HIGUCHI Yuta | ea60e5f | 2013-06-12 11:10:21 -0700 | [diff] [blame] | 1 | package net.onrc.onos.ofcontroller.bgproute; |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 2 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 3 | /* |
| 4 | * TODO This Ptree needs to be refactored if we're going to use it permenantly. |
| 5 | * |
| 6 | * The biggest problem is it leaks PTreeNode references - these need to stay within |
| 7 | * the Ptree as they contain data fundamental to the structure of the tree. |
| 8 | * You should put RIB entries in and get RIB entries out. |
| 9 | * Also we need to get rid of the referencing scheme to determine when to delete nodes. |
| 10 | * Deletes should be explicit, and there's no need to keep track of references if |
| 11 | * we don't leak them out the the Ptree. |
| 12 | */ |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 13 | public class Ptree { |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 14 | private int maxKeyBits; |
| 15 | private int maxKeyOctets; |
| 16 | //private int refCount; |
| 17 | private PtreeNode top; |
| 18 | private byte maskBits[] = { (byte)0x00, (byte)0x80, (byte)0xc0, (byte)0xe0, (byte)0xf0, (byte)0xf8, (byte)0xfc, (byte)0xfe, (byte)0xff }; |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 19 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 20 | public Ptree(int max_key_bits) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 21 | maxKeyBits = max_key_bits; |
| 22 | maxKeyOctets = bit_to_octet(max_key_bits); |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 23 | //refCount = 0; |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 24 | } |
pingping-lin | e2a09ca | 2013-03-23 09:33:58 +0800 | [diff] [blame] | 25 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 26 | public synchronized PtreeNode acquire(byte [] key) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 27 | return acquire(key, maxKeyBits); |
| 28 | } |
| 29 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 30 | public synchronized PtreeNode acquire(byte [] key, int key_bits) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 31 | if (key_bits > maxKeyBits) { |
| 32 | return null; |
| 33 | } |
| 34 | |
| 35 | PtreeNode node = top; |
| 36 | PtreeNode match = null; |
| 37 | |
| 38 | while (node != null |
| 39 | && node.keyBits <= key_bits |
| 40 | && key_match(node.key, node.keyBits, key, key_bits) == true) { |
| 41 | if (node.keyBits == key_bits) { |
| 42 | return addReference(node); |
| 43 | } |
| 44 | |
| 45 | match = node; |
| 46 | |
| 47 | if (bit_check(key, node.keyBits) == true) { |
| 48 | node = node.right; |
| 49 | } else { |
| 50 | node = node.left; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | PtreeNode add = null; |
| 55 | |
| 56 | if (node == null) { |
| 57 | add = new PtreeNode(key, key_bits, maxKeyOctets); |
| 58 | |
| 59 | if (match != null) { |
| 60 | node_link(match, add); |
| 61 | } else { |
| 62 | top = add; |
| 63 | } |
| 64 | } else { |
| 65 | add = node_common(node, key, key_bits); |
| 66 | if (add == null) { |
| 67 | return null; |
| 68 | } |
| 69 | |
| 70 | if (match != null) { |
| 71 | node_link(match, add); |
| 72 | } else { |
| 73 | top = add; |
| 74 | } |
| 75 | node_link(add, node); |
| 76 | |
| 77 | if (add.keyBits != key_bits) { |
| 78 | match = add; |
| 79 | |
| 80 | add = new PtreeNode(key, key_bits, maxKeyOctets); |
| 81 | node_link(match, add); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | return addReference(add); |
| 86 | } |
| 87 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 88 | public synchronized PtreeNode lookup(byte [] key, int key_bits) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 89 | if (key_bits > maxKeyBits) { |
| 90 | return null; |
| 91 | } |
| 92 | |
| 93 | PtreeNode node = top; |
| 94 | |
| 95 | while (node != null |
| 96 | && node.keyBits <= key_bits |
| 97 | && key_match(node.key, node.keyBits, key, key_bits) == true) { |
| 98 | if (node.keyBits == key_bits) { |
| 99 | return addReference(node); |
| 100 | } |
| 101 | |
| 102 | if (bit_check(key, node.keyBits) == true) { |
| 103 | node = node.right; |
| 104 | } else { |
| 105 | node = node.left; |
| 106 | } |
| 107 | } |
| 108 | return null; |
| 109 | } |
| 110 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 111 | public synchronized PtreeNode match(byte [] key, int key_bits) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 112 | if (key_bits > maxKeyBits) { |
| 113 | return null; |
| 114 | } |
| 115 | PtreeNode node = top; |
| 116 | PtreeNode matched = null; |
| 117 | |
| 118 | if(node!=null) |
| 119 | |
| 120 | while (node != null |
| 121 | && node.keyBits <= key_bits |
| 122 | && key_match(node.key, node.keyBits, key, key_bits) == true) { |
| 123 | matched = node; |
| 124 | |
| 125 | if (bit_check(key, node.keyBits) == true) { |
| 126 | node = node.right; |
| 127 | } else { |
| 128 | node = node.left; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | if (matched != null) { |
| 133 | return addReference(matched); |
| 134 | } |
| 135 | |
| 136 | return null; |
| 137 | } |
| 138 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 139 | public synchronized PtreeNode begin() { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 140 | if (top == null) { |
| 141 | return null; |
| 142 | } |
| 143 | return addReference(top); |
| 144 | } |
| 145 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 146 | public synchronized PtreeNode next(PtreeNode node) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 147 | PtreeNode next; |
| 148 | |
| 149 | if (node.left != null) { |
| 150 | next = node.left; |
| 151 | addReference(next); |
| 152 | delReference(node); |
| 153 | return next; |
| 154 | } |
| 155 | if (node.right != null) { |
| 156 | next = node.right; |
| 157 | addReference(next); |
| 158 | delReference(node); |
| 159 | return next; |
| 160 | } |
| 161 | |
| 162 | PtreeNode start = node; |
| 163 | while (node.parent != null) { |
| 164 | if (node.parent.left == node && node.parent.right != null) { |
| 165 | next = node.parent.right; |
| 166 | addReference(next); |
| 167 | delReference(start); |
| 168 | return next; |
| 169 | } |
| 170 | node = node.parent; |
| 171 | } |
| 172 | |
| 173 | delReference(start); |
| 174 | |
| 175 | return null; |
| 176 | } |
| 177 | |
| 178 | static public int bit_to_octet(int key_bits) { |
| 179 | return Math.max((key_bits + 7) / 8, 1); |
| 180 | } |
| 181 | |
| 182 | private PtreeNode addReference(PtreeNode node) { |
| 183 | node.refCount++; |
| 184 | return node; |
| 185 | } |
| 186 | |
Jonathan Hart | 66dffed | 2013-07-16 11:36:00 +1200 | [diff] [blame] | 187 | public synchronized void delReference(PtreeNode node) { |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 188 | if (node.refCount > 0) { |
| 189 | node.refCount--; |
| 190 | } |
| 191 | if (node.refCount == 0) { |
| 192 | node_remove(node); |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | private boolean key_match(byte [] key1, int key1_len, byte [] key2, int key2_len) { |
| 197 | int offset; |
| 198 | int shift; |
| 199 | |
| 200 | if (key1_len > key2_len) { |
| 201 | return false; |
| 202 | } |
| 203 | |
| 204 | offset = (Math.min(key1_len, key2_len)) / 8; |
| 205 | shift = (Math.min(key1_len, key2_len)) % 8; |
| 206 | |
| 207 | if (shift != 0) { |
| 208 | if ((maskBits[shift] & (key1[offset] ^ key2[offset])) != 0) { |
| 209 | return false; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | while (offset != 0) { |
| 214 | offset--; |
| 215 | if (key1[offset] != key2[offset]) { |
| 216 | return false; |
| 217 | } |
| 218 | } |
| 219 | return true; |
| 220 | } |
| 221 | |
| 222 | private boolean bit_check(byte [] key, int key_bits) { |
| 223 | int offset = key_bits / 8; |
| 224 | int shift = 7 - (key_bits % 8); |
| 225 | int bit = key[offset] & 0xff; |
| 226 | |
| 227 | bit >>= shift; |
| 228 | |
| 229 | if ((bit & 1) == 1) { |
| 230 | return true; |
| 231 | } else { |
| 232 | return false; |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | private void node_link(PtreeNode node, PtreeNode add) { |
| 237 | boolean bit = bit_check(add.key, node.keyBits); |
| 238 | |
| 239 | if (bit == true) { |
| 240 | node.right = add; |
| 241 | } else { |
| 242 | node.left = add; |
| 243 | } |
| 244 | add.parent = node; |
| 245 | } |
| 246 | |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 247 | private PtreeNode node_common(PtreeNode node, byte [] key, int key_bits) { |
| 248 | int i; |
| 249 | int limit = Math.min(node.keyBits, key_bits) / 8; |
| 250 | |
| 251 | for (i = 0; i < limit; i++) { |
| 252 | if (node.key[i] != key[i]) { |
| 253 | break; |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | int common_len = i * 8; |
| 258 | int boundary = 0; |
| 259 | |
| 260 | if (common_len != key_bits) { |
| 261 | byte diff = (byte)(node.key[i] ^ key[i]); |
| 262 | byte mask = (byte)0x80; |
| 263 | int shift_mask = 0; |
| 264 | |
| 265 | while (common_len < key_bits && ((mask & diff) == 0)) { |
| 266 | boundary = 1; |
| 267 | |
| 268 | shift_mask = (mask & 0xff); |
| 269 | shift_mask >>= 1; |
| 270 | mask = (byte)shift_mask; |
| 271 | |
| 272 | common_len++; |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | PtreeNode add = new PtreeNode(null, common_len, maxKeyOctets); |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 277 | |
| 278 | int j; |
| 279 | for (j = 0; j < i; j++) |
| 280 | add.key[j] = node.key[j]; |
| 281 | |
| 282 | if (boundary != 0) |
| 283 | add.key[j] = (byte)(node.key[j] & maskBits[add.keyBits % 8]); |
| 284 | |
| 285 | return add; |
| 286 | } |
pingping-lin | a2cbfad | 2013-03-07 08:39:21 +0800 | [diff] [blame] | 287 | |
| 288 | private void node_remove(PtreeNode node) { |
| 289 | PtreeNode child; |
| 290 | PtreeNode parent; |
| 291 | |
| 292 | if (node.left != null && node.right != null) { |
| 293 | return; |
| 294 | } |
| 295 | |
| 296 | if (node.left != null) { |
| 297 | child = node.left; |
| 298 | } else { |
| 299 | child = node.right; |
| 300 | } |
| 301 | |
| 302 | parent = node.parent; |
| 303 | |
| 304 | if (child != null) { |
| 305 | child.parent = parent; |
| 306 | } |
| 307 | |
| 308 | if (parent != null) { |
| 309 | if (parent.left == node) { |
| 310 | parent.left = child; |
| 311 | } else { |
| 312 | parent.right = child; |
| 313 | } |
| 314 | } else { |
| 315 | top = child; |
| 316 | } |
| 317 | |
| 318 | if (parent != null && parent.refCount == 0) { |
| 319 | node_remove(parent); |
| 320 | } |
| 321 | } |
| 322 | } |