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 "logging.h"
   7
   8 struct tdb_layout *new_tdb_layout(void)
   9 {
  10         struct tdb_layout *layout = malloc(sizeof(*layout));
  11         layout->num_elems = 0;
  12         layout->elem = NULL;
  13         layout->ftable = layout->htable = -1;
  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_free(struct tdb_layout *layout, tdb_len_t len)
  26 {
  27         union tdb_layout_elem elem;
  28         elem.base.type = FREE;
  29         elem.free.len = len;
  30         add(layout, elem);
  31 }
  32
  33 static struct tdb_data dup_key(struct tdb_data key)
  34 {
  35         struct tdb_data ret;
  36         ret.dsize = key.dsize;
  37         ret.dptr = malloc(ret.dsize);
  38         memcpy(ret.dptr, key.dptr, ret.dsize);
  39         return ret;
  40 }
  41
  42 void tdb_layout_add_used(struct tdb_layout *layout,
  43                          TDB_DATA key, TDB_DATA data,
  44                          tdb_len_t extra)
  45 {
  46         union tdb_layout_elem elem;
  47         elem.base.type = DATA;
  48         elem.used.key = dup_key(key);
  49         elem.used.data = dup_key(data);
  50         elem.used.extra = extra;
  51         add(layout, elem);
  52 }
  53
  54 void tdb_layout_add_hashtable(struct tdb_layout *layout,
  55                               unsigned int hash_bits,
  56                               tdb_len_t extra)
  57 {
  58         union tdb_layout_elem elem;
  59         elem.base.type = HASHTABLE;
  60         elem.hashtable.hash_bits = hash_bits;
  61         elem.hashtable.extra = extra;
  62         assert(layout->htable == -1U);
  63         layout->htable = layout->num_elems;
  64         add(layout, elem);
  65 }
  66
  67 void tdb_layout_add_freetable(struct tdb_layout *layout,
  68                               unsigned int num_zones,
  69                               unsigned int zone_bits,
  70                               unsigned int num_buckets,
  71                               tdb_len_t extra)
  72 {
  73         union tdb_layout_elem elem;
  74         elem.base.type = FREETABLE;
  75         elem.freetable.num_zones = num_zones;
  76         elem.freetable.zone_bits = zone_bits;
  77         elem.freetable.num_buckets = num_buckets;
  78         elem.freetable.extra = extra;
  79         assert(layout->ftable == -1U);
  80         layout->ftable = layout->num_elems;
  81         add(layout, elem);
  82 }
  83
  84 static tdb_len_t free_record_len(tdb_len_t len)
  85 {
  86         return sizeof(struct tdb_used_record) + len;
  87 }
  88
  89 static tdb_len_t data_record_len(struct tle_used *used)
  90 {
  91         tdb_len_t len;
  92         len = sizeof(struct tdb_used_record)
  93                 + used->key.dsize + used->data.dsize + used->extra;
  94         assert(len >= sizeof(struct tdb_free_record));
  95         return len;
  96 }
  97
  98 static tdb_len_t hashtable_len(struct tle_hashtable *htable)
  99 {
 100         return sizeof(struct tdb_used_record)
 101                 + (sizeof(tdb_off_t) << htable->hash_bits);
 102 }
 103
 104 static tdb_len_t freetable_len(struct tle_freetable *ftable)
 105 {
 106         return sizeof(struct tdb_used_record)
 107                 + (sizeof(tdb_off_t) * ftable->num_zones
 108                    * (ftable->num_buckets + 1));
 109 }
 110
 111 static void set_free_record(void *mem, tdb_len_t len)
 112 {
 113         /* We do all the work in add_to_freetable */
 114 }
 115
 116 static void set_data_record(void *mem, struct tdb_context *tdb,
 117                             struct tle_used *used)
 118 {
 119         struct tdb_used_record *u = mem;
 120
 121         set_header(tdb, u, used->key.dsize, used->data.dsize,
 122                    used->key.dsize + used->data.dsize + used->extra,
 123                    tdb_hash(tdb, used->key.dptr, used->key.dsize));
 124         memcpy(u + 1, used->key.dptr, used->key.dsize);
 125         memcpy((char *)(u + 1) + used->key.dsize,
 126                used->data.dptr, used->data.dsize);
 127 }
 128
 129 static void set_hashtable(void *mem, struct tdb_context *tdb,
 130                           struct tle_hashtable *htable)
 131 {
 132         struct tdb_used_record *u = mem;
 133         tdb_len_t len = sizeof(tdb_off_t) << htable->hash_bits;
 134
 135         set_header(tdb, u, 0, len, len + htable->extra, 0);
 136         memset(u + 1, 0, len);
 137 }
 138
 139 static void set_freetable(void *mem, struct tdb_context *tdb,
 140                           struct tle_freetable *ftable)
 141 {
 142         struct tdb_used_record *u = mem;
 143         tdb_len_t len = sizeof(tdb_off_t) * ftable->num_zones
 144                 * (ftable->num_buckets + 1);
 145         set_header(tdb, u, 0, len, len + ftable->extra, 0);
 146         memset(u + 1, 0, len);
 147 }
 148
 149 static void add_to_freetable(struct tdb_context *tdb,
 150                              tdb_off_t eoff,
 151                              tdb_off_t elen)
 152 {
 153         add_free_record(tdb, eoff, sizeof(struct tdb_used_record) + elen);
 154 }
 155
 156 static tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
 157 {
 158         return tdb->header.v.hash_off
 159                 + ((list & ((1ULL << tdb->header.v.hash_bits) - 1))
 160                    * sizeof(tdb_off_t));
 161 }
 162
 163 static void add_to_hashtable(struct tdb_context *tdb,
 164                              tdb_off_t eoff,
 165                              struct tdb_data key)
 166 {
 167         uint64_t hash = tdb_hash(tdb, key.dptr, key.dsize);
 168         tdb_off_t hoff;
 169
 170         while (tdb_read_off(tdb, hoff = hash_off(tdb, hash)) != 0)
 171                 hash++;
 172
 173         tdb_write_off(tdb, hoff, eoff);
 174 }
 175
 176 /* FIXME: Support TDB_CONVERT */
 177 struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 178 {
 179         unsigned int i;
 180         tdb_off_t len;
 181         struct tdb_header *hdr;
 182         char *mem;
 183         struct tdb_context *tdb;
 184
 185         assert(layout->ftable != -1U);
 186         assert(layout->htable != -1U);
 187
 188         len = sizeof(struct tdb_header);
 189
 190         /* First pass of layout: calc lengths */
 191         for (i = 0; i < layout->num_elems; i++) {
 192                 union tdb_layout_elem *e = &layout->elem[i];
 193                 e->base.off = len;
 194                 switch (e->base.type) {
 195                 case FREE:
 196                         len += free_record_len(e->free.len);
 197                         break;
 198                 case DATA:
 199                         len += data_record_len(&e->used);
 200                         break;
 201                 case HASHTABLE:
 202                         len += hashtable_len(&e->hashtable);
 203                         break;
 204                 case FREETABLE:
 205                         len += freetable_len(&e->freetable);
 206                         break;
 207                 }
 208         }
 209
 210         mem = malloc(len);
 211         /* Now populate our header, cribbing from a real TDB header. */
 212         tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, &tap_log_attr);
 213         hdr = (void *)mem;
 214         *hdr = tdb->header;
 215         hdr->v.generation++;
 216         hdr->v.num_zones = layout->elem[layout->ftable].freetable.num_zones;
 217         hdr->v.zone_bits = layout->elem[layout->ftable].freetable.zone_bits;
 218         hdr->v.free_buckets
 219                 = layout->elem[layout->ftable].freetable.num_buckets;
 220         hdr->v.free_off = layout->elem[layout->ftable].base.off
 221                 + sizeof(struct tdb_used_record);
 222         hdr->v.hash_bits = layout->elem[layout->htable].hashtable.hash_bits;
 223         hdr->v.hash_off = layout->elem[layout->htable].base.off
 224                 + sizeof(struct tdb_used_record);
 225
 226         /* Mug the tdb we have to make it use this. */
 227         free(tdb->map_ptr);
 228         tdb->map_ptr = mem;
 229         tdb->map_size = len;
 230         header_changed(tdb);
 231
 232         for (i = 0; i < layout->num_elems; i++) {
 233                 union tdb_layout_elem *e = &layout->elem[i];
 234                 switch (e->base.type) {
 235                 case FREE:
 236                         set_free_record(mem + e->base.off, e->free.len);
 237                         break;
 238                 case DATA:
 239                         set_data_record(mem + e->base.off, tdb, &e->used);
 240                         break;
 241                 case HASHTABLE:
 242                         set_hashtable(mem + e->base.off, tdb, &e->hashtable);
 243                         break;
 244                 case FREETABLE:
 245                         set_freetable(mem + e->base.off, tdb, &e->freetable);
 246                         break;
 247                 }
 248         }
 249
 250         /* Now fill the free and hash tables. */
 251         for (i = 0; i < layout->num_elems; i++) {
 252                 union tdb_layout_elem *e = &layout->elem[i];
 253                 switch (e->base.type) {
 254                 case FREE:
 255                         add_to_freetable(tdb, e->base.off, e->free.len);
 256                         break;
 257                 case DATA:
 258                         add_to_hashtable(tdb, e->base.off, e->used.key);
 259                         break;
 260                 default:
 261                         break;
 262                 }
 263         }
 264
 265         return tdb;
 266 }