Statistics
| Branch: | Revision:

grapes / som / TopologyManager / topocache.c @ ac9b476d

History | View | Annotate | Download (8.77 KB)

1
/*
2
 *  Copyright (c) 2010 Luca Abeni
3
 *
4
 *  This is free software; see lgpl-2.1.txt
5
 */
6

    
7
#include <arpa/inet.h>
8
#include <stdint.h>
9
#include <stdlib.h>
10
#include <string.h>
11

    
12
#include <stdio.h>
13

    
14
#include "net_helper.h"
15
#include "topocache.h"
16

    
17
#define MAX_TIMESTAMP 5
18
struct cache_entry {
19
  struct nodeID *id;
20
  uint32_t timestamp;
21
};
22

    
23
struct peer_cache {
24
  struct cache_entry *entries;
25
  int cache_size;
26
  int current_size;
27
  int metadata_size;
28
  uint8_t *metadata; 
29
};
30

    
31
static inline void int_cpy(uint8_t *p, int v)
32
{
33
  int tmp;
34

    
35
  tmp = htonl(v);
36
  memcpy(p, &tmp, 4);
37
}
38

    
39
static inline int int_rcpy(const uint8_t *p)
40
{
41
  int tmp;
42
  
43
  memcpy(&tmp, p, 4);
44
  tmp = ntohl(tmp);
45

    
46
  return tmp;
47
}
48

    
49
struct nodeID *nodeid(const struct peer_cache *c, int i)
50
{
51
  if (i < c->current_size) {
52
    return c->entries[i].id;
53
  }
54

    
55
  return NULL;
56
}
57

    
58
const void *get_metadata(const struct peer_cache *c, int *size)
59
{
60
  *size = c->metadata_size;
61
  return c->metadata;
62
}
63

    
64
int cache_metadata_update(struct peer_cache *c, struct nodeID *p, const void *meta, int meta_size)
65
{
66
  int i;
67

    
68
  if (!meta_size || meta_size != c->metadata_size) {
69
    return -3;
70
  }
71
  for (i = 0; i < c->current_size; i++) {
72
    if (nodeid_equal(c->entries[i].id, p)) {
73
      memcpy(c->metadata + i * meta_size, meta, meta_size);
74
      return 1;
75
    }
76
  }
77

    
78
  return 0;
79
}
80

    
81
int cache_add_ranked(struct peer_cache *c, const struct nodeID *neighbour, const void *meta, int meta_size, ranking_function f, const void *tmeta)
82
{
83
  int i, pos = 0;
84

    
85
  if (meta_size && meta_size != c->metadata_size) {
86
    return -3;
87
  }
88
  for (i = 0; i < c->current_size; i++) {
89
    if (nodeid_equal(c->entries[i].id, neighbour)) {
90
      return -1;
91
    }
92
    if ((f != NULL) && f(tmeta, meta, c->metadata+(c->metadata_size * i)) == 2) {
93
      pos++;
94
    }
95
  }
96
  if (c->current_size == c->cache_size) {
97
    return -2;
98
  }
99
  if (meta_size) {
100
    memmove(c->metadata + (pos + 1) * meta_size, c->metadata + pos * meta_size, (c->current_size - pos) * meta_size);
101
    memcpy(c->metadata + pos * meta_size, meta, meta_size);
102
  }
103
  for (i = pos; i < c->current_size; i++) {
104
    c->entries[i + 1] = c->entries[i];
105
  }
106
  c->entries[pos].id = nodeid_dup(neighbour);
107
  c->entries[pos].timestamp = 1;
108
  c->current_size++;
109

    
110
  return c->current_size;
111
}
112

    
113
int cache_add(struct peer_cache *c, struct nodeID *neighbour, const void *meta, int meta_size)
114
{
115
  return cache_add_ranked(c, neighbour, meta, meta_size, NULL, NULL);
116
}
117

    
118
int cache_del(struct peer_cache *c, struct nodeID *neighbour)
119
{
120
  int i;
121
  int found = 0;
122

    
123
  for (i = 0; i < c->current_size; i++) {
124
    if (nodeid_equal(c->entries[i].id, neighbour)) {
125
      nodeid_free(c->entries[i].id);
126
      c->current_size--;
127
      found = 1;
128
      if (c->metadata_size && (i < c->current_size)) {
129
        memmove(c->metadata + c->metadata_size * i,
130
                c->metadata + c->metadata_size * (found + 1),
131
                c->metadata_size * (c->current_size - i));
132
      }
133
    }
134
    if (found && (i < c->current_size)) {
135
      c->entries[i] = c->entries[i + 1];
136
    }
137
  }
138

    
139
  return c->current_size;
140
}
141

    
142
void cache_update_tout(struct peer_cache *c)
143
{
144
  int i;
145
  
146
  for (i = 0; i < c->current_size; i++) {
147
    if (c->entries[i].timestamp == MAX_TIMESTAMP) {
148
      c->current_size = i;        /* The cache is ordered by timestamp...
149
                                   all the other entries wiil be older than
150
                                   this one, so remove all of them
151
                                */
152
    } else {
153
      c->entries[i].timestamp++;
154
    }
155
  }
156
}
157

    
158
void cache_update(struct peer_cache *c)
159
{
160
  int i;
161
  
162
  for (i = 0; i < c->current_size; i++) {
163
      c->entries[i].timestamp++;
164
  }
165
}
166

    
167
struct peer_cache *cache_init(int n, int metadata_size)
168
{
169
  struct peer_cache *res;
170

    
171
  res = malloc(sizeof(struct peer_cache));
172
  if (res == NULL) {
173
    return NULL;
174
  }
175
  res->cache_size = n;
176
  res->current_size = 0;
177
  res->entries = malloc(sizeof(struct cache_entry) * n);
178
  if (res->entries == NULL) {
179
    free(res);
180

    
181
    return NULL;
182
  }
183
  
184
  memset(res->entries, 0, sizeof(struct cache_entry) * n);
185
  if (metadata_size) {
186
    res->metadata = malloc(metadata_size * n);
187
  } else {
188
    res->metadata = NULL;
189
  }
190

    
191
  if (res->metadata) {
192
    res->metadata_size = metadata_size;
193
    memset(res->metadata, 0, metadata_size * n);
194
  } else {
195
    res->metadata_size = 0;
196
  }
197

    
198
  return res;
199
}
200

    
201
void cache_free(struct peer_cache *c)
202
{
203
  int i;
204

    
205
  for (i = 0; i < c->current_size; i++) {
206
    nodeid_free(c->entries[i].id);
207
  }
208
  free(c->entries);
209
  free(c->metadata);
210
  free(c);
211
}
212

    
213
static int in_cache(const struct peer_cache *c, const struct cache_entry *elem)
214
{
215
  int i;
216

    
217
  for (i = 0; i < c->current_size; i++) {
218
    if (nodeid_equal(c->entries[i].id, elem->id)) {
219
      return 1;
220
    }
221
  }
222

    
223
  return 0;
224
}
225

    
226
struct nodeID *rand_peer(struct peer_cache *c, uint8_t **meta)
227
{
228
  int j;
229

    
230
  if (c->current_size == 0) {
231
    return NULL;
232
  }
233
  j = ((double)rand() / (double)RAND_MAX) * c->current_size;
234

    
235
  if (**meta) {
236
    *meta = c->metadata + (j * c->metadata_size);
237
  }
238

    
239
  return c->entries[j].id;
240
}
241

    
242
struct peer_cache *entries_undump(const uint8_t *buff, int size)
243
{
244
  struct peer_cache *res;
245
  int i = 0;
246
  const uint8_t *p = buff;
247
  uint8_t *meta;
248
  int cache_size, metadata_size;
249

    
250
  cache_size = int_rcpy(buff);
251
  metadata_size = int_rcpy(buff + 4);
252
  p = buff + 8;
253
  res = cache_init(cache_size, metadata_size);
254
  meta = res->metadata;
255
  while (p - buff < size) {
256
    int len;
257

    
258
    res->entries[i].timestamp = int_rcpy(p);
259
    p += sizeof(uint32_t);
260
    res->entries[i++].id = nodeid_undump(p, &len);
261
    p += len;
262
    if (metadata_size) {
263
      memcpy(meta, p, metadata_size);
264
      p += metadata_size;
265
      meta += metadata_size;
266
    }
267
  }
268
  res->current_size = i;
269
if (p - buff != size) { fprintf(stderr, "Waz!! %d != %d\n", p - buff, size); exit(-1);}
270

    
271
  return res;
272
}
273

    
274
int cache_header_dump(uint8_t *b, const struct peer_cache *c)
275
{
276
  int_cpy(b, c->cache_size);
277
  int_cpy(b + 4, c->metadata_size);
278

    
279
  return 8;
280
}
281

    
282
int entry_dump(uint8_t *b, struct peer_cache *c, int i)
283
{
284
  int res;
285
  
286
  int_cpy(b, c->entries[i].timestamp);
287
  res = 4;
288
  res += nodeid_dump(b + res, c->entries[i].id);
289
  if (c->metadata_size) {
290
    memcpy(b + res, c->metadata + c->metadata_size * i, c->metadata_size);
291
    res += c->metadata_size;
292
  }
293

    
294
  return res;
295
}
296

    
297
struct peer_cache *merge_caches_ranked(struct peer_cache *c1, struct peer_cache *c2, int newsize, int *source, ranking_function rank, void *mymetadata)
298
{
299
  int n1, n2;
300
  struct peer_cache *new_cache;
301
  uint8_t *meta;
302

    
303
  new_cache = cache_init(newsize, c1->metadata_size);
304
  if (new_cache == NULL) {
305
    return NULL;
306
  }
307

    
308
  meta = new_cache->metadata;
309
  *source = 0;
310
  for (n1 = 0, n2 = 0; new_cache->current_size < new_cache->cache_size;) {
311
    if ((n1 == c1->current_size) && (n2 == c2->current_size)) {
312
      return new_cache;
313
    }
314
    if (n1 == c1->current_size) {
315
      if (!in_cache(new_cache, &c2->entries[n2])) {
316
        if (new_cache->metadata_size) {
317
          memcpy(meta, c2->metadata + n2 * c2->metadata_size, c2->metadata_size);
318
          meta += new_cache->metadata_size;
319
        }
320
        new_cache->entries[new_cache->current_size++] = c2->entries[n2];
321
        c2->entries[n2].id = NULL;
322
        *source |= 0x02;
323
      }
324
      n2++;
325
    } else if (n2 == c2->current_size) {
326
      if (!in_cache(new_cache, &c1->entries[n1])) {
327
        if (new_cache->metadata_size) {
328
          memcpy(meta, c1->metadata + n1 * c1->metadata_size, c1->metadata_size);
329
          meta += new_cache->metadata_size;
330
        }
331
        new_cache->entries[new_cache->current_size++] = c1->entries[n1];
332
        c1->entries[n1].id = NULL;
333
        *source |= 0x01;
334
      }
335
      n1++;
336
    } else {
337
      int nowFirst;
338

    
339
      nowFirst = 0;
340
      if (rank) {
341
        nowFirst = rank(mymetadata, c1->metadata + n1 * c1->metadata_size,
342
                        c2->metadata + n2 * c2->metadata_size);
343
      }
344
      if (nowFirst == 0) {
345
        nowFirst = c2->entries[n2].timestamp > c1->entries[n1].timestamp ? 1 : 2;
346
      }
347
      if (nowFirst == 1) {
348
        if (!in_cache(new_cache, &c1->entries[n1])) {
349
          if (new_cache->metadata_size) {
350
            memcpy(meta, c1->metadata + n1 * c1->metadata_size, c1->metadata_size);
351
            meta += new_cache->metadata_size;
352
          }
353
          new_cache->entries[new_cache->current_size++] = c1->entries[n1];
354
          c1->entries[n1].id = NULL;
355
          *source |= 0x01;
356
        }
357
        n1++;
358
      } else {
359
        if (!in_cache(new_cache, &c2->entries[n2])) {
360
          if (new_cache->metadata_size) {
361
            memcpy(meta, c2->metadata + n2 * c2->metadata_size, c2->metadata_size);
362
            meta += new_cache->metadata_size;
363
          }
364
          new_cache->entries[new_cache->current_size++] = c2->entries[n2];
365
          c2->entries[n2].id = NULL;
366
          *source |= 0x02;
367
        }
368
        n2++;
369
      }
370
    }
371
  }
372

    
373
  return new_cache;
374
}
375

    
376
struct peer_cache *merge_caches(struct peer_cache *c1, struct peer_cache *c2, int newsize, int *source)
377
{
378
  return merge_caches_ranked(c1, c2, newsize, source, NULL, NULL);
379
}