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