git.ozlabs.org Git - ccan/blob - ccan/tdb2/test/layout.c

   1 /* TDB tools to create various canned database layouts. */
   2 #include "layout.h"
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <assert.h>
   6 #include <err.h>
   7 #include "logging.h"
   8
   9 struct tdb_layout *new_tdb_layout(void)
  10 {
  11         struct tdb_layout *layout = malloc(sizeof(*layout));
  12         layout->num_elems = 0;
  13         layout->elem = NULL;
  14         return layout;
  15 }
  16
  17 static void add(struct tdb_layout *layout, union tdb_layout_elem elem)
  18 {
  19         layout->elem = realloc(layout->elem,
  20                                sizeof(layout->elem[0])
  21                                * (layout->num_elems+1));
  22         layout->elem[layout->num_elems++] = elem;
  23 }
  24
  25 void tdb_layout_add_freetable(struct tdb_layout *layout)
  26 {
  27         union tdb_layout_elem elem;
  28         elem.base.type = FREETABLE;
  29         add(layout, elem);
  30 }
  31
  32 void tdb_layout_add_free(struct tdb_layout *layout, tdb_len_t len,
  33                          unsigned ftable)
  34 {
  35         union tdb_layout_elem elem;
  36         elem.base.type = FREE;
  37         elem.free.len = len;
  38         elem.free.ftable_num = ftable;
  39         add(layout, elem);
  40 }
  41
  42 void tdb_layout_add_capability(struct tdb_layout *layout,
  43                                uint64_t type,
  44                                bool write_breaks,
  45                                bool check_breaks,
  46                                bool open_breaks,
  47                                tdb_len_t extra)
  48 {
  49         union tdb_layout_elem elem;
  50         elem.base.type = CAPABILITY;
  51         elem.capability.type = type;
  52         if (write_breaks)
  53                 elem.capability.type |= TDB_CAP_NOWRITE;
  54         if (open_breaks)
  55                 elem.capability.type |= TDB_CAP_NOOPEN;
  56         if (check_breaks)
  57                 elem.capability.type |= TDB_CAP_NOCHECK;
  58         elem.capability.extra = extra;
  59         add(layout, elem);
  60 }
  61
  62 static struct tdb_data dup_key(struct tdb_data key)
  63 {
  64         struct tdb_data ret;
  65         ret.dsize = key.dsize;
  66         ret.dptr = malloc(ret.dsize);
  67         memcpy(ret.dptr, key.dptr, ret.dsize);
  68         return ret;
  69 }
  70
  71 void tdb_layout_add_used(struct tdb_layout *layout,
  72                          TDB_DATA key, TDB_DATA data,
  73                          tdb_len_t extra)
  74 {
  75         union tdb_layout_elem elem;
  76         elem.base.type = DATA;
  77         elem.used.key = dup_key(key);
  78         elem.used.data = dup_key(data);
  79         elem.used.extra = extra;
  80         add(layout, elem);
  81 }
  82
  83 static tdb_len_t free_record_len(tdb_len_t len)
  84 {
  85         return sizeof(struct tdb_used_record) + len;
  86 }
  87
  88 static tdb_len_t data_record_len(struct tle_used *used)
  89 {
  90         tdb_len_t len;
  91         len = sizeof(struct tdb_used_record)
  92                 + used->key.dsize + used->data.dsize + used->extra;
  93         assert(len >= sizeof(struct tdb_free_record));
  94         return len;
  95 }
  96
  97 static tdb_len_t hashtable_len(struct tle_hashtable *htable)
  98 {
  99         return sizeof(struct tdb_used_record)
 100                 + (sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS)
 101                 + htable->extra;
 102 }
 103
 104 static tdb_len_t capability_len(struct tle_capability *cap)
 105 {
 106         return sizeof(struct tdb_capability) + cap->extra;
 107 }
 108
 109 static tdb_len_t freetable_len(struct tle_freetable *ftable)
 110 {
 111         return sizeof(struct tdb_freetable);
 112 }
 113
 114 static void set_free_record(void *mem, tdb_len_t len)
 115 {
 116         /* We do all the work in add_to_freetable */
 117 }
 118
 119 static void add_zero_pad(struct tdb_used_record *u, size_t len, size_t extra)
 120 {
 121         if (extra)
 122                 ((char *)(u + 1))[len] = '\0';
 123 }
 124
 125 static void set_data_record(void *mem, struct tdb_context *tdb,
 126                             struct tle_used *used)
 127 {
 128         struct tdb_used_record *u = mem;
 129
 130         set_header(tdb, u, TDB_USED_MAGIC, used->key.dsize, used->data.dsize,
 131                    used->key.dsize + used->data.dsize + used->extra,
 132                    tdb_hash(tdb, used->key.dptr, used->key.dsize));
 133         memcpy(u + 1, used->key.dptr, used->key.dsize);
 134         memcpy((char *)(u + 1) + used->key.dsize,
 135                used->data.dptr, used->data.dsize);
 136         add_zero_pad(u, used->key.dsize + used->data.dsize, used->extra);
 137 }
 138
 139 static void set_hashtable(void *mem, struct tdb_context *tdb,
 140                           struct tle_hashtable *htable)
 141 {
 142         struct tdb_used_record *u = mem;
 143         tdb_len_t len = sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS;
 144
 145         set_header(tdb, u, TDB_HTABLE_MAGIC, 0, len, len + htable->extra, 0);
 146         memset(u + 1, 0, len);
 147         add_zero_pad(u, len, htable->extra);
 148 }
 149
 150 static void set_capability(void *mem, struct tdb_context *tdb,
 151                            struct tle_capability *cap, struct tdb_header *hdr,
 152                            tdb_off_t last_cap)
 153 {
 154         struct tdb_capability *c = mem;
 155         tdb_len_t len = sizeof(*c) - sizeof(struct tdb_used_record) + cap->extra;
 156
 157         c->type = cap->type;
 158         c->next = 0;
 159         set_header(tdb, &c->hdr, TDB_CAP_MAGIC, 0, len, len, 0);
 160
 161         /* Append to capability list. */
 162         if (!last_cap) {
 163                 hdr->capabilities = cap->base.off;
 164         } else {
 165                 c = (struct tdb_capability *)((char *)hdr + last_cap);
 166                 c->next = cap->base.off;
 167         }
 168 }
 169
 170 static void set_freetable(void *mem, struct tdb_context *tdb,
 171                          struct tle_freetable *freetable, struct tdb_header *hdr,
 172                          tdb_off_t last_ftable)
 173 {
 174         struct tdb_freetable *ftable = mem;
 175         memset(ftable, 0, sizeof(*ftable));
 176         set_header(tdb, &ftable->hdr, TDB_FTABLE_MAGIC, 0,
 177                         sizeof(*ftable) - sizeof(ftable->hdr),
 178                         sizeof(*ftable) - sizeof(ftable->hdr), 0);
 179
 180         if (last_ftable) {
 181                 ftable = (struct tdb_freetable *)((char *)hdr + last_ftable);
 182                 ftable->next = freetable->base.off;
 183         } else {
 184                 hdr->free_table = freetable->base.off;
 185         }
 186 }
 187
 188 static void add_to_freetable(struct tdb_context *tdb,
 189                              tdb_off_t eoff,
 190                              tdb_off_t elen,
 191                              unsigned ftable,
 192                              struct tle_freetable *freetable)
 193 {
 194         tdb->tdb2.ftable_off = freetable->base.off;
 195         tdb->tdb2.ftable = ftable;
 196         add_free_record(tdb, eoff, sizeof(struct tdb_used_record) + elen,
 197                         TDB_LOCK_WAIT, false);
 198 }
 199
 200 static tdb_off_t hbucket_off(tdb_off_t group_start, unsigned ingroup)
 201 {
 202         return group_start
 203                 + (ingroup % (1 << TDB_HASH_GROUP_BITS)) * sizeof(tdb_off_t);
 204 }
 205
 206 /* Get bits from a value. */
 207 static uint32_t bits(uint64_t val, unsigned start, unsigned num)
 208 {
 209         assert(num <= 32);
 210         return (val >> start) & ((1U << num) - 1);
 211 }
 212
 213 /* We take bits from the top: that way we can lock whole sections of the hash
 214  * by using lock ranges. */
 215 static uint32_t use_bits(uint64_t h, unsigned num, unsigned *used)
 216 {
 217         *used += num;
 218         return bits(h, 64 - *used, num);
 219 }
 220
 221 static tdb_off_t encode_offset(tdb_off_t new_off, unsigned bucket,
 222                                uint64_t h)
 223 {
 224         return bucket
 225                 | new_off
 226                 | ((uint64_t)bits(h, 64 - TDB_OFF_UPPER_STEAL_EXTRA,
 227                                   TDB_OFF_UPPER_STEAL_EXTRA)
 228                    << TDB_OFF_HASH_EXTRA_BIT);
 229 }
 230
 231 /* FIXME: Our hash table handling here is primitive: we don't expand! */
 232 static void add_to_hashtable(struct tdb_context *tdb,
 233                              tdb_off_t eoff,
 234                              struct tdb_data key)
 235 {
 236         uint64_t h = tdb_hash(tdb, key.dptr, key.dsize);
 237         tdb_off_t b_off, group_start;
 238         unsigned i, group, in_group;
 239         unsigned used = 0;
 240
 241         group = use_bits(h, TDB_TOPLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS, &used);
 242         in_group = use_bits(h, TDB_HASH_GROUP_BITS, &used);
 243
 244         group_start = offsetof(struct tdb_header, hashtable)
 245                 + group * (sizeof(tdb_off_t) << TDB_HASH_GROUP_BITS);
 246
 247         for (i = 0; i < (1 << TDB_HASH_GROUP_BITS); i++) {
 248                 unsigned bucket = (in_group + i) % (1 << TDB_HASH_GROUP_BITS);
 249
 250                 b_off = hbucket_off(group_start, bucket);
 251                 if (tdb_read_off(tdb, b_off) == 0) {
 252                         tdb_write_off(tdb, b_off,
 253                                       encode_offset(eoff, in_group, h));
 254                         return;
 255                 }
 256         }
 257         abort();
 258 }
 259
 260 static struct tle_freetable *find_ftable(struct tdb_layout *layout, unsigned num)
 261 {
 262         unsigned i;
 263
 264         for (i = 0; i < layout->num_elems; i++) {
 265                 if (layout->elem[i].base.type != FREETABLE)
 266                         continue;
 267                 if (num == 0)
 268                         return &layout->elem[i].ftable;
 269                 num--;
 270         }
 271         abort();
 272 }
 273
 274 /* FIXME: Support TDB_CONVERT */
 275 struct tdb_context *tdb_layout_get(struct tdb_layout *layout,
 276                                    void (*freefn)(void *),
 277                                    union tdb_attribute *attr)
 278 {
 279         unsigned int i;
 280         tdb_off_t off, len, last_ftable, last_cap;
 281         char *mem;
 282         struct tdb_context *tdb;
 283
 284         off = sizeof(struct tdb_header);
 285
 286         /* First pass of layout: calc lengths */
 287         for (i = 0; i < layout->num_elems; i++) {
 288                 union tdb_layout_elem *e = &layout->elem[i];
 289                 e->base.off = off;
 290                 switch (e->base.type) {
 291                 case FREETABLE:
 292                         len = freetable_len(&e->ftable);
 293                         break;
 294                 case FREE:
 295                         len = free_record_len(e->free.len);
 296                         break;
 297                 case DATA:
 298                         len = data_record_len(&e->used);
 299                         break;
 300                 case HASHTABLE:
 301                         len = hashtable_len(&e->hashtable);
 302                         break;
 303                 case CAPABILITY:
 304                         len = capability_len(&e->capability);
 305                         break;
 306                 default:
 307                         abort();
 308                 }
 309                 off += len;
 310         }
 311
 312         mem = malloc(off);
 313         /* Fill with some weird pattern. */
 314         memset(mem, 0x99, off);
 315         /* Now populate our header, cribbing from a real TDB header. */
 316         tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, attr);
 317         memcpy(mem, tdb->file->map_ptr, sizeof(struct tdb_header));
 318
 319         /* Mug the tdb we have to make it use this. */
 320         freefn(tdb->file->map_ptr);
 321         tdb->file->map_ptr = mem;
 322         tdb->file->map_size = off;
 323
 324         last_ftable = 0;
 325         last_cap = 0;
 326         for (i = 0; i < layout->num_elems; i++) {
 327                 union tdb_layout_elem *e = &layout->elem[i];
 328                 switch (e->base.type) {
 329                 case FREETABLE:
 330                         set_freetable(mem + e->base.off, tdb, &e->ftable,
 331                                      (struct tdb_header *)mem, last_ftable);
 332                         last_ftable = e->base.off;
 333                         break;
 334                 case FREE:
 335                         set_free_record(mem + e->base.off, e->free.len);
 336                         break;
 337                 case DATA:
 338                         set_data_record(mem + e->base.off, tdb, &e->used);
 339                         break;
 340                 case HASHTABLE:
 341                         set_hashtable(mem + e->base.off, tdb, &e->hashtable);
 342                         break;
 343                 case CAPABILITY:
 344                         set_capability(mem + e->base.off, tdb, &e->capability,
 345                                        (struct tdb_header *)mem, last_cap);
 346                         last_cap = e->base.off;
 347                         break;
 348                 }
 349         }
 350         /* Must have a free table! */
 351         assert(last_ftable);
 352
 353         /* Now fill the free and hash tables. */
 354         for (i = 0; i < layout->num_elems; i++) {
 355                 union tdb_layout_elem *e = &layout->elem[i];
 356                 switch (e->base.type) {
 357                 case FREE:
 358                         add_to_freetable(tdb, e->base.off, e->free.len,
 359                                          e->free.ftable_num,
 360                                          find_ftable(layout, e->free.ftable_num));
 361                         break;
 362                 case DATA:
 363                         add_to_hashtable(tdb, e->base.off, e->used.key);
 364                         break;
 365                 default:
 366                         break;
 367                 }
 368         }
 369
 370         tdb->tdb2.ftable_off = find_ftable(layout, 0)->base.off;
 371         return tdb;
 372 }
 373
 374 void tdb_layout_write(struct tdb_layout *layout, void (*freefn)(void *),
 375                        union tdb_attribute *attr, const char *filename)
 376 {
 377         struct tdb_context *tdb = tdb_layout_get(layout, freefn, attr);
 378         int fd;
 379
 380         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT,  0600);
 381         if (fd < 0)
 382                 err(1, "opening %s for writing", filename);
 383         if (write(fd, tdb->file->map_ptr, tdb->file->map_size)
 384             != tdb->file->map_size)
 385                 err(1, "writing %s", filename);
 386         close(fd);
 387         tdb_close(tdb);
 388 }
 389
 390 void tdb_layout_free(struct tdb_layout *layout)
 391 {
 392         unsigned int i;
 393
 394         for (i = 0; i < layout->num_elems; i++) {
 395                 if (layout->elem[i].base.type == DATA) {
 396                         free(layout->elem[i].used.key.dptr);
 397                         free(layout->elem[i].used.data.dptr);
 398                 }
 399         }
 400         free(layout->elem);
 401         free(layout);
 402 }