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