returns the next hop
|
---|
| 250 | const item* get_next_hop( const nodeid_t& value ) {
|
---|
| 251 | ring_distance distance;
|
---|
| 252 | item* best_item = NULL;
|
---|
| 253 | for (size_t i=0; i<table.size(); i++) {
|
---|
| 254 | item* curr = &table[i];
|
---|
| 255 | // not not include orphans into routing!
|
---|
| 256 | if (curr->ref_count==0) continue;
|
---|
| 257 |
|
---|
| 258 | // check if we found a better item
|
---|
| 259 | if (best_item==NULL) {
|
---|
| 260 | best_item = curr;
|
---|
| 261 | continue;
|
---|
| 262 | } else {
|
---|
| 263 | if (distance(value, curr->id)<distance(value, best_item->id))
|
---|
| 264 | best_item = curr;
|
---|
| 265 | }
|
---|
| 266 | }
|
---|
| 267 | return best_item;
|
---|
| 268 | }
|
---|
| 269 |
|
---|
| 270 | const nodeid_t* get_successor() {
|
---|
| 271 | if (succ.size()==NULL) return NULL;
|
---|
| 272 | return &succ.front();
|
---|
| 273 | }
|
---|
| 274 |
|
---|
| 275 | const nodeid_t* get_predesessor() {
|
---|
| 276 | if (pred.size()==NULL) return NULL;
|
---|
| 277 | return &pred.front();
|
---|
| 278 | }
|
---|
| 279 |
|
---|
| 280 |
|
---|
| 281 | bool is_closest_to( const nodeid_t& value ) {
|
---|
| 282 | ring_distance distance;
|
---|
| 283 | nodeid_t delta = distance(value, id);
|
---|
| 284 | if (get_successor() != NULL &&
|
---|
| 285 | delta > distance(value, *get_successor() ) ) return false;
|
---|
| 286 | if (get_predesessor() != NULL &&
|
---|
| 287 | delta > distance(value, *get_predesessor() ) ) return false;
|
---|
| 288 | return true;
|
---|
| 289 | }
|
---|
| 290 |
|
---|
| 291 | /// returns the whole routing table
|
---|
| 292 | vector<item>& get_table() {
|
---|
| 293 | return table;
|
---|
| 294 | }
|
---|
| 295 |
|
---|
| 296 | /// returns the last removed item
|
---|
| 297 | const item* get_removed_item() const {
|
---|
| 298 | return item_removed_flag ? &item_removed : NULL;
|
---|
| 299 | }
|
---|
| 300 |
|
---|
| 301 | /// return successor table
|
---|
| 302 | const succ_table& get_succ_table() const {
|
---|
| 303 | return succ;
|
---|
| 304 | }
|
---|
| 305 |
|
---|
| 306 | /// return predecessor table
|
---|
| 307 | const pred_table& get_pred_table() const {
|
---|
| 308 | return pred;
|
---|
| 309 | }
|
---|
| 310 |
|
---|
| 311 | /// return finger table
|
---|
| 312 | finger_table& get_finger_table( size_t index ) {
|
---|
| 313 | return *finger[index];
|
---|
| 314 | }
|
---|
| 315 |
|
---|
| 316 | /// return number of finger tables
|
---|
| 317 | size_t get_finger_table_size() const {
|
---|
| 318 | return max_fingers*2;
|
---|
| 319 | }
|
---|
| 320 | };
|
---|
| 321 |
|
---|
| 322 | /// output routing table
|
---|
| 323 | std::ostream& operator<<(std::ostream& s, const chord_routing_table& t) {
|
---|
| 324 | s << "[pred=" << t.get_pred_table() << " succ=" << t.get_succ_table()
|
---|
| 325 | << "]";
|
---|
| 326 | return s;
|
---|
| 327 | }
|
---|
| 328 |
|
---|
| 329 | #endif /* CHORD_ROUTING_TABLE_HPP_ */
|
---|